Can anyone tell me what the thread size is on a Browning BBR. I have a friend that wants a 300 ultra mag put on. I dont know if the barrel shank will be big enough.
I forget the exact size... but it will handle it... I made a 338-378 on a BBR with no problem... making the magazine feed will be your biggest problem...
Originally Posted by jhilton
The shank is of a BBR is .937 Do you think it would handle a 338 lapua?
I was surprised to see the shank was so small. I was looking for a Weatherby action and got a deal on this bbr. What I was after was the 60 deg bolt lift. I like building one of a kind rifles. I was going to machine chassis system that would except Accuracy International 338 lapua mag. Amazingly the 25-06 mag. with the spacer removed feed great. I am not going to use it I was just messing around. What did you do about the extractor?
Originally Posted by Dennis Sorensen
Does anybody know the barrel shank size for a Weatherby mark V 300 wm
I am trying to figure out if a browning bbr with a shank size of .937 is strong enough for a 338 Lapua. The acting looks so much like a Weatherby I was wondering if the shank size is the same. I know a Weatherby Mark V is strong enough, and I know the 9 lugs of the BBR are strong enough, but that shank looks small. I was told a Ruger No1 has a .937 shanks . Can anybody confirm that?
The shank size needs to be over a 1 1/8!!!!!
The base size of a .338 Lapua Mag is .590!! There is a ratio for it as I think is 2.33 or 2 1/3 times the size of the case? I'll have to go back and look to see what it was. I'll get back to y'all on that!!
Last edited by Rambo; 03-07-2014 at 06:02 PM.
Reason: change the ratio to 2.33
RAMBO IS RIGHT!!! RAMBO IS RIGHT!!! RAMBO IS RIGHT!!!!!
DO NOT build a 338L on any shank less than an inch and an eighth! And this includes (EXcludes actually) the new "large shank" Savage IMO. They got their "larger shank" by cutting shallower threads, as I just found out the hard way, by spending money based on someone else's guess.
I've found the Stiller TAC338 to be sufficiently stout.
I've been pondering the idea of a 338/300Ultra Mag on a Win 70 1.00x16tpi, just because I have a spare action and barrel blank and reamer. I was thinking I'd open threads to 1.062 (or 1.082) then I find out that Ruger chambers the WSM on the #1 with 1.00 tennon so I might just go ahead with it as it is. (Thinking about it but still not convinced.)
I wouldn't ream a bigger chamber on a inch tennon if someone paid me extra to do it.
338 Lapua tenon size
Very good explanation of required tenon size.
http://www.bordenrifles.com/338_lapua.pdf 1.062x16 is marginal at best.
1.125x16 is what is used On Stiller's TAC 338.
Al is correct on the so called big tenon savage. They pretty much cheated to get what was needed but weakened the action by doing so. Had an interesting discussion with Jim on this very method they used and why they did it.
Dan Lilja draws the same conclusion here.
I always re-thread Model 70's to 1 1/16" just so that I will have a complete thread in the receiver rather than the interupted thread they have. When the barrel is tightened into the receiver with the interupted thread, the chamber is distorted; especially if in the WSM or other large diameter chamberings. A complete thread (as in the Ruger, for instance, supports the barrel tenon (providing the thread is a good fit) and there is no problem. Regards, Bill.
Originally Posted by Jay Cutright
I rethreaded the first 8 Winchesters I put barrels on. Then one day a fellar show's up and don't want to spend any money truing the action or rethreading. I just put a barrel on it bedded it into a A5 McMillan and put in a Jewell trigger and it shoots damn good. No sign of any distortion of the chamber either. How would you measure that distortion?
Now I simply chase the threads enough to make good clean threads, true the lugs and action face square to the bolt and leave a little clearance on the barrel threads so the tennon shoulder will square up with the action face when it's tightened.
The owners of the rifles done this way are all happy with what they have.
You can often measure the distortion on a fired case or on a chamber cast. The distortion disappears when the barrel is removed. It is usually not evident if the rifle is chambered for a standard cartridge but is definitely there if the rifle is chambered WSM or even a belted mag. Winchester changed their thread size because of problems with WSM chambers.
If a customer doesn't want the action re-threaded, that's fine but if it's to be a WSM and he doesn't want it re-threaded then he doesn't want me to do it. Regards, Bill