LWRC is one of the finest piston companies on the market, but now they are helping out the DI 6.8 SPC crowd in a big way. Stock up on those 6.8 PMAGS guys!
http://forum.lwrci.com/viewtopic.php?f=5&t=14732&p=163540#p163540
I have to get out of this communist state! 
.
This is going to be a very interesting release to watch!!
Does anyone know if a standard bolt carrier is what these will use
Why is this a big deal? 6.8 uses standard 5.56 upper/lower receivers.
In general yes, but LWRC came up with a proprietary change in dimensions that has a bigger magwell, which Magpul developed a special 6.8 SPC Pmag for, so you can get Pmag goodness with the 6.8. The overall front to back dimensions of the LWRC receivers are the same as GI, but their mating dimensions are different, as is the magwell.
Supposedly, this is open source info.
Ah, right - that’s great. All I meant was that their six8 receivers aren’t at the milspec dimensions. But if they are happily sharing the dimensions with the world for other companies that might want to build to them, even better.
The mag well spec is open source. The larger well is the only way to allow a magazine size that truly allows the rounds to stack correctly and get you the same reliability you expect from a 5.56 gun.
Kind of ironic considering 6.8 SPC had a design requirement of using a standard receiver set. That didn’t work well, so now a receiver set and magazine have been made to properly work with the cartridge.
Wouldn’t be nice if some one designed a cartridge for certain ballistics and size requirement then built the magazine and gun around that? Instead of building a cartridge around a gun and then building a new gun around that cartridge.
7x46…
And 6.8x46mm UIAC as well.
Either 6.5 or 7 are better bore diameters than 6.8.
I"m sure I could search and find the answer, but-
How close are the external dimensions of the Six8 receivers, vs a GI receiver? Barely noticeable or fat and thick?
I was not arguing whether 6.5mm and 7mm were better than 6.8mm. Cris Murray told me via email that he also made a 6.8x46mm round in addition to his 7x46mm UIAC and my point was that both 6.8x46mm and 7x46mm don’t suffer from the OAL constraints of 6.8mm SPC and 6.5mm Grendel.
Where do you get that “it didn’t work well” having the 6.8 SPC fit in a standard receiver set? Have you ever even used one? It’s a hell of a round and the cartridge has replaced my 5.56 for everything except 3 gun. Your statements have no validity, as there is proof everywhere the 6.8 SPC works and works well in a standard receiver.
Who cares if LWRC developed a new receiver set for the cartridge? It’s not imperative to own one to have a fully functional 6.8.
This is pure rubbish. Do some research and get some rounds down range with a 6.8 before you make a statement about it’s reliability and overall function. If you don’t care for the round, that’s the cool thing about the ar platform, shoot a 6.5 or a 300 Wtf or some other caliber.
I’ll echo all that. 6.8SPC in standard receivers works perfectly fine in my experience with PRI & Barrett magazines. I won’t be buying a new set of receivers for a perfectly functional rifle. That said, I’m still glad to see some innovation in the 6.8 dept.
Because you buy off the shelf bullets?
ANY diameter bullet can be made to the same BC, the only difference will be the length and weight.
The mil is moving toward green bullets so all will be redesigned without lead. Using the same formula of 5 diameters long, 3 dia long ogive, 7 degree boat tail, 20 diameters secent ogive transitioning to a 10 diameter hybrid using 8.54 as density both 6.5 and 6.8 bullets will have a G7 BC of .25. The 6.5 will weigh apx 115gr and the 6.8 apx 120gr with the exact same BC.
Lots of comments from people who have NO first hand knowledge.
I do have a 6.8 with a std receiver and alum mags. Hundreds of rounds and no failures of any kind. I push 90g TNT at 3100fps. The LWRC allows the use of PMGs which need thicker walls than alum to properly support the rounds.
I love reading info on this site but like others, too many without first hand knowledge speaking up. Are there better rounds? Depends on your purpose. No one can argue that the 6.8 isn’t an incredibly well suited round for anything out to 500 or so.