ninjajimmy Posted November 30, 2014 Author Report Share Posted November 30, 2014 My Lilja is a 1 in 11 twist. At the normal ranges I can shoot (max of 400 yards) I don't think i'm going to see much of a difference. It shoots 168gr fine. Haven't tested anything heavier yet, but do plan to shoot 175 and 178s. Quote Link to comment Share on other sites More sharing options...
shibiwan Posted November 30, 2014 Report Share Posted November 30, 2014 You'll need an SR-25 specific barrel nut. Boltcarrier.com has the SR-25 specific URX 3.1 rail in stock. The SR25 barrel nut is the same specs as the DPMS-pattern barrel nut.... so you do have some flexibility if you want to use a different forend. Quote Link to comment Share on other sites More sharing options...
Lapp7660 Posted December 19, 2014 Report Share Posted December 19, 2014 Anyone know where I could find good instructions or a video on how to install the bolt catch/release on my SR-25 lower ? It's quite a bit different than all the ar15s I've done. Quote Link to comment Share on other sites More sharing options...
edgecrusher Posted December 19, 2014 Report Share Posted December 19, 2014 There's a few guys here with personal exp who will be along shortly. Quote Link to comment Share on other sites More sharing options...
Rsquared Posted December 21, 2014 Report Share Posted December 21, 2014 Set screw (DPMS/SR-25)? Or pin type (Armalite)? Either way, it's pretty straight forward. We're here to help my man. Quote Link to comment Share on other sites More sharing options...
Lapp7660 Posted December 21, 2014 Report Share Posted December 21, 2014 I got it figured out. it was a pin type Armalite. I'm sure I'll have other questions as I go along. Thanks ! Quote Link to comment Share on other sites More sharing options...
geistacwm Posted December 22, 2014 Report Share Posted December 22, 2014 Lovely build and parts choices. Condolences on the wallet depletion. Quote Link to comment Share on other sites More sharing options...
Lapp7660 Posted December 28, 2014 Report Share Posted December 28, 2014 Need some help with my Knight build. I purchased two barrels both DPMS pattern. I chose the 18 inch for my build and had a tough time getting it into the Knight upper receiver; it was really but I did get it on and lined up. Is that normal for the Knight uppers ? Second question. I am putting on the knight URX rail which came with a barrel nut but the barrel nut is different than what I expected and the Knight Armament barrel nut wrench does not fit it. Any suggestions as what barrel nut wrench will fit it given it's hard to get at with the urx rail. Lastly, what is the torque setting I should use ? Thanks. Quote Link to comment Share on other sites More sharing options...
Lapp7660 Posted December 28, 2014 Report Share Posted December 28, 2014 meant to say, it was really a tight fit but did get it on. Quote Link to comment Share on other sites More sharing options...
edgecrusher Posted December 28, 2014 Report Share Posted December 28, 2014 I think there is a wrench specific to that, and you'll be torquing to 40 lb-ft or so Quote Link to comment Share on other sites More sharing options...
FaRKle! Posted December 28, 2014 Report Share Posted December 28, 2014 Need some help with my Knight build. I purchased two barrels both DPMS pattern. I chose the 18 inch for my build and had a tough time getting it into the Knight upper receiver; it was really but I did get it on and lined up. Is that normal for the Knight uppers ?It's not uncommon for an upper to fit tightly to a barrel extension. It's actually better for accuracy that it's a tight fit (BCM specs their upper receivers tight for this). Use a hair dryer or heat gun to expand the front of the upper receiver then slide or tap the barrel in. Second question. I am putting on the knight URX rail which came with a barrel nut but the barrel nut is different than what I expected and the Knight Armament barrel nut wrench does not fit it. Any suggestions as what barrel nut wrench will fit it given it's hard to get at with the urx rail. Lastly, what is the torque setting I should use ? Thanks.You'll need the 7.62 URX barrel nut wrench. For other SR-25 questions, Ayan at boltcarrier.com is probably the best guy to ask. Quote Link to comment Share on other sites More sharing options...
Lapp7660 Posted December 28, 2014 Report Share Posted December 28, 2014 Ok, the real problem is that the URX 3.1 Rail came with a SR-25 Barrel Nut not a URX Barrel Nut so the Knight URX barrel nut wrench does not fit it. 1) Can the SR-25 Barrel nut that came with the rail be used ? And 2) What wrench will fit it ? Quote Link to comment Share on other sites More sharing options...
98Z5V Posted December 30, 2014 Report Share Posted December 30, 2014 Another question. I got the Rainer Arms 16 inch barrel with the 1:11 twist. Would I have been better off with a 1:10 twist ? I have to receiver sets so I figured the second one I could go with a longer barrel and a faster twist rate for heavier bullets. Does this make sense ? It's probably 1:11.25" twist. Most advertising doesn't go into the decimal range, except for LaRue. The M110 was designed with a 1:11.25" twist to accurately shoot 175gr M118LR ammo at the specified ranges lined out in the contract. That wasn't an accident, coming up with that twist rate, for that round. Knight's Armament did the research, and came up with the rifle that won that contract - and they are good at what they do. Quote Link to comment Share on other sites More sharing options...
Lapp7660 Posted January 1, 2015 Report Share Posted January 1, 2015 Anyone have any ide where I can get an SR-25 URX 3.1 Barrel Nut wrench ? As you all know they are hared to find and the only way to properly torque the barrel nut when building a Knight SR-25 upper. When I do find a place that sells them (they are usually out of stock) but the price is around $300.00. Does anyone make a tool that will work the same and is available. This is frustrating. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted January 1, 2015 Report Share Posted January 1, 2015 There are a few gunsmiths that offer the service - ship your upper, and they'll mount the URX for you. Quote Link to comment Share on other sites More sharing options...
Lapp7660 Posted January 15, 2015 Report Share Posted January 15, 2015 Ok, so I got my SR-25 upper together so I thought. I have DPMS pattern barrel and DPMS BCG that is suppose to match but when I put the BCG into the upper with the barrel it's obvious the cam is no able to move freely; it does not far enough in the upper. Any suggestions ? My first thought is that the DPMS BCG that I have does not match the DPMS patterned barrel that I have. I am open to any suggestions or advice. Thanks. Quote Link to comment Share on other sites More sharing options...
survivalshop Posted January 15, 2015 Report Share Posted January 15, 2015 Need more info . Is the gas tube installed ? Who makes the barrel ? BCG ? Is the assembly well lubed , like dripping wet, almost ? Was the Bolt/Barrel Head space checked ? Are you checking with rifle fully assembled or just the Upper , by its self ? Check for any scuff marks on components & Upper Receiver that may show where components could be binding or interfering with BCG movement . Quote Link to comment Share on other sites More sharing options...
Lapp7660 Posted January 15, 2015 Report Share Posted January 15, 2015 Thanks for replying. Yes the gas tube is installed. I even removed it to see if that was the issue but had the same problem. The barrel is a Brownell barrel 080-001-022WB 18" 308 DPMS Med Mid Gas barrel. No, it's not well lubed but I'll give that a try. I have head space gauges so I will that that as well. I am checking it with just the upper; since I can't get the bolt flush with the back of the upper I can't assemble it. Dan Lapp Quote Link to comment Share on other sites More sharing options...
edgecrusher Posted January 15, 2015 Report Share Posted January 15, 2015 What kind of bolt? Quote Link to comment Share on other sites More sharing options...
blue109 Posted January 15, 2015 Report Share Posted January 15, 2015 I'm not suggesting its a good idea, just sharing experience.....but my first build was with DPMS factory parts and it was so tight I had to tap the carrier in with a mallet. it loosened up eventually, but I suspected the cam pin hole in the bolt was slightly out of spec. Quote Link to comment Share on other sites More sharing options...
Lapp7660 Posted January 15, 2015 Report Share Posted January 15, 2015 It appears the cam is hitting the front edge of the space on the upper receiver where it's supposed to twist in to. It's already made a small dent and roughed up the corner of the space on the upper where the cam is suppose to fit into. Will I be ok smoothing off the burr it created ? It's obvious where its hanging up now. It's almost like the cam is beginning to turn too late Quote Link to comment Share on other sites More sharing options...
98Z5V Posted January 16, 2015 Report Share Posted January 16, 2015 BCG manufacturer? DPMS-patterned, by some other company, or truly DPMS? Quote Link to comment Share on other sites More sharing options...
98Z5V Posted January 16, 2015 Report Share Posted January 16, 2015 The barrel is a Brownell barrel 080-001-022WB 18" 308 DPMS Med Mid Gas barrel. Dan, that's a DPMS-patterned barrel, but not made by DPMS themselves. Contact Brownells and ask them who makes that barrel for them, as it's their house-branded barrel made for them by someone else. Quote Link to comment Share on other sites More sharing options...
survivalshop Posted January 16, 2015 Report Share Posted January 16, 2015 You can remove the Barrel & use the Bolt to check head space, that will eliminate one thing . The Bolt Carrier may be out of spec's or the Upper Receiver , hard to say , How about some Photo's . Did you try more Lubricant on BCG ? Maybe even a small amount of Synthetic Grease on all the contact points . I use Gun Slick grease , but any old grease may help for break in , just don't go crazy with it & try to keep it out of the Chamber . A little dab on the back of the bolt locking lugs also may help . I do not recommend the use of a Mallet , but if the Cam Pin Channel or Cam pin itself has Burr's or some other machining imperfections , it can cause some problems . Quote Link to comment Share on other sites More sharing options...
Lapp7660 Posted January 17, 2015 Report Share Posted January 17, 2015 Wanted to post this so no one else makes this knuckle head mistake like I did. The knight upper receiver is very tight, the barrels do not go in easily even after heating the receiver with a heat gun. I had put the URX 3.1 rails on first and did not notice that the barrel had not seated all the way in and that was the problem all along. I took the rails off and could notice right away; once I fully seated the barrel correctly the BCG functioned perfectly. I am still taking it to a local gun smith and having it checked before I shoot it. Lesson learned. Quote Link to comment Share on other sites More sharing options...
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