Just curious neckdown to 6mm

[speederx7]

here is some more write up on the wssm, from the dtech site:

http://www.dtechsuperstore.com/new_wssm.htm

also, he has a dtech improved 6mm that is based off a 6.8spc cartridge, which makes it a LOT like a 6mm AR

http://www.dtechsuperstore.com/whats_new.htm

[sititunga]

What about the .243 WSSM? I would like a .25 WSSM. I almost purchased a really nice used 6.5 WSSM built by DTECH but due to the case length, bullets need to be seated too deeply in my opinion. For long range hunting with an AR15, Mike at Dtech says the .25 WSSM is king.

But brass life is horrendous with the WSSMs and it's difficult to find mags that feed. Many AR15 builders believe that the WSSM is too much cartridge for the AR15 platform.

[sititunga]

Just curious to know, has anyone neckdown the 6.5 Grendel to a 6mm bullet? What are the performances?

Robert Whitley of 6mm AR builds the 6mm Turbo 40 Improved, it will drive a 6mm 108 gr Berger bullet to about 2850-2900 fps. The BC on this bullet surpasses the 6.5mm 108 and 123 gr Scenars. Whitley has a very good reputation with the highpower crowd. His accuracy and performance claims are very credible.

[sititunga]

AR15 Performance in Colorado were building a 6mm BRX (a wildcat version of the 6mm BR) they have developed a proprietary bolt and barrel extension. The builder was claiming an MV of 3100 fps with a 108 grain bullet. For some reason he`s now stopped making them.

[sititunga]

TG:

The 6 AR isn't kind to barrels. The 6 AR Turbo is less kind. HP shooters don't particularly care and I don't imagine medium and big game hunters would shoot enough.

Those WSSM's made to go through AR-15's are not the heat. Bullets must be very short which means lighter. Much lighter than a standard bullet for that caliber. MV is super high but exterior performance is poor to very poor. I imagine they will kill just as well as anything else but no better, faster, or deader than anything else. So, it comes down to cost and the cost of one of those WSSMs due to rifle and brass is astonishingly high for such an inefficient cartridge.

Stick with the Grendel for hunting.


LR1955

I was talking to a highpower guy who`s running a T40i and he had 3000 rounds through his first without any accuracy fall off. At 3500 rounds he`s still running it at 200 and 300 yds but has switched to a new barrel for the longer courses. He said for someone using it for precision tactical application smacking steel you wouldn`t notice the fall off. He thinks he`ll be able to run the first barrel for 5000 rds before canning it entirely.

[Varoum]

Thanks for the info Sititunga

[speederx7]

But brass life is horrendous with the WSSMs and it's difficult to find mags that feed. Many AR15 builders believe that the WSSM is too much cartridge for the AR15 platform.

what builders? those same builders probably frown on the 50 beowulf too? do you realize the WSSM uppers, as built by oly and dtech are done with ar10 bolts and barrel extensions? define poor brass life on the WSSM... are those with annealed cases?

[sititunga]

what builders? those same builders probably frown on the 50 beowulf too? do you realize the WSSM uppers, as built by oly and dtech are done with ar10 bolts and barrel extensions? define poor brass life on the WSSM... are those with annealed cases?

The Beowulf is not a high pressure round - it just fires a big slow bullet. On the WSSM set-up, a common concern is that the larger barrel extension takes a lot of meat out of the upper receiver which compromises the rigidity and strength of the system. I might be wrong but I think at the very best you`ll be lucky to get 2-4 firings per WSSM case, especially with the stresses caused by the cycling of an AR15 gas-gun.

[StoneTower]

The Beowulf is not a high pressure round - it just fires a big slow bullet. On the WSSM set-up, a common concern is that the larger barrel extension takes a lot of meat out of the upper receiver which compromises the rigidity and strength of the system. I might be wrong but I think at the very best you`ll be lucky to get 2-4 firings per WSSM case, especially with the stresses caused by the cycling of an AR15 gas-gun.

They have to remove 50 thousandths from the upper to get the barrel extension to slide in. Some people are doing much better than 2-4 firings. Remember, the WSSM is a special purpose round in the AR15. You probabily don't go to the range and shoot 500 rounds of 50 Beowulf either. Most people who need/want a WSSM in an AR want it for hunting.

[sititunga]

They have to remove 50 thousandths from the upper to get the barrel extension to slide in. Some people are doing much better than 2-4 firings. Remember, the WSSM is a special purpose round in the AR15. You probabily don't go to the range and shoot 500 rounds of 50 Beowulf either. Most people who need/want a WSSM in an AR want it for hunting.

Standard bolt vs. Oly WSSM bolt. There isn't a whole lot of meat to play with in an upper - the extension that houses the WSSM bolt is quite a bit bigger than a regular 556.

[speederx7]

"thin" upper is easily solved with a low pro or billet machined receiver.

as for WSSM brass life and reloads, this isn't a zombie hoard killer. this is a purpose built long range hunting gun built on the ar15 platform. there is always compromise with wildcat cartridges, that is why they are wildcats!

[sititunga]

Despite the use of a heavy walled upper many believe it is still too much for the platform. Heck some builders even think the BRX is too much.

[LRRPF52]

I've been interested in doing a .257 Grendel for a few years, but it's not top priority. Would be cool to see what the 115gr Bergers do out of an 18-20" barrel. If you could hit 2800fps, that would be a great all-round gun, even for long-range.