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Arisaka Model 38 6.5x50 - Bulge in cartridge

Discussion in 'Handloading and Reloading' started by ping, Nov 28, 2010.

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  1. ping

    ping Member

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    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.
     
  2. NCsmitty

    NCsmitty Member

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    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
     
    Last edited: Nov 28, 2010
  3. rcmodel

    rcmodel Member in memoriam

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    That 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
     
    Last edited: Nov 29, 2010
  4. fguffey

    fguffey Member

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    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
     
  5. 918v

    918v Member

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    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.
     
  6. ping

    ping Member

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    bulge

    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.
     
  7. R.W.Dale

    R.W.Dale Member

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    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.
     
  8. ping

    ping Member

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    Just reloaded

    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 - ...........
     

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  9. ping

    ping Member

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    i took those pictures with my cell phone so they are not great for sure.
     
  10. rcmodel

    rcmodel Member in memoriam

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    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
     
  11. R.W.Dale

    R.W.Dale Member

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    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.
     
  12. mallc

    mallc Member

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    I have a beautiful 6.5x50 JAP Sporter

    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
     
  13. fguffey

    fguffey Member

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    "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
     
  14. ping

    ping Member

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    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.
     
  15. Jim Watson

    Jim Watson Member

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    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.
     
  16. rattletrap1970

    rattletrap1970 Member

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    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.
     
  17. fguffey

    fguffey Member

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    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
     
    Last edited: Nov 29, 2010
  18. 243winxb

    243winxb Member

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    Have it Checked by a Gunsmith.

    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:
     
  19. NCsmitty

    NCsmitty Member

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    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
     
  20. 243winxb

    243winxb Member

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    Your photo is not a normal case head separation.

    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:
     
    Last edited: Nov 30, 2010
  21. ping

    ping Member

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    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.
     
  22. Jim Watson

    Jim Watson Member

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    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.
     
  23. rcmodel

    rcmodel Member in memoriam

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    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
     
    Last edited: Nov 29, 2010
  24. R.W.Dale

    R.W.Dale Member

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    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
     
  25. rattletrap1970

    rattletrap1970 Member

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    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).
     
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