Curious if anyone out there has put together a 7.5" 5.56 rig using the XLP kit with intent to suppress? I just finished one up and am fuming f'ing pissed. I'm also hoping to get some feedback on what further modification I could try before calling Adams Arms. Here's the deal:
I tend to gravitate towards projects that are challenging but also maintain the core aspects of a reliable and accurate rifle system. My original intent was to build the shortest possible 5.56 that can be suppressed without running into muzzle pressure issues that would affect the performance or structural integrity of my suppressor. I figured while I'm at it, I'll go as light as possible without giving up things I personally consider important enough to sacrifice for added weight. One thing I've always despised about piston rifles are the enormous outside diameters of the handguards to accommodate the operating system components. Personally, I move more fluidly and control the rifle dramatically better with slimmer profile handguards. I felt I could make the KAC URX4 - one of my favorite rail systems - work with the 1.55" ID and 1.65" OD. The keymod slots are machined concentric across the entire hand guard which was important as it made it much easier to shorten and maintain the intent of the original design. It's also relatively light for a heptagonal keymod design and it's strength to weight ratio is fantastic.
I spent about 3 weeks doing the machining, blasting, re-coating & testing for drive rod clearance, proper bushing and spring seating, etc. before putting the last run of milling to the test. Ended up with a hair under 4.5mm in clearance between can and end of rail, 1.5mm between guide rod/top of gas block and top of rail, and bushing/spring were seated nicely. Right about here is where I had stopped after the first two rounds of machining after taking note of areas I needed to remove more material. I played it safe to safeguard against reducing the structural integrity of the handguard. This time however, outside of detail work - smoothing edges, trimming burrs, etc. - I was gtg on all dimensional aspects and excited to do some live fire testing after installing my M4-2000. I proceeded to install the brake and was concerned with the spacing between the gas plug and where the threads on the barrel begin. I finished installing the brake and included .051" in shims and ratcheted on the can. It's at this point where neighbors a few miles away likely heard me yell Ffffffuuuuuuuuucccckkkkk!!!!
This is how the adjustment mechanism on the end of the gas plug looks. You depress the button on the top to move the selector and adjust gas settings...
THIS is how nicely this system mates up...
Hmmm, not thinking that's going to work out very well. I did specifically ask Adams Arms via email about the compatibility of the XLP kit with a std pistol length gas set up on a 7.5" tube. They said gtg. They also sell an XLP pistol length kit now - yet they didn't a month ago when carbine length was the shortest gas system available in an XLP kit. Before I go bashing a MFGer for selling something I'm convinced won't work sold as it is on a system they do indeed market it for I figured I would grab some opinions of those who have some ideas on a fix or who have run into some similar issues on highly modified projects. Any input is greatly appreciated! Thanks gents...
I tend to gravitate towards projects that are challenging but also maintain the core aspects of a reliable and accurate rifle system. My original intent was to build the shortest possible 5.56 that can be suppressed without running into muzzle pressure issues that would affect the performance or structural integrity of my suppressor. I figured while I'm at it, I'll go as light as possible without giving up things I personally consider important enough to sacrifice for added weight. One thing I've always despised about piston rifles are the enormous outside diameters of the handguards to accommodate the operating system components. Personally, I move more fluidly and control the rifle dramatically better with slimmer profile handguards. I felt I could make the KAC URX4 - one of my favorite rail systems - work with the 1.55" ID and 1.65" OD. The keymod slots are machined concentric across the entire hand guard which was important as it made it much easier to shorten and maintain the intent of the original design. It's also relatively light for a heptagonal keymod design and it's strength to weight ratio is fantastic.
I spent about 3 weeks doing the machining, blasting, re-coating & testing for drive rod clearance, proper bushing and spring seating, etc. before putting the last run of milling to the test. Ended up with a hair under 4.5mm in clearance between can and end of rail, 1.5mm between guide rod/top of gas block and top of rail, and bushing/spring were seated nicely. Right about here is where I had stopped after the first two rounds of machining after taking note of areas I needed to remove more material. I played it safe to safeguard against reducing the structural integrity of the handguard. This time however, outside of detail work - smoothing edges, trimming burrs, etc. - I was gtg on all dimensional aspects and excited to do some live fire testing after installing my M4-2000. I proceeded to install the brake and was concerned with the spacing between the gas plug and where the threads on the barrel begin. I finished installing the brake and included .051" in shims and ratcheted on the can. It's at this point where neighbors a few miles away likely heard me yell Ffffffuuuuuuuuucccckkkkk!!!!
This is how the adjustment mechanism on the end of the gas plug looks. You depress the button on the top to move the selector and adjust gas settings...
THIS is how nicely this system mates up...
Hmmm, not thinking that's going to work out very well. I did specifically ask Adams Arms via email about the compatibility of the XLP kit with a std pistol length gas set up on a 7.5" tube. They said gtg. They also sell an XLP pistol length kit now - yet they didn't a month ago when carbine length was the shortest gas system available in an XLP kit. Before I go bashing a MFGer for selling something I'm convinced won't work sold as it is on a system they do indeed market it for I figured I would grab some opinions of those who have some ideas on a fix or who have run into some similar issues on highly modified projects. Any input is greatly appreciated! Thanks gents...
