classacked Posted January 5, 2012 Report Share Posted January 5, 2012 On the monolithic set, can you have a BABC pinned/welded then install barrel, or does the barrel, gas block have to be installed first then the BABC?Obviously, I have no clue.... Quote Link to comment Share on other sites More sharing options...
Robocop1051 Posted January 5, 2012 Report Share Posted January 5, 2012 Most gas blocks have a smaller inner diameter than the BABC. That'd be as productive as puttin your shoes on before your pants, not impossible but more work than necessary. I would, at the very least, slide the gb on prior to mounting the BABC. What length barrel are you using that you need to pin/weld the comp?Being that the upper is a mono, I'd assume that your gas block should be in place beforehand... Although I don't know how that would work with those fancy wrenches they use. Seems like you might have one of those tasks ahead of you, where you're gonna wish for tiny hands to reach those tiny spaces. Good luck? Quote Link to comment Share on other sites More sharing options...
classacked Posted January 5, 2012 Author Report Share Posted January 5, 2012 So install gas block, tube, then pin the brake? Then install into the monolithic upper? I live in CT, they require a brake/comp to be permanently attached... Quote Link to comment Share on other sites More sharing options...
edgecrusher Posted January 5, 2012 Report Share Posted January 5, 2012 i think you can have it done ( pinning your brake ) by your barrel supplier, most times, depend on who you are using Quote Link to comment Share on other sites More sharing options...
98Z5V Posted January 6, 2012 Report Share Posted January 6, 2012 Find out if the YHM Specter 2-piece gas block will fit under that mono upper. If it does, problem solved. If it doesn't - it's got alot of meat. You can carve it down to fit almost anything. I stuffed one under a DD Mk18 RIS II rail.If there's no way it's going to work with the Specter, then you have an expensive option at your disposal - YHM 2-piece flip-up front sight, cut down like you'd cut down a standard front sight when you turn it into a lo-pro gas block. That's some coin, right there, knowing ahead of time that you're getting it to cut it up... :o That would work, though.With a pinned FH on a barrel going into a mono upper, the very best solution you'll have will be a 2-piece gas block. Quote Link to comment Share on other sites More sharing options...
Robocop1051 Posted January 6, 2012 Report Share Posted January 6, 2012 If you can, wait till the last minute to pin/weld your comp to your barrel. It will make things MUCH easier. I have never used a monolithic upper, but I assume that it would be much the same as any other upper.1. Install barrel to upper receiver a. Use the Mega Arms supplied barrel nut and wrench to secure the barrel to the receiver.2. Install gas block and gas tube. a. I usually install the gas tube into the gas block first. It helps me line things up later. b. Then I work the gb into place and secure it (taper pin, set screw or clamp) i. This will give you the chance to "fit" your gas block, if needed. ii. Remember to give space for where the handguard cap is supposed to be. iii. If this is a low-pro GB under the handguard, there's usually some kind of relief holes in the handguard to work through.3. Install comp/brake/hider and crush-washer/shim-washer a. Remember to line up (time) the barrel device before making it permanent. b. **Usually this is only required if your barrel is less than 16". The BABC will add approximately +2" to your barrel length.Like 98Z5V said about the Specter... I also like that particular GB butted right up against the handguard. It gives a very sleek and symetrical taper to the longer barrel/handguard combo. Quote Link to comment Share on other sites More sharing options...
Jgun Posted January 6, 2012 Report Share Posted January 6, 2012 If I'm getting it right, because of your state requirement, and the proprietary tool that you need to use with the Mega mono setup, The way I figure it, You have to tighten the barrel first, and can't have the GB on there (even loose), or the barrel nut wrench won't fit, so, after you tighten the bare barrel on the upper, You could then install your gas block and gas tube, and finally, you could have the muzzle brake pinned/welded on after the other parts are in place. If you ever needed to replace the gas tube you should be able to loosen and move the gas block forward without removing the muzzle device. The only hitch comes if you decide you want to remove the barrel, then your going to have to remove the muzzle device to take the gas block off to use the barrel nut wrench. By the way, this might not apply to the BABC because it's not too large in dia, but you might have to remove your muzzle device anyway, even if using a two piece gas block, if the barrel nut wrench doesn't slip over the OD of your chosen muzzle device. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted January 6, 2012 Report Share Posted January 6, 2012 That MA-TEN mono barrel nut wrench should fit over just about every muzzle device out there - minus the Noveske Pig. The hole down the center of that thing is pretty large. Check the relations of the ID of the barrel nut, and the barrel nut wrench - there's not too much out there that it won't clear, as far as muzzle devices go. <thumbsup>Pin that sucker and run some type of 2-piece gas block config. <thumbsup> Quote Link to comment Share on other sites More sharing options...
classacked Posted January 6, 2012 Author Report Share Posted January 6, 2012 You think the wrench would clear a low profile block or just try to find a 2 piece gas block?Or should I scrap the monolithic set up and just go with a 2 piece quad rail?Although the monolithic is one sexy bitch... Quote Link to comment Share on other sites More sharing options...
classacked Posted January 6, 2012 Author Report Share Posted January 6, 2012 I forgot to mention, it'll be based on the DPMS pattern to accept pmags. For stock, a PRS to help balance the heavy front end.Barrel length, thinking a 13.7" with the BABC pinned to bring the OAL to 16.3"Trigger and lpk, undecided.Thoughts so far?Any advice would be appreciated.Thanks <thumbsup> Quote Link to comment Share on other sites More sharing options...
98Z5V Posted January 6, 2012 Report Share Posted January 6, 2012 I highly doubt the wrench would clear any lo-pro gas block, man. You should call up Mega Machine and ask then what the ID of that barrel nut wrench is. That's a number they should have for you. After that, it's finding a gas block that's top-to-bottom (usually the largest diameter on one) smaller than that ID. The YHM Specter requires a rail that's a minimum of 1 5/8" ID in order to clear the block. I've used several of those on builds. <thumbsup> Quote Link to comment Share on other sites More sharing options...
98Z5V Posted January 6, 2012 Report Share Posted January 6, 2012 I forgot to mention, it'll be based on the DPMS pattern to accept pmags. The MA-TEN lower already accepts P-Mags, and other DPMS-type mags. <thumbsup> You can't get a MA-TEN lower that takes Armalite mags. Quote Link to comment Share on other sites More sharing options...
classacked Posted January 6, 2012 Author Report Share Posted January 6, 2012 The inner dimensions (opening) of the hand guard is 1.540" Any advice ? Quote Link to comment Share on other sites More sharing options...
Jgun Posted January 6, 2012 Report Share Posted January 6, 2012 these are the kind of things that I usually obsess over while putting something together, when I don't have the luxury of just duplicating a rifle that I've already seen. I haven't put one of the monolithic uppers together, so I'm just suggesting this as something else you need to be sure of. I don't know which length upper your going to be using, but if your planning to have a long (12" ?) rail, with that -14" barrel you mentioned, your going to have a shorter gas system with a gas block that will be covered by the rail. Now I know from some of the ones I've built, that there is often access on the bottom to tighten the setscrews of the bottom of the gas block (as mentioned by Robocop), but if you should elect to go with the two piece gas block, you may need to cut some type of access holes to tighten it in place, depending on how the GB is designed. As adviced by 98, I think you'd be smart to give Mega a call and ask the tech, if it's feasible to do it. Your State restrictions, may just make the mono upper a poor choice for you. It might be that you would do better with a rail that can be removed to access the barrel nut from the side to be able to remove the barrel from the upper with the gas block and brake still attached. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted January 6, 2012 Report Share Posted January 6, 2012 ^^^ What he said. <thumbsup>The inner dimensions (opening) of the hand guard is 1.540" Any advice ?For this, a Specter gas block needs 1.625" to clear. You can cut one down, but you're looking at reducing the outer "corners" of it by more than 0.05" all the way around. Can that be done? I know I took off more than that to get mine to clear the DD rail, but it wasn't fun, and wasn't easy. <dontknow>Sacrificing this piece right here would be alot easier, but it would also be considerably more money.That thing ^^^ is MSRP of $102. That would work, and be pretty easy to cut down, and would definitely clear. Mounting it, as Jgun said,... you'd have to get creative to tighten it up under that mono rail. Quote Link to comment Share on other sites More sharing options...
edgecrusher Posted January 6, 2012 Report Share Posted January 6, 2012 It all depends on how big that clamp is. We can easily get rid of the sight, but the trick is grinding off just enough material on the two piece block Quote Link to comment Share on other sites More sharing options...
98Z5V Posted January 6, 2012 Report Share Posted January 6, 2012 That YHM flip-up I posted before - that clamp should clear with no cutting. The flip-up part, and it's base, would have to go, but that clamp should fit in the dimensions the OP listed (1.540"). Quote Link to comment Share on other sites More sharing options...
classacked Posted January 6, 2012 Author Report Share Posted January 6, 2012 The monolithic upper does have two small openings on the bottom for gas blocks with set screws @ mid length and @ carbine length.So I THINK the flip up sight (just the clamp) would work.I guess the ? I need to figure out is, is it worth the $100 or just take the easy way out and do a 2 piece quad rail and avoid the guess work.Thoughts? Quote Link to comment Share on other sites More sharing options...
Robocop1051 Posted January 6, 2012 Report Share Posted January 6, 2012 I'm still trying to figure, why must the barrel device be installed first??? All this trouble is alleviated if it is installed last. If this is a "legal" issue... technically an upper receiver assembly is not a functioning firearm, without a lower receiver attached to it. The way I see it, as long as you keep the upper in a non-firing condition you should be on the green side of the lawDon't take my word as gospel. That is my California LEO way of looking at things, and your particular state may view things very differently. I know a lot of guys who buy/own "pistol" uppers and never had any issues with them. Quote Link to comment Share on other sites More sharing options...
classacked Posted January 6, 2012 Author Report Share Posted January 6, 2012 Wouldn't a 13.7" barrel need a tax stamp unless the muzzle brake is perm attached bringing OAL to 16+"? Quote Link to comment Share on other sites More sharing options...
Robocop1051 Posted January 6, 2012 Report Share Posted January 6, 2012 Wouldn't a 13.7" barrel need a tax stamp unless the muzzle brake is perm attached bringing OAL to 16+"?Yes. A "rifle" must have a barrel at least 16" in length, or be registered as a "short barrel rifle". Welding, by simple definition, is to make two pieces of metal into one piece of metal. Thus, if you weld a barrel device to a barrel (turning two pieces into one) you change the overall length of that barrel. I'm just suggesting you do it last, instead of first. Quote Link to comment Share on other sites More sharing options...
classacked Posted January 6, 2012 Author Report Share Posted January 6, 2012 Will places sell a 13.7" barrel without the tax stamp? Or should I just bring the monolithic upper and parts to a class 07 and have them do the work to avoid any hassles? Quote Link to comment Share on other sites More sharing options...
Robocop1051 Posted January 6, 2012 Report Share Posted January 6, 2012 There's no law, I'm aware of, that says short barrels are illegal. It's just illegal to have them on a rifle. It's not contraband. It's the combination of rifle + short barrel. You can order them from whoever you please. Then assemble in the easiest manner possible. As long as the upper is not attached to a rifle, you should be ok. The idiot factor comes present when people own short barrel uppers and store them in the same case as their lower receivers. Whatever you decide to do, do it safely and responsibly. No one should be hassling you otherwise. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted January 7, 2012 Report Share Posted January 7, 2012 Have you found a source for a 13.7" .308 barrel? Which muzzle device are you pinning in place? Quote Link to comment Share on other sites More sharing options...
classacked Posted January 7, 2012 Author Report Share Posted January 7, 2012 Have you found a source for a 13.7" .308 barrel? Which muzzle device are you pinning in place?Nope to the barrel, and when/if I find one, the Battlecomp BABC @ 2.6" brings the OAL barrel length to 16.3"? Quote Link to comment Share on other sites More sharing options...
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