What goes on Inside those Dies anyway??

[Edward429451]

After getting an M1A I began reloading for it, and My sons/BIL's 700 Remmy's. Many of the reloads would not chamber in the 700's. Advice gotten here was to give the sizing die an extra 1/8 to 1/4 turn. In between doing that and even running them through the sizer twice (?) seemed to help a little but did not cure the problem 100%.

I've been doing some reading and have found the true cause aside from the remedy which some suggested. The M1A is a 7.62 X 51 chamber, and the 700's have a .308 Win chamber. The difference being that the 7.62 chamber has an additional .013 of headspace, so when a round is touched off it blows the shoulder further forward than it would in a commercial 308 chamber. Sizing sets it back some, but not enough to ensure correct dimensions for commercial chambers. Rounds that would not chamber in a commercial chamber would chamber nicely in my M1A. Problem identified.

Some of the info I've been reading indicated that not all .308 sizer dies are constructed the same. Some dies do not touch the shoulder at all, merely resizing the neck. Others do. I have Dillon 308 dies. Are Dillon's neck sizers only?

I plan to go to using purely mil spec brass for my M1A, and sticking with 308 brass for any 308's I load for to alleviate the problem in the future. The problem here is that I have a small boatload of 308 brass, which has been mixed, some shot in my military chamber, some in commercial, and want to be able to use it. Can it be done or should I just cut my losses and start from scratch here?


I want to be able to load 7.62 and 308's on the same set of dies. Is this feasible? Should I be using a particular brand of die(s) to accomplish this? Also, even if I had a die that would set the shoulder back enough to make my reloads work in the remmy's, would this be overworking the brass?

Also, since the commercial 308 chamber is shorter than the military chamber, would it be feasible or advisable to have the remmey bored out to mil spec dimensions? (Keeping in mind the charge differences for brass construction.)


Need some input on this to clear the moud.

 

[30Cal]

If the M1A hasn't been rebarreled and the bolt hasn't been fiddled with, SA Inc usually chambers them to 1.631-1.632" which is within the .308Win SAAMI spec. The rifle came with a headspace tag that will tell you what yours is. The chinese M14 rifles are usually at the long end of the 7.62mmNATO spec and you might see a problem if you were loading for both a bolt action .308Win and a chinese M14, but not with an M1A.

Your chambering problem may or may not be related to where the shoulder on the case is located. You are trimming your brass to keep it below the max length, right? It may also be that you are still not sizing enough to set the shoulder back and are only neck-sizing. A case gage would help greatly when setting the sizing die.

How many times has the brass been fired and what in?
Ty

 

[caz223]

Not being a rifle guy, I won't be 100% sure on anything, but I got the distinct impression that after fireforming, the shoulder would be very difficult to move back to the normal position, without creasing the shoulder unless you have the right dies, and lube the snot out of them. Even then, trimming may be required.
You might want to invest in a case gage, this sounds dangerous/frustrating.

The dies that neck size only should say neck size only somewhere on the box or dies.
Sorry that I'm not very helpful, just trying my best.

 

[Abenaki]

Find out how it goes by keeping the brass from each rifle seperat.
But I would also look at a small base sizing die.

Abenaki

 

[Edward429451]

Are the case gauges different for 7.62 vs 308 Win.? I wouldn't think so seeing as the external dimensions are the same.

Anyone got a link to where I can order go no-go gauges?

Why should I get a field gauge? What's it really tell me and how do I use it?

THX.

 

[Master Blaster]

You need to resize the stuff fired in the loose nato chamber with Small base resizing dies, it takes care of the problem.

http://www.midwayusa.com/midwayusa/...ector=all_products&search_keywords=.308+small

 

[Edward429451]

I think I'm going to get a small base sizer, gauges and stick to mil spec brass for my M1A.

Any particular small base sizer better than the rest?

 

[Sunray]

Are you full length resizing the cases? It's a must for the M1A, but the 700 should take them with no fuss. It has nothing to do with head space. Do your reloads work ok in your M1A? The 700 might, I say again, might, have a tight chamber. Still a die is a die. If you're full length resizing the brass, it should be fine.
Can you use the same dies? Yes. I've been loading .30-06 for my M-1 and my 03A4 rifles with the same dies for eons.

 

[Edward429451]

Are you full length resizing the cases?

Yep. Used to screw it down until it touched the shellholder and stop, THR'ers told me to give it an extra 1/8 to 1/4 turn to take any play out of it so thats what I do now. Reliability is better now but some rounds still have trouble in the 700. Actually its 2 different 700s of the same model (700SY). All rounds which have trouble in the 700s have no trouble whatsoever in the M1A.

Could my (Dillon) die need a little length taken off the bottom?

 

[Bullet]

You said your using Dillon dies. Are you loading on a progressive? If so the adjustments in other stations might be your problem.

 

[Edward429451]

I load on a Dillon 550B but I size seperately on a RockChucker. Just charge, seat & crimp on the progressive.

Edited to add...Whoops! No they're RCBS dies. I have too many sets of dies and not enough coffee when I posted that!

 

[Jwar88]

It is not uncommon that a round that is loaded to be a custom fit to a particular rifle's chamber may not chamber at all in another rifle, but ...

If you truly recreate factory round dimensions with your tools, the rounds will fit universally in all chambers.

You need to start by making accurate measurements of your finished rounds and find out which dimensions are out of specification, if any. It could be the cartridge or the rifles chamber. Make sure that your chambers are really clean.

I would begin by taking careful measurements to find out where the problem really lies...otherwise you are stabbing in the dark!

If case dimension was the problem, try another manufacturers dies... Dillon dies are made to function smoothly in their progressive reloaders.... in order to do this they chamfer the bottom of the dies more heavily than the other manufacturers...which means that a portion of the base of the case does not get sized. This has been a known problem with their pistol dies in match chambers. An unnecessary compromise, in my opinion.

I think that the best deal on the market right now are the Hornady New Dimension Rifle Dies. They produce match ammo tolerances and can be found for under $25 at Midway and various other places.

I am not a big fan of totally progressive loading for rifles because I like to hold tolerances closer than the progressives can, and progressives give less consistency on overall length, primer seating depth, etc.., and OAL could be another area where you may be having an issue.

For me, rifle loading is just as fast loaded single stage... the way I do it. But then... I place a high value on quality ... and if it takes me an extra 10 minutes to do it then... so be it!

But I really recommend you obtain a full length resizing die from a major manufacturer...RCBS, Hornady, Redding, Lee... not necessarily in that order...they are all good.


All these considerations aside... perhaps your problem is more one of your loading strategy...

What I mean is...I tune my loads to my individual rifles to be able to maintain minimum headspace for the individual rifle. It stretches the brass less, and gives 50% greater accuracy.

Also, since gas guns need completely different powders and bullet weights to function properly. I would keep the loads separate and provide proper loads for the gas guns and proper loads for the bolts. I simply use military brass in the autos and commercial brass in my bolt actions. Makes life simple.

Now... go do the right thing...

Moderator action: DoubleTap. At Member's request, an inadvertent second posting of the above message was removed. The original has not been changed.
Johnny

 

[Jwar88]

A few more thouthts to ponder...

It occured to me that if none of your rifles have match chambers the rounds should all fit. If you are using RCBS sizing dies... are you using an RCBS shell holder?

Also, and this is big... are you checking case length after you resize and trimming them all to saami minimum? You want to be real careful to do that because long cases can cause serious pressure problems.

When you make sure your chamber is clean, make sure the bolt face is real clean too.

By all means, segregate your commercial and mil brass. It would also be useful to know if a particular brand of brass is causing the problem. You should be able to use them all without problems. You should be keeping track of lots and how many times a group of cases has been fired. Record keeeping is very important, I feel.

I have heard reports that military brass, LC brass in particular, has a tendency to spring back after resizing because it is so hard. I have never experienced this myself ... and I have always suspected that this is the real reason...

I believe that what may be happening is that the expander ball can be putting enough pull on the case neck during it's return trip out of the case that it stretches the shoulder out of spec! This could easily happen as the military brass has a bit thicker, and maybe harder, case neck wall.

The analysis here is long and lengthy but fortunately the solution is simple. I always put a little bit of water soluble case lube on the INSIDE of the neck with a q-tip as part of case lubing. Just make sure to clean it off real good before you load it.

The Hornady expander is elliptical and minimizes this... also Redding offers a carbide expander ball that minimizes neck pull as well, and they have them to retrofit to RCBS dies. For me, the lube method is simple and easy, and since I always give a final cleaning to my brass after sizing anyway, it doesn't really add to loading time.

Also, some mil brass has glue, or cement on the inside of the case neck that is real sticky and needs to be removed with a highly aromatic solvent before loading... like acetone, mek, or lacquer thinner.

Just a few more ideas for you.

 

[Edward429451]

RCBS shellholder. M1A is match, 700's are not. I do not trim to saami minimum, my lee trimmer trims to 2.010 only, but they are uniform and less than max so figured it was ok.

Your idea that the expander ball is stretching the shoulder on its way out may have some merit, I've never lubed a neck. Wouldn't this show up on the calipers if it did? I can find no difference in the measurements. Also hard to get measurements on an angle.

I'm already segregating the brass and will only use military in my rifle from now on. I'm going to get a small base sizer jic and tear down the toolhead and load single stage 30 cal from now on.

Thanks for the ideas.

 

[labgrade]

Just a quick thread skim, Ed ...

How's your bullet seating depth? You may be running the bullet into the lands & nothing to do with the brass sizing at all .... just a thought.

BTW, I still have a 100 count bag of cast .308s set aside for you personally, & we've yet to hook up.

 

[Jwar88]

Troubleshooting is primarily a process of checking off all the factors that are not contributing to the problem till you are left with the possibilities that remain.

Are you trimming before or after you size? Both ways are ok as long as your case is not over max when it is ready to be loaded.

Theoretically... any stretching of the shoulder would show up in a measurement of case length, but sizing itself lengthens the fired case anyway so establishing a reference for measuring this would be problematic.

Labgrade's point of checking bullet seating depth is well taken. Almost any two rifles will have enough difference in leade or throat dimensions to require a different seating depth for optimum results. It's not a matter of OAL but the clearance of the bullet's ogive to the rifling.

If would be informational in the future to do a visual inspection of any cartridge that has a chambering problem to see if there are any scratches on the bullet from the rifling...

but one way to determine seating depth is to make up a dummy round and start the bullet seating process a little long until it will definitely contact the rifling when you chamber it. Then seat it a little deeper in several attempts while trying to chamber the resulting round in your rifle. At some point it will jusssst chamber... congratulations... you have just determined your rifles throat dimensions, and the minimum seating depth.

RCBS and some others make a tool for this. RCBS calls theirs the Precision Mic... Measures headspace and bullet seating depth.

Some of my friends who shoot different M-1's and M-1a's have a dedicated seating die for each rifle .... set to that individual rifles preference... to avoid the nuisance of having to set it each time they change.

Not sure small base dies are the answer just yet...

 

[labgrade]

A nit, but that's exactly what we're doing here - picking nits till you get it just right, no?

"At some point it will jusssst chamber... congratulations... you have just determined your rifles throat dimensions, and the minimum seating depth."

That should read as maximum seating depth.

& that's just for this particular bullet shape - the over all length to the bullet's ogive relative to that particular rifle's lands, etc., yada. A different bullet will have a different OAL - & everything's based on where that bullet shape contacts that rifle's lands.

 

[Edward429451]

I always trim after sizing/decapping b/c my trimmer has to pilot through the flash hole.

Bullet seating depth gives me some variance on the Dillon. Sometimes as much as .010 and I think it should be held tighter than that but they're double checked and adjusted accordingly if needed. So far I've held them to mag length, which isn't a problem. I've never seen rifiling marks come back out on a problem round.

Labgrade, I tried to PM you several times but it wouldn't let me. I figured you may have some personal issues in the air or something and have been trying every now & then to see if your PM's were back on, without success. PM or E-Mail me.

 

[labgrade]

"I figured you may have some personal issues in the air or something and have been trying every now & then to see if your PM's were back on, without success. PM or E-Mail me."

I did (& sorta still do).

Back now, Ed. What's up? Likely best done in a PM, huh?