Bolt won't close on one re load?

T

thefitter

Sergeant
Full Member
Minuteman
May 10, 2010
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#1
I wanted to check the cycling of my first batch of re loads in the AICS magazine to make sure everything would feed.

I tried to load everything as long as I could because my headspace is 2.959, subtracting .040 gives me 2.919. But my OAL is 2.87 because that's the longest I can fit in the mags.

In the first 10 round mag I had one that I could not close the bolt on. Second mag had 2 that were tight but I could close the bolt.

I measured all 3 rounds and I can not find any real discrepancy in their dimensions from the rounds that cycled in and out perfectly.

OAL = 2.875
Ogive = 2.165
Shoulder = 1.630

These numbers pretty much match all the others.

What am I doing wrong? Thanks
 
#2
Re: Bolt won't close on one re load?

Did you have one almost get stuck during re-sizing? I have had a couple that didn't get enough lube and during resizing the rim was warped, and the bolt would not close as a result.
 
#3
Re: Bolt won't close on one re load?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: elcam</div><div class="ubbcode-body">Did you have one almost get stuck during re-sizing? I have had a couple that didn't get enough lube and during resizing the rim was warped, and the bolt would not close as a result. </div></div>


Are you talking about stuck in the shell holder or die? I don't recall anything getting stuck in either.

The press is a Forster CO-AX so it has a spring loaded shell holder.

The only thing else I'm noticing is that the case head is a bit chewed up. This case was probably fired in my M1A. Is that what you meant by warped rim? Thanks
 
#6
Re: Bolt won't close on one re load?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kd185</div><div class="ubbcode-body">have you checked to see if the shoulder needs to be bumped back </div></div>

All the brass was FL re sized and trimmed together. Shoulder measurement is the same as the others. Thanks
 
#7
Re: Bolt won't close on one re load?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: elcam</div><div class="ubbcode-body">I was talking about getting stuck a bit in the die. On the M1A note, I don't mix auto loader brass with bolt action brass, because of potential headspace problems </div></div>

All the brass was FL re sized and trimmed together. Shoulder measurement is the same as the others. Thanks
 
#8
Re: Bolt won't close on one re load?

might not have been run thru the sizer die correctly, I neck size for 2 different savage's in 223 and one time my brother grabbed the wrong ammo. bolt got stuck 1/2 way couldnt close the bolt or open it, had to use a ruber mallet. I had ammo marked but he wasnt paying attention.
 
#9
Re: Bolt won't close on one re load?

if your sure its not binding on the shoulder, then next most likely cause is to check the case neck wall thickness and concentricity... check the overall neck thickness of a loaded round that didnt chamber, leave the bullet in the case and check the measurement in a few places around the neck. Compare this to some of the others that will chamber. Bullets may not be concentric, cases walls are most definately inconsistant, the combination of both can cause binding in the neck area of your chamber due to oversize brass thickness, or badly eccentric brass. Some brass is terrible for this and i had no idea until i started neck turning my brass and could see how bad some of it was.

You also say cases were trimmed, and FL sized but check the neck length from shoulder to case mouth just in case. this can grow over time from the brass flow also and cause problems although unlikely if you FL sized properly and trimmed.

Double check the case head to ogive again, just in case, theres not much else it could be, besides checking the overall concentricity of a loaded round by rolling it over a glass table or similar and looking for wobbles, inconsistant rolling etc...
 
#11
Re: Bolt won't close on one re load?

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">The only thing else I'm noticing is that the case head is a bit chewed up. This case was probably fired in my M1A</div></div>

I had some once fired brass that I was using in my AR and there were a couple that had a small bur from the extractor of the gun that originally fired them. The bur stuck out just far enough to the side of the head to keep the bolt from locking up all the way and they were a mother to get out. I took a small file and got rid of the bur and it cycled fine. Its hard to believe that such a small bur could cause that.

I would guess that if your M1A is the cause, that it would show up more often but stranger things have happened. Clean up the edge of one that doesn't fit and see if that helps.

I had a friend who didn't clean his chamber often (probably ever) and he had trouble closing his bolt once in a while. I cleaned it and there were a lot of small bits of brass in the recessed area where the bolt lugs lock up. After cleaning there were no more problems.

Good Luck
 
#12
Re: Bolt won't close on one re load?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: groper</div><div class="ubbcode-body">if your sure its not binding on the shoulder, then next most likely cause is to check the case neck wall thickness and concentricity... check the overall neck thickness of a loaded round that didnt chamber, leave the bullet in the case and check the measurement in a few places around the neck. Compare this to some of the others that will chamber. Bullets may not be concentric, cases walls are most definately inconsistant, the combination of both can cause binding in the neck area of your chamber due to oversize brass thickness, or badly eccentric brass. Some brass is terrible for this and i had no idea until i started neck turning my brass and could see how bad some of it was.

You also say cases were trimmed, and FL sized but check the neck length from shoulder to case mouth just in case. this can grow over time from the brass flow also and cause problems although unlikely if you FL sized properly and trimmed.

Double check the case head to ogive again, just in case, theres not much else it could be, besides checking the overall concentricity of a loaded round by rolling it over a glass table or similar and looking for wobbles, inconsistant rolling etc... </div></div>

Measured the necks they are within spec of the rest. Rolled it across the table, no wobble.

I went back with my Hornady OAL gauge and did another measurement of my chamber at the ogive this time because I now have my comparator.

2.248 - .040 = 2.208

All my loads measured at the Ogive at 2.165

Thanks
 
#13
Re: Bolt won't close on one re load?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 427Cobra</div><div class="ubbcode-body">What brand of headspace gauge do you have? </div></div>

Hornady OAL gauge
 
#14
Re: Bolt won't close on one re load?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Headgear</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">The only thing else I'm noticing is that the case head is a bit chewed up. This case was probably fired in my M1A</div></div>

I had some once fired brass that I was using in my AR and there were a couple that had a small bur from the extractor of the gun that originally fired them. The bur stuck out just far enough to the side of the head to keep the bolt from locking up all the way and they were a mother to get out. I took a small file and got rid of the bur and it cycled fine. Its hard to believe that such a small bur could cause that.

I would guess that if your M1A is the cause, that it would show up more often but stranger things have happened. Clean up the edge of one that doesn't fit and see if that helps.

I had a friend who didn't clean his chamber often (probably ever) and he had trouble closing his bolt once in a while. I cleaned it and there were a lot of small bits of brass in the recessed area where the bolt lugs lock up. After cleaning there were no more problems.

Good Luck </div></div>

Thanks, I will try that tonight. I hope that's it. This is driving me crazy.
 
#15
Re: Bolt won't close on one re load?

Should and is are two different things.

We had a batch of 1x Win 308 brass from brassmanbrass that 25% would not close in a factory REM chamber after full length sizing. The problem was a the base of the case where the die does not go. The brass was swelled in who knows what rifle; all we know is it did not work.

brassman happily sent us replacement brass BTW.

Also, you might want to research the term headspace a bit closer - I doubt the measurement to the datum line of your 308 cases is approaching 3 inches.
 
#17
Re: Bolt won't close on one re load?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: thefitter</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Headgear</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">The only thing else I'm noticing is that the case head is a bit chewed up. This case was probably fired in my M1A</div></div>

I had some once fired brass that I was using in my AR and there were a couple that had a small bur from the extractor of the gun that originally fired them. The bur stuck out just far enough to the side of the head to keep the bolt from locking up all the way and they were a mother to get out. I took a small file and got rid of the bur and it cycled fine. Its hard to believe that such a small bur could cause that.

I would guess that if your M1A is the cause, that it would show up more often but stranger things have happened. Clean up the edge of one that doesn't fit and see if that helps.

I had a friend who didn't clean his chamber often (probably ever) and he had trouble closing his bolt once in a while. I cleaned it and there were a lot of small bits of brass in the recessed area where the bolt lugs lock up. After cleaning there were no more problems.

Good Luck </div></div>

Thanks, I will try that tonight. I hope that's it. This is driving me crazy. </div></div>

It was the chewed up case base. I cleaned it up and I can now close the bolt. Glad to know it's not my fledgling re loading technique. But I do need to inspect my brass better. Thanks
 
#18
Re: Bolt won't close on one re load?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BigMahi</div><div class="ubbcode-body">Would running the brass through small-base dies solve the OP's problem? </div></div>

I just looked up what a small base die is. I don't think I need one, but I like knowing what it is. Thanks
 
#19
Re: Bolt won't close on one re load?

Small base die can be obtained by taking.002 off your shell holder.Take it down to .048 instead of .050. This is for RCBS Shellholders.Screw the die down to the top of the shell holder.I had a bunch of LC brass i bought would not chamber after sizing.I saw this on a reloading forum and tried it it worked for me.The brass would not chamber in a DPMS AP4 which is notorious for tight chambers.
 
#20
Re: Bolt won't close on one re load?

1SG...yes it will chamber...but the shoulder may be set back too far. Separation city. Get the small base die. The shoulder remains at the correct dimension and the base gets reduced. JMHO
 
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