What grit lapping compound?

[chad]

I want to lapp my 280AI barrel. What grit should I use?

Is it to late? It was a 280 b4 and I am having it reamed to the Ackley. Its been shot im guessing 200 to 250 times,

 

[MudRunner2005]

Unless it produces alot of copper during cleaning, copper-fouls really easily, or isn't very accurate, I'd lap it. But if the bore is nice and smooth, doesn't hold much copper and shoots good, I wouldn't worry about it.

With that many rounds down the tube, I'd think it would be a nice bore already, and you would have noticed a problem a long time ago if lapping the bore was needed.

But, if you've had any major copper-fouling issues, then it won't hurt to lap it.

 

[Mikecr]

Unskilled with lapping, there is no way I would do it where it matters.
What dimensions/attributes are you lapping to? How will you verify?

 

[chad]

I thought you could just run a patch back and forth dozens of times and check to see if it was shinning the bore up. I wasn't aware that you needed to measure your progress. I get that it would wear the rifflings down but with a 400 grit or finer I would think it would take hundreds of strokes. Im just looking to shine the bore up nice so it cleans easier.

 

[Garycrow]

You're a lot more likely to screw things up than you are to help any. I wouldn't attempt to lap a barrel unless I was prepared to scrap it and rebarrel. You can't really lap a barrel like the barrel makers do because they lap it before it's fitted and chambered. Lapping caused the ends of the barrel to be belled a little, the first and last inch or so of the barrel will be slightly bigger than the middle. When the gunsmith fits the barrel he cuts at least an inch off the muzzle end and cutting the chamber takes care of the other end. Trying to lap an installed barrel isn't a good idea.

 

[chad]

Thanks for the info. I understand that.

 

[jeffreykooken]

Thanks for the info. I understand that.

You might try the David Tubb final finish bore lapping system. It is a box of bullets with various grit lapping compounds embedded into the bullet surface. You load these and shoot in order. He has a website. www.davidtubb.com.

 

[MudRunner2005]

You might try the David Tubb final finish bore lapping system. It is a box of bullets with various grit lapping compounds embedded into the bullet surface. You load these and shoot in order. He has a website. www.davidtubb.com.

I would NOT do this, unless your barrel has issues. It works if you have a messed-up barrel, but it will remove a fair bit of barrel life by using this method.

 

[FEENIX]

I too would leave the lapping process to the barrel makers or those that knows what they are doing.

Quality of a barrel starts at the manufacturing process regardless of brand, custom or not ...





... and sometimes other factors are involved ...

 

[Trickymissfit]

I did a Remington barrel with a series of home built laps made out if UHMW. Did not touch the last three to four inches, and really only hit the tight spots and the throat area kinda heavy. Started out with 5a, and finished out with 7a. I used this stuff as an experiment knowing I had better stuff to use, but also in limited quantities. I didn't do it to make it group tighter, but to at least make a dent in it's constant fouling. Yet the last three inches still foul after twenty shots really bad. I did try JB paste on this barrel, and one Savage barrel as an experiment. The Remington barrel was too bad for any serious help, but the Savage did seem to gain a little (only lapped the first twelve inches on the Savage)
gary

 

[Mikecr]

I wanted to add a couple things as I've done some experimenting on barrels past their peak, and with what I've learned scoping & testing them there are things I carried to brand new barrel maintenance.

For one, you need to be leery of terms generalized and research to understanding.
-In the Lilja video, he last shows a brand new bore and describes it as 'mirror finish'. This finish is NOT ideal, and I suspect nothing more than merchandising on their part. Only the lack of other problems holds as good.
-In the Hawkeye video, notice in the last example a 'tack driver'. It is not a polished(mirror) finish. It has a CORRECT surface profile for reduced fouling & lasting performance(grouping).

A bore that shoots really good is not perfect as possible,, it is just right. A balance.
And this is why you need to know what you're doing if you're going to do anything with it.

I use Tubbs FF. It has proven(to me) to work well for new barrel break-in as it lays a lap similar to the best hand lapped bores. I shoot a couple of their TMS bullets every 200-300rnds to dress up lands(they start uneven over time). I haven't seen, or read of Tubb's firelapping hurting any bore, or reducing any barrel life. The truth is this system extends useful life of bores, when used as it should be.
A lot of folks are afraid of this, I was at first, and watched it close with a Hawkeye. No problems.

Also their are 2 different JB compounds out there, both claiming to polish bores. Be careful to get the right one, as one of them actually does polish bores and will instantly cause copper fouling to forever increase.