308 chambering problem

elkkid3

elkkid3

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Minuteman
Sep 26, 2009
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Tonto Basin, AZ
#1
I have a Remington 700 Varmint with the stock heavy barrel and McMillan HTG. I just started reloading, When I shoot my reload's I have a problem with some of the rounds not all. When I try to chamber them the bolt will not lock down, It grabs the round with the ejector but will not allow the bolt to fully close. Factory ammo seems to be fine as well as most of my reloads, probably 10% have this problem.
 
#3
Re: 308 chambering problem

Make sure you are getting a full length size on your brass!
Caliper or mic the diameter just above the rim of the case about 1/8". Look at the case diagram in your loading manual, it should be at .470" or just under that.

Screw your die into the press with the ram all the way up! Screw it down until it just touches your shell holder in the ram. Lower the ram and turn your die another 1/8 to 1/4 turn down. Snug up you lock ring and run the ram back up. You should feel the ram cam over on the die! Then size your brass and check the base diameter.

Terry
 
#4
Re: 308 chambering problem

I forgot to add in the original post that my overall length is good 2.800 on all of them. I checked the case above the rim and they are at .465 and the trim to length is good also. The ones that chamber fine seem to measure the same as the ones that don't.
 
#5
Re: 308 chambering problem

Only lube the body and the neck of cases, none on the shoulders, if you don't have a headspace gauge, remove the firing pin, remove the ejector, now full length resize until you feel a very slight resistence of the bolt, about half way down, at this point verify with other cases and lock the die in place.
 
#6
Re: 308 chambering problem

Your problem is where the case sholder is, and your sholders on the cases are too far forward. This implies that you have not adjusted the sizing die down far enough.

So, find a fired case that has this too long property. Verify that the bolt won't close. Lube, size, try to chamber and close bolt again. Twist sizing die down 1/8th turn and repeat until the case fits in the chamber.

Or buy a RCBS case micrometer.
 
#7
Re: 308 chambering problem

You can possibly have a FL size die with its chamber cut too deep. Look for signs of the die not sizing to the base of the neck. If die is touching shell holder and you still get hard closing you need to either send the die back or get someone with a lathe to take off about .015". I have had to take off up to .025 in order to get a die to size correctly.
You need a Mo Gage or a L.E. Wilson FL case gage to tell if your dies are sizing properly.
 
#8
Re: 308 chambering problem

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hummer</div><div class="ubbcode-body">You can possibly have a FL size die with its chamber cut too deep. Look for signs of the die not sizing to the base of the neck. If die is touching shell holder and you still get hard closing you need to either send the die back or get someone with a lathe to take off about .015". I have had to take off up to .025 in order to get a die to size correctly.
You need a Mo Gage or a L.E. Wilson FL case gage to tell if your dies are sizing properly. </div></div>

When the die is touching the shell holder it crushes the side of the neck (Where it starts to size down to fit the bullet from the powder chamber).

Thanks,

Rhett
 
#9
Re: 308 chambering problem

Sounds like the headspace on the casing aren't bump back enough. Headspace on a bolt should have a min set back of .002 off a fired casing. No more than .005 set back in order to save the brass from being over worked and getting brittle, thus shorting the life of the brass. On semi's, .003 min set back off fired casing and .006 max on set back. This will give you reliable feed and good life to the brass. I use a Sinclair Bump Gage that works very well. The main thing is to have fired casing from that particular rifle so that you know how far back that you need to set back your headspace with the sizing dies.
 
#13
Re: 308 chambering problem

USE A CASE GAUGE TO SET YOUR SIZING DIE!

Damnit! I don't know how many times I have said that on this forum.

If you don't have a case gauge for your neckdown cartridge, DON'T LOAD IT!
 
#14
Re: 308 chambering problem

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Downzero</div><div class="ubbcode-body">USE A CASE GAUGE TO SET YOUR SIZING DIE!

Damnit! I don't know how many times I have said that on this forum.

If you don't have a case gauge for your neckdown cartridge, DON'T LOAD IT! </div></div>


Yes and buy a manual (or three) and read it a few times before you start reloading.

Chris
 
#15
Re: 308 chambering problem

i ran into this with a batch of x51 cases, i sized them the same as the rest of my brass (including LC cases which have worked flawlessly)and it wont let me put the bolt down, it was done the same way on the same dies that work in my rifle so i just discarded that headstamp cases
 
#16
Re: 308 chambering problem

Not all brass sizes the same from different manufacturers. All brass when sizing spring back to the larger dimension to some degree. Some more than others, depends on the manufacturer specs. Also... if the neck is thicker than other manufacturers cases, the expander ball on the sizing die will change the headspace as the expander ball has more friction and stretching the brass. That's why I use an expander die first to straighten out any necks that may have gotten ding during extraction. Then I no longer need the expander ball in the die. I use Redding Bushing Dies with the correct bushing for that particular manufacture brass in order to get the proper neck tension on the bullet and my headspace is more consistent from casing to casing. Case prep is critical to a well manufacture round. It is the largest variable in any of the 4 components
 
#17
Re: 308 chambering problem

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Downzero</div><div class="ubbcode-body">USE A CASE GAUGE TO SET YOUR SIZING DIE!

Damnit! I don't know how many times I have said that on this forum.

If you don't have a case gauge for your neckdown cartridge, DON'T LOAD IT! </div></div>

I don't have a case gauge. Case gauges are for suckas.
 
#18
Re: 308 chambering problem

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 918v</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Downzero</div><div class="ubbcode-body">USE A CASE GAUGE TO SET YOUR SIZING DIE!

Damnit! I don't know how many times I have said that on this forum.

If you don't have a case gauge for your neckdown cartridge, DON'T LOAD IT! </div></div>

I don't have a case gauge. Case gauges are for suckas. </div></div>

There are other ways to do it (measuring tools, etc). But for the inexperienced sheeple, the case gauge is a good/easy way to make sure you're safe.
 
#19
Re: 308 chambering problem

You are relying on an assumption that the chamber of the case gauge is the same as your rifle chamber. They are not. You cannot eyeball your way to the right headspace setting.
 
#20
Re: 308 chambering problem

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 918v</div><div class="ubbcode-body">You are relying on an assumption that the chamber of the case gauge is the same as your rifle chamber. They are not. You cannot eyeball your way to the right headspace setting. </div></div>

I know for a fact that my case gauges are tighter than my rifle's chamber and that if my ammo fits in it, it will fit in my chamber.

After that I neck size anyway, so obviously that ammo will fit in my chamber; it has been fired in it.

There is a reason that a case gauge contains a go and no go line. If you're not bumping the shoulder back, it will be obvious.

Brass that has not been fired in your rifle and does not fit in the case gauge should not be expected to fit in your rifle unless some other measuring device shows otherwise.
 
#21
Re: 308 chambering problem

It's not that they are tighter. Headspace is not about diameter. It's about the length from the breechface to the shoulder, precisely what the OP is having a problem with. The use of a case gauge to set headspace may result in an excessive setting which will ruin brass and cause casehead failure.
 
#22
Re: 308 chambering problem

918v is absolute right. By not having proper headspace, you will either not be able to load the round into the chamber or push back the shoulder so much, that casehead separates from the casing and now you need a case extractor to get the rest of the casing out of the chamber. And that sucks big time. You need the right tools for the right job!
 
#23
Re: 308 chambering problem

I think it was the brass, the brass was given to me by a friend and was not fired in my rifle first. I have no idea how many times they have been fired, I have some one fired rem brass (only fired out of my rifle) that I will try next. Waiting to get a SS so I can shoot some long distance
smile.gif
 
#25
Re: 308 chambering problem

Huh, I am really lost, when I just neck size it everything is fine. When I try to FL size them the press cam's over just like it should but It dents the side of the case like I said before.
 
#26
Re: 308 chambering problem

It sounds like the die is collapsing the case just under the shoulder.

Are you sure your FL die is doing this or does it happen after you seat and crimp?
 
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