6.8mm Remington SPC, 6.5mm Grendel and SSK 6.5mm MPC

[DDMac]

Thought so, Bidah. It's just that Pathfinder said he was looking at a .308 upper, and I wondered how it could be used without a mated lower. Maybe I misunderstood. Wife says I do that a lot.
Mac.

[Pathfinder]

Thought so, Bidah. It's just that Pathfinder said he was looking at a .308 upper, and I wondered how it could be used without a mated lower. Maybe I misunderstood. Wife says I do that a lot.
Mac.

No, my motto is ready, fire aim. Hell, forget ready and just fire.

I did not think about the magwells, was getting twitchy over the 6.8SPC and was looking for alternatives. I have a DPMS M4 on the A-15 lower. I am also a fan of the .308. I may still go with the 6.8 as a lark, sell it if it gets too $$$$$$. On the other hand, the military could adopt it . . . . .   

[texcaliber]

I like the sound of the AR in 7.62NATO man. The more I research the AR-10 systems there is a ton of "big" cals. options and even the "WSMs" shortmags. It looks like you might of started a need in my brain man.   

Thanks     Tex

[someguy]

Take this with a grain of salt, but I have heard on fairly good authority that at least two federal agencies have placed significant orders for AR's chambered in 6.8SPC that will be announced/fulfilled in 2008.  Should see more adoption of the cartridge and more surplus ammo.

And no, I don't own one.     That'll change before long, though.

[Bidah]

Well I have said this before, but if I currently had an AR-15 in 5.56, and did not have the investment in ammo and rifles in .308, then I would get an upper in 6.5/6.8, get some mags, and start buying ammo for it.

Even though I do have the .308's, I am still very much looking to get an upper in one of these calibers, probably two. 

-Bidah

[Sponsor]

[Crescendo]

+1 to comments above.

If you are looking to play shooting games, or if you are looking for a SD round and believe your engagements are within 150 yards, 5.56 is your round.  In fact for matches, 5.56 will be cheaper and allow you to be faster because of lower recoil.

Here's my quick assessment of the 6.5 Grendel vs the 6.8 SPC debate.  Both hit harder than a 5.56 at all ranges.  Out to 300-400 yards or so, there is very little difference between 6.8 and 6.5...although 6.5 will be just slightly flatter in trajectory.  Beyond 400-500 yards, 6.5 G will take over with more retained velocity and flatter trajectory.  6.8 SPC will have the theoretical edge in reliability because of the slightly more tapered case...probably only will notice that in full auto. 

So, if you want something for short range and/or games -- 5.56
If you want a harder hitting round in an M4/intermediate range set up -- 6.8 SPC
If you want a harder hitting round that will carry out further with 20-24" barrel -- 6.5 Grendel

That said, I just set up a 24" Overwatch upper on a PRS-stocked lower for my DMR rifle -- in 6.5G

KPR - thanx for the nicely stated and informative post.  It appears one of the hazards of forum posting is sorting through individual likes and dislikes before the basic question gets answered.

Thanx again 

[gary4447]

For use against no armor BGs (bad guys)  within 150 yards, do any of the newest and best rounds offer a significant enough advantage over 5.56mm to warrant a new upper? I am assuming they all run on AR platforms.
 Mac.

Probably do not offer a lot over 5.56 inside 200 yards.  Yes they do run on AR platforms, ammo is pricey and not a lot to choose from.  Reloading is the way I am going (less expensive) even though bullet selection if limited.  Hornady and Sierra 110gr SP and Vmax, 115gr hollow point.  Remington 115gr Ultra corelockt soft point and 115gr FMJ.  Uses 270 caliber bullets of 115gr or less.