Quarter Bore Resurgence
- Thread starter 257Roberts
- Start date
I do like your number with the 131s and the 7.5 barrel. I'm doing one up the same for my 25-284 in a 24". Sure hope 3100 is possible with accuracy in this setup. Been hearing it's pretty common to get 3200 with a 26" barrel so guessing it's realistic. Those Blackjacks are pretty awesome bullets. Hornady says nothing on the drawing board for a heavier .257 bullet. Berger's 133/135 look pretty good right now also
None of those will be 2000rds accurately. 1200-1500 if you’re lucky. For the high octane calibers I strongly urge to run a maximum of 1:7.5tw. 1:7.75-1:8 would be better if going after the 3200+ range. Keep it around 295k-305k RPM.
The main thing to note with the longer .25s is that you will likely need a custom reamer for the longer freebore (unless going 25CM or 25x47, JGS and Manson have you covered) you will likely want to spec 0.131”+ of freebore to optimally seat the bullets out.
In this case, when you don’t stick to SAAMI OALs the regular ‘Bob will definitely not keep up with the Ackley’Bob. I can run mine over 3200 but it seems to like ~3070 and ~3160 with the Blackjack.
Another simple option would be to go with a 25x55 Swede. Cheapest of Lapua Brass and just a bushing swap in the dies. Good powder volume and will be capable of 3000 no problem in a modern action with a good barrel.
I have similar plans bouncing around in the attic for a SA ‘cat based on the 284 or ???. Maybe next years project...I have been seriously tossing the 25 Souper idea about.
IF we can come up with reamer & dies, i'd like to give Fuj's SA284 a try in SA25-284.
Or whatever he names it.
Years ago, my buddy and I got on the WSM bandwagon and built 25-300WSM rifles, both on Win Model 70 Classic long actions.
Great cartridge but finicky. Have been a 25-06 fan for decades now and own 3.
If you want to push fast twist heavy bullets, you need at least a SAUM to get the desired 3000+FPS. The WSM is better and faster.
Food for thought.
Cheers.
Great cartridge but finicky. Have been a 25-06 fan for decades now and own 3.
If you want to push fast twist heavy bullets, you need at least a SAUM to get the desired 3000+FPS. The WSM is better and faster.
Food for thought.
Cheers.
My last 6.5-284 barrel I had ran to 1800 still carrying .5. Impressive IMO. The current barrel is at 1200 and still doing excellent. Hoping for the same or even more as I didn't run it past 2950 w/4831sc. May get 2000 from it. Pretty sure I won't get that much mileage from my 25-284. I'll run it as fast as I can and still maintain .5" accuracy. Sometimes it's not what we expect and other times much faster. Time will tell. Luckily it's a hunting rifle so either way, it'll last year's before replacing it.
The .25 Creedmoor is nearly identical and requires no fire forming. I had a .250AI and really liked it but there is no way I’d consider one over the .25 Creedmoor nowadays.
John
For some reason I have it in my mind that the Creedmoor is shorter? I am sure I am wrong.
Do you know where I can find dimensions for a 25 Creedmoor? Been looking...
I agree, if the 25Creed is close to the 250AI, there is no way I'd pick the Ackley over something easier to work with.
Post#26 has a cartridge size comparison. I think you posted it. Looks like the 250 is quite a bit larger case. I don't think that comparison chart is accurate. The 25CM has more case capacity than a 250 does.
I think it's only 2-3 grains of H2O different. The ackley would make it very close. Creedmoor having 44-45 vs 42-43 for the
Standard 250.
According to Sierra manual- 5th edition, the .250 AI has "about 10% more case capacity than the parent case. The case has one of the greatest gains from the Ackley design at 17% velocity increase. The 6.5 x55 closely follows by 13.7%. I have both and would do it all over again. I don't have a Creedmore to compare but I believe the capacity would be somewhat less.
Ya I read online those H2O capacities. They weren't from my experience. I just was trying to get a comparison. I'm sure yours is more accurate. Seems like they may be fairly close tho in the non-ackley 250.
Agreed. However AFAIK I am limited to Win. and RP brass. Also, of note is that the industry max pressure for the 250 Savage is set at 45k CUP in deference to lever action rifles. Quite sure the Creedmoor exceeds that by quite bit. The Creedmoor wasn't around when I built the .250 AI.
Very good point. Certainly gives the advantage to the CM. These days it seems the 250 to the 25CM is like the 260 to the 6.5 CM, such a shame. In your case I see the point.
Big fan of the .257. Been on this weird .284 kick as of late.
(SA284, and Phase-1 threads) I have sample lots of the
original release Black Jacks. Gives me a tug now and then.
I'm not much of a speed demon but this short .284 case I
just finished up has a water capacity of 46.9, and 6GT has
about just over 43 grs of the wet stuff. Hmmmnnnnnn.
I doubt anything this year though.
(SA284, and Phase-1 threads) I have sample lots of the
original release Black Jacks. Gives me a tug now and then.
I'm not much of a speed demon but this short .284 case I
just finished up has a water capacity of 46.9, and 6GT has
about just over 43 grs of the wet stuff. Hmmmnnnnnn.
I doubt anything this year though.
Ccrider
Gold $$ Contributor
I have hunted deer with a .25 cal for the last 20 years -.257stw. 92 to 100gr. bullet at 3900 plus fps is hard to beat. Devastating on deer.l Flat shooting low recoil. Very accurate rifle. Will shoot .25 moa with just about any load.
While it is my first choice for a hunting rifle by far, it is not a benchrest gun.
While it is my first choice for a hunting rifle by far, it is not a benchrest gun.
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.