Roadk9

Well that sounds like an invitation. I will test this batch of loads out and determine which one my AR likes best and get back to you.

I did a price check on a selection of premium .308 ammo. The local Academy has a good selection of Hornady and Federal items. The prices though are really high. So I accessed AmmoSeek and checked availability of the same ammo. I found I could order most of the same Hornady and Federal loads from Carolina Munitions at substantially lower prices. CM uses UPS for shipping and that is expensive. However when I added up the unit price and the shipping it was still $20 less than buying from Academy when the local taxes were applied. ??? So I have a selection of premium ammo headed my way to test in my M5E1 Carl

Wow! what a nice offer. But I'll defer to the skilled services of my local gunsmith on that. I have a drill press, but using bits that small, on a $300 barrel, makes me nervous. Said 'smith has the tools and experience to get the job done. I will ask him to open it to .090 to .100. I am using an adjustable gas block so I can close it down to whatever allows it to function best once I reassemble it. I'll take this opportunity to thank you all, especially 98Z5W, and the new guy Floydie for the suggestions, advice and guidance. You are appreciated.

On that note: I built my first 1911 in 1976 in Augsburg, Germany. I mailed most of it home when I DEROSed in January 1977. That got the attention of CID who promptly intercepted me on my way to Rhein Mein for a MAC flight. In a quiet interrogation room later I was presented with the evidence of theft of US Govt poverty and read my rights, to which I responded with the documentation of the purchase of said property from one retired US Army Colonel living in Seattle, WA. Some embarrassed agents then gave me a ride to try to make my flight, which I missed, causing me to arrive at Ft Dix too late to process, further causing me to spend one cold assed weekend there waiting until the processing center opened on the following Monday. Ah the memories.....

Hah! I disassembled the gas system today (just now). I used drill bits to measure the holes. What I found is simple, the marking around the port on the barrel covers the port (centered) the same marking on the gas block is centered on the port there. So the gas block is aligned correctly. I dropped a .125" bit into the gas block and it went into the tube. Double checked that. So the tube and the block are .125". The barrel though is not so pretty. All I could get in the port is .0625", and that doesn't go in smooth. The barrel is an 18" mid port design, I think the port could be larger.

Got it, and will remember that for future builds.

I am not sure of the gas block alignment. I had the gas block installed by a local gunsmith. I will pull it and make the check you describe. Today at the range with the BCG really dripping with oil it worked much better than previously. The Tubbs spring seemed to allow the BCG to travel its full range most of the time. I say most because there still were a few times where it didn't, and a jam resulted. But on two empty mags it did lock open on the bolt lock. I don't think the buffer tube, spring or buffer are causing the problem now. The next check as described by jtallen83 will be done tomorrow. If I can find the thread he mentioned I will check that and maybe I will need to open the gas port more. I don't think the adjustable gas block should need to be all the way open to allow the rifle to function properly. This is a real learning experience, I am enjoying it, mostly because I see that the rifle is capable of real accuracy. At least it is when I figure out out how to get a good shooting position consistently.

Thanks all for the suggestions. I will use more oil today when I try it with the new spring. Lots more oil.. the gas block alignment will be the next check if things don't go well today..

The overall result then is instead of overtravel I now am seeing under travel. For my next test I am using the Tubbs flat-wire AR10 spring. If no improvement I'll try the original Aero Precision spring. I will keep the gas block wide open. Meanwhile, the accuracy I'm seeing makes this effort worthwhile. I still need practice hence the two flyers.

Hi All, I'm back with the update. The genuine Armalite AR10 buffer kit arrived and was installed. I did no substituting. Went to the range yesterday and shot 20 rounds. I started with the gas block set at 5 clicks open. I had taken the time to do a thorough cleaning prior to installing the Armalite kit. The results: It would eject the spent case but the bolt didn't move far enough to strip a new round off the magazine. The bolt would contact the new round's case and push the cartridge nose into the barrel and that is where it would stop. I am using the Federal Match only so I decided the try a different magazine. No change, then I started opening the gas block. By the time I got to 14 clicks open it would actually feed correctly maybe once or twice. Then I got the idea of trying to see how far the bolt is moving back in recoil. I put one round in a mag and shot it. The photo shows the result. The bolt only got far enough to clear the mag follower not the bolt catch.

I will get on it now. Armalite is out with no prediction of when. I guess it's worth the extra $13 to get it from EuroOptic. Thanks again.

Aha! I thought, when looking at a pic of the Armalite system, that they were showing a AR15 system with the longer buffer. But it's intentional and the tube is longer too. Now it makes sense that it would be a better unit. An H3 buffer should be 5oz and help to tame the stronger recoil of the .308. Then doing the math my 2.5" buffer and 7" tube gives about 3/16" clearance between the Carrier and the tube. The Armalite system then should give me 5/16" clearance in addition to the recoil reduction. I'm convinced and will order the Armalite system tonight. When it's in and tested I will post the results here. Thanks again.

Guys, I have looked at the Armalite kit and the buffer looks longer than the one that came in my Aero unit. What is the length and weight of the buffer in the Armalite kit?

That sounds like like you used to work on Harley Davidsons in the past. But it is a good idea until I get a better buffer system in place. Meanwhile after giving the unit a good cleaning I compared the buffer in my Colt AR to the one in the Aero unit. The Colt is 3/4" longer and .28oz heavier?????

This "teacher" is also a Reserve Police Officer. I guess he is what the Liberals in California would consider a responsible gun owner.

98, also if the buffer pad is being compressed then I made it worse by opening the gas block more instead of closing it down?

98, I agree it shouldn't have the room to hit. So I measured the buffer and bolt carrier. then I dropped the buffer in the tube, no spring, and lowered the carrier in. Pics below. The only way the carrier could hit the receiver or tube is if the buffer pad deforms under recoil.

Wow, that was quick! As has been realized here the complete Aero lower came with buffer tube, buffer and spring assembled. I will check the depth of the tube today and research the Armalite setup. What is the optimum tube depth? And what if I used a longer buffer instead of changing the tube? A quick check shows the tube depth is slightly less than 7". The buffer is an SAA unit and 2.5" long. I will sideline the M80 ammo and get more of the Federal instead. The Saker will stay in the safe until this is resolved. Thanks for all the suggestions.

Thanks Guys.

Hi guys. I'm new and it was suggested to me that if I wanted to get opinions on a problem I need to first post the build list. So here it is Aero Precision M5 complete lower, M5E1 complete upper and 15" Handguard. Ballistic Advantage (Hanson) SS .308 18" barrel and nickel boron BCG Melonite gas tube (mid), Radian Charging handle SLR adjustable (titanium) gas block, AAC Brakeout, and shim kit Geissele SSA/E trigger. Magpul, Stock, grip, RSA, ASAP, PMAGs. Unrelated but what the heck: LaRue LT112 scope mount Burris XTR II 5-25X50 Silencerco Saker 7.62 Now for the problems: fail to feed occasional, stovepipe, also occasional, fail to eject(but trying to feed another round) fail to reset trigger occasional. Additional information. To break in the barrel I have been using M80 ammo I had leftover. Its dirty. I started with the GB at 7 clicks open that allowed the bolt to hold open on an empty mag. Now I'm up to 12 clicks open. I have disassembled it tonight and will give it a thorough cleaning. I have ordered a SSS Flatwire Buffer spring. and have a case of Federal GM308M to use for further shooting. One puzzling item I discovered when taking it apart are two areas of impact where I didn't expect. Photo is posted below. I think the BCG is impacting the Buffer tube in two places. That is why I ordered the flatware spring.

You're suggesting I list what I used to build the unit in a separate thread to allow others to make suggestions? Hmmmm.

Just ordered a flat Buffer spring from Brownells. My newly built AR10 is doing crazy things like, fail to feed, stovepipe, fail to eject.

Hi All. I am an old shooter living in St Pete, shot my first AR in the Army in 1973. Currently I have 4 ARs two in .223 one in .300 BLK and my latest build a AR10 build on the Aero Precision M5 base. I found this site by looking for discussions on buffer springs. I will do a site search on this. Anyway I'm sure there are plenty of persons here who know a lot more about ARs than I do so I expect to learn a few things. Below is a pic of the AR10