Hi.
I got an offer yesterday.
I spoke to a buddy that had two original (new) 50 BMG. barrel to sell. It started to shine "new project" in my eyes at once!!!
My question is: Is the rifle-twist in those barrels usable for any other 50's, like 500 A-Square, 50 Alaska, and such???
Or is it only proper for the BMG??
I belive they are approx. 125-130cm long, and are very thick.
He offered them to me for a very fair price.
I've always wanted a 50 BMG though!!

Most of us use 1:15 twist barrels for the .50 BMG. I built my 500A2 using this twist and it does stabilize a 535 gr Woodleigh at least for 50-100yrds reasonably well. I used this twist and throated the gun in order to shoot 640 gr. Military bullets for plinkers in it. Most of these barrels are 1.75 inch diameter for 1.5 inch threded shanks common to modt .50 BMG actions. Be prepared to start spending big bucks when you deceide to enter .50 BMG land.-Rob

460:
Did you buy the barrels?

The magazine "V�penjournalen" had an article some years ago by a guy that used a brno 602 action + a BMG barrel to make a really cheap .500 A-Square with a homemade laminated stock.
(he blasted a little cow moose with a 600 grainer, but it still walked 15-20 m before it collapsed.. So much for "shock effect"!)

Aren't MG barrels chrome lined? How do you deal with that in terms of chambering etc...? Seems like it would be a lot of work turning down that big mamma-jamma and you could buy a blank for a lot less cash than time and effort for the freebee.

The american 50 cal barrels, assuming milsurp, are all chrome lined, and will destroy most reamers. If these are not milsurp, snatch them up, and yep, there are good enough for most applications, although you may find the twist a little fast for "light" .510 bullets and lead.

I would wager that anything more than $100 is too much for a blank, though, of unknown maker/quality/recourse.

jeffe

The twist rate for the 50 BMG would be too slow for the 500 A-Square. The 50 BMG usually has a 16" twist while the 500 A-Square should be using a 10" twist. You need to have more twist per a barrel length to stabilize a heavy projectile at a lower speed. I just ordered a 50 caliber barrel from PAC-NOR for one of my 50 caliber wildcats and it will have a 9" twist, which should be one of the fastest standard twists out there. Good luck.

Mingo,
not to be contrary, but faster twist means more pressure, all else being equal.

Actually, shorter/lighter bullets require less twist to stablize, see remington 244 vs rem 6mm, the only difference is twist. There would be no reason to use a faster twist that 1-15 or 16, due to bullet length/stablize. Barrett uses a 1-15.

http://www.realguns.com/calc/riflingtwist

the link about is a twist rate calc

Since the 50 bmg "shoots" a 750 grain (match) that is 2.550 long, it should only "require" a 15.3 twist.. and shorter bullets would require less twist...

IMHO the BMG barrels are too fast, but not anyting too much, but the chromelining will destory reamers.

On chromelining.

I have watched one of the best benchrest gunsmiths in the country use fairly inexpensive twist drills to step bore blanks to save wear on his PPC reamers.

Could one not simply drill out the chrome bore of a milsurp barrel to the depth of the case neck and then use a good reamer?