FOGeologist

Purchased: Crows Foot Adapter For All Guntec USA Handguard Barrel Nuts (.308 Cal) (#WRENCH-JK-308) from Tactical Transition. I have had to suffer with Guntec's bogus multi-wrench for too many installations. Done with that. $30.22 delivered.

My Waterboard data: 1. PSA Gen 1 upper and lower. Can't stuff full PMAGS into receiver at all. Have to download 1 round. Even partial mags have to be aggressively slapped into the mag well; been like this since Day One. Suspect bought incorrect bolt stop? 2. Dumping PSA Gen 1 receiver set for Aero Precision M5 2 Sep 22. Set should be here late this week. 3. New barrel: Faxon Big Gunner, 18", rifle length gas. Stock port is 0.093" which is normal, according to Faxon. Mine was clogged like a sonofagun with debris of every kind: carbonaceous powder residue, pieces of gook, parts of old shoes, a piece of a Tennessee license plate, and a Democrat voter registration card of a person who died in 1869. Clear now. Note: Positive ejection was never a problem - it was far too hard, timed at 5 o'clock, and flying 25' away like it was an H&K 91/G3. Will leave muzzle device off rifle until function checks are complete. 4. Gas system: Adjustable gas block with 8 clicks from almost completely blocked to "fully semi-automatic" (LOL), or as you Normies might say, "fully open." 15" gas tube, flowing freely. Tube is inserted 3/8" into gas key on KAK BCG. May have to think about a longer tube. Method of testing will be: Fire commercial ammo with adjustable gas block fully closed, then open it a click, fire rounds, and keep doing this until the weapon ejects properly every time. 5. BCG: KAK heavy duty with dual ejectors. These love to smear case-heads when handling high pressure loads. Do far less damage when load is in spec. 6. Tube and Buffer: Currently running 7" deep, no name mil-spec with 3.8 ounce PA-10 buffer. Tube is not perfectly run in to the end of the ring, but no evidence of impact of BCG to the ears on the threads or anything; changing to Spike's Tactical SLAX-500 7-7/8" buffer tube with either Sprinco Red or Armalite spring, whichever I can get a hold of, and a 5.7 ounce, 3.25" Armalite H3 buffer, which is in my possession. 7. Handguard is a Guntec Keymod special from six years back. Please don't bust my balls over it. Have torqued to 40 lbs-ft using their nearly useless wrench. 8. Powder loaded was X-Terminator. Turns out it's really suited for small caliber stuff, and works the treat in the 3 AR-15s I have. Not viable for 150-grain and up projos in a 30-cal bore. Results prove it - velocities 200 fps higher than a much longer barrel should produce, primers popping all over the place, and case-head smears. Will load up trial load with 165 grain Hornadys on Varget or some other better-suited powder. 9. Rifle has been completely disassembled down to component systems, and will be carefully rebuilt and test-fired using commercially-loaded ammo to initially set operating pressures, and for function and zeroing purposes. All components should be here for final assembly within two weeks, and initial testing should occur by 21 September. Looking for low pressure signs, function, accuracy, reliability.

Today: Ordered a .308 Winchester headspace gauge rental from Reamer Rentals. Both cheaper and easier to do this than to find a gunsmith, who will charge me $50-$100 to do this, and take 5 months, with me pestering him 4 times per week after month 4 <rolleyes>. $31 both ways.

Intro: Built .308 AR from Gen 1 PSA gun in 2016. Gun ran, but did not run well. Some changes were made... gun worse than previous. See thread "Ship of Theseus" thread previously made from late August 2022. Rebuilding now with different receiver, this time with knowledge gleaned from this site. Will make one post per decision/action per day taken.

I am getting loads of great advice in this thread. Thanks for your help!

Hmm, making sense. I will hang with the 3.25 H3 Armalite buffer and replace the tube with Armalite 7-7/8” ( I think). Can I still use my Sprinco Orange or do I need the Armalite spring?

Loading manual: Western Powders. Powder: Ramshot X-Terminator. Cases: Lake City, various. Previously reloaded commercially. Once fired by me. Suspect primer crimps were over-reamed or pressed. Bullets: Hornady FMJ-BT cannelure, 150 grain Starting load: 40.8 grains and velocities are supposed to be 2723 fps on 24" test barrel (Actual average of 5 shots 2830 fps on 18" Faxon Big Gunner) NOTE: Awful accuracy and would not cycle action (Did not try to adjust gas) Max was loaded to 45.3, and oddly got the best group of the day. 3 of five primers popped out. Group was still awful, like 8" at 200 yards. Worst pressure signs, tons of ejector smearing (meaning dwell time was a mess)! Should have stopped firing at 43.8 grains. Highest velocity I saw was 2933 fps. With accuracy so poor I moved to Barnes 168 grain TTX SP bullets; starting loads (same powder) 38.3 grains, moving in .5 grain increments up the ladder to 42.6 grains. Accuracy a mess. Primer going crazy at 41.1 grains. Hell, I didn't even record velocities since the gun was barely shooting, and primers were popping, I couldn't load a magazine into the rifle because Palmetto State Armory's Gen 1 dimensions were just about useless. When I cleaned the rifle, I found a primer that had hammered itself into the chamber face and was just pounded thin enough to allow the bolt to seat. I think that bastard had been in there from my previous range session where I couldn't see it, and had messed everything up with this range session. There was a host of other crap in there too.

Hmmm, if I go rifle length, I’ll need to change stocks away from my feather-light MFT stock. Mission with this gun was to build something no heavier than an AR 15 rifle. Plus, I’d need a rifle length buffer. I think I do have both components laying around, however.

Hmmmm. I'm shopping right now... I can return the buffer to Primary Arms and buy a shorty 5.3 ounce... or I can buy a new tube. I find it deeply weird that no manufacturer bothers to, I dunnow, MEASURE AND REPORT the length of their tubes. You know, provide factizoids for us builder-types to ensure we buy components that match our needs. Why in 2022 does an internet customer need to coach a partsmaker to break out a ruler and type in a couple lines of text in an online site?

Thanks for your responses. Sprinco Orange came in… 28 coil. H3 buffer arrived as well; it’s 3.25” or thereabouts, far too long for the 7” tube. Maybe I could get a longer tube, but I think I’ll send it back in exchange for a 5.4 ounce 2.5” buffer instead. I am using Western Powders guide for my 8lb jar of X-Terminator. I wish I had just bought Varget. Varget is what every smart person SHOULD be using for every centerfire big-bore rifle cartridge they reload. Hell, I used it to build a pin-accurate .223 load nearly 20 years back for a 52-grain Sierra Match King flat-base bullet that shoots a dream from the AR platform.

Scope is tight. It’s a nice VX Freedom 3 - 9 x 40 chosen as a balance between magnification and weight. Mount is tight. I was having weird problems with two scratches on the neck of the extracted cases; with the barrel off, the chamber is 1000% easier to inspect and clean. I think the barrel extension is a touch new and still not broken in. I will polish the feed ramps a touch to ensure the sharp edges are OK. Yes, the PSA Gen 1 has M4 feed ramps as does the Faxon Big Gunner. I did buy the Aero M5 upper and lower set yesterday. Should be coming in to my dealer early next week. I should be able to assemble and test end of next week.

Both of my barrels were very tightly fit into the receiver. Torques met the spec; I’ve been using Guntec free-floated fore-ends on my rifles (yeah, I know you’re shaking your head right now, thinking of going a different way here shortly) and attaining the required torque with their godawful wrench is like being killed. another note: velocities are off the chart high… like 2890 at starting loads with X-Terminator. 2990 at midpoint with strong signs of pressure: an 18” barrel should produce a couple hundred less FPS THAN A 24” test barrel. I will rent a headspace gauge and remove my extractor and ejectors and HS this muther to ensure I don’t have a freak show of a bolt head or something.

Intro: I am Nick, "FOGeologist," a long-time complainer on gun forums about everything under the sun. Don't take anything I say too seriously. I wanted a .308 AR for a long time, since I saw what accurate hammers they are. Never had an AR-15 that wasn't the "cat's meow," so I thought, "Wouldn't that be great in a larger caliber?" Yes, you are shaking your head right now. But that was a long time (and a lot of ignorant suppositions) ago. WHAT I DID: I am truly a SUCKER for a good bargain. When our friends at Palmetto State Armory came out in the early teens with their PA-10, I bought a Gen 1. I was teaching then, and making 35% of a normal salary, so I scrimped and saved and bought parts to go on the stripped lower. I got a PA upper, acquired a take-off 16" bull-barrel from a DPMS that had been rebarreled, and bought parts to fit the gun - KAK 18.2 ounce double-ejector BCG, an ar-15 carbine-length 7" depth buffer tube, PA-10 3.8 ounce 2.53" buffer. And an 11", 27-coil spring (I believe it's a PA spring). Full assembly was completed in 2016. The gun was... hard to load - DPMS mags had to be slammed into the well. Fully-loaded mags weren't functional; you have to download one round from max to get them to function. Furthermore, the gun was hypersensitive to hot loads, showing primer cratering, ejector smearing. It could shoot anywhere between 2.5 MOA and under 1 MOA, but that DPMS barrel was NATO spec. I bought a new Faxon 18" Big Gunner in .308 in 2020 to try to tame the weight and pick up some FPS, along with an 8-pos adjustable gas block and the 15" gas tube for rifle-length gas performance. I just checked the port on the Faxon - I stuck a .093" drill bit into the hole and it barely clearances. I have been showing high pressure signs on the case heads again - ejector smears, flattening, then popping primers. Ejection is extremely positive to 5 o'clock. I think I am under-buffered and undersprung, and am ordering a 5.4 ounce buffer and a Sprinco Orange spring in accordance with the gunsmith suggestions on this site. Accuracy was incredibly, horrifically bad, like 13" at 200 yards - with my handloads. I think it's possible a primer got stuck on the chamber face and the rounds were going into the chamber crooked - the first round would be 9" right of the group. I found it (and shards of other brass on the chamber face) at the end of my shooting session. Yes, I know how MF'n dimwitted that was. Now I am thinking that I am going to dump that PSA lower and upper; there's an Aero M5 on AR15 Discounts at a bargain price. I will rebuild this gun until I get it right.