Fire Lapping an M1 Garand

[rewster]

I would like to see if I can tighten up the groups I get with my match reloads. I've been told that fire lapping can rejuvenate an old barrel. The bore measures out at 1 1/2.

Since I might want to do this on as many as six 30 cal. barrels, I figure it would be wiser, from a cost standpoint, to buy the lapping compound kit and impregnate (leave it alone Sip ) my own bullets rather than buying the one time use pre-impregnated bullets.

Has anyone done this and how did it turn out ?

[sar4937]

There is a lot of controversy regarding fire lapping of new barrels. I don't see how lapping in a worn barrel would improve it.

[James57]

I don't see fire lapping as a good option in any case except if the barrel in question has a rough bore (rust, pitting, etc). You are in effect making the bore larger. So fire lapping would be a last resort before rebarreling for me. If you think smoothing the bore would help, try the JB bore polish from MidwaysUSA. The J-B Bore Brite would be my choice but make sure you have all the copper and powder fouling out first. I use it after cleaning to smooth up rifle barrels. It helps to cut down on copper fouling in the future and also really smooths out the barrel. Just my experience anyway, James

[ACP230]

The NRA used to have a bulletin on match prepping the M1. A lot of it was about bedding the action and stabilizing the handguards.
I wonder if that would do more than barrel work to tighten up your groups.

[growr]

What are your requirements? NRA High Power Matches? If so, a Garand delivering 2 minutes of angle is good, 1.5 is even better but not easily accomplished.

That means essentially at 200 yards your groups are about 2 inches, 3 inches or so at 300 and 6 inches at 600 yards which is well within the X ring of any of those targets.

What are you using for your loads now? What kind of accuracy are they delivering now, what are you expecting it to deliver?

There are many gun builders that specialize in M1/M1A building and can they ever deliver!!

A barrel with 1.5 throat erosion is just getting going....glass bedding and careful consideration to your components is key to making the M1 run.

Most M1's do their best work with 4895/4831 powder and a 168/173 bullet. The 173 is what is used in M72 match ammo....I usually try to replicate M72 ammo and call it good.

Randy

[Ron H.]

Originally Posted by rewster

I would like to see if I can tighten up the groups I get with my match reloads. I've been told that fire lapping can rejuvenate an old barrel. The bore measures out at 1 1/2.

Since I might want to do this on as many as six 30 cal. barrels, I figure it would be wiser, from a cost standpoint, to buy the lapping compound kit and impregnate (leave it alone Sip ) my own bullets rather than buying the one time use pre-impregnated bullets.

Has anyone done this and how did it turn out ?

Sir, what exactly do you mean by "The bore measures out at 1 1/2"? Are you talking about throat erosion or muzzle wear? Throat erosion of 1-1/2 is no problem--the barrel is still near new. Muzzle erosion of 1-1/2 isn't bad, either, but it might be good to have the muzzle crown touched up.

Like some others here, I'm not convinced of the value of fire-lapping an M1's bore. Usually if a Garand won't group, the problem is more with the stock rather than the barrel. A loosey-goosey stock will make even a brand-new Krieger barrel look bad.

Hope this helps, and Semper Fi.

Ron H.

[Pocketfisherman]

Before I firelapped a well worn used barrel, I would first try to clean it aggressively with a copper solvent like Butch's bore paste followed by regular Hopps. I'd do that repeatedly until the patches come out clean with zero copper residue.

[brucev]

Before you start in on the barrel... go to the Civilian Marksmanship Program website and look at the information you will find available regarding the M-1 rifle. Address the major points of concern, i.e., fit of stock and gas cylinder, tightness of rear sight, etc. Use good ammunition of known good quality. The Greek HXP M-2 ball sold by the CMP is excellent. It is my standard for evaluating any M-1 rifle. Spend time drying firing the rifle to get used to the way the trigger feels as you take up the slack and then break the shot. Use good marksmanship technique and fire from a solid sandbag rest. Blacken your sights with soot from a candle or carbide lamp. A standard service grade M-1will usually put 10 rounds into maybe 4 inches at 100 yds. I've had some that were very loose and used that, with attention to the above concerns, ended up producing 10 shot groups of under 3 inches. A rifle with a breech measurement of 1.5 will not likely have any issues with the muzzle crown unless it has been abused/damaged. Such a rifle will almost certainly produce very good on target accuracy. I have been shooting them for over 20 years and consider them to be one of the most effective easy to shoot rifles available. Go slow and educate yourself as to how the rifle works, etc. Good luck with your M-1 rifle!

[rewster]

Looks like I've got some other things to attend to before I consider fire lapping

Thanks a lot for the help, everyone !!

[ArchAngelCD]

I'm glad you reconsidered. IMO the only thing you will achieve fire lapping your Garand barrel is speed up the time when you will have to replace that barrel. Most used Garands have already been shot to half their barrel life expectancy. Don't waste your barrel...

[FTG-05]

You might want to look into buying the "NRA Guide to Gunsmithing". It has a detailed article on accurizing and M-14/M1A; some of that could be used on your Garand. I used it years ago to accurize my Mini-30 and it ended up working pretty good to accurize it.

Most of it is common sense stuff; you might need some specialized tools (like gunsmithing screwdrivers) but you probably need those anyway if you're interested in working on your guns.

Good luck.