Resizing Dies too Long or Am I Doing Something Wrong?

[GLShooter]

Borrow a 308 die from someone and try it. Maybe you need a small base die.

A small based die won't make a difference in shoulder location other than that it would be a different die with dimensions that were different than the original. IMHO

Greg

[7of7]

I'd just chuck it up in my lathe, and take about .02 off of it, and call it good. That way, there is more adjustment, and if needed, he can go way down there... But, having a die that does prevent you from going to far is well worth it.. I just size them so they will fit.
I had the same kind of issue with my weatherby, the ammo used in my other rifle, wouldn't chamber, so, I had to resize the brass.. all the stuff that I had resized already needed to be done as well.
I wasn't to happy.. but, now it is all good. I carry a broken case extractor with each rifle.. just in case..

[frank_1947]

I don't know where your getting 3.6 or whatever you said with a hornady headspace gage headspace for a .308 is 1.630 min and max 1.640 according to Saami specs

[Lloyd Smale]

watch shaving the shell holder. I have a new 7mag that needed the same and shaved two shell holders broke them both and stuck cases in the die both times. Ground down the die and it worked fine. Ended up just buying a small base die to size them. The small base die not only takes the bottom of the case down a bit more but will allow you to push the shoulder back a bit too. I was shooting once fired brass from a gun that obviously had a bigger chamber then my remington.

[Kevin Rohrer]

I don't know where your getting 3.6 or whatever you said with a hornady headspace gage headspace for a .308 is 1.630 min and max 1.640 according to Saami specs

That's the raw measurement I get including the length of the case gauge. Subtracting the length of the gauge (2.003) from the raw number gives me a headspace of 1.630" (3.633-2.003=1.630"). I think I need to bump the shoulder back a bit more to 1.627".

I've been looking for headspace sizes but haven't found them in any of my reloading manuals.

[Larry Gibson]

Kevin

Your measurements are correct with that gauge. A couple things; fired cases from an M1A using .308W or milsurp spec ammo will most often have a longer cartridge headspace than that of the chamber. Let me suggest this to get a chamber headspace measurement with your tool and dies. If you know how and can remove the extractor, ejector, firing pins and associated small parts from the bolt and reassemble the rifle.

Back the die out of the press 1 turn from the shell holder.

Size a case that has been fired in your rifle.

Trim the case mouth back to a case aol of 2.0" (don't want the case mouth the give a false fit).

Insert the case into the chamber and ease the bolt forward. Do not let it slam as that will partially size the case. The bolt should not close (the case should not yet be fully sized). If the extractor and ejector are still in the bolt push on the oprod until the extractor snaps over the rim, it still should not be fully closed. Gently extract the case.

Wipe off and relube the case. Turn the die in 1/16 of a turn. Size the case, wipe lube off and repeat trying to chamber.

Continue with 1/16 die adjustments until the bolt just closes and the oprod goes fully forward.
When that happens the case is sized to the headspace of the chamber of your rifle. This is the maximum case headspace for your chamber. Measure that case headspace with your tool and write it down. Then adjust the die to size your cases .001 - .002" shorter case headspace for reliable functioning.

Larry Gibson

[Char-Gar]

I have two comments, but bear in mind I have never loaded for an M1A. But I think is is a basic Garand action that has been modified for the shorter round and a detachable magazine.

1. Some times we can get lost in the minutia of reloading and forget the basics.
2. In a Garand, we don't want to do partial resizing on cases. We FL size and take the reduction in case life that comes with that. We don't want to run the risk of a too long round and a slam fire in a dirty chamber. We want a little wiggle room with the loaded round.

These things are no bench rest rifles and properly set up/tuned will win the match without bench rest reloading.

[Kevin Rohrer]

Larry,

This is the information I need and I appreciate it. I follow what you are saying, but could you explain why a cartridge fired in my rifle would end up w/ a longer headspace than the chamber it was fired in?

[ReloaderFred]

Kevin,

The theory is that the action of the M1A/M14 is so fast that there is still pressure inside the case and barrel when the bolt unlocks and starts to the rear. This causes the case to stretch while it's being extracted.

I tested this theory on my Standard M1A by closing the gas valve and firing the rifle as a bolt action, manually working the bolt to eliminate any possibility of case stretching beyond the chamber length. In "my" rifle, there was no difference in headspace measurment of the fired brass between firing the same load manually or in semi-auto mode. I can't test my National Match M1A in the same manner, since they modify the gas valve so it can't be closed on those rifles.

I measured the brass from both of my rifles with my RCBS Precision Mic dies to come up with a sizing die setting. The NM rifle does have a slightly shorter chamber than the Standard rifle does, but by only about .001".

You might close the gas valve on your rifle, if it's not a match rifle, and see what your results are.

Hope this helps.

Fred

[Larry Gibson]

Kevin

ReloaderFred gives you the theory and what he found. I did the same test years ago using several M14s (I had 20 of them in very nice condition in my arms vault) using reloads, M118, M80 and Special Ball ammuntition. Wasn't a for sure thing with any specific ammo in all the rifles. Seemed it just depended on the particular rifle and particular ammunition. On those that did increase case headspace on extraction (about 55 - 60% of the time if I recall correctly) the increase was .001 - .003". Having to bump that shoulder back that additional amount is one reason some rifles only got 3 - 4 firings per case and some got more with the same loads (mostly 41.5 gr 4895 under the 168 MK back then). Even using the same loads from the same dies there was a difference in case headspace of the fired cases and the number of reloads per case individual match grade M14s with match chambers cut with the same reamer. That's my "theory" on that anyways. It does happen but not always. The X - die solved the problem any ways.

Larry Gibson

[Kevin Rohrer]

I don't have a Match rifle. How do I close the gas valve?

[ReloaderFred]

Up at the base of the gas cylinder there is a screw just under the barrel. If you use a dime and push in on the screw, you can turn it 90*. That will close off the gas port. This was used for rifle grenade launching from the M14.

After you've fired about 5 rounds to get an average, don't forget to open the valve again.

Hope this helps.

Fred