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+--- Thread: How Short is too short (/showthread.php?tid=13089)
How Short is too short - yoni - 03-31-2017
In 5.56 I think the shorties you can go is the 10.5" barrel and still get good results on meat with the round.
I know some people that have been getting good results with 300Blk down to 8".
So my question is how short can we go with the 6.5?
Seems a lot of guys are doing 12.5", but at that length I would stick with a 14.5" with flash suppressor permanently attached.
How Short is too short - explorecaves - 03-31-2017
In the closed 12" GB thread, BFT wrote this:
Quote:Regarding barrel length, as I've studied the issue and tried to see a pattern and figure out rhyme or reason, I see SBR barrel lengths all over the place. AA has their 10.5 echoing what the SEAL boarding parties use. But why did the SEALs choose 10.5? In the industry, 11.5 and 12.5 are common. Why 11.5? Why 12.5? When the Army tried to develop the XM8 carbine, they settled on 12" as the optimum standard length. Why? LaRue sells a 12". Lilja sells an 11.5" and a 12.875". Is there some magic in 12.875"? What I see, in the final analysis, is guys just pick a length and run with it.
So my thinking is to split the difference between the common 11.5 and 12.5. I know the claims are that a 10.5 on a carbine gas system is just fine for reliability, but I like a little more barrel, a touch more dwell time, in front of the gas block. For a product line, I like that 12 is different enough from 16 to make the SBR a different animal. If I start creeping up in length, then the whole point of an SBR becomes moot and why not just make it a 14.5 or a 16?
So that brings us to 12".
And LRRPF52 posted this regarding the 12" barrel:
Quote:With 123gr factory AMAX, SST, and ELD-M, you'll be in the low/mid-2300's for speed.
Supersonic out to 975yds at 2340fps mv.
Expansion out to 350yds with 123gr SST with 887ft-lbs of energy.
0yd 2340 1495 -2.5
100 2178 1295 0
200 2023 1117 -4.9
300 1874 959 -18.2
350 1803 887 -28.5
400 1733 820 -41.5
500 1601 700 -76.4
600 1477 596 -124.9
And if I remember correctly, switching to the 129 gr ABLR with its lower required expansion velocity, you will be good significantly farther.
How Short is too short - Bigs28 - 03-31-2017
Precision firearms posted this with some accuracy and velocity info.
Short barrels with Grendel
Hello Horde:
Just thought I would let you guys know about a test we did recently on Short Barrels. We tested:
7.5 Bartlien at 100 Yards. Groups averaged 1.5 Inches 2000 FPS 123 Match King
8.5 Bartlien at 100 Yards. Groups Averaged 1.4 Inches 2100 FPS 123 Match King
10.5 Bartlien at 100 Yards. Groups averaged .9 Inches 2200 FPS 123 Match King
12.5 Lilja Blank Chambered by PF at 100 Yards. Groups .75 2300 FPS 123 Match King
14.5 Lilja Blank Chambered by PF at 100 Yards. Groups .5 2350 FPS 123 Match King
14.5 Krieger at 100 Yards. Groups averaged .38 2375 FPS 123 MatchKing
We have most of these available for shipment with 2 weeks. They are chambered - Just need Muzzle Threaded.
We also have 7.5, 8.5, 9.5, 10.5, 12.5 in Criterion although we have not tested accuracy extensively. 12.5 we tested shot under 1 moa.
There are some good replies to read as well.
http://www.65grendel.com/forum/showthread.php?13307-Short-barrels-with-Grendel