J E Custom
Well-Known Member
I thought I would pass this along to the shooters that don't reload, and other members that have/will encounter this "NEW" problem.
Gun smiths will normally Head space between .0015 and .003 to allow the rifle to shoot almost any brand of ammo unless the owner wants something special and reloads themselves.
The first time I encountered a problem with factory ammo, it was a belted case with out of SAMMi spec. belt thickness. After checking the chamber head space and it was .002 verified with another head space gauge, I measured the cases (New and loaded) and found them to be .0025 greater/thicker than the head space gauge. So without altering the chamber beyond SAMMi specifications, we discarded the out of spec. Ammo and moved on. this was about the time that the ammo shortages hit us and it was hard to do but the bolt would not close on it and forcing it just didn't seem like a good idea.
Recently a rifle came in with a problem of not wanting to fire a large percentage of different brands.
These were shouldered cases, so we started looking at firing pin problems after checking head space and confirming it was good. (.0025). (For the last 5 years it had fired everything fed to it and just started this recently).
The firing pin had .062 protrusion and was also fine.
Now comes the problem, With everything else checking out, we looked at the new ammo and was shocked at what we found. After placing .003 thousandths shims on the bolt, (With the ejector and firing pin removed) most of the cases would not touch the bolt, so we placed .005 thousandths shims
on the bolt face and found many (40 to 60%) that still allowed the bolt to close easily. We checked all the rounds in each box (20) and found zero consistency. some had the maximum clearance per SAMMI and many went as high as .010 to .011 head space adding the .0025 built in the rifle.
These rounds would just barely mark the primer with the firing pin. We also discovered that the firing pin hole was deeper than the primer thickness and would recess below the case head when it was struck by the firing pin, further worsening the problem.
It appears that since the ammo shortages, the Ammo manufactures don't care about the quality of there ammo because they can sell as much as they make.
We only found a couple of brands that checked out to be within SAMMI specifications. Several more
would fire but were very inconsistent and had totally different firing pin strikes.
I am not advocating that everyone get into reloading to solve this new problem, just trying to make everyone aware of the current quality of factory ammo. Chamber reamers are still within SAMMI specifications and Ammo should also be, But apparently they don't care or no one is checking it.
Be aware
J E CUSTOM
Gun smiths will normally Head space between .0015 and .003 to allow the rifle to shoot almost any brand of ammo unless the owner wants something special and reloads themselves.
The first time I encountered a problem with factory ammo, it was a belted case with out of SAMMi spec. belt thickness. After checking the chamber head space and it was .002 verified with another head space gauge, I measured the cases (New and loaded) and found them to be .0025 greater/thicker than the head space gauge. So without altering the chamber beyond SAMMi specifications, we discarded the out of spec. Ammo and moved on. this was about the time that the ammo shortages hit us and it was hard to do but the bolt would not close on it and forcing it just didn't seem like a good idea.
Recently a rifle came in with a problem of not wanting to fire a large percentage of different brands.
These were shouldered cases, so we started looking at firing pin problems after checking head space and confirming it was good. (.0025). (For the last 5 years it had fired everything fed to it and just started this recently).
The firing pin had .062 protrusion and was also fine.
Now comes the problem, With everything else checking out, we looked at the new ammo and was shocked at what we found. After placing .003 thousandths shims on the bolt, (With the ejector and firing pin removed) most of the cases would not touch the bolt, so we placed .005 thousandths shims
on the bolt face and found many (40 to 60%) that still allowed the bolt to close easily. We checked all the rounds in each box (20) and found zero consistency. some had the maximum clearance per SAMMI and many went as high as .010 to .011 head space adding the .0025 built in the rifle.
These rounds would just barely mark the primer with the firing pin. We also discovered that the firing pin hole was deeper than the primer thickness and would recess below the case head when it was struck by the firing pin, further worsening the problem.
It appears that since the ammo shortages, the Ammo manufactures don't care about the quality of there ammo because they can sell as much as they make.
We only found a couple of brands that checked out to be within SAMMI specifications. Several more
would fire but were very inconsistent and had totally different firing pin strikes.
I am not advocating that everyone get into reloading to solve this new problem, just trying to make everyone aware of the current quality of factory ammo. Chamber reamers are still within SAMMI specifications and Ammo should also be, But apparently they don't care or no one is checking it.
Be aware
J E CUSTOM
