Re: new Remington 700 SPS Tactical .308 Range report
If you alreeady know this, please do not take offense.
SAMMI chamber specs allow some plus or minus variation. The distance from the bolt face to the shoulder in the rifle's chamber is called headspace. The shoulder is where the cartridge diameter is reduced from the cartridge body to the cartridge neck.
You can typically get a gunsmith to check the headspace on your rifle. I have never had one charge me. I think their professional ethics may be that they don't charge for what is a safety inspection.
A cartridge may not chamber because (1) the shoulder on the case is too far forward for that rifle's chamber or (2) the overall case length is excessive to fit in the space allowed for the case.
It is not unusual for # 1 to cause a problem between rifles if you are only neck sizing the cases. Cases shot in the rifle with the shorter chamber will chamber in either rifle. Cases shot in the rifle with the longer chamber will not chamber in the rifle with the shorter chamber. Full length resizing the case should take care of the problem. Not switching cases between rifles when neck sizing will also avoid the problem.
# 2 may be a problem if the overall length of the case is excessive. When a case is too long, the forward end of the chamber will crimp the front of the case neck into the bullet, preventing normal release of the bullet from the case neck when the powder ignites. This can result in high pressures possibly damaging to the rifle or the shooter's or bystander's well-being.
Trimming the case to a reloading manual "Trim to" length will take care of the problem. Typically, "Trim to" lengths are 0.010 inch less than max cartridge length. As a batch of cases are loaded and fired, a sample should be checked to see if they need trimming again.
The reloader is responsible for checking the overall cartridge length with a good caliper or case length gauge; see Brownells.com, Midway.com, etc.
After trimming, one needs to check the loaded cartridge's neck diameter after a bullet has been loaded into the neck. Excessive neck diameter can also result in dangerously high pressures. At this point the cases may be retired, or the reloader can perform inside or outside neck turning to reduce the thickness of the case neck walls.
You can get this information from practically any current reloading manual. Reloading ammunition is a not trivial matter, and one needs to become educated in the subject to create safe and effective rounds. A current reloading manual is your friend. I have used Sierra and Speer manuals over the years. Both have good general information on reloading.
I hope this helps.
