Perch Posted May 27, 2020 Report Share Posted May 27, 2020 Hello, My name is Steve, moved to Texas from Commiefornia with my GF about 1yr. Ago. Love to shoot & build firearms! Got into building them in CA when they banned AR pistols from being sold. I read that the only way to get one legally in Ca. was to build it yourself so I bought a jig & router and have been building ever since! Actually just took the next step and bought a benchtop vertical mill so I can do more modifications as well as make parts myself. Main reason I joined here is to get some much needed help/advice on an AR10 build I did chambered in 6.5 creedmoor. Ill start a thread in the appropriate section once I figure out what section that is exactly lol,, but brief rundown is a Jauggernaut Tactical 80% lower/upper, JP supermatch 22" 6.5 creedmoor with +2 gas, Surefire socom muzzle break, JP .936 adjustable gas block, JP VMOS BCG and a JP SCS for .308 with the multiple spring kit. I took it out for the first time about a month ago and was tuning the gas system. Got it cycling consistently and locking back on last round but at the very first click where it would lock back it was ejecting brass at 1-2 o'clock like ita overgassed and was denting the rim of the cartridge consistently. Its my first time tuning a gas system on any firearm so I'm a complete noob. So when I got home later that day and was cleaning it I noticed the AGB was slightly off-centered. 🙄 Anyway fixed that and its aligned perfectly now but wanted to get some advice on how I should go about this. As I'm sure you all know the VMOS BCG and the JP SCS can both be adjusted to add more/less weight to the BCG or more/less weight to the SCS, as well as change the springs to add more tension or less. So my question is if I go about tuning the gas system to lock back on last round and everything is cycling, but I'm getting brass ejected @ 1-2 o'clock again and slightly bending the mouth of the cartridges, what should I turn to next? Or should I start out with the spring rate/weights on buffer system first or should I adjust weight on the BCG? Should I add more weight or less weight? How about different springs on the SCS? I'm pretty lost in this situation, hoping now that the gas block is aligned correctly I won't have this issue after tuning it but hoping for the best but planning on the worst. So what do you guys think? I'll go find the correct forum section and copy/paste my issue there. Here's a couple pics though. Thanks in advance for any info, even if it doesn't work I appreciate the effort! Steve Quote Link to comment Share on other sites More sharing options...
sagebrush Posted May 27, 2020 Report Share Posted May 27, 2020 that's an awful lot of variables. if you want it to shoot any load you put in it, I would put a 308ar toolcraft bcg and an armalite carbine kit (tube, spring, buffer) and call it good. welcome from oregon Quote Link to comment Share on other sites More sharing options...
98Z5V Posted May 27, 2020 Report Share Posted May 27, 2020 That's a Race Gun that you built, with a shiit-ton of complicated Race Gun Parts. You complicated shiit with complicated shiit. This won't be easy. If you're denting brass, it's hitting the brass deflector HARD, and denting the brass. Overgassed. If you're ejecting at 1 and 2 - many say that's a sign of overgassed. I don't give a shiit where my brass ejects, as long as it gets out of the gun everytime. But, if it's damaging brass... ...do you reload? Yes = that could be an issue. No = the gun is cycling, getting brass out, and maybe beating up internal parts over the long run. Your call. Quote Link to comment Share on other sites More sharing options...
Matt.Cross Posted May 27, 2020 Report Share Posted May 27, 2020 I can't tell you where the rim damage is coming from, but the case mouth dent is coming from the ejector spring being jacked up on steroids. If you aren't reloading, I wouldn't worry about anything except whether or not it's ejecting rounds reliably. This isn't a small AR and all that 'ejection pattern' horsewaffle from the small AR world doesn't apply. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted May 27, 2020 Report Share Posted May 27, 2020 11 minutes ago, Matt.Cross said: This isn't a small AR and all that 'ejection pattern' horsewaffle from the small AR world doesn't apply. My sentiments, exactly. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted May 27, 2020 Report Share Posted May 27, 2020 With the amount of JP Race Gun Parts in this build, the best bet for diagnosing what's going on with your gun might be a real telephone call to a tech at JP Enterprises... Quote Link to comment Share on other sites More sharing options...
jtallen83 Posted May 27, 2020 Report Share Posted May 27, 2020 Welcome from Iowa, via Missouri! Quote Link to comment Share on other sites More sharing options...
Perch Posted May 27, 2020 Author Report Share Posted May 27, 2020 1 hour ago, Swiftab said: Welcome to the forum. I use this Gas Block Alignment Jig. They will help you get it perfect. https://www.kawvalleyprecision.com/KVP-AR-15-Gas-Block-Dimpling-Jig-p/kvp-dimpling-jig-.750.htm Was about to buy one of those actually but came across a video of a guy using an uncooked spaghetti noodle cut flush to top of barrel to line the holes up.. so basically the spaghetti sits down through gas port but is held but is held straight up from the section that goes through actual port on barrel.. then you put gas block on and turn gun upside down to make sure the small piece of spaghetti falls into the gas block freely, tightening gas block down and flipping rifle right-side up so spaghetti drops back down into barrel and then using a cleaning rod to break piece of spaghetti to get it out.. The longer part breaks off and falls over, and the little piece that was holding it vertical that was in the gas port falls down into barrel. Worked great! Thank you for the link though, always appreciate any positive advice! My one issue with buying the jig was that they only worked on certain barrel sizes and gas blocks. For example I just built a MK18ish clone recently and the spacing for the Geissele gas block was something like .1 off of the KAW jig for where the dimple needed to go if I remember correctly. Quote Link to comment Share on other sites More sharing options...
Perch Posted May 27, 2020 Author Report Share Posted May 27, 2020 15 hours ago, Matt.Cross said: I can't tell you where the rim damage is coming from, but the case mouth dent is coming from the ejector spring being jacked up on steroids. If you aren't reloading, I wouldn't worry about anything except whether or not it's ejecting rounds reliably. This isn't a small AR and all that 'ejection pattern' horsewaffle from the small AR world doesn't apply. Good to know, I thought ejection pattern was more important. It was running 100% though even with the gas block not centered. 😒 Appreciate the advice, definitely puts my mind at ease and I won't worry about the brass as long as it doesn't stay in the gun after I pull the trigger. 😉 Quote Link to comment Share on other sites More sharing options...
Perch Posted May 27, 2020 Author Report Share Posted May 27, 2020 15 hours ago, 98Z5V said: That's a Race Gun that you built, with a shiit-ton of complicated Race Gun Parts. You complicated shiit with complicated shiit. This won't be easy. If you're denting brass, it's hitting the brass deflector HARD, and denting the brass. Overgassed. If you're ejecting at 1 and 2 - many say that's a sign of overgassed. I don't give a shiit where my brass ejects, as long as it gets out of the gun everytime. But, if it's damaging brass... ...do you reload? Yes = that could be an issue. No = the gun is cycling, getting brass out, and maybe beating up internal parts over the long run. Your call. Nope, not reloading but I do save my brass from my 6.5 to give to some who does reload. I guess that will be their problem then. Cant complain much about free brass so all good! Thank you, sir! Appreciate your help! Quote Link to comment Share on other sites More sharing options...
Perch Posted May 27, 2020 Author Report Share Posted May 27, 2020 15 hours ago, sagebrush said: that's an awful lot of variables. if you want it to shoot any load you put in it, I would put a 308ar toolcraft bcg and an armalite carbine kit (tube, spring, buffer) and call it good. welcome from oregon thank you Sagebrush. It was actually cycling fine with 3 different rounds, just ejecting the brass forward Shot some remington 120gr. Or maybe it was 130gr., Soft point i believe? Also Hornady 140 ELD-M, and Hornady 143gr. ELD-X precision hunter. I built it for longer distance shooting and for fun because I like to build stuff and tinker. Had never built an AR10 before so wanted to give it a try. Everything cycled i was just concerned about where my brass was ejecting, I thought it was more important but going off of what others have said I guess it isn't that important on Ar10s Quote Link to comment Share on other sites More sharing options...
Rsquared Posted May 27, 2020 Report Share Posted May 27, 2020 Welcome from Maryland. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted May 28, 2020 Report Share Posted May 28, 2020 5 hours ago, Perch said: It was actually cycling fine with 3 different rounds, just ejecting the brass forward Make that buffer heavier, and it'll change the ejection pattern more rearward. It'll cut down on the dented case mouths, too. Quote Link to comment Share on other sites More sharing options...
Perch Posted May 28, 2020 Author Report Share Posted May 28, 2020 2 hours ago, 98Z5V said: Make that buffer heavier, and it'll change the ejection pattern more rearward. It'll cut down on the dented case mouths, too. Awesome! Planning on going to the range this weekend so I will give that a try. I'll let you guys know how it goes. Thank you for your help, I appreciate it very much! Quote Link to comment Share on other sites More sharing options...
98Z5V Posted May 28, 2020 Report Share Posted May 28, 2020 11 minutes ago, Perch said: Awesome! Planning on going to the range this weekend so I will give that a try. I'll let you guys know how it goes. Thank you for your help, I appreciate it very much! Give up some of the details on how you're making this JP buffer - heavier. It'll help us better understand this system, and tweak it in the future. Quote Link to comment Share on other sites More sharing options...
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