Muzzle Wear on My New Inland

[shamrocks]

Charlie, I believe it to be a real Inland stock that someone added the CC to after thinking about it. The channel measured a little over 4 inches if I measured it correctly. I think I mentioned the HI in the sling well is worn much more than the CC and the OI on the handguard is similarly worn. I always appreciate opinions and advice but I didn't pay a premium price for this one so no real worries about the CC on my part.

[painter777]

Only thing that matters is you being happy.
So you've got a long channel.
I tend to call the Type III lo-wood stocks that came with the later long channel a 'Late Type III'
Could only guess when/how the M2 cut was made.

Your metal has that been together a long time look.
I'd guess the stock was 'Added' to it.

Just nice to see you back around.
Better yet with a good shooter.

Cheers,
CH-P777

[Patrick Chadwick]

The trouble with muzzle wear is that it is usually assymetrical at the crown. This can be a sort of statistical chance thing at first, but any unevenness, such as a nick, tends to lead to a vicious circle: Where the bullet base first parts company with the barrel, there will be a puff of very hot, very fast gas coming through the gap before the base has completely left the muzzle. That tiny puff on one side pushes the bullet off the barrel center line, giving it a skew. The mechanism is similar to throat erosion - if not so severe - the spot tends to be eroded and the unevenness will be worsened. Maybe be only microns. But work out how much skew over the length of a bullet will give a bullet 1 MOA yaw, and the result is awfully small.

If all this did was to divert bullets off course by a couple of MOA in a consistent direction, the deviation could be corrected by the sights and there would be little trouble. Unfortunately, since the bullet is rotating, it is not a simple straight-line deviation, and tiny differences in velocity will vary the effect of the "kick" produced by the nick or wear on the crown, and thus the magnitude (and direction) of the deviation from the barrel center line. In other words, the group opens up all over.

Nicks and uneven wear caused by careless cleaning are the major causes, and the worst offender is a dirty pull-through cord or a chain (as favored in Germany). Careless cleaning can, in fact, be over-enthusiatic cleaning. No-one can pull anything through a barrel dead straight down the barrel center line over a distance of a yard without touching the sides, which is why the Swedes and the Swiss had little sleeves to fit over a cleaning rod and protect the muzzle. Without this precaution, some poor grunt cleaning the heart out of the barrel to please sarge is probably doing more damage to the muzzle than a sackful of ammo. Bad experience has taught me that the shiniest barrels can be the worst.

So what is to be done? Just recrown the barrel. It is explained in detail, with good photos, in the very first chapter of "Accurizing the Factory Rifle".
If you have a delicate touch, you can probably get a crown cutter and do it yourself. If not, go to a good gunsmith (i.e. one who doesn't just want to sell you a rebarrelling job) and it will be the best 10-15 dollars, euros or whatever that you ever spent on your rifle.

In the case of the rifle that is the subject of this thread, I would do this before spending more on ammo. You may well find that the dispersion of the shots shown in the targets is much improved. Of course the ammo and the shooter also play a role...

[browningautorifle]

Well written Patrick...

[Patrick Chadwick]

A lighting-fast guide to detecting many (not all) fake marks without having a clue about stamp styles:

Get a really good watchmakers eyeglass.

1. Wear over marking - could be OK (not guaranteed).
2. Marking over wear - fake, unless assured arsenal reworking.
3. Wear elsewhere, but not just around the marking - a remarkable coincidence, or - a fake. The surface has been reworked to disguise 2.

Wear inconsistency is one of the surest guides to detecting non-original artefacts with no particular expert knowledge, just a good glass and careful observation. Stamps and styles, are easier to fake than consistent wear.
Consistent does not mean the same everywhere, but consistent with that which would be shown by a genuine object - more on exposed or handled surfaces, less on sheltered surface, in corners etc. A sanded stock is the most obvious example that comes to mind of something that is not consistent with genuine wear.