Good evening, all.

*****I posted this in the SBR forum, and one of the good folks over there thought this forum might be able to lend a few thoughts.*****

Well, I was getting ready to purchase a complete BCM lower and complete BCM 9" upper with QRF for a 300 Blackout build when I suddenly started thinking of the 6.5 Grendel. I began digging for ballistic information and, unless I completely misunderstood everything I read, the 300 only comes out on top in the realm of suppression. I know it's heresy, but I have no desire to run a suppressor; I wanted the 300 for up close and personal, and still be able to reach out to ranges out to 100 yards. The 6.5 gives me the up close capability, and a longer effective range, if need be, with more punch. On to my questions.

I'm looking at two options on opposite ends of the quality/cost spectrum, and, as always, would greatly appreciate your input.

The first is a 12" made with complete PSA upper, complete PSA lower, and a BCM 10" QRF for a cost of $680. Second is a complete BCM lower, 11" Alexander Arms kit, and BCM 10" QRF for a cost of $1175. Am I gaining a great deal more for the extra $500, or will the PSA build function perfectly fine? Both companies are applauded in articles and forums for their customer service, and their respective quality levels, so I'm not fretting going either way. $500, though, buys a fair amount of ammo and magazines :D

Thank you in advance for your thoughts.

Aaron

I bought the PSA 12” Nitride pistol kit in 6.5 Grendel and so far it has functioned 100%.   I can not own a suppressor because of where I live but the PSA upper kit comes assembled with an adjustable gas block.   I have not shot my 12” 6.5 Grendel past 50 yards but so far I like what I’ve seen on accuracy.   In the real world if this 12” PSA 6.5 Grendel will produce 1.5-2 MOA groups I’ll be more than happy.    Alexander Arms developed the 6.5 Grendel and they are known for producing accurate barrels.   The PSA might be more of a gamble on accuracy but PSA has good customer service.   AA also has good customer service if you encounter a problem.

For the price difference you could even buy a replacement barrel for the PSA.   I say it is hard to go wrong with either but boils down to luck of the draw on accuracy with any rack grade barrel.

I just built my own starting with a Faxon 12" group buy barrel.

Used an AA upper, PF lower, LaRue MBT-2S trigger, Maxim PDW brace with buffer and extra power spring included, Bootleg adjustable carrier since I'm shooting suppressed.



Given your stated goals, any center fire cartridge from the AR15 will reach out to 100yds with ease.

The only advantages the 300 Blackout has are magazine capacity/commonality, and lots of ammo on store shelves including China Mart.

Those might be important for you.

If you want the most performance from the AR15, 6.5 Grendel is the cartridge to beat, even in SBRs or pistols.

At 100yd most anything will work fine, to include even like pistol cartridges. I like the 300blk for super short (single digit) barrel lengths. I really dig the 6.5G for that 12”ish length. My 12.5” has quickly risen to be one of my favorite rifles. I think the PSA will likely shoot looser than the AA. How much will that inch or less difference matter at 100yds, and is it worth the cost difference? That’s for you to decide. Unless it was mostly for shooting groups at a bench, I’d probably opt for the PSA personally.

I bought the same 12" PSA upper. If I don't like how it shoots, I replace the barrel down the road. No big deal. For the sale price many of us got it at, it's a no brainer.

I have an 11" AA barrel I built an upper for.
The lower is a complete Aero Precision with Magpul higher end furniture and a good two stage trigger from Texas trigger company
Total $400
Upper with AA barrel and Aero upper and Aero rail
AA bolt and NIB carrier Aero Gamma brake
Total $600
It shoots MOA with Wolf and ELDM and SST
I can't ask for more

I threw together an 11" AA upper, and as the above poster stated, it shoots Wolf surprisingly well.

I have yet to strap my magneto-speed to it to see what kind of velocities it's achieving

I purchased a 12 inch upper Sulzar Firearms. 12 inch faxxon match barrel. $525
Sulzar Firearms

@thewestvirginian

Grendel does have mo powah from any barrel lefnth than either 300BO or 556, maybe even 6.8 depending on legnth.    It was not really designed for SBR applications but being a low pressure round it works amazingly well as such and it hs external ballistics and terminal ballistics superior to any of the other rounds.  It really is a hell of a chambering w/i the confines of the AR.

If  you dont want to suppress and you want an SBR for both defense and hunting than 6.5 all the way.  You can read lrrp52s threads about the capabilities of his 12.5”.  You can hunt w 556, but your margins are thinner for humane/trackable kills, of course.

If you are only looking for a defensive sbr for out to 0-2 or wven 300yds any of the other above mebtioned chambering would work great, INCLUDING 556  ...

id get a 556 in 11.5 or 12.5”. Probably the 11.5”. 12.5 is a litter better externally, but it is hardly worth a tax stamp or pistol brace IMO.  But going from 11.5 to 10.5” many people report noticable increase in muzzle blast.  Id use a JP or BF meyer 3 prong flash hider indise of a thordsen BD 180 (blast deflector cone) in any barrel legnth or chamvering if I was not needing a suppressor mount.  Those are hands down the best flash suppressors available and they already decrease DBs to the shooters ear and the BD 180 helps even more.

Why do i not recommend 300 BO?  Its dirty little secret is that it can be chamvered, sometimes, in a 556 chamber, depending onthe crimp and the ogive of the bullet.  It is a real risk and requires extrordinary process controlls to ensure that you do not grab the wron mag or accidently load the wrong loose cartridge in your range ammo can tray into the mag etc.  unless tou really want to shoot subsonic as an option I dont think it is of worthwhile benefit over 5.56, not even close.

6.8 is also good for a hunting/defense SBR, just has a bit less effective range.  And, sometimes people, even to this day, have to tweak their 6.5g mags.  There was a thread here a couple mo ago.  Some people had zero problems w mfg A, orhers had 0 w mfg B, other had problems with one or both mfgs, some had zero problems at all.  I dont think that 6.8 mags tend to need to be messed with/tested so much

If i was interested in 6.8, but not in a custom light weight build, I would use a LWRC Six8, or its receiver set so i could use the Six8 Pmags.

Good luck!

I went with a 12" 6.5G and I'm very pleased with it.  LaRue Stealth 2.0 upper, Odin barrel, Bootleg carrier, JP bolt, have an EA Vox in jail for it.

Attached File

I chose the Ballistic Advantage 12.5” barrel and sba3 brace.  This barrel length seems to be a sweet spot between muzzle velocity and size/weight.  I did look really hard at the Alexander Arms 11”.  I have a16” AA that shoots very good with everything I have put through it.

Thank you all so very much for the thoughts, and the photos.  I can't tell you how appreciative I am of everyone's help with this.  I decided to go lower cost for now just on the off chance I am not enamored with the setup.  If it works well, I may go Alexander in the future, especially if I decide to get a longer barrel, say 18" or 20".

Thanks so much again, and have a great day!

Aaron

Two words in favor of the 6.5 Grendel, "Do It" You won't be disappointed... Glad I built one in 12.5", it has become one of my top favorites. PSA or Alexander Arms both fine choices with PSA coming in a little cheaper and like you said, you can always re-barrel the PSA. Just keep in mind though, if you go with a Ballistic Advantage tube (first hand) or Faxon barrel un-suppressed, they are light on gas for the lighter weight (100gr and lighter) projectile factory ammo.

Okay, so it was more than two words... but as always...

Just my .02 worth