7-08 to 7x57

[cowboybart]

I have a Husky 146 action that I want to put a barrel on.
I have several new Browning octagon A Bolt barrels, one of which is in 7-08.
I want to marry these two!

The minor OD of the barrel threads are .985" and the OD needed for the Husky is .980" I could clean up the existing shank and re-chamber to 7x57 Ackley.
If I want to stay with the standard 7x57, how much do I need to shorten the shank in order to clean up the 7-08 chamber?? I have some room before I get to the octagon section, but want as much round barrel for cosmetics and fitting the existing stock.

 

[DaveTooley]

The 7X57 has more than twice the body taper of the 7-08. By my quick and dirty calculations you'll have to shorten it by about an inch. Probably a little more.

 

[cowboybart]

Thanx Dave. I am OK with shortening it about .75", but I really don't want to go more than that.
I have to take about .3" off of the tenon anyway. So I think I'm gonna take the .3 off, then do a chamber cast, then do some measuring. If I can get by with another .5-.7" off, I'll go the standard 7x57 route. If I have to take more than that off, I'll leave it and go the Ackley route.

 

[DaveTooley]

I'd plan on the improved version.

 

[std7mag]

Or leave it 7mm-08. The 2 are essentially ballistic twins.

7mm-08AI (improved 40°) is an option also.

 

[jackieschmidt]

I'd plan on the improved version.

^^^^^^^^

 

[cowboybart]

Or leave it 7mm-08. The 2 are essentially ballistic twins.

7mm-08AI (improved 40°) is an option also.

I don't trust the Husky to handle 7-08 pressures

 

[std7mag]

I don't trust the Husky to handle 7-08 pressures

It's based on the large ring Mauser action.
It'll handle the pressure from a 7mm-08 just fine.

There are old Mauser actions that have been converted to 308 for South American militaries that still come up for sale every now and then.

And Husqvarna is known for using quality materials to begin with.

As I said, the 7X57 Mauser and 7mm-08 are essentially ballistic twins.
I built my daughter's 7X57 Mauser on a WWII action that was made on consignment for Germany.
She's using the 120gr Ballistic Tip over a charge of RL17.
The 120gr only because she is recoil sensitive.

I built a 284 Win on a Whitworth Mark X action. The action Whitworth used is an FN. The donor rifle was chambered in 270 Win.

So, yeah, I have no doubt that she'll withstand the pressure.

 

[Jonnyofalltrades]

The Husqvarna 146 was built on FN Mauser 98 actions.
Unless something has happened to the action over its lifetime to reduce its strength, there is absolutely nothing to worry about as far as strength goes.
If it's strength HAS been compromised, the difference in bolt thrust between 7-08 and 7 X 57 is pretty meager insurance...

Edit: I reread your first post, and see that you refer to a thread diameter of .980", so it must be a small-ring. Husky was good at using whatever actions they could get or make.

I still wouldn't worry about it. Post 1901 small ring Swedish built Mausers are extremely strong. Pre1901 the case hardening wasn't deep enough, IIRC.
I have one of each. Very different metal properties, case depth on the earlier one is maybe 5 thou.
I tried to blow up the later one, as it had been badly bubba'd. I couldn't blow it up.

 

[cowboybart]

Mine says 146, but it is a SR Mauser action. No third lug and no gas deflection shield on the shroud. It has the thumb cut in the receiver rail. Originally this was a 9.3x57. I'm a lot more comfortable at 7x57 pressures. If I go the Ack route, I will still keep pressures low, but I realize bolt thrust will be reduced with the Ackley.

 

[cowboybart]

There are old Mauser actions that have been converted to 308 for South American militaries that still come up for sale every now and then.

They are not converted to 308. They are converted to 7.62 CETME. The CETME is loaded to lower pressure even though the outside dimensions are the same as the 308 Win. Repeated shooting of 308 ammo in them will cause gross lug setback or the front ring separating from the rear. Because nobody knows what "repeated" means or how many times that receiver has been fired with 308 ammo - it is a gamble with your eyes, face and brain. Do you like those odds??

 

[Jonnyofalltrades]

By all means, carry on. I like the 7 X 57 better than the 7-08, anyway.
This sounds like a very fun and rewarding project!

 

[dthomas]

You could always load the 7mm08 on the light side.

 

[cowboybart]

Until I die or sell it. Then it becomes like a 28 Nosler barrel for a Contender.