A M1 with a disconnected opp rod , so as to fire singles . Every , say 8 12 shots although some times 4 shots and it happens . Primers are backed out of casing about .0010 .0015" ?. I can't figure what could be wrong ?. These are well with in load data for 30/06 . I mean to the low middle of the road reloads . Anybody experience this happening to them or have a theory as to what might be going on ?.

Excessive head space ?. Why doesn't it do it every time ?.
My other M1 doesn't do it it . It has the opp rod connected though but what difference does that make ....

quote:

Originally posted by Dr.K:
A M1 with a disconnected opp rod , so as to fire singles . Every , say 8 12 shots although some times 4 shots and it happens . Primers are backed out of casing about .0010 .0015" ?. I can't figure what could be wrong ?. These are well with in load data for 30/06 . I mean to the low middle of the road reloads . Anybody experience this happening to them or have a theory as to what might be going on ?.

Excessive head space ?. Why doesn't it do it every time ?.
My other M1 doesn't do it it . It has the opp rod connected though but what difference does that make ....

I would ck the headspace first. See if a no go guage will chamber

I would guess that the locking lugs are trying to rotate open a little increasing the headspace. I don't think it is a good practice trying to alter the normal operation by making a single shot from a semi auto that has no way to keep the bolt closed tight. Doesn't the op rod aid closure?

i gotta agree 110% with bfrshooter, the operating rod and spring hold the bolt into battery. your primers were coming out because the bolt was coming unlocked - this could be a bad scene

Do you "uniform" your primer pockets? If not, may be reason primers don't back out every time-some pockets are tighter. I also think the disconnected op-rod is the basis.

No op-rod = no go! Put it back, put it back!!
What you have created by removing the op-rod is an ideal situation for an out of battery fire that could potentially hurt you, let alone destroy the rifle.
Secondly, what have you done to contain/control/divert the gases that would have normally been used to operate the bolt?
No matter how you slice it, it's a bad situation you've created.

Wait ; wait a minute !. Op rod is still attached it's not hooked up to the piston end !!. Sorry I didn't mean to imply I had removed it , just disabled it !. Gas plug is out so it wouldn't operate the bolt !. Bolt can't rotate or come unlocked when in battery !. If that was the case I wouldn't be here !.
Yes I uniform my primer pockets . The primers backing out of the pockets happens with Commercial brass more so than with Military brass .

It still happens and it's erratic . so why if it was a head space problem , it doesn't do it every time ?.

Cartridge spaces on the shoulder all specs are good to go . Normal pressures nothing excessive 4895 middle of the road loads 2575- 2625 FPS .
Accurate arms 2495 does it to .
Now my other Garand doesn't ?. I've got a friend and his does it to !!!??. He had his checked for head space it's fine according to the gun smith . I would sure like to find out why it's doing this . Hopefully a M 1 Gun Smith on the site will take a look at this . Thanks to every body who replied ...

What it sounds like is that an occasional case has been insufficintly sized, holding the bolt from going into complete battery. These guns will fire when slightly out of battery.

Maybe a small-base die is is order or just screwing your sizer in a little more. That might have the effect of shortening case life, but it is better than an out-of-battery KABOOM.

Your loads are too light. Most 30/30s do the same thing due to low pressure. The primers back out and holds the cases forward when it fires.

Loads are only 100 FPS under specs so that shouldn't be a factor . Small base dies are used . A friend is going to pull the gas plug on two more of his M1's and we'll see what happens .

I've got 3 Garands he has several . One of mine does it one of his does it . My other one does not either does his other one . DCM re arsenalized both of them .
My third one well we will never know !.
It's an all numbers matching Springfield original that was never issued !. It was still packed in cosmoline .

Back to the problem . I shall keep you posted as to what happens when we try two more of his .
Oh his other Garand that does the same primer back out , was taken to a gunsmith for head space check a few years ago . It was fine !. I never had mine checked as I assumed DCM would not have sold re barreled M1's that were not in spec !.
What is odd is the fact other powders cause this regardless of load specs . But not always He's using commercial brass I use Military brass .
So go figure and we have swapped loads no difference !.

What powder are you using? It could be a low pressure issue. Gas sytems work in a pretty narrow range. I have noit seen this in either of my M1s, one in .308 one in 06.

I had this happening in my savage 30-06 bolt action. My first suggestion to try and solve this would be to not fully resize your cases. usually it is a headspace issue, although with an auto, it could be something else I'm not aware of. try just neck resizing and see if that solves the problem. it could just be a bad batch of brass that has oversized primer pockets.

Powder H4895 Acc 2495 , H4350. Blc-2 .I have as my friend has neck sized also makes no difference we can point to .
It happens infrequently is what concerns me . If it were all the time well I would send it off to a Smithy in a heart beat . I'm not opposed to doing that if I knew what was causing it !.

But why does his also do it and our other two don't ?. It makes no dam sense what's so ever . There are NO SIGNS of pressure leaks around the necks or shoulders. Normally that's the first place you look for soot .
We checked primer pockets , that was our second area of checking after the neck & shoulder .

I use military brass he uses commercial brass although we have done the reverse it made no difference we could see .
It's very difficult when it happens randomly to say oh that's it , or Yea that's what caused it . Because it happens again . My primer pockets are .1265 -.127 " in depth with a Dia. of .2085 - .2090 . Primers them selfs are .212 - .214 normally match Feds 215 . Some times I use Win. which are same size Large Rifle primers .

We have a standing bet as to whom will get the first single hole 5 shot group . So far he is slightly ahead of me . With a .425 " at 100 Yd.

I'm still out around .625 " . The best in his was with Accurate Arms 2495 I believe a 165 or 150 grain projectile ?. I'll find out this next weekend when we try two more of his Garands with plugs pulled .

Mine likes Sierra 168 with 44.2 grains BlC-2
by far the more consistent load . I've grouped better on an average than he has. But that's not the bet !!...