polishing/lapping barrel

[mtbugle]

I have some 03 and 03-A3 barrels that of course get lots of copper plating when ever I shoot them. I am aware many use jb cleaning compound for 100 passes or so to smooth new barrels as break in.  Does this work well for the rougher military surplus barrels or are the machining marks too sever for this. I know better than to think it will make a match barrel out of it, but I would prefer not to have to spend a week cleaning it after shooting. ps these are not pitted or abused, just the military less than finely finished bores.  Thanks Don.

[Mikey]

mtbugle:  I would not use jb cleaning compound on a rifle barrel.  There are much better bore lapping compounds than jb. 

If you want to lap that bore, drop on down to Veral Smith's forum (down the line here) and find what he recommends for lapping bores.  Or, you can go to the Beartooth Bullets website and obtain a bore lapping kit from them.

As for the quality of that 03a3 barrel - not less finely finished and not necessarily rougher, either.  Mil-spec barrels are meant to have a longer life than sporter barrels and may require a lot of rounds to smooth them out a bit or break them in.

Lapping will help smooth the bore but you have to make sure you use the proper compound or you could ruin your barrel.  HTH.  Mikey.

[mtbugle]

Thankyou for the post.

[Swampman]

I had a S&C 03A3 with a frosty bore from using corrosive ammo at some point in it's long life I suppose.  Some Marine Corp armorers suggested cleaning it good with Brasso and a stainless bore brush.  It made a big difference in the way it looked and shot.

Brasso will ruin your bronze brushes by the way.

[PigBoy Crabshaw]

Mikey, What don't you like about JB's? Thanks -g

[Mikey]

I think the jb's contains too large a grit.  Best thing to do is check out the Beartooth Bullets website for what they say about the use of jb's - I think they prefer a much finer grit for lapping bores.  You can also search Veral Smith's forum here at Graybeards for posts or threads about fire lapping or bore lapping.  Good luck.  HTH.  Mikey.

[S.S.]

I have never found enough of an increase in accuracy afterwards to make it worth all the hastle.

[Swampman]

I'd rather wear out my barrel with bullets.

[Mikey]

Mil-spec barrels are made for long life and it would probably take you a lot of rounds - and I mean a lot - to wear out your barrel but that doesn't mean it will shoot any better for you than it would if it was lapped.

Lapping removes roughness and minor obstructions in the bore and allows the barrel to shoot or group more consistently and that makes lots of folk much happier with what they have rather than cursin' an inaccurate rifle.

The barrel making process, as I understand, is not the gentlest on the bore.  The barrel blank is inspect for straightness, etc., then chambered and rifled.  After it looks to be a 'within specs' barrel then it gets stamped and drilled and machined for its sights, name, caliber, slots, etc and all these procedures can create minor obstructions to the bore that interfere wiht good accuracy.  Lapping helps remove those 'impurities' and in every case in which I have lapped a bore the accuracy has improved. 

I would, again, suggest you visit Veral Smith's forum for more insights on lapping and also visit the Beartooth Bullets website for their informationon lapping.  HTH.  Mikey.

[WILD_WEASEL]

For the better part of the 30 years I’ve been shooting my preferred cleaning method has been a bronze brush followed by a tight patch both soaked in Hoppes #9.  While cleaning up a Mosin Nagant I bought for my son this just was not cutting it.  To facilitate getting the bore in shape I started with an electric bore cleaner (home made) to remove the majority of fouling followed by three sessions of J&B Bore Shine to smooth out a few rough spots.  With subsequent cleanings I use my normal routine of Hoppes #9 brush and patches.  After a few other tweaks; free floating barrel and replacing cocking piece I now have a rifle that easily shoots into 3 or 4 inches at 100 meters, from a stone cold barrel to searing hot for under $90.00! 

Something I tried this weekend made the trigger pull noticeably smoother.  In my shooting box I had a tube of Chip McCormick (sp) trigger job in a tube, which actually looks like malibnium grease.  Anyway I put a dab where the trigger and sear spring assembly contact and the trigger pull was much improved over using just Break Free CLP.  So it is worth a try.

See you at the range.