Pondering a wildcat build

[oregonmarkv]

I had a 270 win. reamed to 270 Gibbs years ago and even with a 22in barrel I believe it was running about 3350fps with a 130bt and RL-22 powder.

[Northern hunter]

The 6.5 in the 06 case has been with us 12 years before the 270 win, it was known as the 256 Newton. A- square standardized it in 1997 I believe, but only one company that I know of builds rifles in this caliber that is Cooper of Montana with no manufacturers of the ammo. Nosler at one time made the 6.5-06 a-square brass. Some day soon I hope that you can buy it off the shelf.

[dubyam]

Another great -06 based 6.5 is the 6.5-280RCBS Improved. Fred Huntington developed it back in the last 1950s, shortly after the 280Rem was introduced. I've been trying to talk myself into this one for years, and almost did so a few years ago, but the gunsmith I was going to use talked me out of it based on case forming difficulties for which he didn't care, so I postponed it. It's still bugging me, so I'm likely to revisit it sometime. Maybe in a rebarreled Colt Light Rifle or a 6-lug Mark V to build a lightweight platform. I suspect it would be a ball in the northern Alabama mountains where I hunt - as is my 30-06 Colt Light Rifle - but it might also be a dandy pronghorn and mule deer rifle, too.

[7mmweatherby]

I was comparing 140 gr 6.5 vs 270.....7mm those two shoot flatter per weatherby ballistic chart and 257 sneaks in there with the 80 gr lii flatter

[dubyam]

Everyone here knows I'm a lover of the 270Wby. I'm very likely its biggest fan. And it's also no secret I don't believe the 6.5mm craze will make all these various 6.5s last very long. I suspect all the Nosler rounds will be gone within a decade, though they may be kept alive by Nosler just because. But even I have to admit when you compare equal weight for caliber bullets (with similar sectional densities) you find the 6.5-300Wby to be flatter than any of the short Weatherbys. It's not terribly noticeable out to 500yds, but at 700, 800, 1000, and beyond, the differences become significant.

Comparing a 130gr 270Wby to the 130 or 140gr 6.5 is an illogical comparison,  since they are different weight classes for their respective bores. The true comparison is between the 140gr 6.5, 150gr .277, and 160gr 7mm. Do that, and the 6.5 wins the flatness contest every time. Alternately, compare a 140gr 6.5, 130gr .277, and 140gr 7mm, and the same thing happens.

Can't defy the laws of physics.

[7mmweatherby]

I hear ya Dubyam I was surprised to see the 270 and 7mm compare with 6.5 with all the hype I assumed 6.5 was going win 500 Daytona by a lap but I see its fender to fender race I looking at 140 gr in all three at the 500 yd mark 270 is 21in  7mm is 23 in 6.5 is 23.3 i see 270 being flattest in that weight ,in most hunting situations and shots are well within that range 270 and 7mm awesome hunting cal

[badsection]

I see having your own unique wildcat as a pretty cool idea, just don't make the same mistake the guy did with my long sold Mark V sporter 338 Rem Ultra mag did.  A sub 8lb. rifle, including scope and mounts in a caliber like that made it one of a kind that very few would shoot!   

[musicman]

One of the premier custom gun builders here in the States has been offering the 6.5/.257 chambering for years.  I cannot think of his name, but most of y'all would recognize it.  I think it would be a really versatile cartridge.  But it would be right in the league of the .264 Win. Mag.  One pointless wildcat I would entertain, would be blowing out the 6.5 Swede, and putting a Weatherby shoulder on it.  But it would be about like the 6.5 Remington Magnum, or the 6.5/.284.  Just about everything imaginable has been done with bolt gun cartridges.  Lever gun cartridges still have some gaps to be filled.  Stuff based on the .444 Marlin, .45-70, .450 Marlin, .375 Win., and the .454 Casull cases.  And Marlin or Winchester needs to figure out a beefier action to handle the .460 Smith and Wesson.  That would open up all manner of cool ideas.  .416/.460; wouldn't that be a smoker.  I like Zonie's ideas on the sabots.  I think that someone like Hornady should put a little thought into that direction.  Those would be especially great in lever gun cartridges, but bolt gun as well.  Even the .30 Carbine, with sabots in .22 or 6.5; those would be little sweeties.  I always figured that the BATF put the brakes on sabot development, because then you would have projectiles that could not be "traced" to a specific firearm, unless they found the sabot.  MM

[truck driver + 2]

What put the hurts to sabot rounds like the Remington accelerator was accuracy. The rate of twist in say a .30 cal barrel wouldn't stabilize the bullet once the sabot was left behind. You would have to have a barrel specifically twisted for the sabots and then that would be all you could shoot in it.

[Montucky]

Well I started this thread and let it mature for a while before getting back in. I checked out the link Danno posted. That was cool reading about the speculation and hope of a new weatherby cartridge before it, the 6.5 300, was announced. Didn't get to the end since it's 400 posts long, but a way cool read.

 Glad to know about the custom shops that do it already, good source of die dimensions and stuff. And finding out it's fairly common gives me hope it would be a good build.

And I am pretty set on using the short weatherby as a parent cartridge, mostly because I really like the looks of them. Even though the 06 iterations sound like good performers.

Musicman, I always wanted to do a lever gun that used a magnum case shortened to 1.75 inch. That way I could just take the winmag and weatherby brass with split necks and cut it down and repurpose it for the lever gun. It would basically be a 450 Marlin just a quarter inch shorter. Kind pointless overall but would give used cases a longer use.

[musicman]

The twist rates on the big calibers, which would be the ones benefiting the most to sabot, are for sure too slow to stabilize the smaller calibers.  So the .444 Marlin, .45-70, and .44 Mag. would not work.  There are some common twists though, that ought to work.  I also read that the accuracy problems might have been that although the sabot was spinning at the correct twist, that didn't mean that the actual projectile was; supposedly there was slippage.  And the slippage varied from shot to shot.  Remington tried this, what twenty-five or so years ago.  Maybe with new technology, and a second try, something that would be more consistently accurate could be developed.   I would love to have some saboted .44 magnum rounds that held a little 90-100 gr. .30 Carbine type of projectile, or even a round ball, to dispatch small animals.  I have included a general list of general, but not necessarily all twist rates for common cartridges.  MM

.17 HMR = 1 in 9"
.22 Long Rifle = 1 in 16"
.222 Remington = 1 in 14"
.223 Remington = 1 in 12" (varmint rifle)
.223 Rem./5.56mm NATO = 1 in 7" (AR-15)
.22-250 Remington = 1 in 14"
.243 Winchester = 1 in 10"
6mm Remington = 1 in 9"
.240 Wby. Mag. = 1 in 10"
.25-06 Remington = 1 in 10"
.257 Wby. Mag. = 1 in 10"
6.5x55 Swedish Mauser = 1 in 7.5"
.260 Remington = 1 in 9"
.264 Win. Mag. = 1 in 9"
.270 Winchester = 1 in 10"
.270 WSM = 1 in 10"
.270 Wby. Mag. = 1 in 10"
7x57 Mauser = 1 in 9"
7mm-08 Remington = 1 in 9.25"
.280 Remington = 1 in 9.25"
7mm WSM = 1 in 9.5"
7mm Rem. Mag. = 1 in 9.25"
7mm Wby. Mag. = 1 in 10"
.30 Carbine = 1 in 16"
.30-30 Winchester = 1 in 12"
.308 Winchester = 1 in 12"
.30-06 Springfield = 1 in 10"
.300 WSM = 1 in 10"
.300 Win. Mag. = 1 in 10"
.300 Wby. Mag. = 1 in 10"
7.62x39 Soviet = 1 in 10" (Ruger)
.303 British = 1 in 10"
.32 Win. Spec. = 1 in 16"
8x57 JS Mauser = 1 in 9.25"
.338 Win. Mag. = 1 in 10"
.340 Wby. Mag. = 1 in 10"
.357 Mag. = 1 in 16"
.35 Remington = 1 in 16"
.35 Whelen = 1 in 16"
.350 Rem. Mag. = 1 in 16"
.375 H&H Mag. = 1 in 12"
.378 Wby. Mag. = 1 in 12"
.416 Rem. Mag. = 1 in 14"
.416 Wby. Mag. = 1 in 14"
.44 Rem. Mag. = 1 in 20"
.444 Marlin = 1 in 20"
.45-70 Govt. (Marlin and Ruger rifles) = 1 in 20"
.450 Marlin = 1 in 20"
.458 Win. Mag. = 1 in 14"
.460 Wby. Mag. = 1 in 16"

[Blackbear3]

30 cal Accelerator  Sabots and sabot bullet seater link.

http://www.eabco.net/search.asp?keyword=Sabots&search=

[zonie]

As it was told to me by someone that would know the reason Accelerators cause flyers was sometimes a bullet would not spin at same rpm as the sabot when fired.  In other words the bullet slipped in the sabot.   What I had in mind was a really good sabot maybe a precise 2 piece with knurling or ridges on the inside that bite into the bullets jacket slightly to reduce any bullet  rotational slippage .  Most likely built out of some type of lightweight metal,  possibly a means of catching air on the front of the sabot causing an instant release of the sabot upon exit of the barrel.  It would also need some type of sabot seating tool to compress the sabot down on the bullet with zero gaps creating a perfect fit causing no out of balance rotational stresses.   Worst case scenerio you could always fuse some type of high intensity polymer on the outside of the bullet that didn't separate as a sabot would, basically a bullet core of a certain lighter weight high BC if so chosen , and then encapsulate with a thick polymer outside of lightweight material that stayed with,  and as part of the bullet,  somewhat  reducing rifling twist importance.   Hornady has that new  bullet tip polymers that suppose handle the friction deformations,  might be something to look at.   With a little R & D I don't think that one would be that hard to do  I could even be a press fit and leaving the original exposed tip or hollow point intact for bullet expansion considerations. 

[7mmweatherby]

I don't know if you call it a wildcat or not don't see much of the old school 308 Norma mag lots of bullet selection in 30 cal I don't believe any manufacturer chambers for the old round

[.257]

I would think it would be very hard to market a sabot bullet. No rifling on the bullet when fired, and would be confusing to get the correct caliber. So very hard to match fired bullet to gun at crime scenes. JMO