The winter weather here in Wyoming has convinced me I need a project. I have a 450 Rigby and a custom 416 rigby nearing completion, so I thought it would be cool to also have a 275 Rigby. I know it is pretty much the same round as the 7x57 Mauser. I can't find a barrel specifically for the 275 Rigby, would I be OK ordering a 7x57 barrel from Pacnor for the 275 Rigby?

Same barrel, same reamer, just a different stamp on the barrel.

Jerry Liles

Thanks Jerry! That is what I was gathering from my research, but I wanted to check with the people who really know what they are doing before I screwed something up. I'm sure I'll screw something up in the execution, but at least I'll have a good plan!

Does the 275 Rigby have an 8" twist?

Also was the bullet .284 or .285 in the 275 Rigby?

This doesn't answer your question but a correct answer might help you.

Any modern barrel will be .284 and so will all your bullets. Many 275s were made for the hi velocity 140 grain bullet so twist does not have to be as fast as for the 175; I just built one using a 7x57 barrel with a 9 inch twist and I engraved it for the light bullet. My theory is that if I want to shoot heavy bullets, go to a bigger caliber.

As the others have posted. FWIW on an original Rigby the sights will be set for either of only two bullet weights.

175 grain or the "High Velocity" 140 grain. I think that one rifle was catalogued as a "No 1" and the other as a "No 2"?

I'm no Rigby expert although I did visit them in London when they were in a basement in Pall Mall around the corner from William Evans, Chubb and Churchill, Atking, Grant and Lang's establishments in the 1970s.

Thanks for the great information everyone.

Might wanna check reamer specs. I believe the 275 Rigby is throated for the 140 gr. bullet. That could possibly cause some pressure problems down the road with a heavier bullet.

You could ask Kent and get it straight from the horse's mouth.

kent@johnrigbyandco.com

Here's his AR profile info so you could send him a PM.

http://forums.accuratereloadin...profile&u=3081046571

The 275 was made in both 140 and 175 bullet weights; I am not sure if the throats and twists differed, or only the sights. When I built mine, I had a reamer ground especially for the 140 grain bullet since I did not want to shoot 175s and figured a short throat would be more accurate.

When you order your reamer you should send a dummy cartridge and they will grind your throat to match it. There are no SAAMI specs for the 275 anyway so get a 7x57 reamer with a custom throat. As they come standard, they are throated for a 175. If you try to load a 175 grain bullet into a 140 throated chamber, (unless seated very deeply) you will not have pressure problems as it won't go in at all; you will have chambering problems. I went through all this last fall when I built my 275.

As info, here is exactly what is engraved on the barrel of the Rigby .275 that I have in hand:

Sighted For Rigby's Special High Velocity
John Rigby & Co. 13 Sackville St. London W.
.275 Bore Cartridge Pointed Bullet 140 Grs.

I'm in the middle of rust bluing the gun for a customer. The bores are plugged with wooden dowels so I'm unable to measure rate of twist. If you want to know, send me a reminder e-mail in about a week at : mrrove@rogers.com

Best,
Ron Vella.

Do we agree that a 275 Rigby is just an English gunmakers name for a 7x57 ?

In my Ruger No.1a (the short light one), it will happily shoot bullets from 120-175 gr, 5 in a row, into 1" or less once the fore end was free floated.

It actually like the Privi 175 semi pointed factory ammo the best, often putting 3 in 1 hole and the 4th & 5th within 1/2" of them.

140 TSXs and the Privi factory stuff land wihin 6" of each other (up & down) at 300 yards which means a "backline hold" would kill any big game at 300 with either.

If you want serious 275/7mm loads get an older Hornady book which shows 7x57 loads for modern rifles (outpacing the 7mm08). Not for 93/5 Mausers or Rolling Blocks !

If I had a classic 275 that had fixed sights, unmarked as to regulation, I was trying to get it to shoot to, I believe you would have to start with a heavier bullet at the velocity from the good old days. That said, front sights are easily changed to raise or lower the POI.

If I were building one from scratch, I'd get a 1 in 8.875 twist as Barnes says that it the twist for 120s, 140 and 150 Barnes and they are my only hunting bullet. Throat would be set for Barnes 150s @2.99" + 50 thou for jump. Any lighter ones could be seated out as I do in the Ruger.

The 120 TSX can easily be nudged to 3000+ fps in a 26" barrel and no deer would ever die any slower vs a 130 270.

Now how about a 7.8 x 63.3 like this one ?

Yes, Rigby needed a small bore and Mauser already had an excellent one; no sense in re-inventing anything, other than a new name.