Lilja Short Barrel... New Poll

[Variable]

If that would hit 20 ounces or less at 12.5" then I'd be in.

[cory]

If that would hit 20 ounces or less at 12.5" then I'd be in.

There'd be no way of knowing until one is made, but if the M4 came out to be 23-25ozs I'm confident this one would be in the 19-21oz range.

AR740


M4

[Variable]

Now instead of a trunk monkey I need a savant monkey versed in calculating material densities and volumes.

[Variable]

I would tend to agree; it just looks "right." Now, should one go with the tech specs one wants or how cool it looks?

You guys are looking at pics with A frames installed. I do admit I love my 11.5" 6933, but a 12.5" can look pretty sexy too. When you add a rail of the right length for your application they can look downright perdy!

ETA: Stolen Arf pic of a 12.5"er with a 12" SAR rail and a barking spider.




Food for thought--- If you can squeek 2300fps out of a 12.5" barrel with the 123gr. SST, that'd give you 807ft lbs at 400 yards with a velocity of 1719fps. Hornady says their 123 SST still opens down to at least 1700fps... That's here in WV. Out where Paul is, he could probably shoot to the moon!LOL I don't know the minimum velocity for the Amax bullet.

I love the stubby tubes, but at the shorter lengths, every inch really counts IMHO.

ETA #2: An old quote from Dave in the Arf archives talking about his 12" barrel----

I had a few spare minutes today so I threw a few rounds over the chrono.
Pretty pleased. AA's 100 grain Berger load is clocking just under 2,500 fps.
Their 123 grain load is running 2,350 fps. That will retain 1,000 ft-lbs at 300 yards.
That's more than a 5.56 SBR has at the muzzle....I need to build some handloads."

http://www.ar15.com/forums/t_3_121/513669_12_inch_6_5mm_Grendel_build____.html

The links to here in that thread are unfortunately lost of course (they now link to totally unrelated threads here). They were pointed at the old board. We lost a bunch of data...

Anywhoo... With careful loads, I don't think there'd be a problem getting more steam than folks would think out of a 12.5" tube. A light handy SBR good to 400 yards would be pretty darn sweet.

Peep Stickman pics of a 12.5" w/CMR rail.....

https://www.flickr.com/photos/stickgunner/8963593070/in/photostream/

https://www.flickr.com/photos/stickgunner/8960263857/in/photostream/

[Variable]

I might have to register as a lobbyist for the 12.5" lobby.

14.5" barrel with 14" CMR. Muzzle to rail ratio would be identical. Just mentally deduct 2" from the whole thing.LOL



ETA: Bummer. Just found out the 12" CMR rail is actually 12.58" long. Too long for a flush fit against a threaded on can on a 12.5" barrel.

[txgunner00]

I don't recall ever seeing any 7" twists in grendel. As far as I know, the 7.5" twist on the 10.5" and 14.5" Sabre barrels are as tight as it ever got. There could be something out there though I guess. Definitely a Bill A. question on whether 7" would be good.

The one thing I can say is that a 7.5" twist stabilizes 160gr. Bullets in my 10.5" barrel. Would an 8" twist do it? I dunno?

My 1:8.75 Satern barrel stabilizes the 160s. 1:8 should be GTG.

[txgunner00]

Tentatively put me down for a lightweight 12.5". If I can't get the problems worked out with my Sabre barrel I might need a new one.

[cory]

My 1:8.75 Satern barrel stabilizes the 160s. 1:8 should be GTG.

What length is your Satern barrel?

[txgunner00]

20"

[BjornF16]

Do we have any data about port sizing and timing for the short barrels?...iirc, AA spent quite a bit of time getting their 10.5" barrel right

[cory]

Do we have any data about port sizing and timing for the short barrels?...iirc, AA spent quite a bit of time getting their 10.5" barrel right

In the original thread I started Hanka said he talked to Bill A. and he recommended a 12.5" with a 0.073" gas port.

Since I've been thinking about a 12.5", about two weeks ago I asked Bill A. how he'd set it up. He said a 12.5 with a carbine length gas system and an H2 buffer he'd go with a port diameter of 0.073".

Alexander Arms used to sell a 10.5" and I know Bill wouldn't have signed off on it if it wasn't at least as reliable as Mk18. So maybe any differences in "reliability" between 10.5, 11.5, and 12.5 are negligible.

John

[cory]

I got us another deal to go with these barrels. Check out the 4th post of the thread.

http://www.65grendel.com/forum/showthread.php?8831-Lilja-Short-Barrel...-New-Poll&p=96522#post96522

[cory]

There has been a change. We're not getting a 10% discount from Spike's Tactical, we're getting a 20% discount.

[Bwild97]

WoW!! Where do I send my money?

[cory]

Twist Rate

The reason Lilja doesn't do 1/2" twist is because they don't have the tooling. The tooling required costs a few hundred dollars.

If we can get a 25+ order here, Lilja will get the tooling to do the 7.5" Twist. However, it will cut into our additional discount.

Personally I don't mind paying a few more dollars to get the nominal twist rate. What do y'all think about it?