btate868 Posted September 22, 2012 Report Share Posted September 22, 2012 good afternoon gents,figured id ask the experts a quick question. So my barrel, bcg, gas tube and block arrived today. The barrel is a DPMS 16 inch I got a pretty good deal on along with the bcg and it has the two indents for set screws on a gas block. Now would it be safe to say that with the barrel indexing pin seated and barrel nut properly torqued I can put the gas block on the barrel and everything will be fine? The indents on the barrel do not exactly line up with the set screws on the YHM gas block so could I just push the gas block all the way back to the raised portion of the barrel then tighten the screws down? I am a little lost as to how far the gas tube is supposed to be in the receiver or if its fine when all put together the right way. Thanks in advance everyone. Quote Link to comment Share on other sites More sharing options...
Robocop1051 Posted September 22, 2012 Report Share Posted September 22, 2012 Pictures are worth a thousand words.... Very few items for the .308 are "plug and play" unless your bought them from the same manufacturer. Some fitting my be required. Quote Link to comment Share on other sites More sharing options...
washguy Posted September 23, 2012 Report Share Posted September 23, 2012 Hi Btate ! In short nope, since you dont know the history of the barrel. You never wanna push the gb all the way to the last ridge and then tighten down....cause remember if you had an old school handguard the end plate would be there.....and you cant have the gas tube going into the upper too far.. Here's what I would do:install your barrel with your barrel nut that comes with your rail. of course you will refer to your rail instructions.....so after the barrel is on I would slide the gb on the barrel...of course the gas tube is already installed on gb....use the indent closest to the extension and tighten down allen screw leaving the screw closest to muzzle out...so now you have the gas tube lined up in the barrel nut going into the upper....now take the upper out of the claw,point the muzzle down and drop the bcg/handle into the upper...it should go into battery...if it does ...then thats the proper position of gb....so back out the screw a lil apply loctite to it tighten down.....then do the same thing with the other allen head...you r'e not caring where it is relative to indent. The space between the gb and the ridge should be about a credit card thickness away...... :) Wash Quote Link to comment Share on other sites More sharing options...
btate868 Posted September 23, 2012 Author Report Share Posted September 23, 2012 Its all different parts, this was supposed to be a budget build so I seen a good deal on the barrel and bcg, both Dpms and got those then bought a yhm low pro gas block and fulton upper. Is there any way to know how far the tube should sit in the upper receiver? The pics of thew gas tube in the receiver are with the has block pushed tight against where the barrel gets thicker, you can see the screw tore up the metal a bit on the one indent on the barrel. The other pic shows how the screws wont line up with the indents. Quote Link to comment Share on other sites More sharing options...
btate868 Posted September 23, 2012 Author Report Share Posted September 23, 2012 uploading the pics took so long you already replied washguy, the barrel and bcg are new but take offs (what I was told), I already torqued the barrel nut so I will do as you suggest, I have the FF tube and gas block back off and ill redo and let you know. thanks for the quick responses. ill post another pic here in a minute after its together Quote Link to comment Share on other sites More sharing options...
washguy Posted September 23, 2012 Report Share Posted September 23, 2012 Hi Btate Is there any possible way you can contact the seller of the barrel and ask him what gas block he had on there?....that would make things easy...then you could get that gas block....those indents were done by someone that had a specific gas block inhand.....thats would I would do....prolly not what you wanna hear. :) Wash Quote Link to comment Share on other sites More sharing options...
btate868 Posted September 23, 2012 Author Report Share Posted September 23, 2012 ok so the bcg and handle dropped in fine, this is the gas block at a credit card space away from the lip and how far the gas tube is sitting in the receiver. added after seeing the post: not what I wanted to hear lol but not a huge problem either, I didnt know those indents were put on by someone. I will shoot him and email in a minute and ask what was on it Quote Link to comment Share on other sites More sharing options...
washguy Posted September 23, 2012 Report Share Posted September 23, 2012 Hi Btate I went and got a 308 out of the gunsafe and using a dial indicater...the gas tube on this 308 protrudes 0.9230 into the upper measuring from the end of the extension....that help? :) Wash Quote Link to comment Share on other sites More sharing options...
washguy Posted September 23, 2012 Report Share Posted September 23, 2012 Hey Btate Im thinkin you are gtg by the way it looks...if it goes into battery and I do see a correct space there on the outside of the barrel, but cant "judge" the exact amount of tube in the upper....I say go shoot it...not worrying bout the allen closest to the muzzle...where it ends up. if it cycles you are golden! :) Wash Quote Link to comment Share on other sites More sharing options...
washguy Posted September 23, 2012 Report Share Posted September 23, 2012 Hi Btate you didnt say whether it was a dpms super sass barrel...if its that....it has its own specific gas block you must use :) Wash Quote Link to comment Share on other sites More sharing options...
IM_JOHNNYV Posted September 23, 2012 Report Share Posted September 23, 2012 Best way to tell how far the gas tube should be inserted is to put the bolt into full battery, insert the gas tube into the key, then back it off approximately an 1/8" (you'll see that the tube at this point will be exposed inside the receiver about 1"). As for the way the gas block "should" be installed is to snug the screws into the barrel just enough to mark them, then take the barrel and spot drill the marks with a 3/16" bit the depth of the drill point taper.This works for me...... Quote Link to comment Share on other sites More sharing options...
btate868 Posted September 23, 2012 Author Report Share Posted September 23, 2012 I appreciate you looking at your own rifle for me, I will measure it when I get a chance tonight and compare to yours. Its not the Sass, its the 16 inch with a .750 seat. Ill also try what you suggested johnny, if what I have here is close to what you guys have im gonna shoot it when I get the chance and hopefully all goes well. Thanks again gents, this is the quickest and most helpful forum im part of. Quote Link to comment Share on other sites More sharing options...
survivalshop Posted September 23, 2012 Report Share Posted September 23, 2012 The real thing you should be thinking about is , the alignment of the gas ports , the gas tube ( if proper length for the gas system ) will be ,where it is , in the gas key. If its the proper length gas tube for the system ,it will work properly, if the barrel & gas block gas ports are aligned properly & the barrel port size is correct. Quote Link to comment Share on other sites More sharing options...
btate868 Posted September 23, 2012 Author Report Share Posted September 23, 2012 I looked at everything with my flashlight and things seem to be ok and lined up, the items I bought are the correct parts so im assuming, which I hate to do, everything will work that way it should. Unfortunately I wont get to test this until after this semester. Quote Link to comment Share on other sites More sharing options...
Dusty44 Posted September 23, 2012 Report Share Posted September 23, 2012 You are using a low-profile gas block? The FF tube covers it up?Then all that should matter (correct this Washguy, if needed) is that the set screw closest to the breech fits into the hole/dimple closest to the breech and that with a finger closing the breech end, a breath of air blown into the muzzle escapes through the gas tube. Then Lock-Tight the two set screws and torque them down.I feel like I missed or misunderstood something else. The gas tube is held in position in the gas block with a roll pin? That holds the gas tube in proper place; the gas tube has its own port that has to face the barrel and the ports in the barrel and gas passage in the gas block?In recoil, I think, the rifle/barrel will jolt toward the shooter. Everything attached will be left behind, or, seem to move toward the muzzle. So the set screw in the gas block that fits into a dimple properly keeps the gas block from moving, must be solid at the end of possible travel to keep the gas block from moving toward the muzzle. A second (or more) setscrew(s) can help, but are really just gravy.My recent purchases of gas blocks (and almost everything else) were not the item at the top of the online catalog listings but from somewhere a long way down the list. Prices were manageable. Midwest Industries and even Troy steel gas blocks for mid-$30 prices instead of the $70 - $200 at the top of the listings.Other savings: Under $10 A2 flash suppressor instead of the pretty and pretty expensive offerings; Badger handle parts with some reasembly of the charging handle was almost 10 cents on the dollar(?); I do splurge on a CAA grip-- under $40 and better than any other brand. Including Magpul. My opinion. (No 'humble': I am a Metal Dragon and a Leo Horoscope sign.) <lmao> Quote Link to comment Share on other sites More sharing options...
washguy Posted September 23, 2012 Report Share Posted September 23, 2012 Good Call Dusty! Then all that should matter (correct this Washguy, if needed) is that the set screw closest to the breech fits into the hole/dimple closest to the breech and that with a finger closing the breech end, a breath of air blown into the muzzle escapes through the gas tube. Then Lock-Tight the two set screws and torque them down. :) Wash Quote Link to comment Share on other sites More sharing options...
btate868 Posted September 23, 2012 Author Report Share Posted September 23, 2012 I just read this post and tried it and it worked so i thing everything should be good to go. this was a pretty good idea thanks dusty Quote Link to comment Share on other sites More sharing options...
btate868 Posted September 23, 2012 Author Report Share Posted September 23, 2012 Missed the first part Dusty, it is a low pro gas block from YHM with a 12 inch FF tube from YHM. The tube originally came on a Fulton 22 inch upper I bought but I replaced it with a troy MRF 13.8 because I wanted an uninterrupted top rail then I used the YHM on this new build, I like the look of longer tubes on carbines that cover the gas block. The lower is from the Fulton 22 inch upper I just put it on here for the purpose of the pic. Quote Link to comment Share on other sites More sharing options...
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