Sabre Defence AR15's, barrels, and low-profile gas blocks

Taman

Taman

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I've got a 16" midlength gas Sabre on order and I've got a question or two for those that already have them (I'm sorry I'm a little fuzzy on these issues in general):

- Do your barrels have divots for mounting a low profile gas block? Ive got the LaRue block, and they mount with two set screws on the bottom that are maybe 1/2"(?) apart. If it does, I think at least one divot should be visible on the underside of the barrel between the two front sight post pins.

- Or do barrels only come with either divots OR pin slots for a FSB, not both? Does anyone make a low-profile gas block that uses the slots for FSB pins?

- If anyone has a midlength sabre, what's the barrel profile under the handguards? Pics would help greatly. :D

I'm asking because im planning on mounting a 12" free float railed handguard on it.
 
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The sabre barrels probably don't have any divots on them and you would most likely have to put them on there yourself or have a gunsmith do it. If I were you, I'd get a Vltor clamp-mounted low profile gas block instead. Its way easier to install and is actually stronger than the dimple design.
 
The rank of Ar-15's thread is already 4 pages and yet no one knows anything about this???...

Come on... someone out there must be able to answer some of this...

EDIT: So are the detents an SPR type barrel thing only? The LaRue free float handguards sit pretty close to the barrel, so I'd be worried about a clamp-on type block not clearing...
 
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I have a CMMG 16 inch middy barrel with a Larue low pro gas block and Larue 12 inch rail. It had a pinned front sight post when I got it. The Larue gas block covers both pin slots. I dimpled the barrel and then locktighted the set screws in to place. To add to the holding, I drilled a hole through the side of the block and the edge of the barrel. I then put a roll pin through it. Now I have a pinned and set screwed gas block. This seems like a lot to go through, but piece of mind is worth it.
All this being said, if you only plan on shooting small amounts every now and then, the set screws will work. I put alot of ammo through my barrel, so even with 5 round mags, it gets a work out.
In the end, stick with the pinned sight base and grind it down or put a set screwed gas block on it. Clamp on gasblocks will work free with lots of shooting.
YMMV,
Hoddie
 
The screws from a clamp on gas block will not clear the opening in the Larue rail. I had an MI low profile gas block before the Larue and it was a ##### to put under the rail. Had to slide it on and then tighten it trough the holes in the rail and then attach the rail to the barrel ring. PITA
Just be aware that whatever rail you plan on getting may not clear the gas block. Maybe stick with one make of rail and gas block. I have had good experiences with Troy and Samson rails over pretty much any thing however mainly because of the 2 piece design.
Larue always works IMHO.
Again, just my $0.02
YMMV.
Hoddie
 
I like the profile of the larue rails much much more than anyone else's. Plus I already have them. :D

Seems like most of the high end companies like LaRue, Troy, and Knight's use set screws for detented barrels for their gas blocks. Vltor offers both set screw and clamp on. Daniel Defense uses clamp on blocks, but I think that kinda makes sense given that one of the biggest selling points of their rails (which by all accounts Ive heard are great) is that you don't have to take apart anything major to mount them.

In any case, clamp on gas blocks aren't an option. Nor is cutting down the FSB.

If most of the quality gas blocks out there are set screw, wouldn't most of the high"er" quality AR barrels have detents for them? If not, why hasn't Troy or Larue made a gas block that just pins in the same way the FSB does? :confused:
 
Taman said:
If most of the quality gas blocks out there are set screw, wouldn't most of the high"er" quality AR barrels have detents for them? If not, why hasn't Troy or Larue made a gas block that just pins in the same way the FSB does? :confused:
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The best quality gas block is the FSB that will come attached to your barrel.

Gas blocks don't come set up for pins because they'd have to be installed on the barrel at the factory. You can't simply pull off a FSB and reinstall pins on a gas block, the chance of the holes lining up are quite remote since the FSB and barrel are drilled together to ensure that everything lines up properly.

A gunsmith could drill the gas block of your choosing, but he'd probably be drilling a new hole in the barrel as well, but since you'll be paying him to dimple a barrel anyway, why not have him drill and extra hole while he's at it.
 
I don't have one but I do believe that they are government profile, and come with the FSB taper pinned.

I actually believe that Wolverine said that anything is possible and to contact them with your requirements. If it hasn't shipped from England yet I'd see if it was possible to get is shipped with a low profile gas block pinned in place, which it sounds like that's what you really want.
 
It's starting to look like I'm going to have to phone Wolverine on monday and find out if they can have this done custom for me. Although I'm thinking I might be asking more than is possible. :(

After spending countless hours searching google for info for the past week or so, I have come to a conclusion: KevinB sure does get around a lot. Also, I still havent been able to find a clear definition for barrel contours/profiles. From what I can tell, government profile/contour is the one that narrows under the handguards and then thickens to 3/4" past the gas block shoulder to the muzzle. If that is so, what is the profile called when it remains ~3/4" throughout the length of the barrel (with the exception of the gas block shoulder, of course)? Would that be HBAR? SPR? Medium? Mid-weight?

As far as the gas block, I think I've got 3 options:

-(Ideal but insane and not going to happen) It doesnt look like Sabre's low profile gas block would clear a LaRue handguard. So maybe I could send the LaRue gas block to Wolverine and they could send it to Sabre UK. Sabre could then make a barrel with a shoulder a little further forward to compensate for the lack of a handguard cap, and then instead of drilling out two taper pin slots, they do the two divots for the set screws, mount my gas block, then taper pin it where they feel would be appropriate. Then they ship the rifle assembled with a barrel nut, my gas block, gas tube, etc... but with no handguards, no FSB, and no handguard cap. That would definitely make me happy, but I'm thinking that might be bending over a little too far backwards for everyone else involved.

-(Second choice) They make up one of the rifles with the shoulder for the gas block moved up, divot the barrel for set screws, and ship the rifle without a FSB, handguards, or cap. Once I get it and install everything, Loctite the set screws and then stake the s**t out of them with a punch?

-(Third) I'm told what I can do with myself :)D) The rifle comes exactly how it normally would.

Thoughts?

KevinB? Big_Red?
 
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It is possible to shave down the front sight in order for it to clear the hole in the Larue rail. I have done it, as well as lots of people on this board. This would give you the best method of attachment, pinned, plus the ability to use a free float rail.
If you request all that stuff to be done, you will pay through the nose. Just get it factory, then modify the crap out of it. Or as you have stated, get just the barrel with the barrel extension and add the stuff when you get it. This is how mine came originally. The front sight base was drilled on an angle so it was tilted to one side. This was done by a "gunsmith". I just added the Larue lowprofile gasblock and haven't looked back.
Again, my $0.02,
YMMV.
Hoddie
 
I appreciate the insight :) The replies to this thread ARE helping me to clarify in my own mind what it is that I want.

The thing is, I'm REALLY opposed to cutting down the FSB... Among other reasons, I really don't like the idea of having to cut up a $2000+ AR. Seems to me if I'm spending the money I should be able to get it how I want. As for paying extra, I'm not really to worried about that right now. This project has already run into the thousands and any illusions I had about a budget went out the window in August.

Maybe what I should aim for is to have them build the rifle with the gas block shoulder moved up and have detents/divots done instead of the FSB. Then they can ship it with everything assembled except the handguards/cap and the gas block/fsb. Once I finally get it I'll just do the gas block myself (or get my gunsmith to do it). if the set screws get loctite, sit in the factory divots on the barrel, and them I stake the screws fairly heavily, that should be LOTS I would think, right? I mean, its not exposed.. it sits underneath the rail and really i dont think it could be exposed to any hits like a FSB might... and if its staked well, the screws shouldn't loosen...?

I can't believe what a pain it is to do a rifle securely that is pretty much this:

IMG_7734.jpg


(for anyone wondering thats the green tipped steel core ss109/m855 from TSE in the above pic)

This is a pic of the bottom of the LaRue gas block inside that 12" LaRue rail on my armalite:

IMG_7737.jpg


I dont think anything but LaRue or Vltor's set screw blocks will clear (or a cut down FSB prolly would, but nty)
 
Taman,

First, it's completely unnecessary to move the FSB shoulder forward - they run just fine with a tiny space between the FSB and shoulder when the handguard cap is absent.

Second, PRI, LaRue, or any similar (they're all mostly copies of these two) low-profile gasblocks will work, and set-screwing them in place takes a very minimal effort. Why not drill the divots yourself? Since everyone in the business (Armalite, Bushmaster, Colt, Diemaco, DPMS, Sabre, LMT, and whoever else) uses a different jig for FSB pins (And tapered or straight pins, but that's a whole matter apart), and mostly you can't find commonality within the same manufacturer, it's impossible to find something that will line up with the factory FSB pins.

Get your rifle, take off the handguard cap and delta ring, throw on a LaRue or PRI low-pro block, line it up the best you can, drill two divots for the set screws, use a file to put a bit of a point on the screws, torque her on with some blue loctite, and be done with it.

I cut down my Armalite FSB to work with a Troy rail system - took about three dremel cutting wheels and about twenty minutes. Saved $100 on a low pro, though I did end up just buying one later anyway.

It's a lot easier than you think, and sending a block to Sabre UK is just ridiculous. Just do it yourself. KevinB (IIRC) said that a retarded monkey could build an AR, and he's not far off.

Brad
 
PaveHammer said:
First, it's completely unnecessary to move the FSB shoulder forward - they run just fine with a tiny space between the FSB and shoulder when the handguard cap is absent.
Click to expand...

I know, but I figured it would be nice to not have that gap and just butt the gas block to the shoulder.

PaveHammer said:
Get your rifle, take off the handguard cap and delta ring, throw on a LaRue or PRI low-pro block, line it up the best you can, drill two divots for the set screws, use a file to put a bit of a point on the screws, torque her on with some blue loctite, and be done with it.
Click to expand...

Im thinking this is what will eventually end up happening.

PaveHammer said:
It's a lot easier than you think, and sending a block to Sabre UK is just ridiculous.
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I know its ridiculous, I just didnt think it would be that ridiculous. After thinking about it some more, it is.
 
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Your thinking about this way too much.

You say that it seems so hard to get it done yet I still don't think that you bothered contacting Wolverine at all. Have you seen all the different variations that Saber builds? I saw a picture of at least one low profile gas block on their website, I bet they'd be willing to install it on your barrel for you, who knows they may even pin it on, or drill a detent for you.

Even if they can't accomodate you, people have given you a few simple options, all of this stuff is easily done.
 
Whoa guys... I posted to find out about mounting these because I wasnt sure how they usually mount, and what barrels would/wouldn't have divots etc. I had actually asked wolverine about it a little while back and they had said they weren't sure but had thought so.

When I say that I've found it difficult to get this done, it's not because of Wolverine; in fact Wolverine has been fantastic to me. But not everything for this is coming from Wolverine... and I was just commenting on how difficult it is to find out who's selling all the other stuff I want. Add to that, I am still unable to find a guide/info/definitions for barrel profiles.

I'm not trashing cutting a FSB or clamp gas blocks, I was only trying to explain they're not going to work for me... I still aprreciated the info though.

I was interested in hearing how guys like hoddie and kevin, whom I know both run pinned blocks, had done theirs. Maybe someone might have done something I hadn't thought/heard of?

I thought this was a discussion forum?:confused:

Anyway, I meant no offense to anyone.
 
Here is a Stag 16 inch barrel that I cut the front sight down with a bench grinder and angle grinder. Pretty easy to do. Hardest part was the fact that it was brand new out of the box when I did it. :runaway:
barrel.jpg

Here is my 16 inch middy CMMG barrel that has a Larue lowprofile gasblock. Setscrews and then pinned with a roll pin between the screws. This ain't gonna move. The Larue gasblock with take up that small gap from the front handguard ring too, so won't have to worry about that.
HPIM0735.JPG

HPIM0737.JPG

I appologise for the photos. It is not one of the things I am good at.:D
Hope this helps anyway.
Hoddie
 
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hoddie said:
Here is my 16 inch middy CMMG barrel that has a Larue lowprofile gasblock. Setscrews and then pinned with a roll pin between the screws. This ain't gonna move. The Larue gasblock with take up that small gap from the front handguard ring too, so won't have to worry about that.
HPIM0735.JPG

HPIM0737.JPG

I appologise for the photos. It is not one of the things I am good at.:D
Hope this helps anyway.
Hoddie
Click to expand...

This is interesting... :cool:
 
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