I was under the impression that the BLK was designed for DI guns. The MDR is supposed to be piston, is that going to hinder reliability at all? I’d prefer it over the 6.8 in this platform because it only takes standard AR mags and 6.8 mags aren’t known to be super reliable from what I’ve heard (excluding the Magpul/LWRC solution). However I would stick to 5.56 if the piston is gonna hurt the .300.
In the “C” configuration, the MDR is shorter than an 8" SBR, and the full-size version is still shorter than that same SBR with stock extended (I’m looking at LWRC’s Six8 UCIW for comparison). I have high hopes for this rifle, regardless of release date.
The short barrel version of the MDR in .300blk has the potential to be the greatest CQB gun ever. It will be way shorter than the M4 and from what I see the BLK does better out of a 10.5" barrel than the 5.56 does out of a 14.5. You will have a gun much shorter, that will feel lighter since most of its weight will be on the back of your hand shooting a great cartridge for that barrel lenght compared to the standard M4.
As far as reliability that will depend on how they engineer the platform. Not all piston systems are equal and the details will make the difference. Reliability of any chambering is something we won’t know for sure till the gun is released and tested in each chambering.
The 6.8 conversion taking standard 6.8 AR mags may not be set in stone and may not even be the case. I emailed them saying what I like about the platform and what I would like to see from it. One of my requests was for the 6.8 conversion to take the 6.8 Magpul mags(I ask anyone else who feels the same way to do the same thing). I think the average person spending 2K+ on a rifle won’t mind proprietary mags if it means increased capabilities and reliability. The gun is at least a year away from being released according to desert tech so I think many things are far from finalized.
I think the 6.8 offers no advantage over the .300blk in the short barrel configuration. I know the 6.8 is more powerful, but we are talking about a 10.5 barrel, nobody reasonably expects to be super effective beyond 400 yards with such barrel and both calibers easily the 400 yards mark and since the BLK has the better logistics…
Now in the 16" config the 6.8mm becomes more interesting.
Both the 6.8 and 300 were designed for short barrels. The 300 is more interesting to me also because it can be suppressed easier. 5.56 compatibly etc. I honestly don’t know if I would get a 6.8, but I know I won’t if they use the standard 6.8 AR15 mags. I think if they are going to offer 6.8 they should do it right and make another mag well block for the 6.8 Pmags.