JT303

Like the CMP shirt !! I went to the North store late last year for the end of year blow out. (I couldn't find a nice T-shirt while i was there) but...... Scored a nice SA Happy Easter brother

Yep, exactly what I was thinking as well. Gonna set that up after my drilling time.

Its currently not locking back on empty nor feeding after ejection. Hopefully the opened port will correct that issue. I got the adjustable GB because I may want to be able to bleed off if I go with a suppressor in the future. Happy Easter !

I was running full open (SA ADJ GB) 18 clicks. I took video of my shots showing the bolt carrier barely ejecting spent single rounds and DF jammed every multiple loaded mags. Cyclic timing is definitely off. Gonna open Gas port .01mm or so and then reassemble and test fire next week. Right now im just using Fed GM 168 BTHP factory loads. Overgassed should be throwing cases forward. Im getting 3 oclock little drop out of ejection port. But I will keep that in mind. Thanks !

Yes, Gas block had only seen 20rnd for barrel break in. Now that I took it off, I will need many more. Let me know if you can see this attached pic. Its gouged where the end of the spring meets the center of the buffer stop ring. The damage aligns with the spring. To me, that is saying its too much force in spring compression. No other damage on the lower receiver or bolt carrier is observed.

I noticed in your aero build that you used a Aero rifle length tube. I have a Breek arms Rifle length spring and buffer. My coils measured kind of long and the buffer is 5.4oz. I am curious as to what your buffer spring length, # of coils and inside depth of the tube is? Also, if you have any nasty gouges in your buffer as I posted in this thread? I'm gonna be drilling my gas port a bit tomorrow and out to the range next week for test fire. Pretty sure I need a bit more gas with the current set up but also have a feeling my spring is too strong still. I took a chance on a good deal with Breek arms on the buffer tube set, but they are supposedly up to spec. Anyway, thanks again brother from another branch. Stay safe

The bits from there are actually manufactured near me. go figure...........(but they charge more at the source, thanks IL😂🙃) I am so moving out of here.

Thanks 98 !! Sweet site ! That makes it easy and stay consistent too. I was searching for a nice set and couldn't find anything decent out there nearby. Wound up just ordering 2.2mm (pk of 5) for 10$ on amazon. Will be here Sat and will get it opened up a notch. Probably will order that set next week too. Cant have enough extra tools/bits for future builds. 🙂 98. You should teach some online courses or YouTube some stuff. I'm not Mr. internet but I'm sure your experience and knowledge would help many out there with future builds. Great info !

That was my next step, and the JB welded T15 did the trick. The extractor set has been on my wish list for a while anyway. Gonna go get some HF left bits for future use. Hey for $8.50 cant go wrong if it saves me time in the future.

Got a measurement of 2.12mm (.0827) approx. (See pix below in thread). I am really not far off from 98 port recommendation for .0936 sized barrel. Got some 2.2mm bits ordered to give it a bit more opening. (I have a 2.35mm bit just in case I need more) I still think the spring and buffer are too much, but Im going with everyone's consensus for the combined expertise to increase gas first. Thanks!

Success. JB weld a T15 torx head and some overnight Uncure debonder did the trick. The carbon on the gas port is perfectly centered (sorry bad pics) Measurement I did the best i could. I came up with it currently just a little loose using a 2.0 mm bit. The 2.35 bit does NOT fit. I also used a caliper and came up 2.12mm So by my math, if I should open it up to 2.2mm to make it .086 per recommendation by 98. (IT IS A .093 size BULL Barrel). Gonna try and find a 2.2mm cobalt bit right?

Yeah, I ordered a little extraction set which is basically the same thing. I should have just went and bought that to begin with, but I was trying not to strip it too badly or mess up the threads, but I wound up stripping it that anyway. Threads still okay. Tried smacking and JB welding a torx head and gonna try that with uncure fluid. If not, its getting drilled out. I have always hated little allen head screws. Wish someone would come up with something better.

Yes, I have a 0.936" gas block diameter. As soon as I can get this messed up Allen gas screw out I will let you know what the current port size is. getting an extractor tool tomorrow and some uncure fluid.

Its all fun and games until you strip a gas block screw. Dang it. Now gotta get some more tools. Will advise my port size after I get that bugger off.

I was unaware that carbine stocks were more troublesome than Rifle lengths on the 308 platform. My intention was also use this lower and swap the upper out with a 6.5 CM in the future. Hoping that one lower works with others is a money saver. 🙂

Awesome advise 98 and all. All things have been pointing me to the gas port size. I should have taken that measurement BEFORE I installed it but I had faith BA was going to port the barrel correctly. I have also cleaned and wiped the parts down before taking these photos. I will take your advise and run it much more wet going forward. I grabbed a set of small HSS mm drill bits to measure the port and will try to get that number back to everyone. Yes, I do agree that I am throwing money at parts I probably don't need, but that also gives me more parts for another build. (LOL) 😁 Gotcha all on wide open gas block. (The reason I got one was eventually, I may go suppressed and wanted that flexibility in the future) one day. Any advise on the bad knicks on the buffer? I dont think those gashes and the tube/spring sizing is right. I only have a small dremel sized drill press so if I need to open the port up any advise on the drilling part? Just do it with hand electric or ? I know, nice and slow..... Recommendations for best port size based on 20" BA Bull barrel SS approx 6.5" from gas port to muzzle (Not including comp) ? Saw in other posts suggested .093 to .096 for 20" but just checking. Thanks JT

Hello all, I have been building AR15 for a while now and just completed my first DPMS Aero 308 build. Mostly Aero/Ballistic advantage parts (upper/lower M5). First time to range for barrel break in resulted in failures to cycle or lock back on single round. Loading multiple rounds also resulted in base over boat failures and jams. Single round fired ejection occurs but is very weak at 3 o'clock. Gas system is SA adj confirmed at full open (18 clicks). 20 rounds so far and consistently the same malfunctions. After reading the forums several times over, I am going to first try a carbine length M5 buffer from Aero instead of the Breek arms rifle length combo. The reason is I believe is that the buffer itself was gouged by the spring (See pic). I believe that the rifle length tube and spring may be out of spec as I did measure them several times (see below). Breek arms charging handle as well. I also ordered a JP SCS-10K and odin works AR10 buffer (carbine) to play with on the cycling. If it runs correctly, great. If not, I will the try to open the gas port. I believe that the gas port is correct size, but will measure and confirm if the buffer issue doesn't fix cycling. It should be noted that the barrel is a BA bull barrel with a Apollo Max ultradyne muzzle break. Very minimal recoil with this comp which makes me think that has something to do with the cycling/timing and gas pressure. I know I will need to shoot it several times more (as 98 recommends maybe up to 200 rds) for sealing of ports etc. Just looking for some advise on the buffer/carbine combo swap and if anyone has experienced similar issues with Breek arms. Also, any tips on opening up gas port after next test fire too. 1. Aero M5 Lower/Aero Upper 2. Buffer weight 5.44 oz 3. Buffer Length 5.269 inches 4. Extension Buffer Tube Internal depth 9 23/32nd inches 5. Breek arms Rifle length buffer and tube/spring combo Coil is 12 11/16ths depth, 35 coils, gray in color 6. Rifle Length gas system Bought in kit from Ballistic advantage special 7. Gas tube length=Rifle 8. Photo looking directly thru magwell 9. Photo of bolt face 10. BCG Clearance and bolt stop 11. Gas journal and gas port diameter .936 gas block SA adjustable. Gas port to be measured if weights correct issue 12. Photo of description of malfunction and issue fail to lock back on last round or cycle properly. 13. Extra photos Thanks ! JT