IIRC, 1/4" on an M2 Ball round is about 0-1 on a gauge, 3/16" is 1+, 1/8" is 2+, and 1/16" is about 3+. My Inland has a tad over 3/16" on an M2 Ball round, and shoots VERY tight groups.
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IIRC, 1/4" on an M2 Ball round is about 0-1 on a gauge, 3/16" is 1+, 1/8" is 2+, and 1/16" is about 3+. My Inland has a tad over 3/16" on an M2 Ball round, and shoots VERY tight groups.
remember some carbines were subjected to a "shoot to destruction" test of 6,000 rounds
If nothing broke, the gun was cleaned, crated up and issued along with the rest. so barrel ware with the low pressure - low velocity round was evidently not an issue. Even with the 30-06 rifles there were no ord. dept. gauges or specs. to reject rifles for muzzle ware, Only throat erosion
Can't speak specifically to those 6K round "shoot to destruction" tests, but the endurance test described in my Ordnance Inspector Training Manual (SA-ITM-S201, 1951) required that
Lots were "passed" if not too many things broke during these tests. The actual "test" rifle was sacrificed, regardlessQuote:
Originally Posted by 935.35
One more thing; an excellent barrel can still fail the bullet test or muzzle wear gauge if it has been roughly and improperly cleaned many times with a jointed steel G.I. rod. The government had a procedure for this which was to simply back-bore the muzzle to get to the good lands. You always check for a 'counter-bore' before accepting a bad muzzle wear indication.
I agree with that. I have two that eat my gauge but will shoot under 4" at 100 yards.
I-44 and JimF,
Agree 100%
On our way down to New Orleans (post Katrina) we looped by my good friends in Bhama. He brought out a counter bored carbine that shot (rested) groups as tight as 4"- 5" at 100yrds.
Can't recall the maker, but do recall it was the first counter bored carbine I had seen shot.
I couldn't see where you could ask for more out of the carbine.
I sold a late WRA barrel some years back that was slick clean inside. Though it had a pretty large divet between the lands (Ridges) down about 3" from the muzzle. Using my Poor Mans Muzzle Gauge, it still showed 1/4"+ exposed.
Only thing I could figure that could have damaged it was a jointed cleaning rod. Don't have it anymore, but at the time was even able to get a picture of that Divet. That divet was deep and elongated. Friend thought a possible drill gun and stainless cleaning brush went crazy. But as stated bore was super clean, unless if they had tried a brush/drill gun, maybe a brush could have broke off causing the damage.
But then..... Could've been a little of both, Damaged by the jointed rod, then a attempt to lighten it up with a spinning brush........... :dunno:
CH-P7
SOME carbines that had completed the 6K tests were released for issue. Others were definitely not.
https://www.milsurps.com/images/impo...94ffab_z-1.jpg
There you go Dave,
Now that looks real nice.
Thx,
Charlie