PDA

View Full Version : Counterbore?



Mr Peabody
03-29-2012, 05:56 PM
My old #1 BSA doesn't shoot to consistent and I believe it's because there isn't any rifleing left at the end of the muzzle. From the breech to about 3/4's of and inch from the muzzle there appears to be decent enough rifling to stabilize a bullet. Would counterboring the muzzle be an effective way to return some accuracy? Thanks for some thoughts on this.

Mooseman
03-29-2012, 06:00 PM
It would...The Russians have done Many Mosins like that. Just make sure the counterbore is concentric to the bore itself.

John Taylor
03-29-2012, 08:16 PM
Sometimes it works, sometimes it don't. It's worth a try, can't hurt it any more.

Mr Peabody
03-29-2012, 10:16 PM
My thinking too. I've got a decent enough replacement barrel for it; so far no one has the gauges or experience to put it on. If it was an AR platform I'd be covered up with smart guys.

Mooseman
03-29-2012, 10:24 PM
You could have the barrel trimmed back and recut the crown too...more expensive than a quick counterbore job.

Rich

wgr
03-30-2012, 12:48 AM
You could have the barrel trimmed back and recut the crown too...more expensive than a quick counterbore job.

Rich

my thinking too. just cut an in. off and recrown

KCSO
03-30-2012, 09:24 AM
You can get your accuracy back with a counterbore but it has to be a GOOD one. You can't simply run a drill bit into the muzzle and expect great things. Center the bore on a lathe and bore and ream and it willl probably work IF you get past the rifling wear.

Mr Peabody
03-30-2012, 09:31 PM
Thanks for the well thought out answers guys. It helps.

shotman
03-30-2012, 09:45 PM
need to just take out the lands If you get too much out it will tend to throw the bullet . and you need to cut the lands SQUARE it will lead if you try a taper like a drill bit

x101airborne
03-31-2012, 07:01 AM
Brownells sells a muzzle facing tool for use in a drill if you want to go that route. I had a really bad 8mm barrel that I wanted cut to 20 inches and crowned. Gunsmith said he could get to it in about 2 months. Three days from Brownells, 3 minutes in a chopsaw, and 10 minutes with that tool and it shoots GREAT. Maybe I got lucky, but "Buster" is taking down piggies out to 250 yards with great consistency.

ASSASSIN
04-01-2012, 03:29 PM
How long is the barrel now?

Strip the gun down and send me just the barreled action. I'll cut the barrel and recrown it for you. I won't charge you for the work but, I ask that you pay the return shipping - unless you are within easy driving distance to Vinita....

A

x101airborne
04-01-2012, 07:38 PM
A generous offer indeed!!

John 242
04-01-2012, 09:43 PM
I don’t understand why counter-boring would be preferable to cutting the barrel back?

I know the Russians used to counter-bore Mosin-Nagants, but if I am not mistaken, the reason they did so was to keep the rifle in the standard issued configuration. In other words, they counter-bored to keep from scrapping a barrel and keep barrel length the same as other rifles. From what I’ve read about Russian counter-bored Mosins, some shoot well, while others not so much.

What I’m getting at is that if it’s not important to keep the barrel to the stock length, why not cut an inch or so off the end and re-crown it? Wouldn’t that be a easier fix?

Cutting and crowning seems straight forward enough, but counter-boring seems to me, an inexperienced student, as if it would be more difficult to pull off correctly.

By the way, what’s used to do a counter-bore, a piloted bit of some sort?

John T.

bruce drake
04-02-2012, 01:36 AM
Bayonets. If you cut the barrel back you can't mount the bayonet. A counter-bore preserves the barrel length for the attachment of the bayonet. Russians still enjoy fixing bayonets to their AKs so its more than just tradition for them.

Bruce

Tokarev
04-02-2012, 02:06 PM
I don’t understand why counter-boring would be preferable to cutting the barrel back?
John T.

Lots of hardware to move if barrel cut (front sight, bayo lug).
Full wood stock does not help either.

Mr Peabody
04-02-2012, 10:16 PM
I'd like to keep the wood and all the rest of the rifle as genuine as possible. 15 years ago they were cheap enough to throw away and just buy another. I'll find someone within driving distance to swap out barrels for me. THANKS for all the thoughts.

wallenba
04-02-2012, 10:39 PM
Had a worn bore issue a year or two ago with my No.1 MKIII. I kept checking Numrich, Sarco and buymilsurp.com. Eventually Numrich showed one in stock. I snatched it up at $45, paid another $100 to have it installed (thank you member "Tedly", @ D&D guns ). It slugged .311, so a pig in a poke worked out for me. Anything would have been better than what I had though.
So keep trying to score a new barrel.

caseyboy
04-02-2012, 11:20 PM
If it were me, I would try the counter bore first. If that didn't work out, then I would cut back the barrel and recrown it.

Screwbolts
04-03-2012, 06:48 AM
I believe the counter bore could easily be cut with a throuting reamer. that would give you a clean, centered counter bore.

Ken

Tokarev
04-03-2012, 10:32 AM
Counter-bore (with pilot shank but w/o pilot)

John 242
04-03-2012, 10:29 PM
Major Bruce Drake… bayonets… Roger, that makes sense to me. I didn’t think about mounting the bayonet. I was figuring that the Russians were simply being thrifty by not trashing a worn barrel that sill had some life left in it.

Tokarev, thanks for the picture of the counter-bore cutter and the explanation. I wasn’t tracking exactly what model rifle Mr Peabody’s BSA was. I should have put a little more thought into it. I’m assuming that the rifle is a No. 1 Lee-Enfield type rifle. In my mind I was picturing a BSA sporting rifle for some reason. Being a fan of older firearms and especially military surplus rifles, it would be a shame to have to cut back the barrel on an otherwise fine example.

Mr Peabody, I figured that was your reasoning for counter-boring, but I wasn’t sure. I wish you success with your rifle.

Thank you all for educating me. I appreciate it.
John T.

missionary5155
04-05-2012, 06:09 PM
Greetings
Had an M1 Garand H&R with a very bad muzzle. Would shoot 6 inch patterns at 50 yards. So I thought I could not loose a thing. Took a 3/8 ths bit, built a guide jig on the work table, mounted the barrel in my vise and countered bored about 1.5 inches.
That barrel then shot 4 inches at 100 yards with the RCBS 308 180 gr FNGC. I then decided to drill the barrel top with 3 1/4 inch holes in the counterbored area. Just about eliminated all muzzle climb. Shot that barrel several years till I came across a new H&R barrel.
Then there was a 44/40 down here in Peru with a very bad muzzle. Tried a half inch bit 3/4 inch deep but no help. Cut that barrel back one inch and it shoots well.
Mike in peru

gidgaf
04-18-2012, 12:50 AM
There's a lot of reasons to do it.
A few decades of improper cleaning, and there's a little ridge or two in that last bit.
When you put the gun down, you put muzzle down on the ground- a few decades later there's a dent.
Sometimes lube don't make it all the way to the end.
Some powders are a bit abrasive, and once that pesky bullet is out of the way the high velocity fire can scour up the end.
That end of the barrel take a lot of beating over the years! And not being able to hit a paper plate at a 100 yards isn't a thing to be proud of.

I've mentioned it here before- I likes me old Mausers, I likes shooting big cast slugs.
Folk that know me know that, and when they get a *** bolt gun they talk to me.
I can take an old metal ruler and show them the end of the barrel is bent. Sometimes it really is!
Yes shortening the barrel makes it real easy. Did any of youse ever compare a 308 with a 16" barrel vs a 22"? Sure it's only supposed to be 150 fps diff- but there's a *lot* of fire and noise out of that little barrel!
Brownells has that great kit- take a half inch off max, counter bore another inch out of that 24 to 29 incher, and the 100 yd groups just got half sized. It don't look bubba got to it and it shoots good. And no eyebrow brushing blast, neither.

Junior1942
04-18-2012, 08:46 AM
I chopped my Turk Mauser's barrel off to 20" and now the "fire and noise" is so bad I don't like to shoot the rifle. One of these days I'm gonna add a 3" pipe to the end of the barrel. The ol' warhorse shoots way better than a $59.95 rifle ought to shoot.