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Hipshot
09-24-2010, 09:54 AM
Hi, I've heard that some Navy Arms Smith carbines have barrel problems and you have to get the barrel relined for any kind of accurate shooting. Any truth to this? Can I tell by the Italian proof date code ? The date code is BL in a square (1998). I have a chance to get an unfired one at a local gun shop.
Thanks for any information

Joseph Plakis Jr, 00302V
09-24-2010, 12:16 PM
Some of the early Italian Smiths had tapered bores. Unfortunately they started out small at the breach end and opened up at the muzzle. These are the guns that definately need relining. The easiest way to tell if you have one of these barrels is to push a bullet through the barrel.

Joe Plakis Jr
Hampton Legion

R. McAuley 3014V
09-24-2010, 12:32 PM
I heard a story similar to what Joe Plakis and John Holland have remarked of how a batch of the early repro Smith Carbines had got through with the barrels rifled in reverse, so the bores are larger at the muzzle than the breech, except that what I heard came from Bobby Hoyt. He said that when the barrels were heat-treated, the heat-treating was not done in a vacuum such that the hardness of the metal was not uniformly applied, and so the interior portion of the bore was softer than the breech and muzzle. Thus when the barrels were rifled, the cutter cut a little deeper where the metal was soft than where it was hard, and while the bores were not rifled in reverse, because this hardness was inconsistent inside the bore, the depth of the rifling is deeper where the metal was soft. This allows gas to escape around the bullet while it is travelling up the bore, and between the loss of pressure and the bullet being forced to expand then to compress on its path to the muzzle (much like a choked barrel), while this works fine in shotguns, it doesn’t work so well in rifles.

Some of the barrels can be remedied simply by “lapping” the bore: taking a new cast bullet and driving it through the rifled bore using a 1/2" wood dowel to imprint the rifling on it. Then using lapping compound (i.e. jeweler’s rouge paste), coat the bullet in compound and realigning the bullet with the rifling, the idea is that by passing the coated bullet through the bore repeatedly (20 to 30 times or more), this will slowly wear away the higher portion of the “high” rifling and smooth out the bottom of the grooves, making the bore more uniform from the breech to the muzzle. It may require more than one slug to get the bore uniform. For some barrels, this is usually the first step in correcting this problem, and if not successful, then relining the bore is the next step. If you want more information, talk to Bobby Hoyt.

The Smith Carbine I had that Bobby relined in 2003 had the Italian date code of BN (2000), so this problem has re-occurred since the first Pietta carbines arrived in the early 1990s. Before it was relined, the carbine shot all over the place (like a hose pipe); and after it was relined, if I missed anything at 50 yards as small as 2-inches in diameter, it wasn't the carbine's fault.

Hipshot
09-24-2010, 08:02 PM
Ok, first off, thanks for the information. I went back to the shop with some swedged .520 pure lead balls, a short starter, an aluminum shotgun cleaning rod and a leather mallet :) . I asked the owner if I could slug the bore with his help :roll: He said I could buy the Smith and take it home to slug the barrel and bring it back tomorrow if I wasn't satisfied, as long as the gun was in the same unfired condition. I just finished sluging the bore, Frist I sprayed the bore and the ball liberaly with WD40, I had to rap the short starter pretty hard a few times to start the ball. I then used the end section of the cleaning rod and taped the ball into the bore I added another section of cleaning rod and continued to tap the ball the rest of the way thru the bore the taping stayed pretty constant and I could tell little difference, I then tried another ball only this time after starting I tried pushing the ball thru instead of tapping it with the mallet. It took more force than I thought it would but seemed to get a little easier once I got the ball moving. There did not seem to be any place in the bore where the ball was loose and then got tight again. Starting the ball took the most force with the rest of the way pretty constantly tight. The bore is like a mirror and the slugs look polished where they contact the lands and groves after sluging. I don't know though, I wouldn't want to keep this gun to have the bullets shoot all over the target, and if I fire it, it's mine, what do you think? Also how do I mic the ball with three lands and grooves?
Thanks again

09-25-2010, 01:53 AM
Sounds like the gun is OK. If there were any significant problems, you would feel the slug suddenly go very loose toward the muzzle end.
As far as measuring the groove diameter; when you put the slug into your micrometer, turn it so the jaws will measure the maximal diameter. When you size your bullets, use that measurement, or even a thousandth or two larger.

mike owsiak
09-25-2010, 09:26 AM
you can get a micrometer from STARRETT or MITUTOYO that will measure 3 or 5 sides i bought mine 7-8 years ago for about $300. new...i always have it with me at the nationals...............MIKE