Stopping Rifles, .375 - .450 - .505 Gibbs

[Ardent]

Was doing measurements and specs, OAL, balance point from butt, and so forth on the guns for the article and discovered something I never knew; the RSM came in different barrel contours. I had always assumed the .375 used the same contour as the .416 and .458, and while the .505 is based on an earlier RSM, it's still a 23" barrel just much heavier. I'd shot both and hadn't noticed until tonight!

 

[BigUglyMan]

I was under the same impression. In fact it had been stated several times in print that the 375 used the same contour as the bigger bores which made it heavier than necessary. I guess we should have fact-checked them a little, eh?

 

[Ardent]

Indeed I'd read the same, they're close, and don't even immediately catch your eye as different. I calipered the barrels at 12", and the muzzle and the difference is roughly 0.10", the heavier barrel also has quite a bit longer chamber by roughly an inch.

 

[Dogleg]

What have you done to that Winchester? LOL

Made it into a culling machine.

 

[stickhunter]

Was doing measurements and specs, OAL, balance point from butt, and so forth on the guns for the article and discovered something I never knew; the RSM came in different barrel contours. I had always assumed the .375 used the same contour as the .416 and .458, and while the .505 is based on an earlier RSM, it's still a 23" barrel just much heavier. I'd shot both and hadn't noticed until tonight!

That's interesting, Ardent, because I'd heard about the barrel contours being the same as well (although I suspect it may have been from you!) I believe Steve told me that the rifle was originally a 416 Rigby, but I'd been meaning to call Ruger to confirm. With the measurements that you took, would it still be feasible to rebore/rechamber the 375 to something like the 505?

Another thing I found interesting about the RSMs is the foreend harness that transfers recoil to the main lug:

I posted a thread about that a while ago:

http://www.canadiangunnutz.com/foru...bedding-and-505-Gibbs-chamber-cast-*pictures*


I presume that the modern RSMs also have this type of bedding?

 

[Ardent]

It would (the .375), but I believe it would be severely light, there is a substantial amount more "beef" in the heavier barrel. Indeed, exact same fore end system, very skookum!

 

[1899]

Goble's has a sale on a new CZ550 in .505 Gibbs - $3,295.

 

[Bowie]

Another thing I found interesting about the RSMs is the foreend harness that transfers recoil to the main lug:

I presume that the modern RSMs also have this type of bedding?

Sako 85 rifles also do this - or at least the big ones do, albeit not quite as far up the forearm.