25 cal

[Kevan]

I read a lot of interesting info on the Roberts, most from John Barsness. He was once a devotee of the AI version and then gave it up as not enough ballistic improvement to justify the extra work of fireforming, and the attendant costs of rechambering and fireforming. The gain in powder capacity is about 12%, and given that velocity increases at one-quarter the increase in powder capacity, velocity increase is about 3%, or 100 fps with most bullet weights. Not really a huge jump.
He had much to say as well about shooters who insist that the .257 Roberts works best in long actions so one can have a full three-inch OAL. That gives a four percent increase in capacity, and therefore a massive one per cent, or 30 fps, velocity increase.

Yeah, you need the new rifle. Go for something a bit less common....8mm Mauser?

I spent many years shooting a 257 Roberts before curiosity got the better of me and I had it rechambered to the Ackley round and I couldn't be happier with it.
As far as fireforming being extra work and cost, how can that be when all you have to do is chamber a loaded 257 Roberts round, fire the damned thing and eject a fireformed Ackley case ?
Velocity increase is more than 3% with a lot of bullet weights and with lighter bullets it is very close to a 25-06.
Another plus with the Ackley is greatly reduced case trimming.
I'm on my second 275 Ackley and my 25-06 usually sits in the safe.

Don't get me wrong Kilo Charlie, I respect your opinion, just mentioning my personal findings, and yes to anyone interested in the 257 Roberts it is an excellent round.... I'd buy another in a heartbeat !

 

[KDX]

I read a lot of interesting info on the Roberts, most from John Barsness. He was once a devotee of the AI version and then gave it up as not enough ballistic improvement to justify the extra work of fireforming, and the attendant costs of rechambering and fireforming. The gain in powder capacity is about 12%, and given that velocity increases at one-quarter the increase in powder capacity, velocity increase is about 3%, or 100 fps with most bullet weights. Not really a huge jump.
He had much to say as well about shooters who insist that the .257 Roberts works best in long actions so one can have a full three-inch OAL. That gives a four percent increase in capacity, and therefore a massive one per cent, or 30 fps, velocity increase.

Yeah, you need the new rifle. Go for something a bit less common....8mm Mauser?

The guy who wrote this article would probably disagree with you.

 

[SuperCub]

you have just given an exact description of the old faithful, .243 Winchester!
Only the 243 is a tad better ballistically, because of the slightly smaller diameter bullet.

Very true, but no one actually likes the 243. OTOH the 257 is VERY desirable to a gun nut, not to mention ..... COOL!

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