I researched both the 6.5 Grendel and 6.8 SPC pretty heavily and initially decided on the Grendel. It seemed to have all the terminal ballistic advantages of the 6.8 but with better exterior ballistics. I bought an AA Overwatch upper and built an 18" SPR.
Building the upper was a nightmare...what with many delays and difficulties in getting parts (I only bought top-end parts for it). Brass was expensive, reloading info was scarce. In the end, accuracy was good but not mythical like the caliber has been built up to be. That is with factory and many variations of reloads.
I realized I was trying to get a lightweight, handy CQB caliber with better performance than the 5.56 as well as a great long range caliber. While not completely mutually exclusive, it is difficult to do both. I still think the Grendel is an interesting caliber for what I REALLY WANTED TO DO (better ballistics, terminal out to 500 yards) the Grendel wasn't it. I sold the uppers and built a 6.8 upper.
It is showing very good accuracy (hovering right around MOA), has better terminal effect than 5.56, can hang with a 308 for the distances that I'm interested in and has the advantage of much wider distribution. Grendel needs to be less "exclusive" if it wants to make up the gap.
I've also decided that if I want a long range rifle semi-auto rifle, I should build a long range semi auto rifle...probably a AR10 in .260 Rem or 6.5 Creedmore.
I had a very long phone conversation with John Holliger of White Oak Armament. There's a lot of talk about the SAAMI vs. SPC-II chamber and the pressures created in each...his view is that it is a lot of hoo-haw about nothing unless you are trying to hot rod the cartridge and make it into a .270 Win.
Here's my 6.8 SPC AR that I built to thumb my nose at the Obamessiah
- DPMS 5.56 lower
- Stag/CMT M4 upper
- Badger Gen II TacLatch
- RRA 2-stage NM trigger
- VLTOR stock
- WOA 18" SS SPR profile barrel and bolt
- PWS FSC30 flash hider / comp
- YHM front sight
- Brownells HK-type rear sight
- ERGO grip
- Magpul triggerguard
- MI low profile gas block
- YHM FF rifle-length quad rail handguard
- MI sling mounts
- EoTech 511 (now with a 4x magnifier)
- PRI mags
