Gunsmithing Question about barrel lapping

[jeep505090]

Tired the search on the site first but didnt get any good results for barrel lapping, so i am asking the audience.
"Is their a benifiet to lapping modern barrels?(have seen a few articles refering to older surplus rifles with this), if so what is the prefered technique? and what are the prefered materials needed to accomplish this? Iam looking for more personal results and first hand experince from the members here as iam hesitant to trust anything thrown out accross the internet. Thanks for your input.

 

[oneshot onekill]

Re: Question about barrel lapping

Honestly, probably any standard "Factory" Barrel could use lapping but I wouldn't attempt it myself for the simple reason it involves removing material from the bore with an abrasive... That just freaks me out!!!

Let an expert do it.

 

[BOLTRIPPER]

Re: Question about barrel lapping

before i would want to lap a barrel....for any reason ....i would want a hawkeye and a video recorder

 

[GasLight]

Re: Question about barrel lapping

If I were going to try and lap a factory barrel, I would need a reason to start with, and then I would do it with the Tubbs fire-lapping system or something similar. Any aftermarket barrel is going to come lapped most likely already. The effort and expense on an actual hand-lapping setup is likely cost prohibitive when weighing the gains and the cost of a new barrel.

Dave

 

[jeep505090]

Re: Question about barrel lapping

thanks for the reply all who took the time, most barrels do come in pretty good condition but having looked through my barrel with a bore scope hooked up to a monitor( not a hawkeye those are friggin expenisve but nice) on an undisclosed rifle as to not give that company bad publicity or start problems i noticed many horizontal striations in the metal although accuracy is exceptable to an extent i wondered if lapping would improve the finish of the barrel, i understand lapping can be done with a grease based compound and a lead slug but can it be done with a patch and rod to smooth out some ruff spots and possibly chatter marks from the broach? tubbs finishing bullets look impressive and would most likely be benificial for a one time fix for the heck of it if the problem was with multiple barrels of the same type quality ect... could there be a more cost effective way than firing of a box of tubbs final finish or can a patch with compound do in a pinch?

 

[Johnsusername]

Re: Question about barrel lapping

Lapping the barrel changes the bore size.

What you're thinking of doing is dangerous.

Take it to a professional.


John

 

[BOLTRIPPER]

Re: Question about barrel lapping

eric ...the tubb stuff is a great tool that i use breaking in a barrel....BUT I ONLY USE JUST 3 OF THE FINEST GRIT BULLETS HAND-LOADED DOWN...AND CLEAN THOROUGHLY BETWEEN EACH FIRING...

then there is the ISSO paste...it polishes the bore and works real well at getting the chatter marks smoothed out.

go slow and deliberate take your time and you will savvy great results.

 

[The_Punisher]

Re: Question about barrel lapping

Less is more and more is too much! You will want to be careful if hand lapping, especially near the the chamber and crown for obvious reasons. I have heard guys claim results on both sides for the Tubb firelapping system.

 

[mike_l]

Re: Question about barrel lapping

hand lapping requires lead and some lapping compound. it also requires cutting off at least one inch off each end of the lapped barrel. starting and stopping points get oversized. this makes the barrel uniform from end to end and takes out any inperfections

 

[jeep505090]

Re: Question about barrel lapping

thanks again guys just seeing how deep this was going to be before i thought about getting into it... the ISSO paste sounds like a safer method to try i will look into that more thanks again all.

 

[Clark]

Re: Question about barrel lapping

I lapped one 10 years ago. I poured molten lead into a lapp. The grinding compound is embedded in the lapp. I made a bore guide. I think I would get big muscles before I got small groups.

These days, I get a factory rifle, and if it does not shoot like a dream, I pull the barrel and cut threads and chamber on a custom barrel that has been lapped and stress relieved at the barrel factory.
I am now buying Lothar Walther in Chrome moly and Shilen select match in stainless.
I also have barrels by Lilja, Hart, Krieger, Pac-Nor, and Parker Hale.

Douglas and Green Mountain make good barrels, but they are not factory lapped.

 

[steelcomp]

Re: Question about barrel lapping

I was just having this discussion with someone who's opinion I respect. He forwarded this link to me:

http://74.125.95.132/search?q=cache:71-Ee_FCqsoJ:www.brownells.com/.aspx

Not saying yea or nay on lapping. I don't know enough about it other than what I've learned here on SH. I have an inexpensive Adams and Bennet stainless barrel (unfired) that I'm going to experiment with using the above method. From what I hear, the A&B barrels are OK, just a little rough on the finish and take quite e few rounds before they "smooth" out and quit collecting copper. I thought maybe some light honing might speed up the process.
I've got a new Bartlein coming for another build, and there's no way I'll touch the finish on that barrel, but my guess is the A&B could use it.

 

[mj2evans]

Re: Question about barrel lapping

I used the Tubbs bullets on a Savage 308 barrel that fouled badly (carbon more than copper). The lapping (not really lapping as the real lapping process is hand pushed lead slug) did help make the barrel a little easier to clean, accuracy was still good, and the throat length grew. I think it was worth doing in this case but it won't turn a factory barrel into a custom barrel.