Arisaka Model 38 6.5x50 - Bulge in cartridge


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ping
November 28, 2010, 01:57 PM
I bought some norma brass and used 120gr sierra hpbt. Using IMR4895 and used range of weights frm 33.0 to 34.5 gr.

After each case was extracted it had a slight but noticeable bulge near the head of the cartridge. My COAL was 2.800 and trimmed to 1.975.

I got home and resized them fully with my lee dies. It cleaned them up nicely from the exterior point of view. I am going to reload one this afternoon and see if they have any problems and then full then resize again. Has anyone had any problems in this area with the arisaka model 38.

Also i am using the rcbs guide and it says coal should be 2.800 while the literature in my lee dies says minimum is 2.920. Wonder why such a difference in opinion??? Any feed back on this would be greatly appreciated.

ohhh, one more - is there a tool to adjust the front site. or do you just juse a brass punch and keep tapping on it - gosh hope not as that is not easy. thanks in advance.

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NCsmitty
November 28, 2010, 02:44 PM
Is there anyway that you could post a picture(s) of the defective cases?
It would probably be wise not to shoot the rifle until you ascertain why the cases are bulged.
It's possible that the rifle has been rechambered for another cartridge at some point in it's life. Or maybe the headspace in the rifle is bad. Maybe the chamber has something wrong with it.
You may have a safety issue here.

If you're not sure what to do, take the rifle and fired cases to a qualified gunsmith for a professional opinion.

Don't worry about adjusting the sight at this point.

In case you don't know how to load pictures, take pictures and copy to the computer, then use the Advanced posting and upload the pictures to the site.



NCsmitty

rcmodel
November 28, 2010, 02:49 PM
literature in my lee dies says minimum is 2.920That is wrong.
MAX COL = 2.992".
MAX case length = 2.008"
Trim Too length = 1.998" (Not 1.975".)

An expansion forward of the case heads internal web taper is perfectly normal in any rifle with a semi-loose military chamber.

It won't hurt anything, and the sizing die will return it to normal.

You do need to watch for a stretch ring at that location inside the case though.
Use an L-Bent paper-clip or wire to reach down inside the case and feel for a thinner spot where the case has stretched.

If you can feel the ring, the headspace is allowing excess case stretch, and the case is going to break there pretty shortly.

That can be prevented by adjusting the sizing die to just barely kiss the case shoulder instead of pushing it back to factory specs.


PS: I do agree with NCsmitty in that we are flying by the seat of our pants here based only on your verbal discription. A picture would be nice, and safer!

Many 6.5 Japs were rechambered for 6.5/.257 Roberts and various other wildcats after WWII, as there was no 6.5x50 ammo in the U.S. anywhere then.

rc

fguffey
November 28, 2010, 03:24 PM
The Arisaka the strongest receiver in the world??? And then there is Norma brass, the best brass in the world???? And then someone gets a bulge, can not be the receiver or the brass unless it happens to me, Norma brass for the 6.5x50 in my opinion based on my experience could have case heads that are too soft, I have cases for the 6.5X50 so when someone tells me how wonderful they are I can say " Yes, I have some" , I do not tell them I do not use it. Measurements I keep up with, the deck height of the shell holder, the thickness of the case head from the head of the case to the top of the (cup) web (and yes I know there are many that can not measure the case head thickness because the top of the web is convexed), the protrusion of the brass from the chamber and head space or to put it another way I check the effect the sized case will have on offsetting the effects of head space. For most of the reasons listed above I do not have a 6.5X50 Arisaka chambered rifle, I have 6.5 Japanese 257 Roberts. This solves all or most of the problems, I use 30/06 commercial cases to form brass, the R-P 30/06 case head is .260+ thick from the head of the case to the bottom of the cup (top of the web), when I want to live dangerously I use Military 30/06 brass like LC etc, on the military brass the case head thickness is .200 + a little.

If you have bulges after firing your cases, stop firing the rifle, do not size the cases, the column of brass that protrudes from the chamber must support the 22/7 diameter squared, .7854 of the area of a circle, a bulge is nothing but bad news.

As to the strongest receiver in the world, I hear that all the time, seems people repeat what they heard and or read, after someone tells me how strong the receiver is I had them a receiver and ask them how the receiver I just handed them compares with the Japanese receiver, they they tell me the receiver I just handed them has a front receiver ring that is cut more than half way through from front to back, the cut is wide, wide enough for the extractor, so I have no problem going to the 6.5 Japanese 257 Roberts, and then I tell them "To heck with the receiver, I want the cases Ackley used, when something blows up it starts with the case, from there it goes to the receiver".

F. Guffey

918v
November 28, 2010, 03:49 PM
Slight bulges at the case head are normal. Chambers are larger than the case. The case expands to seal the chamber. The case does not spring back the same amount it expanded. A sizing die will not reduce the case back to original specifications, but it will reduce the bulge enough to allow the round to chamber again.

ping
November 28, 2010, 03:56 PM
Yes, these are norma cases. i went ahead and ordered a box of 20 a while back so i could have some brass to mess with. In firing these I had bought i did not get the bulge - only after reloading them using the 120gr sierra hpbt and well under the max load in the powder. I used the coal of 2.80 and trimmed to 1.975 - could i be trimming them to much. I noticed rcmodel said 1.998. If they would not bulge i would neck size and be done but since the bulge you dont have much choice. I wish i had a picture but i resized all of them. I might have another one in a few though. :) The original ammo i got was norma like i said and had a real long blunt bullet. i decided since i had the brass to try the 120gr bullet per my rcbs manual. then i get this bulge on all 20 rounds. everyone of them. i dont really want to rechamber - it is just nice to have and just wanted to try and reload for it. I am going back to my shed and try reloading one and fire it and see what i get.

R.W.Dale
November 28, 2010, 04:32 PM
I have an issue with several of the replies made thus far applying modern day commercia firearm logic to a military arm designed well over a century ago

. I've only owned type 99's but have been around a T38 or two and I've not seen one that wasn't hard on cases producing bulges exactly as described. The chambers are typically quite generous as reloaded brass life wasn't high on the imperial Japanese army's list of priorities when they accepted the cartridge for service.

If I was gonna shoot a type38 I wouldn't be feeding it the most expensive cases I can find.

ping
November 28, 2010, 04:41 PM
Well i reloaded one of the bulged ones that i had full length resized and from all outward appearances looked great. cleaned up good. Two of the pictures are the same cartridge just different angles. I noticed this time they bulged much different and the case actually has a slight wrinkle. Just for the heck of it i resized that same case and reloaded it again. the last picture of it separated it she result. So strange how the original ammo did not produce the bulge. Looks like if i plan to reload this i will get one reload if i even decide it to be worth it. I will hardley every shoot this rifle i just reloaded because - ...........

ping
November 28, 2010, 04:51 PM
i took those pictures with my cell phone so they are not great for sure.

rcmodel
November 28, 2010, 05:26 PM
Oh good grief!! :what:

Cease & Desist immediately!!!

You are darn lucky it hasn't blown up in your face already!!

You have dangerously excessive headspace!!!!!

Looks like it has been re-chambered to some other caliber as I suggested earlier.

It is certainly not safe to shoot it with 6.5x50 ammo.

rc

R.W.Dale
November 28, 2010, 05:32 PM
I agree DO NOT fire the rifle any more.


However I disagree that the gun has been rechambered, the fired case still certainly looks like 6.5x50mm it just looks like one fired in an excessively out of spec chamber.

mallc
November 28, 2010, 05:32 PM
I have a beautiful 6.5x50 JAP sporter. Overall length is 38", you can't see the join line between barrel and receiver, the blue is deep, it's fitted with Lyamn sites and a ribbon cut American walnut stock.

I run 32 gr of IMR 4895 under a 140 gr spitzer. It shoots like a dream to about 200 yards. It's not at all hard on brass - no bulge, no ring and it ejects flawlessly.

I'm sorry Ping, but you have a sick rifle. You really need to have it looked at.

Scott

fguffey
November 28, 2010, 10:01 PM
"I have an issue with several of the replies made thus far applying modern day commercial firearm logic to a military arm designed well over a century ago"

I know the head space of a chamber before I fire it and I do not have a head space gage, again I can check head space on any chamber at least three different ways with out a head space gage in thousands and that is not go, no and beyond. I have only one standard with two variations, rim, belted and rimless.

I did not see the bulge, the Model 38 is a copy of the Mauser meaning when the bolt is rotated to close the case is not supported by the bolt on the left side, this allows the case to be pushed to the left by the claw extractor, the extractor pushing on the case causes a half moon dent around the case, so I would call it a dent, others call it a bulge. Under no circumstance should there be a bulge, there are circumstances where the head of the case can have varying diameters, the diameter of the head of the case must not expand, if what he is calling a bulge is uniform around the case ahead of the case head then I would say the chamber is worn, again I did not see the bulge.

His rifle has two smoke holes in the top of the front receiver ring, when I test fire a Model 38 I cover the receiver with a white towel, after firing I check to see if the towel looks like it was snake bit with two black smudges where the smoke holes are located, the separated case head looks black soot covered meaning the case did not seal the chamber because of low pressure, just a guess but I believe there are fundamental errors being made when sizing the case, again I would check head space first then fire and then adjust the die to prevent moving the shoulder back more than necessary.

Having said that and keeping up with more than thought at a time, 8mm57 cases have been fired in 8mm06 chambers with out case head separation, case stretch or bulges, when 8mm57 cases are extracted from an 8mm06 chamber ( after having been fired) they are extracted as 8mm06 cases with short necks, an NO!!!! the shoulder did not move forward, it was erased and became part of the case body and the neck got shorter because it became part of the shoulder. The shoulder of the 8mm06 is ahead of the 8mm57 by .127, firing the case in the longer chamber to some is described as having excessive head space, then we go back to Hatcher, he moved the chamber forward on the 30/06 chamber thinking he was going to create head space issues, instead he designed the Hatcher 30/06 Modified chamber, at the time he did not know it. Again, I have 6.5mm50 ammo by Norma, I will not use it, some new others once fired.

The part of the case that can not be sized is the case head, .125 thousand of the case head is prevented from being sized by the shell holder deck height, then there is the radius on the mouth of the die.

"modern day commercial firearm logic to a military arm designed well over a century ago" shooting old rifles is not like shooting pool, there is no english (except when I use the companion tool to the press the feeler gage to size cases in thousands to off set the effect of head space) allowed, the rules have not changed, the rifle is either safe to shoot or it hangs on the wall, again I do not have two standards, for guns or people.

There is what appears to be another problem with the case that separated, the case neck looks as though it has two different diameters or someone tried to neck size it, if the case separated when sizing removing the front of the case could have been a problem.

Again I am a fan of measuring before and after.

F. Guffey

ping
November 29, 2010, 08:51 AM
I do appreciate all info for sure. What i dont understand is if it is unsafe than why did the new ammo not produce the bulge etc. only after the reload did this occurr. I must be doing something incorrectly. I did not neck size it was full size for sure. It was given to me so i might just hang it on the wall. The bulge that i saw was after i reloaded the new ammo. I should have taken a picture of that. The picture posted is 2nd reload and the separation is the result of 3rd reload. this separation did not happen during reloading it happened after it was fired. Just so weird why the new ammo did not produce the bulge. i got 3 more rounds of the original norma so i will fire one tonight just to verify. That stuff is expensive for sure. shessssh.

Jim Watson
November 29, 2010, 09:12 AM
I suspect you full length sized the brass by screwing the die all the way down on the shellholder maybe even with a little extra to bump the press handle over center. That may well have set the shoulder back too far for a sloppy military chamber.
Next batch, back off the sizing die and size the empties just enough to chamber freely.
Whilst not up to Mr Guffey's level of measurements, it will give you a chance to safely and economically shoot the gun.

rattletrap1970
November 29, 2010, 09:19 AM
That looks like a headspace issue to me. You are lucky you're shooting a Type-38 and they are as good as they are. I would say you definitely have to get that rifle looked at by a gunsmith.

I have a Type-38 that I had rechambered for 6.5x55 Swedish, the brass I make is from .30-06 that I run through a 7mm-08 die, then into a 6.5x55 die. After their first firing as a 6.5 I anneal the necks as this metal was never a case neck before. And even with all that going on, I have never had anything like that happen. Again, headspace issue.

fguffey
November 29, 2010, 09:41 AM
Ping, as I said in the post above, I believe there are errors being made in the reloadiong process, again, I have an Eddystone M1917 with .016 thousands head space, for me that is not a problem, I form cases for that rifle that are long enough from the head of the case to the shoulder to off set the effect of head space,I add .014 thousands to the length of the case between the head of the case and shoulder, when these cases are fired.....002 thousands head space.

It is possible you are going about from the other direction, you are forming the cases by firing first, that works meaning you fired, formed and then made a mistake, you full length sized the case, this is what I call case travel, I am a fan of cutting down on case travel because the head of the case is hard? and and when moved back and forth separate...just like your case.

I determine head space first then form, and fire, you fired then formed then sized back to minimum length. Forgiven, that is what happens when you chamber a minimum length case in a maximum length chamber and fire, what you are not forgiven for is the insistence of starting over every time you fire and resize the case if you are full length sizing. The first tool someone is going to get you to purchase is a head space gage, then another and then another and after $200.00+ you will have a case comparator, Sinclair something or other etc..

The only tool you have for sizing is your press with a shell holder and die, after purchasing all those tools (nice to have) you are still left with sizing cases with the press, shell holder and die, SO, why not figure out why the manufacturer put threads in the press and on the dies, I would take a 7mm W FL die and open the mouth of the 6.5 case then start necking the 6.5 case down with the 6.5m50 die starting with a gap of .010 thousands between the top of the shell holder and bottom of the die, after neck sizing the case and preventing the sizing process from moving the shoulder I would remove the case and attempt to chamber the case, if the case chambers without resistance the chamber is longer than your test case, if that happens I would add .005 to the .010 thousands gap and start over. Going either way, with a smaller gap or larger gap, when sizing there will come a point when the case chambers with slight resistance. after determining the gap every time I sized cases for that chamber I would adjust the gap to cut down on all that case travel.

And the first tool I suggest you get is the companuion tool to the press to the press, the feeler gage, it is a standard, transfer and gege, anything used by reloaders like a stick and pencil I can do with a feeler gage, and I wonder has anyone measured the width of a pencil mark, like cutting a board with a mark, is the mark cut through the canter or to either side of the mark.

F. Guffey

243winxb
November 29, 2010, 09:53 AM
The gap between the bolt and barrel face seems to be to large, as if a replacement barrel was installled, but needing 1 more turn into the receiver, then headspacing it. :confused:

NCsmitty
November 29, 2010, 10:08 AM
I know that no one posting expects Ping to become a reloading expert over night.
The case shown certainly exhibits a problem with reloading procedure and/or the firearm.
We need to first view a once fired case, fresh out of the rifle, before any attempt is made to reload. The photo needs to be as clear as possible for viewing.

It is possible that the apparent headspace problem is the result of the reloading and sizing error as mentioned by others.
It's difficult to diagnose a problem like this without having the fired case and the rifle in hand to view and measure.
It's always good to have a competent gunsmith check the rifle and fired case for safe shooting and reloading.



NCsmitty

243winxb
November 29, 2010, 10:11 AM
The gap between the bolt and barrel face seems to be to large, as if a replacement barrel was installled, but needing 1 more turn into the receiver, then headspacing it. This is my Guess. :confused:

ping
November 29, 2010, 10:30 AM
Yep, i am not a real real expert yet guys. i can reload and stick with safe stuff etc. i probably should not have reload that after the 2nd one but i was so curious and i got what i expected - separation. I have 3 cartridges of the original norma and will fire one tonight and take a picture. maybe i will try what mr watson said also and back off the sizing die. When it comes to head spacing it gets confusing. That is the distance from the face of bolt to the head of cartridge right. just trying to talk this through - and if there is to great a distance between them the cartridge tries to come back onto the bolt and esentially fill that space. Is that correct. you would think once the firing occurs it would seal against the walls and not move but this may not be a true assumption on my part. I really dont want to rechamber or anything. it is sort of a novelty of my guns but i would like to shoot it once in a while - safely.

Jim Watson
November 29, 2010, 10:53 AM
The literal definition of headspace is, as you say, the distance from the bolt face to the head of a cartridge all the way in the chamber. Mr Guffey described setting his at .002".

Most Internet Discussions of headspace are talking about the headspace CONTROL measurement, which is the distance from the bolt face to the datum line on the shoulder in the chamber. I don't know what that is for 6.5 Jap, it is not a common round listed by SAAMI; but you will see numbers like 1.630" minimum, 1.640" maximum mentioned for .308.

rcmodel
November 29, 2010, 11:30 AM
and if there is to great a distance between them the cartridge tries to come back onto the bolt and esentially fill that space.That is correct.
The problem lies in the fact chamber pressure expands and locks the case tightly to the chamber wall, with it driven all the way forward against the headspace shoulder by the firing pin impact.

Then the rear of the case has to stretch far enough to fill the chamber tightly against the bolt face.

That in turn causes it to break right where yours did.

I mentioned in post #3 that you should use a bent paper-clip to reach inside the fired case and feel for that stretch ring. Did you do that?
I think you are going to find a bad one after the first firing of your new ammo.

As for the problem you are having?
I have seen a lot of cases stretched out of rifles with excess headspace.
I have seen a lot of cases cracked by pushing the shoulder back too far with the sizing die.
They always look just like the ones in post #20.

But I have never ever seen any with a bubble-gum bulge around the case like yours, right over the stretch ring!!

And I'm not convinced it would even be possible to do that by over-adjusting the sizing die.
(Assuming the die & shell holder are not really really defective)


While we are at it, take a close look at your rifles receiver.
See if the rear tang in the stock is a separate part from the receiver, with a joint.
Or forged, cast, or welded in one piece with it, having no joint.

If the latter, you have a Type 38 Training rifle that was never intended or tested to shoot anything except blank ammo.

They are totally not safe with full power bulleted ammo, and could result in the bubble-gum bulge you are getting.

rc

R.W.Dale
November 29, 2010, 12:12 PM
I still say there's a little more in play here than just headspace. The fired cases look like they had to expand to fill a chamber that's massively oversized around the case body down towards the head. As Ive noted on many arisakas

The headspace could measure spot on and you can still have a rifle that EATS brass if the case has to expand too far outwards unsupported. Much like the case with MG fired 7.62x51 nato cases.

That's where my comment about modern sporter practices above comes from the assumption is the chamber is too deep and the rest is fine. Well the chamber might not be too deep, but it might be way too big around. A chamber cast would certainly tell the tale

rattletrap1970
November 29, 2010, 12:29 PM
You know it probably wouldn't hurt to do a casting of the chamber of that thing. Then check it with a headspace gauge. That would rule out a problem with the rifle AND let you know what you are dealing with as far as the chamber. I mean, who knows, it could have been rechambered for some other caliber. Mine is 6.5x55 Swedish and it doesn't say it anywhere on it (although, now thinking about it, I probably should stamp that somewhere).

243winxb
November 29, 2010, 12:48 PM
The American Riflemen Reprint lists a Type 38 Training rifle as smoothbored.

rcmodel
November 29, 2010, 02:21 PM
Not all of them were smooth-bore.
They also used reject or worn out Type 38 barrels.

I have seen both kinds on GI bring-backs with the cast or welded receiver tang.

rc

ping
November 29, 2010, 06:06 PM
131340

131341

131342Well I shot a new round that is a norma 156 gr softpoint. As you can see from the picture there is no bulge. Previously I trimmed to 1.974 and full length resized like i always do bringing the die down to the plate and then a slight 1/4 turn. Then seating bullet with coal of 2.80.

This time I trimmed again to 1.974 but when full length resizing I took die to top of plate and back off just a bit. Then seated bullet but this time to 2.920 which is what the lee data sheet says is the minimum. I had been doing a coal of 2.800 per my rcbs book which if i believe the lee data sheet would make it below the minimum.

anyway after firing the reloaded cartridge as indicated above got a very very slight bulge hardly even a bulge and much much less than my previous reload.

Anybody got any ideas. I have added 3 pictures. one is the original cartridge before firing - the next is right after firing and the next is after being reloaded and fired. I am probably making more of this then i should and just hang it on the wall but i sure am baffled and want to learn a little on the way. sure appreciate everyones input. And please know i am being safe - i dont fire this near my face and actually have this mounted and pulling the trigger off to the side. anyway the 2 things i changed were the coal and full length resize backup off. hmmmmmmm.

Jim Watson
November 29, 2010, 06:37 PM
It is still showing a stretch ring and might not last but another shot or two.

kaferhaus
November 29, 2010, 07:26 PM
Back the sizing die out a full turn. Size a piece of brass and see if it chambers in the rifle. If it does, check to see if the neck has been sized enough to hold a bullet. If it has, reload that case, fire it and check it for the ring.... bet it's gone.

Typical excessive headspace problem.... find out how much minimal sizing you need to do for the brass to still chamber and your headspace issue with that brass is over.

243winxb
November 29, 2010, 07:45 PM
full length resize backup off. You need to be able to measure how much your backing off. A feeler gauge can be put between the shell holder and FL die when setting it up. If you dont have a feeler gauge, cut 5 shims made from a soda can. Each will be about .003" to .004" thick. Put a hole for the decapping pin in the middle. Size a case with about .015" between the shell holder & FL die. Then see if case will chamber before loading. The bolt should turn a little hard for a snug fit of the brass in the chamber.

mookiie
November 29, 2010, 09:34 PM
243winxb,
I saw the case head separation pictures you posted under the title "Arisaka Model 38 6.5x50 - Bulge in cartridge" . I need some help if you don't mind, I am seeing that exact problem in my reloaded brass for my .303 British MK 1 NO 3. I reloaded some sellier and bellot once fired cases with a 174 grn fmjBT bullet and 38.5 grns of IMR 4064 powder and on the firing with the cases I saw the exact same thing you have in the pictures - some cases just have a crack around the back and others came right off. Do you know what is causing this? I posted under http://www.thehighroad.org/showthread.php?t=556060 this thread. Hope you can help.

ping
November 30, 2010, 07:56 AM
Yes Mr. Watson you are right the right is still there and probably like you said get one more firing. I am going to try what kaferhaus recommended when i get home tonight and let all know. I sure have learned alot from everyones experience. Only got 2 more norma cartridges not fired left. Man that stuff is expensive from Midway. I would do the test now but the work thing is getting in the way. shesssh.

243winxb
November 30, 2010, 08:27 AM
Mookiie, Neck size your brass with a neck die. http://www.midwayusa.com/viewProduct/?productNumber=199697When the brass will no longer chamber you will have to use a full length sizing die. But control how much you push the shoulder back by placing a shim or feeler gauge between the shell holder & die when adjusting it. Start with a shim of .015", size your brass. Will it chamber with a little extra bolt pressure. If you can not close the bolt, try a smaller shim maybe like .012" or smaller till the bolt closes on the empty case. http://www.brownells.com/.aspx/lid=12897/GunTechdetail/Gauging_Success___Minimum_Headspace_and_Maximum_COL

fguffey
November 30, 2010, 11:09 AM
Ping, the measurement Jim Watson is referring to when measuring the effect the case has on head space is: Datum 3/8"/.375 to the head of the case 1.584. I went to the Big Town Gun Show two weeks ago and came home with 40lbs of datums, $20.00. It takes me less time to makeup a datum than it takes me to look one up. The .375 datum is the same datum used on the 30/06. 7.7 Japanese, 25/06 and 25+ other chambers, you don't have a .375 datum? Make one, drill a 'straight' hole in a metal block and...you are done, then there are improvements on that design but who would remember where they got the ideal, you do not have a drill, drill press and a means of drilling straight, go to a hardware store, a bolt supply store or somewhere they sell wire, Fastenall is a good place to start, and, Harbor freight, all sell plates with holes, some are plastic, others are metal, by what ever means once you have acquired the .375-3/8'th hole drop the case fired or unfired into the hole until it contacts the plate then measure the height of the protruding case above the plate, then write the measurement for for comparison after the case is fired, then measure the case again by placing it in the .375 hole and measure the height of the case above the DATUM, the difference should tell you the amount of stretch or effect the chamber had on the case when it was fired, same for sizing, before sizing drop the case through the hole and measure, THEN, size and measure again, the difference between the two measurements will indicate shoulder set back, and do not go for the "you need a neck sizer die" "You need a bushing die" first learn to get all the use you can out of the die you have, I prefer the versitle full length sizer die, it sizes, partial full body sizes, neck sizes with improvement in techniques and methods, I have all those other die, I refer to them as nice to have.



The diameter of the case can be measured, BUT, there seems to be some that believe I am trying to overload you, I have no clue as to their motive, I do not have five different ways to tell you if you are going to reload there are methods, techniques and knowledge you to need master, after a few years of correct practice I hope you do not take on the attitude your opinion is the only one that is important.



It was suggested you do a chamber cast,,,then in the same sentence it was suggested you check the cast of the chamber for head space, it can be done by a very few, one of the very few that can/has done that wouldn't.



F. Guffey

mallc
November 30, 2010, 06:57 PM
You ought not shoot that gun until you have the chamber looked at. All the tinkering in world on the round won't fix a bad gun. A good bore scope can quickly answer your question. It's possible to cast the chamber but whatever is allowing the bulge may well lock the cast in the receiver and then you'll have a real mess!

You don't have to be in a hurry to solve this mystery...

Scott

Steve Marshall
November 30, 2010, 08:34 PM
In your first set of pictures you can readily see that the brass expanded quite a bit ahead of the case. I would say that your chamber is grossly oversized there. That could be the way it was manufactured but not likely. More likely is Bubba polished the chamber.

NCsmitty
November 30, 2010, 08:59 PM
I've been giving some thought to the "bulge" in the sequence of reloaded case.

Does it sound feasible that the bulge was formed in the sizing process when the case partially collapsed along the stretched fracture line and then fired?
I keep wondering how the strange ring in the cases had been formed, in the pictures that Ping had taken, if the chamber is smooth.
A thickness of case could push a ring out when fired.

There's no doubt in my mind that the rifle is at the least, experiencing headspace problems, and not being able to inspect the rifle, who knows what other issues it may have.

Has anyone else got an idea about the ring, as I had never seen anything quite like it.



NCsmitty

rattletrap1970
November 30, 2010, 09:01 PM
Again, I wonder if the rifle was re-chambered and not marked. After reading this thread I punched mine indicating that is it now 6.5x55 (not 6.5x50)

ping
November 30, 2010, 09:11 PM
Well I fired one of my original 156 grain norma cartridges and as usual there is no problem. With this said does that not indicate that the gun is not potentially a problem. anyway - I reload it and did like kaferhaus said and run the die down to the plate and then i backed it off 1 1/2 turn. I went a little more..... It did resize the mouth enough and i could chamber in the rifle also. I then primed and all loaded. I fired it ejected the shell and all looked fine. So - what does this indicate. Did I replicate the original cartridge as it has no problems either. one person said use a bore scope. Not sure exactly what that is. Is it just putting a light down the barrel and viewing. Not sure. Not sure what casting a chamber is. Sorry to ask all these questions but I just dont know.

fguffey: you said alot there and i got to digest that. datum and all. I know to many questions but gosh i want to know.

NCsmitty
November 30, 2010, 10:15 PM
So - what does this indicate.

Essentially you are compensating for the stretched brass by backing off on the full length sizing die so the brass is the size of the chamber. This reduces the sizing and stretching and eventual case separation that you observed previously.

This is not to say that your rifle is good, as I personally think that the headspace is too long and out of spec, and that's why you had the problem.
You should be very cautious, as you are not experienced and could have a problem if you continue to shoot the rifle without someone knowledgeable inspecting it for you. No one here wants that to happen.
Be safe!



NCsmitty

rcmodel
December 1, 2010, 11:24 AM
Post #3:
Use an L-Bent paper-clip or wire to reach down inside the case and feel for a thinner spot where the case has stretched.

Post #23:
I mentioned in post #3 that you should use a bent paper-clip to reach inside the fired case and feel for that stretch ring. Did you do that?
I think you are going to find a bad one after the first firing of your new ammo.

I'm still waiting for the OP to do this on a new once fired case.

I guess you can lead them to water, but you can't make them drink!!!

rc

ping
December 2, 2010, 03:33 PM
used a paper clip and I cannot feel anything different. Ok, so i understand a little more about how basically it is filling the chamber when not fully sizing. Well I will just put the rifle aside as a collectable i guess. Just funny how new ammo just shoots fine and not problems with the brass. I guess when i resize partially it is putting it back closer to how the original brass came. Is that a fair assessment. I will not continue to bore everyone with this. I do appreciate everyones help.

NCsmitty
December 2, 2010, 04:39 PM
I can see that you are getting the basics here. The first time that you shot factory ammo, the case expanded to fill the chamber. If you had measured the case length before firing with a vernier, and then measure it after firing, you would see the difference in length in tangible numbers.
Then when you initially sized the case for loading, you squeezed the case back down to a shorter size again, and after firing, a more visible line around the case appeared as the case was stretched again, and the brass got thinner at the stretch line.

Now fast forward to when you shot the factory ammo a day or two later, but then you raised the die so it didn't shorten the case when you loaded it. The case fit the chamber and the case stretching was nearly eliminated. The fired round that you reloaded came out looking fairly good, as you mentioned.
So you see, the rifle does have an issue, but you can work around it by fitting the brass to the chamber. You just have to be cautious in not loading the cases too many times, and create a dangerous situation. Now you know what to look for when firing that Arisaka.

I'd still feel better if you had someone knowledgeable check it over.

NCsmitty

Carl N. Brown
December 2, 2010, 07:07 PM
If the chamber is oversize, stretch should show up more measuring base to shoulder, rather than base to neck; in fact if the neck of the fired case looks shorter than the neck of an unfired case the chamber is really oversized. (think firing a .308 in a 30-06)

NCsmitty
December 2, 2010, 08:59 PM
If the chamber is oversize, stretch should show up more measuring base to shoulder, rather than base to neck

Your right, Carl N. Brown, but Ping is a newbie reloader and giving him a reference point on the shoulder for a measurement might be an exercise in futility to show him that the excess headspace is growing the case after firing. The easiest for him was the overall case length. I don't know that he has a vernier to use.



NCsmitty

MEHavey
December 3, 2010, 01:17 AM
In your first set of pictures you can readily see that the brass expanded quite a bit ahead of the case. I would say that your chamber is grossly oversized there.
Have y'all considered that the Norma brass head diameter is grossly undersize compared to the chamber? I say this from seeing the same lopsided "bulge" back in `88 when I fired my FIL's 6.5 Jap reloaded using (that same) new Norma brass. The case ahead of the web tries to expand to the chamber walls but can't take the solid head with it -- case separates around the circumference right there.

IIRC addressed the problem by sizing/forming/trimming .243 cases (Head diameter 0.471" and using them instead.

Others' experience?

ping
December 4, 2010, 05:44 PM
ncsmitty - thanks for good info. I did learn something from this so that is good. I wish i had someone I knew to take it too and just have them look it over but dont really know of anyone in the area. Like you said if i shoot once and reload and full length like you said i should safely get 2 shots. I dont shoot this hardly ever. Got plenty of other guns i dont have issues with. just a good learning experience. I think i will though measure a new round before firing and see what the difference is. gosh those things are expensive though. i see midway has just the brass might try that and see what i get. again thanks all for the info and hopefully someone else reading this thread can glean some good info.

Jimfern
December 5, 2010, 12:35 PM
I have a Arisaka 38 Carbine that I've reloaded brand new Privi brass for once. I noticed the same problem with my brass. My old Hornady manual says the brass should measure .447" at that area. When I resize with my RCBS dies, I measure it at .445". Shot out of the carbine, the brass measures .454" so my brass is expanding roughly .01". I bought it at a gun shop in East Texas a few years ago and it had been sporterized, although it looks like they only worked on the stock.

Is that similar to what you are seeing?

I went and pulled my rifle and it doesn't look worn out or abused (other than the sporterizing). In fact, almost all of the bluing is on the barrel/receiver is still there, so I'm wondering if this is a design feature and may explain why there are two vent holes in the receiver. Just my two cents, but I think I'm going to get the head space checked on it before I shoot it again.

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