QUARTER BORE SST??

[RockyMtnMT]

I have to say it. It's not the only 7 twist bullet out there. Our 128g Hammer Hunter is a dedicated hunting bullet for 7 twist. Lead free and stellar accuracy and terminal performance. Target bullets in the works.

Steve

 

[257 Blackjack]

I have to say it. It's not the only 7 twist bullet out there. Our 128g Hammer Hunter is a dedicated hunting bullet for 7 twist. Lead free and stellar accuracy and terminal performance. Target bullets in the works.

Steve

The more the merrier IMO. As market volume in 25 gets bigger everybody wins! Maybe not the barrel shops spitting out 6mm tubes like it's going out of style lol.

 

[yorke-1]

I have to say it. It's not the only 7 twist bullet out there. Our 128g Hammer Hunter is a dedicated hunting bullet for 7 twist. Lead free and stellar accuracy and terminal performance. Target bullets in the works.

Steve

This bullet is the reason I haven't decided what to do with the .257 blank I ordered. I'm just waiting to hear some more feedback about how the 131 Blackjack bullet holds up at higher velocities. I know the Hammers will hold up to 3400 fps, even in a 1-7" twist.

 

[RockyMtnMT]

This bullet is the reason I haven't decided what to do with the .257 blank I ordered. I'm just waiting to hear some more feedback about how the 131 Blackjack bullet holds up at higher velocities. I know the Hammers will hold up to 3400 fps, even in a 1-7" twist.

We are running the 128g Hammer Hunter in our 7" twist 257 Bee with Norma MRP at 3250fps. With .244 g7 bc from shot drops makes for a reliable killer to 900y at 3000' elevation.

Steve

 

[yorke-1]

We are running the 128g Hammer Hunter in our 7" twist 257 Bee with Norma MRP at 3250fps. With .244 g7 bc from shot drops makes for a reliable killer to 900y at 3000' elevation.
Steve

The original idea I had was a case a little closer to either the 6.53 Scramjet or STW in capacity, so 3350fps + is a very realistic number.

My PRS super star wannabe buddy want's me to do one of the more mild 25s (25 Creedmoor or 25x47 Lapua) but I kind of like the idea of a 25 SST if I don't go full overbore.

 

[257 Blackjack]

The original idea I had was a case a little closer to either the 6.53 Scramjet or STW in capacity, so 3350fps + is a very realistic number.

My PRS super star wannabe buddy want's me to do one of the more mild 25s (25 Creedmoor or 25x47 Lapua) but I kind of like the idea of a 25 SST if I don't go full overbore.

The 25 SST should nearly achieve or surpass the target velocity you reference depending on barrel length, and do it significantly more efficiently than the 6.53 Scramjet or STW.

You can't talk overbore guys out of being overbore lol, but achieving target velocity as easily as possible helps everything. The SST will still look real cool and shoot plenty fast so it could still feel overbore.

The 131 ACE running at 3000 fps which should be achievable from F-Class type 25x47s and will be achievable from PRS Match style 25 Creedmoors is plenty of ballistic efficiency for nearly every realistic use. It's basically doing what a 28-30" 260 AI used to do but in a shorter, more efficient combination. It's outdoing what 30" 284's and Shehane will do with 180's.

That being said I know a 25-260 AI / 25-308 AI / whatever name you want to call it will run our 131s to 3200 fps in Match barrel lengths. My 260 AI used to launch 140s at 3111 fps from 28" using Palma brass. I never tried 130 gr 6.5s in that 260 AI due to obvious BC loss.

I'll be necking down my 260 AI brass to 25 cal and sending the dummy round off tomorrow morning to have a reamer made since I have a pile of 260 AI Palma laying around.

This cartridge will be my F-Class setup until the 25 Blackjack prototyping, testing, and production is completed.

Let us know if you do go 25 SST - there's a number of guys that are, including me on an Impact 737, and I'm trying to keep track of them for feedback.

 

[MudRunner2005]

The 25 SST should nearly achieve or surpass the target velocity you reference depending on barrel length, and do it significantly more efficiently than the 6.53 Scramjet or STW.

You can't talk overbore guys out of being overbore lol, but achieving target velocity as easily as possible helps everything. The SST will still look real cool and shoot plenty fast so it could still feel overbore.

The 131 ACE running at 3000 fps which should be achievable from F-Class type 25x47s and will be achievable from PRS Match style 25 Creedmoors is plenty of ballistic efficiency for nearly every realistic use. It's basically doing what a 28-30" 260 AI used to do but in a shorter, more efficient combination. It's outdoing what 30" 284's and Shehane will do with 180's.

That being said I know a 25-260 AI / 25-308 AI / whatever name you want to call it will run our 131s to 3200 fps in Match barrel lengths. My 260 AI used to launch 140s at 3111 fps from 28" using Palma brass. I never tried 130 gr 6.5s in that 260 AI due to obvious BC loss.

I'll be necking down my 260 AI brass to 25 cal and sending the dummy round off tomorrow morning to have a reamer made since I have a pile of 260 AI Palma laying around.

This cartridge will be my F-Class setup until the 25 Blackjack prototyping, testing, and production is completed.

Let us know if you do go 25 SST - there's a number of guys that are, including me on an Impact 737, and I'm trying to keep track of them for feedback.

This is what I've been wanting to build... It's basically a modernized version of the .257 Roberts AI. And thats should make for a perfect short-action 1/4-bore using these new bullets. That's more like what my buddy was wanting to build for his daughters and wife to learn to hunt. Even less recoil than the .25 SST. And you can buy Lapua Palma .260 Rem brass everywhere for fire-forming, so that would make life super simple.

Basically, if you build a .260 AI necked down to .257, and give it .010" body taper and a 40º shoulder, I'd be highly interested in a reamer and die set.

 

[HARPERC]

The more the merrier IMO. As market volume in 25 gets bigger everybody wins! Maybe not the barrel shops spitting out 6mm tubes like it's going out of style lol.

Most of them will adapt. Well until some fool want's a 1-6" twist anyway!

 

[yorke-1]

The 25 SST should nearly achieve or surpass the target velocity you reference depending on barrel length, and do it significantly more efficiently than the 6.53 Scramjet or STW.

You can't talk overbore guys out of being overbore lol, but achieving target velocity as easily as possible helps everything. The SST will still look real cool and shoot plenty fast so it could still feel overbore.

The 131 ACE running at 3000 fps which should be achievable from F-Class type 25x47s and will be achievable from PRS Match style 25 Creedmoors is plenty of ballistic efficiency for nearly every realistic use. It's basically doing what a 28-30" 260 AI used to do but in a shorter, more efficient combination. It's outdoing what 30" 284's and Shehane will do with 180's.

That being said I know a 25-260 AI / 25-308 AI / whatever name you want to call it will run our 131s to 3200 fps in Match barrel lengths. My 260 AI used to launch 140s at 3111 fps from 28" using Palma brass. I never tried 130 gr 6.5s in that 260 AI due to obvious BC loss.

I'll be necking down my 260 AI brass to 25 cal and sending the dummy round off tomorrow morning to have a reamer made since I have a pile of 260 AI Palma laying around.
This cartridge will be my F-Class setup until the 25 Blackjack prototyping, testing, and production is completed.

Let us know if you do go 25 SST - there's a number of guys that are, including me on an Impact 737, and I'm trying to keep track of them for feedback.

I'm a short barrel guy, so if I can hit 3350fps from a 25" barrel I'd consider it a win. The 25 SST would be a great fit in a specialty pistol though with an 18" barrel. That way I could still hit the 2950fps velocity window and keep it in a compact weapon.

The best way to regain velocity after hacking 10"+ off of a barrel is to increase the powder capacity significantly. In the specialty pistols with 18-20" barrels a 30-06 will match a 308, 300 WSM matches a 30-06, 300 RUM matches the 300 Win Mag. At the extreme end of the spectrum, an 18" 6.5x338 RUM improved will beat 264 Win Mag and a 338 SnipeTac beats 338 Lapua. Efficiency is over rated! LOL

 

[MudRunner2005]

I'm a short barrel guy, so if I can hit 3350fps from a 25" barrel I'd consider it a win. The 25 SST would be a great fit in a specialty pistol though with an 18" barrel. That way I could still hit the 2950fps velocity window and keep it in a compact weapon.

The best way to regain velocity after hacking 10"+ off of a barrel is to increase the powder capacity significantly. In the specialty pistols with 18-20" barrels a 30-06 will match a 308, 300 WSM matches a 30-06, 300 RUM matches the 300 Win Mag. At the extreme end of the spectrum, an 18" 6.5x338 RUM improved will beat 264 Win Mag and a 338 SnipeTac beats 338 Lapua. Efficiency is over rated! LOL

Actually, in the world of wildcatting and cartridge design, it's everything.

 

[HARPERC]

[QUOTE="yorke-1, post: 1458406, member: 11960"......At the extreme end of the spectrum, an 18" 6.5x338 RUM improved will beat 264.Efficiency is over rated! LOL.....[/QUOTE]

How many of those 10-18" does one have to fry before a big accuracy change occurs?

 

[MudRunner2005]

How many of those 10-18" does one have to fry before a big accuracy change occurs?

My guess would be UNDER 500 rounds of barrel life.

 

[HARPERC]

I can't say "efficiency" isn't a factor for many of P.O. Ackley's branch of the family wildcat tree, but there is an entire branch with the same longevity, that faster, further, heavier, is more important to.
How would you measure accuracy, and how much decline has to occur before it's meaningful for you?

 

[RockyMtnMT]

Actually, in the world of wildcatting and cartridge design, it's everything.

York-1 actually designs his own reamers and builds the rifles and pistols. He then plays the the elr game very well with them.

Just sayin...

Steve