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Short barrel lengths? - Printable Version

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Short barrel lengths? - Constitutionalist - 03-27-2021

Just looking for people to share their thoughts on shorter barrel length Grendels. I got my first Grendel when factory brass was hard to find and the 6.5 Grendel wasn't SAAMI approved yet. In fact, my first one uses the .125" bolt face depth. In those days, people were leaning toward longer barrel lengths to get as much of the performance the Grendel was capable of as they could. Almost no one was talking about anything shorter than 18" and most discussions I heard were between 20" and 22" with 24" coming in a strong 3rd. Both of mine have 20" barrels. I trained many years ago with the M16A1 and never found the 20" barrel to be unwieldy. My 5.56 ARs are 16" and they are bit handier, but not that much.

So anyways, what's up with these 12" and 14.5" Grendels?

TIA for the insight!

John


Short barrel lengths? - 41bear - 03-27-2021

Short = Handy. In my neck of the woods the longest shots I might take are around 50 to 125 yards plus hitting the 80 mark next month light is always better. The very longest shot I could possibly take is 400 yards punching holes in paper from a bench and I have both an 18" and 16" to add flavor to that end. I have to say though that the 11.5" Alexander is my favorite and has proven to be able to do everything I ask of it. JM2C


Short barrel lengths? - Bigs28 - 03-27-2021

I use my grendel for hunting. Some people use theirs to push for as long a range as they can. Im comfortable shooting deer or hogs out to around 275 yards with my 12" where i hunt i rarely can see passed 100 yards so a small compact lightweight rifle is all i need.


Short barrel lengths? - VASCAR2 - 03-27-2021

The 12” length is handy for CQB or around vehicles. The 12” pistol barrels don’t require NFA like SBR’s and easier to transport if crossing state line. Living on the border where your regularly going into a neighboring state the pistol is just handy. The 12” 6.5 Grendel has more energy than short 5.56/223 so your still getting a step up in performance out of the AR-15. For most uses having 17, 24 or 26 rounds of 6.5 Grendel isn’t a significant disadvantage as having 20, 30 or 40 round mags with 5.56/223. In a pure combat or competitive 3 gun environment I can see the advantages of the 5.56/223. For my uses I’d rather have a 12” 6.5 Grendel AR-15 than a 12” 5.56/223.

I still have 16”, 18” and 20” AR-15’s and like and use them all. If I had to pick just one AR-15 it would probably be an 18” or 16”.


Short barrel lengths? - Constitutionalist - 03-30-2021

Thanks, Guys! I'd never really considered a short barreled Grendel until now. After doing some more reading I'm thinking I may end up building a "pistol" Grendel AR so I have the option of making it a rifle and then going back to pistol. (My wife is mad at you, BTW.) Now I have to look into the lengths of the various components.

I think I may know where to get a fresh stripped lower....

Be safe!

John


Short barrel lengths? - lazyengineer - 03-31-2021

[Image: 282b205f-8dd2-4061-8728-dde5e4ab4c30_zpsuqnm5t2u.jpg]

The Grendel shines in the shorter configurations. It's a little casing, so doesn't hold much powder and doesn't have a lot of volume to run a sustained pressure reservoir of gas. Meaning it's gonna tap out faster than something like Creedmoor, where 63,000 PSI in that big volume casing is a lot of gas to push and keep pushing the bullet down a long barrel. Longer is still "better", but not as much so as a larger volume casing that runs higher pressure is going to do for you.

So in just a 12", that sucker is 1000 ft-lb out to nearly 300 yards. That's game-dropping power. 800 ft-lb past 400 yards, which is also game-dropping, though more on the large-varmint sized level. It's supersonic out to 900 yards, meaning it's still accurate on paper out to .. well, probably 800 yards, before transonic stuff starts to happen. Out of a 12" BBL. Cross reference that with even a 16" .223 rifle, and it's jaw-dropping how much more effective Grendel is.

Just MHO, but running a 22" Grendel misses the entire point. The point of Grendel is the most ass you can fit into a small framed AR. And to capitalize on that - run a small AR. I personally think the 12" BBL "Pistol" is about to go away and wouldn't advise anyone start there in 2021. Which leaves sticking with a 14.5 pin and weld; which you can legally run as a rifle.

Just my opinion.


Short barrel lengths? - bakabone25 - 03-31-2021

The above post is exactly why we run 2 12" grendel rigs for hunting. Well put there lazy...


Short barrel lengths? - funnelcake - 03-31-2021

I built a shorty using a cut-down 16” M4 type barrel. Cut right at end of M4 cut (11.3” IIRC) and threaded 9/16-24 (not enough meat for 5/8).

So far, with a cheap 1-6, it’s acquitted itself well. I gave my nephew free choice to take any rifle he wanted deer hunting over the winter & after shooting 4 or 5, he picked the stubby Grendel!


Short barrel lengths? - Oso Polaris - 04-02-2021

The only minimum length consideration is if you are planning to use a suppressor then most suppressor manufacturers have set a minimum barrel length for safe use (Thunderbeast is minimum length 11.5").


Short barrel lengths? - Edddyjoe - 04-03-2021

Just finished a 12 inch monster barrel from sixfive arms. Finished it off with a forward comp and just a cheap foam covered buffer tube. Anchor the foam pad against my cheek and the red dot is lined up. Thing is a blast to shoot. Grouping around 3 inches at 75 yards with wolf. Plenty good for the local whitetail deer. Think I found my new favorite rifle/pistol.


Short barrel lengths? - AllyeViper - 04-05-2021

I put together a 10" grendel last year using a barrel from x-caliber. I have only put a couple hundred rounds through it though with ammo costing what it does, but so far it has been great. I wouldn't hesitate to shoot a deer out past 200 yards with it.