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Loaded rounds fit AR but not Bolt action how to guage.

MAHLMAN

Sergeant of the Hide
Full Member
Minuteman
Figured out today that the reason some loaded rounds would not chamber in bolt actions but would in AR-10's (rounds are 308) is that an over crimp pushed the shoulder in and the case a bit out. Enough to cause undue force to be required to chamber a round in the bolt action.

Is there a gauge that would allow me to check a loaded round for this type of problem? I have a Dillon brass gauge and the loaded rounds all check fine in it so apparently I need a different gauge then the Dillon to verify size of loaded rounds for something like perhaps minimum SAAMI specs perhaps? Is there a chamber gauge for loaded rounds?

Not sure how to word this so bear with me if I am asking the wrong questions or need to supply more info.
 
A Redding BODY ONLY die will fix your bulge at the shoulder.

They also have a Small Base BODY ONLY die if your bolt gun chamber is tight.
 
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If you're going to crimp do it in a seperate operation from seating. Get a Lee factory crimp die OR a taper crimp die.

The crimping shoulder in most seating dies is too abrupt. This makes for inconsistent crimping with ANY variation in case length or neck thickness. Some will hardly be crimped at all, others will be overcrimped to the point of collapsing the shoulder and causing the bulge of which ye speak.

These gages are what you seek. They are cut with chamber reamers so they check ALL dimensions-not just certain length measurements at certain points. I drop EVERY ROUND I load into one of these before it gets put in the ammo can. If ultimate reliability in feed and function is important to you, click on the reloading banner on this page: https://jprifles.com/1.5.1.2_maint.php
 
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The problem sounds like the adjustment of the seating die if the shoulder is bulging during seating. The seating die probably has a taper crimp and needs to be set up accordingly. Check the instructions. @mtrmn has the best solution of not using the seating die to crimp. When crimping I also use the Lee FCD.

Since you have two different 308s and are using the same cases in both the case gauge is a must have in my opinion. About the last thing you want is a case stuck in the AR-10.
 
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THANKS all for the answers. I will be trying the suggestions out and I think the answer will become evident.

"Get a Lee factory crimp die OR a taper crimp die." I am using one it was just set to crimp too much. I have backed off on the crimp and the new rounds chambered fine in the bolt action.
 
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Just a little note here for anybody reading this. MOST RIFLE seating dies have crimp function built in, but it most likely will NOT be a taper crimp. It will be what I've always called a roll crimp, which is very abrupt. If your die has a TAPER crimp, it will probably be noted in the description and instructions.
 
A Redding BODY ONLY die will fix your bulge at the shoulder.

They also have a Small Base BODY ONLY die if your bolt gun chamber is tight.
This Redding Body Only die was the answer to making the loaded rounds work. Didn't require much and able to do it without lube. Took some test rounds to my 308 bolt action buddy that did not fit before and they now fit like factory rounds according to him. Waiting for the gauges to come in to check it all by also but as of right now problem solved.
 
This is what you are looking for:

SG308WIN_1-600x600[1].jpg
 
If you are loading for AR10-go balls deep and get a Dillon .308 carbide die. It is small based and will be smooth as silk. Yes lube is required but the effort required is easy.