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Posted: 5/8/2013 12:35:25 PM EDT
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I have an adams arms mid length upper, i recently bought a samson mid length rail to go on it, unfortunately when i tightened the forearm around the barrel nut it seemed to have loosened it, and now that ive tried tightening it im worried because the piston rod doesnt align into the receiver. should i completly remove the barrel nut and try to relalign it, or should i keep trying to tighten it more so it lines up, im worried about over torquing it. also i dont have an upper receiver vice. any suggestions? thanks for the input guys.
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Quoted:
I have an adams arms mid length upper, i recently bought a samson mid length rail to go on it, unfortunately when i tightened the forearm around the barrel nut it seemed to have loosened it, and now that ive tried tightening it im worried because the piston rod doesnt align into the receiver. should i completly remove the barrel nut and try to relalign it, or should i keep trying to tighten it more so it lines up, im worried about over torquing it. also i dont have an upper receiver vice. any suggestions? thanks for the input guys. I had the SAME problem with my Samson Evo rail and AA middy kit. I read that looser torque is better for accuracy than tighter torque. But in the case of an AA kit we really are at the mercy of keeping proper side to side ALIGNMENT which is ever so critical for proper functioning (lowest gas rod friction possible is the key after you have achieved proper GAS HOLE alignment). We are more at the mercy of a little higher torque settings possibly) in order to maintain strict positioning of the gas block and NO movement (rotation)of the barrel. If your barrel rotates, this will cause BINDING and potentially DAMAGE your AA kit and or upper receiver. You can BEND your gas rod among other things. You can even mess up the gas hole alignment and cause short stroking. So whats all this mean? Well, higher torque settings to KEEP that barrel nut where it is supposed to be! How much is too much? I am not sure. Some one who is a machinist/gun smith please tell us. I do know that on a DI gun torque settings can be as low as 35 to 40 Ft lbs. This is tricky to measure. You almost need two people. You use the special tool (multi tool usually) to tighten your milspec barrel nut. The multi tool/wrench has a square HOLE that accepts a 1/2" drive. If you have a 3/8" torque wrench, use an adapter(Duh). Sometimes it just take more than one attempt. I used about 48 ft lbs on my final alignment thinking that was plenty to hold the barrel from shifting. It was not strong enough in the end. I needed to rotate the nut one more tooth and the end torque was (I forget...50 something ft lbs). I hope THAT will be enough. NO WHERE have I seen the advice to use any kind of loctite. Just the opposite. ALL the sites I read talk about lithium grease or never seize, not loctite. I dont see why not, but I have not done that yet because I just have not read of any pros or cons about its use. May some of you out there have knowledge about this?....loctite on a barrel nut for an AA build? I prefer to clamp the BARREL, not the upper when tightening the barrel nut. You can damage the upper IMO if you use that as a brace when torquing. NEVER use the upper as a brace when working on any muzzle devices like flash hiders or muzzle brakes. Clamp the barrel ONLY!!! You can snap a barrel pin or worse if you clamp your upper and torque on the muzzle! DONT do it! Ever. I LOVE my Samson Evo rail, but I have to admit the clamping arrangement of the rail leaves much to be desired. You need to REALLY torque on those LONELY two clamping machine screw allens. I use a small drive and allen BIT to tighten mine, NOT an allen key!!! i know I may have raised more questions than answers, but I fixed my loose barrel nut with out resorting to anything out of spec. Someone should publish the MAX torque on a Milspec barrel nut. I am FAIRLY certain that AA gives some specific numbers on their website concerning barrel nut torque settings. There is a LOT of info on their site. A LOT of VERY good info. Start by STUDYING their FAQ section. They spent a lot of time on this!!! It's incredible and FULL of great info! |
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From the build it yourself section, first post
clicky Torque Values: Compensator (Flash Suppressor) - 15 to 20 Ft. Lbs. Barrel Nut - 30 Ft. lbs. Minimum, not to exceed 80 Ft. Lbs. to align the next slot in the barrel nut. Carrier Key Screws - 35 INCH pounds to 40 INCH pounds. Lower Receiver Extension (Buffer Tube) Rifle - 35 to 39 Ft. Lbs. Carbine - Tighten the locking nut to 40 INCH pounds plus or minus 2 INCH pounds. Above advice is all sound. If your nut is hand tight, it is very wrong. (off topic) I looked into the Phase 5 lever you mentioned the other day VS the BAD lever. I couldn't find much in the way of where and how they engage. It seems the version 2 that is one complete piece is the simplest way to go if you really need the lever though. Slick design |
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Quoted:
I have an adams arms mid length upper, i recently bought a samson mid length rail to go on it, unfortunately when i tightened the forearm around the barrel nut it seemed to have loosened it, and now that ive tried tightening it im worried because the piston rod doesnt align into the receiver. should i completly remove the barrel nut and try to relalign it, or should i keep trying to tighten it more so it lines up, im worried about over torquing it. also i dont have an upper receiver vice. any suggestions? thanks for the input guys. you could make upper receiver vise blocks with 2x4s. just tighten the barrel nut to the next tooth slot or borrow/buy a torque wrench...if you buy it return it or sell it if you dont want it. as stated...30-80 ft lbs torque range. |
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Quoted:
Quoted:
I have an adams arms mid length upper, i recently bought a samson mid length rail to go on it, unfortunately when i tightened the forearm around the barrel nut it seemed to have loosened it, and now that ive tried tightening it im worried because the piston rod doesnt align into the receiver. should i completly remove the barrel nut and try to relalign it, or should i keep trying to tighten it more so it lines up, im worried about over torquing it. also i dont have an upper receiver vice. any suggestions? thanks for the input guys. you could make upper receiver vise blocks with 2x4s. just tighten the barrel nut to the next tooth slot or borrow/buy a torque wrench...if you buy it return it or sell it if you dont want it. as stated...30-80 ft lbs torque range. Exactly. Use the next tooth. Note that manufacturers DO want you to use a grease (lithium or moly) on your barrel nut threads. ALSO, you run less risk of damage by clamping the BARREL only. You can use smooth jaws, a barrel vise insert or what my machinist uses...a swatch of leather. I have never marked a barrel using any of these methods. IF the gas block area of the barrel is VACANT and available, then use that surface for clamping. You do not need a huge long clamping area to keep your work from rotating. This clamping method allows you to easily transition to any flash hider or muzzle brake work as well. Caution: Never EVER clamp your upper and then put a wrench on any muzzle device. I see this happen ALL the time. It is a miracle there are not more disasters in the wake of this faulty practice. |
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Quoted:
From the build it yourself section, first post clicky Torque Values: Compensator (Flash Suppressor) - 15 to 20 Ft. Lbs. Barrel Nut - 30 Ft. lbs. Minimum, not to exceed 80 Ft. Lbs. to align the next slot in the barrel nut. Carrier Key Screws - 35 INCH pounds to 40 INCH pounds. Lower Receiver Extension (Buffer Tube) Rifle - 35 to 39 Ft. Lbs. Carbine - Tighten the locking nut to 40 INCH pounds plus or minus 2 INCH pounds. Above advice is all sound. If your nut is hand tight, it is very wrong. (off topic) I looked into the Phase 5 lever you mentioned the other day VS the BAD lever. I couldn't find much in the way of where and how they engage. It seems the version 2 that is one complete piece is the simplest way to go if you really need the lever though. Slick design Sigh, It seems my command of the English Language is insufficient...cue visual aids. I love photos too. Dont get me wrong. They are just a pain to deal with. But in this instance nothing will quite illustrate what I am talking about as well as some nice close ups! :) I apologize for the sizes. I did re size these photos much smaller, but not as small as I would have liked. But they do show what I was referencing a few posts ago. Unfortunately, I do NOT have any photos of the BAD lever installed. You will just have to visualize! Think of a SANDWICH. Alright? The BOLT TAB is the MEAT and the BAD LEVER is the BREAD(TWO slices). Some upper receivers have VARYING degrees of bulge. IF you have an upper with a larger than "normal" bulge, then the inside clamp of your BAD lever(that slice of bread) will interfere so much as to START TO ACTUATE the bolt stop. That "slice of bread" has little or no clearance and the thickness will force the tab away from the upper and towards the position where it will lock your bolt back. I did not realize it at the time, but my BAD lever's rear clamp pushed so much on my upper's bulge that it HALF accuated the bolt tab that it was clamping. Every shot I took vibrated the gun so that the bolt catch actually would completley accuate. In other words, every shot I took would result in the bolt being locked back no matter how many rounds I had in my mag. I could physically hold the catch to prevent accuation and the gun would cycle, but that was not a solution. Removal of the BAD LEVER was a solution. Enter now, the Phase V tactical ONE PIECE bolt lever. Notice the THINNESS of the "meat". There IS no "sandwich" effect anymore with a one piece unit. In fact the entire unit does not even TOUCH the bulge in the upper. Notice the gap I have....about the width of a dental pick or credit card. NOTE: There are TWO one piece versions of the Phase V. I have the version that is designed for SIDE LEVER charging AR15's. The only differnce is that my version has even MORE clearance than the standard one piece. I got my version to be certain I had PLENTY of room between the back of my bolt tab and the bulge in my upper receiver. Problem 100% solved. CUE more visual aids! Go to this link: http://www.phase5tactical.com/products/ You will see all lined up the : EBRv1 EBRv2 and the EBRv2-SC. The first is the Extended Bolt Release, version 1 which is a SANDWICH type like the Magpul B.A.D.. Second is the Extended Bolt Release version 2 which is their standard one piece BR. It MAY have enough clearance if your upper has a large bulge. The last is the Extended Bolt Release version 2 Side Charging. This is also a one piece. It is identical to the EBRv2 except that it has even more clearance in the TAB area. See my embedded PHOTOS in this post for a close up of that lever installed. I have a Bushmaster Carbon fiber upper that has a larger bulge than Milspec. Therefore, a Magpul B.A.D. lever will not fit properly due to the inner clamp being too thick for the situation.. The EBRv2-SC has plenty of clearance. It is perfect for my application. As to your TORQUE settings, are they WET or DRY values? There is a significant difference. What it the source of your settings for the CARRIER KEY SCREWS? They are Grade 8 I do know. I did find max torque values for SS matching size. I was finding only MINOR differences in MAX torque settings for SS VS Grade 8 in larger sizes. The max torque for SS I found was 15inch lbs for dry and 20 inch lbs for a wet machine screw of that size. It was an 8-24 I THINK...MAYBE an 8-32. I recall the 8-24 size. In the past I have snapped my share of small machine screws. These days I am so much more careful. They can be nearly impossible to extract sometimes. I always feel compelled to constanly remind everyone to BUY a good HEAT GUN for $35. No, not your wife's hair dryer. I have damaged small screws during removal attempts even with BLUE loctite on occasions. With RED, forget it. You will snap those really small screws in a real jiffy without a LOT of heat. Even grade 8's! 
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