Bore Lapping/Polishing

[yat3b35]

Most of my question was answered when I read a post made on or near 8/22/06 concerning barrel break in. First a comment then my question. After reading the forum I feel there are a bunch of knowledgeable people visiting it, so where better to ask my question.After having my 700 Rem. re barreled with a Hart heavy contour varmint in .308 to use at our groundhog shoots, I went through the process of "breaking in the barrel".One shot and clean for about a dozen shots,then fire a 3 shot group and clean,then another 3 shot group and clean and so forth.
I read that all Hart SS barrels are hand lapped, thus there should be no marks near the muzzle of my barrel?. Well there is and it looks like it is from the drilling process,the marks are across the groves as well as the lands.I get bad fouling at that point.
Now my question. Has anyone used either the Tubb final bore polishing ammo,or the Wheeler engineering bore lapping kit ? Does it work,or is it a bad idea, or a waist of time and money ?

 

[tightneck]

How does it shoot? That is the most important thing. I wouldn't shoot those abrasives through a custom barrel unless I had just given up on the barrel because it simply wouldn't shoot.

 

[Forum Boss]

If it shoots well, don't mess with it. Hart, and most custom barrel makers, hand lap their barrels. In order to avoid the possibility of belling near the muzzle, the lappers will often stop a bit short of the muzzle. Much better to have a little choke at the muzzle than to have a bore that spreads out a little bit.

If it's fouling badly right in the last couple of inches, you can always use a swab,from the muzzle) with some 50 BMG or Sweets and knock the copper back.

I Haven't used the Wheeler kit, but The Tubb abrasive bullets do almost all their work in the first 30% of the barrel.

My instinct is just to leave it be for now, but see how many shots you can get before you see accuracy fall off because of the fouling. You may be surpised.

 

[Bobs243Ackley]

I would never recommend shooting abrasives through a high quality, aftermarket barrel, such as your Hart. If this mark becomes an accuracy issue, you might want to get in contact with the folks at Hart to make arrangements for them to examine the barrel to see if they might need to help you.

Cordially,
Bob Blaine

 

[Preacher]

I have used Tubbs final finsh in a few factory rifles the really needed it bad, but no way will any of my custom barrels see any of it...

 

[Spotcheck_Billy]

Ask your barrel maker what he thinks of running abrasives through his handiwork - then step way back and duck!

 

[yat3b35]

Not sure how it's gonna shoot yet.Still in the early stages of working up loads.It took my gunsmith most of last summer to get it ready for me. I have had a couple of loads that shot under 1/2 moa at 100 yds. but that is nowhere near what I want out of it.I don't want to try to get best loads in the winter as they most likely will not be the best in summer.
I can usually get two strings of five rounds off before I notice heavy fouling near the muzzle, then I clean with Butch's bore shine, lightly oil the barrel and start over.
A fellow shooter loaded three rounds at the range for me and they shot very well,but when I weighed the powder charge from the dummy round he gave me to take home I was shocked at how low the charge was.He uses Berger 135 match bullets with 43.8gr Varget.I could not find in any of my several loading books that low a charge of Varget even for the 150 grainers,so I wrote Hodgdon teck support and asked them about that load. They said it would be ok,but to go no lower.It can't be getting much vel. with that low charge. The best load I've gotten so far is with the Berger 175VLD's with N550 running a full grain under max load 44.8gr with no pressure signs yet.That group is just under 1/2 moa at 100 yds. VihtaVuori loading book calls for max of 45.8,but don't want to try that until weather gets warmer.Strange but only other powder that gave me any kind of respect full group is IMR 3031, but as I said it's still early in the game for the new barrel. I've run about 150 bullet down the tube so far.
Thanks for the reply and advice. I will not be using abrasive bullets in my barrel.

 

[chino1969]

Do Not, I repeat Do Not try any of the fire lapping methods on a quality barrel like a Hart. I have a Hart 1:14" light varmint contour in a 6mm BR that has some marks across the lands 3/4 of the way down the muzzle. I've examined the marks with a bore scope and it looks like either myself or the previous owner used incorrect cleaning methods. It may have been like that when the barrel was new from Hart. This barrel will shoot it's a-- off! I don't worry about the marks because a pretty barrel that won't shoot is worthless. Take the time to break it in and go from there; don't jump to conclusions.
Chino69

 

[yat3b35]

Advice taken, I will not shoot any abrasive bullets . Thanks for the input all.

 

[USAPatriot]

Ask your barrel maker what he thinks of running abrasives through his handiwork - then step way back and duck!

On the otherhand if the barrelmaker let out a bad one, they should be the ones ducking. Reputations and whole businesses rise and fall on such small details. The customer is top dog in this particular hunt, not the manufacturer's feelings. I would definitely talk to them and see what they have to say. -Rod-