Someone educate me on barrel shank diameter

[JJMoody]

Looking at re barreling a BAT HRPIC in a lapua based cartridge. Someone I respect very much on the topic advised a 1.25 shank diameter. Problem is, there's a barrel in the classifieds I'm really eyeballing with a 1.2" shank. Is it just a matter of meat around the chamber or aesthetics on the action or something else I'm not smart enough to talk about? Please advise....

 

[Buck Fever]

Try not to buy someone else's problem but that difference is so minimal that it really shouldn't matter.

When I was picking my latest barrel profile, I did choose 1.250" shank but I was lucky and the profile I wanted had that size. There were a lot more 1.200" options and some pretty close to what I picked but most of them were significantly lighter barrels.

If the profile is right beside the shank, it should be ok unless it is someone else's problem barrel. This is why I like new, if anything doesn't work, i know who to blame.

It was late, I was dumb.

 

[shortgrass]

Your 'friend' was making good sense The Bat HR has a 1 1/8" x 16 t.p.i. thread in it for the barrel to screw into. And, it is about the 'meat' around the chamber. Most use a 1.3" to 1.35" dia. 'shank' for Lapua based chamberings, as well as a 1 1/8" diameter thread. Makes for a good shoulder to shoulder lock-up of barrel to receiver as well as provide the 'safety factor'. If I remember correctly, the Bat HR has a 1.35" front ring diameter (on the outside).

 

[Buck Fever]

Shoot, I missed the part about Lapua. I think the thing that threw me was the 1.250", I was stupid and assumed you were talking about a roughly Remington 700 sized action.

I guess I shouldn't post that late at night.

Disregard my previous post.

 

[sable tireur]

From the BAT website:

Our model HR has a Remington 700 Long action footprint. This action is 8.860" long and 1.35 inches in diameter. Average weight is (integral rail 36.4 oz) and varies with options chosen. This is normally a repeater action but can be ordered as a single shot. Load port can be cut for almost any 700 LA bottom metal including the extended Wyatt boxes. Ejector port length is 3.52 inches and barrel tenon is 1.125 x 16 tpi.

When you take the time to compare the action dimensions, the only difference is the action thread diameter with the Remington at 1.0625 x 16 tpi and the HR is 1.125 x 16 tpi. This means that the wall thickness on the HR is actually thinner than on the Remington. But the HR allows for (needs) a larger diameter shank on the barrel to accommodate the larger diameter Lapua cartridge.

 

[Alex Wheeler]

I wont use 1.2" shanks on the Bat HR. It would leave about .037" of shoulder on the the barrel. I stick to the 1.250 shanks. Bat uses a 1 1/8x16 thread tenon which increases the thickness of the chamber walls and allows for larger lugs on the bolt, which is why its the only one I use for the Lapuas and Normas.