This is a discussion on M1 Carbine muzzle erosion question! within the Steel and Wood forums, part of the Rifle Forum category; I am looking at a M1 Carbine and asked about the condition of the muzzle. The seller does not have a gauge but inserted a ...
I am looking at a M1 Carbine and asked about the condition of the muzzle. The seller does not have a gauge but inserted a .308 round. The bullet penetrates the muzzle leaving about 1/4" from the tip of the muzzle to the shell casing. How would you rate this barrel?
What the price of the carbine? The barrel should shoot great. I copied this from a really good post on the CMP forum for you.
Test the muzzle. Get a USGI 30-06 M2 Ball round for a tool. Hold the carbine muzzle up and put the M2
round in point down. If the case mouth touches the barrel crown, it has been cleaned to death. You are
usually out of luck although such worn muzzles often provide acceptable accuracy. If the bullet ogive
holds the case mouth up a 1/16" or so above the origin of the rifling at the bore/crown interface, there is a
chance of a good shooter for several thousand rounds. If the bullet holds the case mouth 2/16" above the
origin of the rifling at the bore/crown interface, there is half the barrel life left. If 3/16", 3/4 the barrel life.
If it holds nearly a full 4/16", it is a near new barrel.
I'm no real expert, just a casual M1 Carbine owner, but I'd say that's a pretty good deal unless the rifle is just ragged-out completely. It's about what you would have paid CMP for a rack grade rifle.
Read the general rack grade description on the CMP's site and assess the overall condition of the rifle you're lookig at now in comparison.
As they say, the devil is in the details, but the muzzle wear looks pretty minimal.
Here's the muzzle of my carbine "measured" using a carbine round. (I didn't know at the time that it had to be a .30-06 round, I had just read .30 cal... See, I told you I was no expert.) My rifle shoots great, though. It will hold 4-5" at 100 yd. sitting, sling supported. I'm guessing the wear on the rifle you showed to be even less. Should be a good shooter.
That looks to be a very good barrel.
Carbines, like Garands price more according to the scarcity of the piece parts.
Probably $450 is on the low end for something that shoots reasonably. The sky is the limit for rare versions.
For reference. I paid $600 for an Underwood receiver & barrel with mixed other parts. The barrel measured under 1 on the CMP gauge. It had a flip rear sight and no stake marks (never had been upgraded to an adjustable).
High-Speed info! I tried an M2 Ball round in my Garand to see if it worked. Showed 1/4 inch between the muzzle and the case mouth (what a relief). I had never measured it before, and didn't really want to buy a muzzle wear gauge for just one rifle that I didn't shoot a lot. Now I'm going back with my gauges to measure the round itself, just to validate where the .300, .301, and .302 marks fall.
I had made a quick measurement with an M2 Ball 30-06 round, but went back with my Starrett vernier caliper and micrometer to do some confirmation. On that particular round, the .300 dimension was 8/32 from the mouth of the brass. The .301 dimension was 7/32 from the mouth, and the .302 dimension was 6/32. When you reach .303, someone said that you then have the equivalent to a 303 British round.
Conclusions: A 1/32 inch difference is extremely difficult to determine with the eye alone. An M2 ball round has a fairly short taper, and it would be easy to make a mistake and think something is better or worse than it actually is. A longer muzzle wear gauge with a longer taper would be better for accurate measurements. And finally, it doesn't make much difference because it's not the ultimate indicator of how the rifle shoots, just one factor among many. Like Orlando says, only real way to tell is to shoot her.
Years ago myself and lots of other guys used a .308 flat based bullet as a muzzle wear gauge. If the bullet wouldn't begin to fit in the bore BACKWARDS, the barrel was considered good to go. That eliminates bullet curve issues, and differences in depth of bullet seating in various cartridges, and at the time cost only a few cents.
Here is a photo comparison someone put together that shows a relative measurements on an M1 garand muzzle using an M2 cartridge and a muzzle gauge. They could be used as a relative comparison on an M1 carbine as well.
Remember that everything is relative. Muzzle wear gauges all vary some, muzzle crowns can affect the readings, and even M2 bullets vary as well.