280 Ross barrel

[eliwhitley@yahoo.com]

I purchased a 280 Ross barrel labeled as 338. I want to put it unto a military MK lll action I have. The problem, the barrel mics to 0.31 at the muzzle and a 280 Ross cartridge drops and fits in the receiver like a glove.

Anyone have any idea of what I might have or recommend re-chambering it to which 338 cartridge?

Thanks, Don

[Surpmil]

It sounds like you have a barrel that was rebored, but what is the exterior profile, that of an M10 .280 sporter or a Mk.III?

[eliwhitley@yahoo.com]

It's a sporter off a M10. Marked 280 Ross, Proved 28 tons. It has been re-bored, to large to be 280 ,but I do not think re-chambered. What are your thoughts.

Thanks, Don

[Bluenoser]

A groove diameter of 0.31" sounds like the bore could be .303 Brit - possibly done due to the lack of suitable diameter bullets for a .280 Ross. I think you should do a chamber cast and a cast of the rifling with Cerrosafe. I wonder if it could be a .303/280 Ross wildcat, but have never heard of one. The markings suggest it is not a Mk. III barrel rechambered to .280 Ross.

[Surpmil]

First step would be a careful examination with a borescope to see how well the re-bore went.

You'd probably want to slug the barrel at a few different points along its length to see if the ID is consistent - after all, someone pulled the barrel for a reason!

I'm not knowledgeable enough about cartridges and loads to suggest a combination, but it wouldn't take long to figure out probably.

At .310 you're very close to the nominal diameter of .303 Br, so that would at least give quite a few bullet options if correct.

[eliwhitley@yahoo.com]

Thanks, I will try that.

---------- Post added at 12:25 PM ---------- Previous post was at 12:23 PM ----------

A 303 Brit won't chamber. I was hoping someone might know of a wildcat with this information. I'll have to get slugged and cast.
Thanks

---------- Post added at 12:35 PM ---------- Previous post was at 12:25 PM ----------

Yes, I was thinking wildcat but never heard of any. I thought someone might know with this info.

Thanks

[Bluenoser]

You said "A 303 Brit won't chamber"
I assume you are saying a 303 brit cartridge won't chamber. That could be due to a difference in case dimensions. I was/we were suggesting the possibility of a 280 Ross case necked up to 303. You really need to do a chamber cast.

[eliwhitley@yahoo.com]

OK, thanks

[Surpmil]

...the barrel mics to 0.31 at the muzzle and a 280 Ross cartridge drops and fits in the receiver [aka "chamber"] like a glove

...