What's the difference between a .25 and .257 slug?

[Stretch]

Yeah, might be a stupid question but I'll ask it anyways. I'm interested in long range target shooting and one of the "go to" rifles is a Doug Noble .257 Airforce Condor. But how different is that rifle from some other .25 caliber, heavy, high ballistics coefficient slug going 1,000 fps?

 

[Motorhead]

.257 has a Differing twist rate for what is generally a longer and heavier slug than what .25 cal pellet rifles shoot. The .257 IS NOT a pellet shooter but dedicated slugger.



65 grain .257 https://cdn.shopify.com/s/files/1/0794/5877/products/20220128_144534_540x.jpg?v=1643403130

55 grain .25 https://cdn.shopify.com/s/files/1/0794/5877/products/20190821_144103_540x.jpg?v=1566423761

 

[JimD]

.007 inches (approximately),

 

[MrP]

I have Doug Noble guns with .25 and .257 barrels, both TJ barrels and same twist rate so you can get a nice .25 slug gun as well.


i was puzzled like you and when I asked around a while back I was told that folks settled on .257 because of the availability of the barrels and molds for heavier longer slugs not because of the magic of .007 inch. 

 

[Stretch]

I have Doug Noble guns with .25 and .257 barrels, both TJ barrels and same twist rate so you can get a nice .25 slug gun as well.


i was puzzled like you and when I asked around a while back I was told that folks settled on .257 because of the availability of the barrels and molds for heavier longer slugs not because of the magic of .007 inch.

Thanks, that's very helpful information.

So is there a "typical" twist rate for .25 caliber air rifles? I read someplace that Doug's TJ barrels have a 1:14 twist. One of the rifles I'm looking at has a 1:17.7 twist. Not many manufacturers publicize their barrels' twist rate. Is 1:17.7 pretty common?

 

[MrP]

That I don’t know. Just that 1:14 is typical for those barrels and that pellet guns often have slower twist rates. I think LW barrels on AF guns are ~1:18 but am not sure



there are some good heavy 25 Cal slugs that do well in the LW barrels. The NOE bbt molds come in 40, 50, and 60 grain weights, I have the 50 and 60 grain as the 40 grain has been out of stock these last 2 years I think.