is there such a thing as 6-300wm?
- Thread starter cath8r
- Start date
240 Gibbs is hot hot, so that would be a boomer. I can't imagine it would be much off the 6mm WSM, minus esthetic differences.
There is such out there. Between Dave Kiff at PTG for reamers/HS guages and Clay at Prophet River ordering Redding custom dies, most anything is possible. I have a. 6.5 RUM, its fast and hard on the throat too. Mostly, cause I choke up over 140 SMK's reading 3600FPS on the Chrony, but whatever. If you can, start with an donor action that you can build into something else when the moment passes and you want something else.
I'd recommend a Rem 700 and a very, very good barrel.......
Custom tooling should cost $250-300, dies $150-200, so $4-500 more than a custom in a normal caliber.
Add in the cost of a barrel blank and you are $1000 into your given wildcat, so make sure you have everything figured out before you start building.
There is such out there. Between Dave Kiff at PTG for reamers/HS guages and Clay at Prophet River ordering Redding custom dies, most anything is possible. I have a. 6.5 RUM, its fast and hard on the throat too. Mostly, cause I choke up over 140 SMK's reading 3600FPS on the Chrony, but whatever. If you can, start with an donor action that you can build into something else when the moment passes and you want something else.
I'd recommend a Rem 700 and a very, very good barrel.......
Custom tooling should cost $250-300, dies $150-200, so $4-500 more than a custom in a normal caliber.
Add in the cost of a barrel blank and you are $1000 into your given wildcat, so make sure you have everything figured out before you start building.
Last edited:
I have a 240 Gibbs, and built a 6mm Mach IV a while back. That is a 7mm Rem Mag necked down to 6mm with the shoulder pushed forward and the case improved. The round was scary fast, designed around the 85gr Barnes X bullets by Ross Seyfried. Basically a 4000fps laser beam. - dan
As with all seriously overbore cartridges, there are diminishing returns. There is a limit of velocity that can be attained from a conventional cartridge/bullet combination, and making the case bigger and bigger doesn't keep pushing velocity up. The limit is around 5,000 fps.
But they sure are a lot of fun
Look up 22 Eargesplitten Loudenboomer (22/378) that only achieved 4600 fps. Might do a little bit better with some of the newest powders.
And of course the current velocity champ, the 17 Flintstone Super Eyebunger (17-250)
But they sure are a lot of fun
Look up 22 Eargesplitten Loudenboomer (22/378) that only achieved 4600 fps. Might do a little bit better with some of the newest powders.
And of course the current velocity champ, the 17 Flintstone Super Eyebunger (17-250)
Last edited:
This.
As far as the .240 Weatherby goes, not even close - it has less capacity than the .30-06. In this game of diminishing returns, however, it actually isn't too far off what the OP's cartridge would do. With some of the new powders, and perhaps a really fast twist barrel, and maybe Chinchaga bullets' 126 grain 6mm bullets, it would be interesting, and . . .umm, . . . flat!
The 240 Gibbs has 68gn capacity, the 240 Weatherby 63gn, the .244 H&H Magnum has 83gn, with a 30 inch bbl and 74gn of N570 quickload predicts 3800fps for a 90 gn Berger VLD, that is if the bullet stays intact !
Such a cartridge would be extremely close to a 257 Weatherby in performance: 3600fps for a 100gr bullet out of a 24" barrel!
A 25 or 26 caliber cartridge would be much more practical but you don't sound like the practical type of guy
Alex
A 25 or 26 caliber cartridge would be much more practical but you don't sound like the practical type of guy
Alex
SavageLapua
CGN Regular
- Location
- Mining brass near Red Deer
I know this is no 6mm... But how about a 6.5mm Allen Mag
Allen Magnum Wildcats
SL
Some of the modern high performance members of the 6.5mm family
Left to Right: 6.5mm W.S.M., 264 Winchester Magnum, 6.5mm S.T.W., 6.5mm Allen Magnum and 338 Remington Ultra Magnum case which is used to form the 6.5mm Allen Magnum. The 6.5mm A.M. boosts velocity by 200 fps with all bullet weights.
Parent Case: 338 Remington Ultra Magnum
Recommended Bullets: 100 and 120 grain Ballistic Tip, 130 and 140 grain Accubond, 142 gr Sierra Matchking.
Recommended Powders: Ramshot Magnum, H-US869, WC-860 and WC-872
Recommended Primers: Federal 215 Large Rifle Magnum
Velocity Performance:
Bullet Weight Muzzle Velocity(30" barrel length)
100 gr. 4100 fps
120 gr. 3800 fps
130 gr. 3700 fps
140 gr. (Accubond) 3550 fps
142 gr. 3550 fps
Ballistic Performance:
Bullet Weight: 120 gr Accubond @ 3800 fps, 250 yard zero, 10 mph
Yardage velocity wind drift Energy TOF(sec)
400 2879fps 8.4" 2209ft/lb 0.363
600 2484 20.1 1644 0.587
800 2122 38.3 1199 0.849
1000 1794 64.6 857 1.156
Bullet Weight: 142 gr. ULD RBBT @ 3550 fps, 250 yard zero,10mph
Yardage velocity wind drift energy TOF
400 2863 fps 6.8" 2584 ft/lbs 0.376
600 2549 16.1" 2049 0.598
800 2255 30.4" 1603 0.848
1000 1978 50.6" 1233 1.132
1200 1714 78.2" 926 1.458
Recommended Uses: The 6.5mm Allen Magnum is designed to be a dedicated hunting round for use on light to medium big game at moderate to long range. With 100 to 130 gr bullet weights, the 6.5mm Allen Magnum is extremely flat shooting but the heavier 140 and 142 grain bullets perform better ballistically at long range. The 6.5mm A.M. is not intended to be used as a high volume varmint round.
Effective Range: When using 100 to 130 grain bullets, the 6.5mm AM can effectively harvest light to medium big game species out to 600-700 yards with easy. With heavier, higher BC bullets, it offers legit 800 to 1000 yard reach on pronghorn to smaller deer species.
Pros: Extremely flat shooting, good selection of commerical bullets, very low recoil.
Cons: Cases are somewhat involved to form, barrel life is relatively short and suitable reloading powders are somewhat limited.
Allen Magnum Wildcats
SL
It was a little faster than my 257, but that could easily be simply the variations between two similar rifles. When I do it again I will use a longer barrel. - dan
You're going about it all wrong, all you really need to try out a wildcat is the reamer and a barrel. Built many, many and unless it is something I'm going to keep and use, I never buy HS gauges, dies or any of that other stuff, in fact I usually look for a take off barrel for 50-100 bucks and a finish reamer from Dave is 129 bucks. For dies I have more than 100 sets so I can usually find a combo to make brass to fit or I butcher a garage/gun show 15 dollar set to make brass initially. In this case 6mmX300 wm it's super easy to headspace a belted mag with out gauges, then run your 300 WM brass into a set of 264 WM dies far enough to neck down then I happen to have a set of 243 WSSM dies I bought on sale 'cause nobody ever wanted a 243 WSSM anyway, for 25 bucks, run them into this die until bolt closes and voila 6mmX300WM cartridges. Good chance you'll have to reduce neck thickness on this case and if you want to use W-W brass you'll probably need to anneal the necks and shoulders.
If you want to stick to 24 or 26" barrel chances are you can find a take off 243 or some of the bench boys might have some longer 6X47 or the like, personally I wouldn't bother with anything less than 30" on a cartridge like this or you may as well stick with a 6mm/284.
