25 Creedmoor

[TX Badger]

Using Nosler load data wouldn't it be a better comparison to use the 100 grain bullet for both? Seems that would apples to apples it since they would both be 25 calibers at the point of comparison. If I am right that's 50.9 to the Creed and 56.6 to the Bob AI. If I am wrong that's fine I've been wrong before lol. Personally I would go off my own water test as it's something I can see and repeat. I think the 25 creed would be fun and I know the Bob AI is fun but sourcing brass isn't my favorite for the Bob.

I was trying to account for how much capacity would be lost to the bullet. The 100s in each probably would not seat past the neck much. So I selected the heaviest/ longest in each caliber. Then you'd have to figure the 131 is going to be longer than the 120 .257 bullet so you'd lose a gr. or 2. I don't have the measurements handy but I'd bet the 131 ace would be similar length to a 140 .264. I know it's a lot guess work but I bet it's not far off.

 

[codyadams]

I was trying to account for how much capacity would be lost to the bullet. The 100s in each probably would not seat past the neck much. So I selected the heaviest/ longest in each caliber. Then you'd have to figure the 131 is going to be longer than the 120 .257 bullet so you'd lose a gr. or 2. I don't have the measurements handy but I'd bet the 131 ace would be similar length to a 140 .264. I know it's a lot guess work but I bet it's not far off.

To throw another wrench into this.....
If your having a custom twist barrel specifically for the 131 anyway, you would be a fool not to have it throated for the 131's. So, you actually wouldn't loose any capacity.

 

[TX Badger]

To throw another wrench into this.....
If your having a custom twist barrel specifically for the 131 anyway, you would be a fool not to have it throated for the 131's. So, you actually wouldn't loose any capacity.

That's for sure, unless you wanted it to mag feed in a short action.

 

[okie man]

You guys kill me! All the quarter bore bashing I've heard for years now we put creedmoor begins .25 and it's the coolest! Bet if you put it behind 308 it would make Winchester's version obsolete! Lmao

 

[TX Badger]

You guys kill me! All the quarter bore bashing I've heard for years now we put creedmoor begins .25 and it's the coolest! Bet if you put it behind 308 it would make Winchester's version obsolete! Lmao

I've been pushing for this development for .257 for years. I'm not a basher. And I don't think it's a creedmoor thing, at least it isn't for me. I just want a cartridge where I can get good brass and push the new 131s. So I'm debating x47, creed, and x284....

 

[okie man]

It's been done with the 308 case and rsum. Like a lot of other cartridges over time, some stick, some don't. None really do more than others! Pick a speed you wanna push a bullet of any caliber and there's a cartridge that already does it!

 

[CA48]

25 Creedmoor with the 131gr BlackJack COAL 2.920"

 

[Deleted member 48126]

25 Creedmoor with the 131gr BlackJack COAL 2.920"
View attachment 108939
View attachment 108940

That's awesome! Thanks for sharing!

 

[xsn10s]

Well that just made the 6CM and 6.5CM market drop.

 

[reubenski]

2.920? That should allow you to chase the lands for a good 500rds before you start smashing your tips against the front of the mag.

 

[CA48]

That was just a bullet I seated in a case for a visual. Would probably be better with a COAL of 2.900" or less. But I haven't put much thought into it yet.

I'm using accurate mags that allow 2.980" oal. But if I was to run 2.920" and burn out .060" of throat in 500 rounds something is seriously wrong with that barrel. Plus I will most likely be jumping the bullet some.

 

[TX Badger]

Well maybe there won't be much loss in usable capacity...

 

[reubenski]

I have tracked throat erosion on 6 Dashers, 6.5x47's, and a 6SLR. .004-5" per hundred is the norm. A little less in the first 4 to 500 rds but they usually pick up. My current 6SLR (243W dimensions) has a .075" freebore. It starts at 2.820" on a new throat. After 1200rds now I'm at 2.880". I hope to get to 2000 legit 1/4 moa rounds so I'd be at 2.920" by the end.

You'll want to have a short FB on a bullet that long. I'd seat that bearing surface/ boattail junction all the way down to the neck/ shoulder junction and see what the COAL is. At 2000rds I'd expect somewhere in the neighborhood of .100" erosion. You've got a .270" neck on that CM case. I'd want at least half the neck holding the bullet by the end, so realistically you could start the FB so the Blackjack is .030" up from the neck shoulder junction when seated agaisnt the lands, that way when it's new you can jump at least .025".

 

[User4302021]

It's been done with the 308 case and rsum. Like a lot of other cartridges over time, some stick, some don't. None really do more than others! Pick a speed you wanna push a bullet of any caliber and there's a cartridge that already does it!

25 Creedmoor is the new 257 Roberts. It is kind of comical how ideas are reborn!

I have always loved the quarter bore and I really hope this takes off, if for no other reason than to finally have another quarter bore in the public conscience.