rebs
Gold $$ Contributor
Thank you, I will leave it alone
lapping a barel
- Thread starter rebs
- Start date
I believe the key to keeping a bbls accuracy as long as possible is to keep the throat smooth. That is what lapping and throat maintenance bullets are all about.
My process ( right or wrong) is to JB the throat area of my bbls every 200-250 rounds.
This does not prevent throat cracking, but it removes the sharp edges the cracking creates.
On setting a bbl back: I don't know what benchresters do in this regard but noted MR and LR shooters have told me that if you are going to set a bbl back, don't wait until it has accuracy issues. Set em back at the half way point. So, let's say you are shooting a 6XC, which would have a competition bbl life of 2400 rds. , set it back around 1200 rds.
If you would/could measure the diameter of the lands, you would see that it is not just the throat that is wearing. The entire bbl is slowly increasing in diameter. That is what suggests setting em back at the half way point. I am sure that many will dispute that statement but I have found the 1/2 bbl life setback works well.
I don't think that it is cost effective to pay someone to set a bbl. back. If you are doing the lathe work yourself, that is another story. Working on my own rifles, bbl work is cheap!
My process ( right or wrong) is to JB the throat area of my bbls every 200-250 rounds.
This does not prevent throat cracking, but it removes the sharp edges the cracking creates.
On setting a bbl back: I don't know what benchresters do in this regard but noted MR and LR shooters have told me that if you are going to set a bbl back, don't wait until it has accuracy issues. Set em back at the half way point. So, let's say you are shooting a 6XC, which would have a competition bbl life of 2400 rds. , set it back around 1200 rds.
If you would/could measure the diameter of the lands, you would see that it is not just the throat that is wearing. The entire bbl is slowly increasing in diameter. That is what suggests setting em back at the half way point. I am sure that many will dispute that statement but I have found the 1/2 bbl life setback works well.
I don't think that it is cost effective to pay someone to set a bbl. back. If you are doing the lathe work yourself, that is another story. Working on my own rifles, bbl work is cheap!
Last edited:
Alex Wheeler
Site $$ Sponsor
You want the throat sharp, not rounded off. Thats why guys set barrels back. Jb or iosso can be necessary, but I dont use them until they are. At that point your just trying to salvage what you have. The peak is gone.
I lap a few bbls but since I do not consider myself a pro at this, I do it when I have little or nothing left to lose, for starters. That said, I've actually had a good success rate but if I do it for anyone other than myself, the first thing I tell anyone is that this can go good or it can go really bad...no promises.
Like others have said, you really need to pour your own lap and make or modify the jag for the job. There's a little art to this part and we haven't even started yet.
I prefer a soft lead lap about 3" long...4 may be better toward the end... and no finer than about 320 grit aluminum oxide grit vs some of the harder stuff because aluminum oxide will break down finer as you lap and become a better lap within a few strokes..maybe a dozen or so.
One thing you DON'T want is for the bbl to become too smoth. It'll foul like crazy if you lap/polish to a pretty mirror like finish. Most bbl makers stop short of 320 grit.
It's actually pretty easy to feel tight and loose spots once you get going though, even on a high end bbl, but I default to what I said earlier...I'm not a pro and the bbl makers generally know what they are doing much more so than I
Bottom line, don't try to make a new bbl better but only do this if you have nothing to lose trying it. It's very much about feel and some people just don't have it. If you do a lot of them, I think you can loosely approximate how many strokes of different grits to use to get what you're after but you might scrap a few along the way, too.
I'd say that the first few were 50/50 but since then, I feel much more confident the results will be good. It's definitely something that I learn as I go though. Like Alex said, I think the most important area is the throat. I think if you can smooth that are out without significantly rounding the corners, you're probably almost there. Easier said than done son pour multiple laps and just play with them.
Just do it...if you have nothing to lose. I can't explain what you're looking for but can only say that if you have a feel for it and creep up on it, you'll learn and may improve a bbl...or scrap it..either way. Just play. It's mostly time and you learn either way. At least that's how I look at it...fwiw
Bbl makers will LOVE you!
Take this for what you paid for it. Lol!
Like others have said, you really need to pour your own lap and make or modify the jag for the job. There's a little art to this part and we haven't even started yet.
I prefer a soft lead lap about 3" long...4 may be better toward the end... and no finer than about 320 grit aluminum oxide grit vs some of the harder stuff because aluminum oxide will break down finer as you lap and become a better lap within a few strokes..maybe a dozen or so.
One thing you DON'T want is for the bbl to become too smoth. It'll foul like crazy if you lap/polish to a pretty mirror like finish. Most bbl makers stop short of 320 grit.
It's actually pretty easy to feel tight and loose spots once you get going though, even on a high end bbl, but I default to what I said earlier...I'm not a pro and the bbl makers generally know what they are doing much more so than I
Bottom line, don't try to make a new bbl better but only do this if you have nothing to lose trying it. It's very much about feel and some people just don't have it. If you do a lot of them, I think you can loosely approximate how many strokes of different grits to use to get what you're after but you might scrap a few along the way, too.
I'd say that the first few were 50/50 but since then, I feel much more confident the results will be good. It's definitely something that I learn as I go though. Like Alex said, I think the most important area is the throat. I think if you can smooth that are out without significantly rounding the corners, you're probably almost there. Easier said than done son pour multiple laps and just play with them.
Just do it...if you have nothing to lose. I can't explain what you're looking for but can only say that if you have a feel for it and creep up on it, you'll learn and may improve a bbl...or scrap it..either way. Just play. It's mostly time and you learn either way. At least that's how I look at it...fwiw
Bbl makers will LOVE you!
Take this for what you paid for it. Lol!
Last edited:
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.