Hand Lapping & Cryo

[Big John]

I used the search option and was amazed that no one yet has started a topic about hand lapping. I have a pistol barrel I need hand lapped and cryo'd, and the gunsmith I get my stuff done through is now retired. Im wondering if any one knows a good barrel smith in Southern California (San Diego / Orange Counties) that does good hand lapping jobs on pistol barrels. Also, is there any one other than 300 Below to do the cryo work?

[Fjold]

Are you lapping completed barrels?

I was always told that lapping should only be done on unfinished blanks because as the lap enters and exits the bore it tends to wear the edge unevenly. So after lapping is completed you cut the chamber (that gets rid of the ovalling at the entry point) and then cut 1" off the muzzle end to get rid of the damage there and crown it.

[Big John]

The gunsmith I use to go through hand lapped several rifle barrels for me, turned out great. The first was an LTR barrel, the second was a Yugo M-48 mauser barrel (put a period scope/mount on the rifle and wanted to make it easier to clean and a little more consistant). After having him hand lap them both and having the LTR cryo'd, they were much easier to clean and the consistency improved quite a bit on both. Ive never had a pistol barrel hand lapped or cryo'd before since I've always either been happy with it as is, or bought a match barrel to replace the factory one. This is a factory Beretta M-9 barrel (not sure if there is any difference between the 92FS and M-9 barrel other than the chamber specs, SAAMI vs NATO), with a total of 50 rounds through it. Im wondering wether I should get it hand lapped and cryo'd or just buy a match grade replacement barrel.

[ocabj]

I'm not a fan of hand lapping a factory barrel. Shoot the gun and be happy. Otherwise, get a custom match barrel.

Here's a nice thread with varying opinions on hand lapping:

http://www.benchrest.com/forums/showthread.php?t=14179

As far as pistol barrel, I don't see the benefit. Are you looking to smooth out any rough tool marks in the bore? I'd be more concerned about the slide to frame fit and barrel lockup in the slide. Are you shooting EIC pistol? I'm interested to know of any good EIC / Bullseye gunsmiths that work on Beretta 92 series. I haven't seen much on the Internet on accurizing the Beretta. The AMU has done quite a bit of research and work on the Beretta, but none of there methods are well known by the public.

[dw1784]

This is a factory Beretta M-9 barrel (not sure if there is any difference between the 92FS and M-9 barrel other than the chamber specs, SAAMI vs NATO), with a total of 50 rounds through it. Im wondering wether I should get it hand lapped and cryo'd or just buy a match grade replacement barrel.

r u saying u got a lemon? My neighbor's M9 and 92FS are both very accurate out of the box. Besides the finish(older 92FS are better) and the plastic guide rod in the M9(metal in the 92FS), both are the same and interchangeable. Maybe u should try customer service first?

[6079Winston]

I'm pretty sure the M-9 barrel is chrome lined, which should be really easy to clean and probably outlive the rest of the gun. I don't think chrome can be lapped either. If you can find a smith to accurize a Beretta, that would be neat to see at the range, at least a first for me to see at the range.

[Big John]

As far as pistol barrel, I don't see the benefit. Are you looking to smooth out any rough tool marks in the bore? I'd be more concerned about the slide to frame fit and barrel lockup in the slide. Are you shooting EIC pistol? I'm interested to know of any good EIC / Bullseye gunsmiths that work on Beretta 92 series. I haven't seen much on the Internet on accurizing the Beretta. The AMU has done quite a bit of research and work on the Beretta, but none of there methods are well known by the public.

The benefits for hand lapping a barrel are less fouling, easier & faster cleaning, and better consistancy. Doesnt matter if its a rifle barrel or a pistol barrel. There is the Beretta 92CB which is single action only with a barrel bushing like that of a 1911, that is what the AMU was using for a little while. Now they use over sized locking blocks that the AMU Master Armorer hand fits, to get rid of the barrel wobble. They tighten up the slide to frame fit, obviously.

r u saying u got a lemon? My neighbor's M9 and 92FS are both very accurate out of the box. Besides the finish(older 92FS are better) and the plastic guide rod in the M9(metal in the 92FS), both are the same and interchangeable. Maybe u should try customer service first?

No I did not get a lemon, I got a factory M-9. Its plenty accurate for most peoples standards. There are a number of differences in the 92FS and the M-9. First and formost, the chamber specs, NATO vs. SAAMI standards for chamber pressure for M-882 112gr ball vs. SAAMI 115gr ball (different reamer). The rear sights are different, the guide rods are different, the M-9 is made in the US, is marked M-9 and lacks the warning labels.

[drawn]

As far as Cryogenics go,http://www.cryogenicsinternational.com/shooting.htm
Charles is a great guy and usually has a quick turn around. He is in Scottsdale, Az very close to the Scottsdale Gun Club and Dillon Reloading.

[Big John]

As far as Cryogenics go,http://www.cryogenicsinternational.com/shooting.htm
Charles is a great guy and usually has a quick turn around. He is in Scottsdale, Az very close to the Scottsdale Gun Club and Dillon Reloading.

Thanks a bunch! I've always been pleased with 300 Below's cryo services, but they are fairly far away and the turn around time can be quite long if they are busy with DoD contracts (they do the heavy caliber barrels, 20mm, 25mm, 30mm, ect.). They seem to be doing alot of those lately.

[randy]

Big John

What are your standards for Beretta accuracy? How far are you shooting and what group size are you looking for?

[Big John]

Big John

What are your standards for Beretta accuracy? How far are you shooting and what group size are you looking for?

I preffer my defense/combat pistols to shoot under 10 MOA (pie plate @ 50 yards) with ball ammo, off hand. Precision rifles should shoot half MOA or under, prefferably quarter MOA. AR's should hold 1 MOA or better.

I dont have a whole lot of firearms like some do, but the ones I do have I make sure they are good to go.

[Big John]

I ended up hand lapping the barrel myself, taking my sweet time doing it to make sure I got it right. I did the traditional hand lapping treatment with the lead slug being pushed through the bore from throat to muzzle with a caliber specific push rod and a bore alignment guide for the push rod. I used a medium lapping compound first, then the fine grade lapping compound, then I used an extra fine lapping compound I had to special order from Battenfeld. I also used the fine and extra fine lapping compound on the sear/trigger contact points which made a noticable improvement in the crispness of the trigger break. I then sent the barrel, locking block assembly, slide, frame, et-cetera (everything metal) to 300 Below. It took a little longer than it use to as I expected it to, since 300 Below is quite busy with military contracts; but she is a very sweet shooter now.

The original factory M-9 was shooting a tiny bit over 8 inch 5 round groups at 25 yards (33.5 MOA) during a 50 round string of fire, that is before it was fully broken in as well... I'm sure it would have been shooting better as soon as the barrel was broken in. Well, she now shoots an average 1.4 inch 5 round groups at 25 yards (5.86 MOA). That is with 2006 head stamped Lake City M-882 9mm NATO (112gr FMJ @ 1265 FPS) ammunition. It is also much easier to clean, I only used 5 more cleaning patchs to clean up after 300 rounds of NATO surplus 9mm as I did to clean up from 50 rounds of Remington UMC 9mm ball ammo during the initial break in.

[ar15barrels]

I ended up hand lapping the barrel myself, taking my sweet time doing it to make sure I got it right. I did the traditional hand lapping treatment with the lead slug being pushed through the bore from throat to muzzle with a caliber specific push rod and a bore alignment guide for the push rod. I used a medium lapping compound first, then the fine grade lapping compound, then I used an extra fine lapping compound I had to special order from Battenfeld.

How did you control for belling at the muzzle?
Did you push the slug out the front every time, only pushing from breech to muzzle, or did you stroke back and forth?

[Big John]

How did you control for belling at the muzzle?
Did you push the slug out the front every time, only pushing from breech to muzzle, or did you stroke back and forth?

I pushed it from throat to muzzle only, which I know takes longer to lap that way but its the way I wanted to do it since that is the way the bullet travels and I did not want to harm the muzzle crown at all.

[ar15barrels]

I pushed it from throat to muzzle only, which I know takes longer to lap that way but its the way I wanted to do it since that is the way the bullet travels and I did not want to harm the muzzle crown at all.

Good job.
Have you ever considered fire lapping?
I have done it to a couple barrels with good results.