Quoted:
What exactly does unsupported chamber mean??
Unsupported is the portion of the case, usually the area of the feed ramp and/or extractor, where no steel comes in contact with the case.
It has only been a problem when 2 conditions conspire – it extends into the portion of the case where the wall is thin and there is substantial working pressure involved…
This is with the round fully chambered and not an ‘out of battery’ condition!
The 45 ACP does not operate at enough pressure for this to be a factor.
The 9mm is much greater and bears consideration.
The problem really surfaced when the 40 S&W came on the scene in early Glocks. The 40 S&W is running a pretty high chamber pressure and the early Glock barrels had a generous ramp cutout to accommodate feeding of this round.
Some cases failed. Glock then made modifications and it was corrected.
Keep in mind that the “problem” was limited to the 40 S&W round or at least it mostly occurred with that round…
The 10mm (even higher pressure) could not be offered on the same frame so a better feed ramp was made from the start.
But in the vast majority of incidents, it was the particular cartridge that was the problem. The failed round itself was an overpressure. An overpressure that exceeded the upper limits of SAMMI
and the extra safety factor designed into the firearm!!!
But how much Overdesign do you need for the unwashed, uninformed stupid shooter??? If 150% isn’t enough would 200% be right? Maybe 300% overbuild?
Quoted:
I've got a stock Colt Commander (unsupported chamber) with thousands of rounds through it.....I shoot only factory FMJ or Speer GDHP out of it ....never had a problem.
Please explain – I have never seen any Colt that had an ‘unsupported chamber’?