Too much time on my hands and too much imagination.
I was thinking about a 25 on the 22 Nosler case and it started to make some sense (If wildcats make sense to you). About 20% case capacity increase and 150-200 FPS increased velocity over a 24-45 Sharps. I thought if you could rechamber a 25-45 and use off the shelf mags https://www.midwayusa.com/product/2228516192/ you could have some good thump for not too much investment. I need some input on shoulder angle and position if anyone has a cartridge creator program. I had the idea of using the same shoulder position of the 22 Nosler and the neck junction of the 24-45 for ease and cost savings. What do you think?

I have the 25-45 Sharps in my QD but haven't yet created the 22 Nosler (didn't do the 24 Nosler either). Will do both and see if I can post the schematics.

Big question for your thought process... What is your target bullet weight? And is that C&C or monolithic construction?

Reason I ask is that the body of the 24 Nosler is shorter than the 22 Nosler but it also uses longer bullets.

Pending that, my comment is that it'd be easier to just upsize the selected Nosler to 25 caliber maintaining the Nosler' shoulder position and shoulder angle. Then you could just swap out the reloading die bushing(s) for the correct one(s) for 25 caliber.

Seems that'd be the easiest and cheapest way to go...

Thanks for the help Capo!
Let’s just play with the 25-22 Nosler right now. As for bullets, I was thinking for this cartridge light to medium weights since this would not shine with heavier bullets. a 25-24 nosler would be better for high BC bullets but that is the idea behind the 24 Nosler already.

I created your 257 Bobcat, aka: 25/22 Nosler, in QuickDesign (QD) and imported into QuickLOAD (QL) for "what ifs". For drop data, the QL results were imported into QuickTARGET (QT) for comparison.

87gr Sierra SP 1610 with 24" barrel:
* The 25-45 Sharps (31.00 H2O Overflow): 3000 fps from 24" barrel (factory specification)
- Drops: 100yds = -2.11", 200yds = -9.05", 300yds = -22.34"
Regarding the 25-45 Sharps stated factory loading velocity, all powders that I used to obtain the specified 3000 fps had pressure levels above the SAAMI PMax 60000 psi...

* 257 Bobcat (38.87 gr H2O Overflow):
- 31.00 gr Alliant AR-Comp *C*T (101.8 % fill) = 3098 fps @ 52831 psi
- Drops: 100yds = -1.97", 200yds = -8.47", 300yds = -20.74"

Using Sierra 100 gr SP 1620:
25-45 Sharps: 22.25 gr Alliant RL 10X *C (102.7 fill) = 2672 fps @ 54206 psi
- Drops: 100yds = -2.62", 200yds = -11.31", 300yds = -27.55"
25-45 Sharps: 22.00 gr Alliant RL 7 (99.0 fill) = 2668 fps @ 58922 psi
- Drops: 100yds = -2.40", 200yds = -11.42", 300yds = -27.66"
257 Bobcat: 29.25 gr Alliant AR-Comp *C*T (99.9 fill) = 2886 fps @ 53890
- Drops: 100yds = -2.11", 200yds = -9.53", 300yds = -23.32"

Using Sierra 117 gr SP 1640:
25-45 Sharps: 20.50 gr Alliant RL 10X *C (100.4 fill) = 2419 fps @ 53164 psi
- Drops: 100yds = -3.28", 200yds = -13.70", 300yds = -32.78"
25-45 Sharps: 20.50 gr Alliant RL 7 (96.7 fill) = 2426 fps @ 58891 psi
- Drops: 100yds = -2.87", 200yds = -13.29", 300yds = -31.97"
257 Bobcat: 27.00 gr Alliant AR-Comp *C*T (96.5 fill) = 2626 fps @ 53019
- Drops: 100yds = -2.51", 200yds = -11.53", 300yds = -27.55"

Note: I ran pressure levels for the 25-45 Sharps using a 55000 psi PMax and a 60000 psi PMax. The 257 Bobcat pressure levels were maintained at the 22 Nosler’s 55000 psi PMax.

And finally…
I did create a 25/24 Nosler in QD and imported it into QL for comparison to the 25/22 Nosler, aka: 257 Bobcat. For perspective:
25/22 Nosler (257 Bobcat): Shoulder to COAL = 0.871”
25/24 Nosler: Shoulder to COAL = 1.076”

* 115 gr Berger VLD 25513 (1.188” length)
25/22 Nosler: 24,40 gr Alliant RL 10x *C (92.8 fill) = 2583 fps @ 53695
- Drops: 100yds = -2.74", 200yds = -11.20", 300yds = -27.32"
25/24 Nosler: 22.50 gr Alliant RL 10x *C (97.0 fill) = 2520 fps @ 53775
- Drops: 100yds = -2.93", 200yds = -11.95", 300yds = -28.80"

*131 gr Blackjack Hammer (1.415” length):
25/22 Nosler: 22.20 gr Alliant RL 10x *C (93.7 fill) = 2503 fps @ 54068
- Drops: 100yds = -2.85", 200yds = -11.87", 300yds = -27.89"
25/24 Nosler: 20.25 gr Alliant 10x *C (98.3 fill) = 2427 fps @ 54052
- Drops: 100yds = -3.05", 200yds = -12.80", 300yds = -29.76"

* Assumption for this “what if” is that the 131gr Blackjack Hammer will properly seat in both cartridges while still maintaining the 2.260” COAL…

Thanks Capo!
Those figures line up with what I had guessed. The light to medium bullets seem to shine with up to 200 FPS gain over the 25-45 and pretty flat shooting to 300 yards with up to 100 grain bullets. The 257 Bobcat outshoots the factory 24 Nosler pretty good too. That is enough to put the fear in some deer and make the pigs squeal. In a bolt action with longer OAL the high BC bullets would become more desirable. I think there is a decent argument for this cartridge. What are your thoughts?

Boomie,

This was an interesting “look” into the AR15’s limitations:
1) bolt diameter and bolt composition/strength - safety limitations with reference t cartridge PMax pressure...
2) magazine’s COAL limitations - one line of magazines allow a 2.336” COAL vs the standard 2.260” COAL...
3) standardized barrel lengths - 16” to 20” barrel lengths vs bolt rifles’s typical 22” to 26” barrel lengths...
All of these are limiters to the performance capability of the AR15 platform.

And of course all of the issues are well known but to attempts to eliminate these limitations typically result in much heavier and bulkier firearm.

We also are aware that the military, and their contractors, have enhanced the performance of the M16/M4 and newer variants by enhancing the strength of the bolt assembly to safely accommodate enhanced performance of the 5.56 cartridge pressure increase from 55000 psi PMAP to 60000 psi PMap.

Now back to your question...

If the desired end result is to safely meet or exceed the performance of the venerable 250 Savage cartridge in the AR15 platform then the 257 Bobcat (25/22 Nosler) cartridge accomplishes this.

The 250 Savage gained it notoriety by pushing an 87gr .257 caliber soft-nose spitzer bullet at 3000 fps. I don’t recollect the relating CUP pressure PMap but it certainly is not above a Piezo’ 55000 psi PMap.

Unless the factory 25-45 Sharps 87gr ammunition is loaded with a “superformance” powder not available to the public, or not available in QL v3.9, then it is loaded to a pressure level between 62000 psi and 63000 psi to reach its 3000 fps performance with a 24” barrel length loaded at a 2.260” COAL.

The 257 Bobcat is able to exceed 3000 fps at under 55000 psi with a 24” barrel length loaded at a 2.260” COAL. Loading this cartridge to a 60000 psi PMax results in a higher velocity with greater down-range performance.

And yes, using magazines having a 2.336” COAL ability could allow greater performance or perhaps a reduction in pressure levels while maintaining velocity levels. I did not check this out but can later today.

That’s my thoughts...

Great observations
Worth mulling over a bit
Those 131 Blackjack Hammers would be getting 6.5 Grendel adjacent performance!
That could be a potent package for longer OAL mags or bolt actions like the CZ 527. 600 yard supersonic?

On a side note... Do you think the 22 Nosler necked to 308 would push the 160 grain Hornady FTX 30-30 bullets @2300 with a 2.26” OAL and case trimmed to 1.75”? I don’t know if there are off the shelf mags that would feed these but a 30-30 equivalent on the 22 Nosler case would be interesting. I think the 30-30 shortened to 1.75” on the 22 Nosler case would feed from off the shelf mags and be a fun round but I am wondering if the 30-22 Nosler would be better at attaining traditional 30-30 performance.

Swell thread guys. Sounds like a capable wildcat.

i THINK i HAVE A REAMER FOR THIS ONE, NEVER USED IT AND DON'T KNOW WHERE IT CAM FROM

Did Santa put it in your stocking?
You must have been good this year!
Any thoughts on this wildcat idea Mr. Kobe? I think this could be a sweet round in a mini action but would need your skills to feed well with the rebate. My main thought was an AR15 conversion. Bill, you have good taste