Dewey Mack

Ejecting at 1:00?....doesn't sound under-gassed to me. My rifle doesn't eject that far forward unless I have the suppressor on. Sounds over-gassed and needing an AGB from my experience, not a larger gas port. I have used the Superlative Arms (clamp-on) with success. 0.020" slop around the firing pin sounds...VERY out of spec. It should be closer to 0.005" or less for precision shooting. I'm running toolcraft "HP" double-ejector bolts in my rifles which fixed my cratering/punctures and launches the 308 brass about 10feet. Gas tube extending 3/4 of the way into the cam cut out increases pressure time on the bolt = over-gas-like reaction. Gas block journal size? 0.093" should be good enough. That's what my rifle-length 18" 308 is at, and it needs AGB full-open just to cycle the orange spring + 5.6oz buffer, granted it's a much shorter barrel. I stepped down in spring and changed to A5 tube setup. It still fits my PRS Lite stock and many more spring/buffer options to play with. It also cycled fine with KVP 2.5" buffer and KVP AR10 carbine spring in the 7" buffer tube. Hint: check out my new post about spring data. I HIGHLY recommend you get the rifle running correctly (without primer cratering/punctures) with good basic (not cheapest) factory ammo before working on reloads. Otherwise you don't have a baseline to know what exactly is causing a problem. You're changing too many variables at once. Fixing your rifle should be methodical, just like reloading.

At the risk of releasing this too early, I think this might help everyone building or tuning their large frame "non-standard" rifles: Tested Buffer Spring Data I used this idea from Blowback9.com when I was building my PCC. He made a spring tester for testing various springs for the "gentle recoil system." He only tested the springs for M4 carbine bolt-open/bolt-closed positions because that was the only data he had to compare. So I was inspired and created my own spring tester with multiple positions marked for M4, A5, and Rifle Length compression for AR15 and LR308. So far, I have tested 24 different springs (all of which I purchased) and are new or otherwise noted. My brother-in-law has the Aero 308 carbine and rifle springs which I should be testing soon as well. Yes, I actually spent money on this because I'm SICK of the industry not helping out the average joe and tired of tacticool keyboard warriors recommending springs when there is ZERO ACTUAL DATA behind any of their recommendations--[not meaning this forum, but Reddit/AR15.com/etc]. I tried to provide links to most of the springs in the "All Springs Tested" tab. This can be very useful for not only large-frame but fine-tuning all AR platforms. Keep in mind, most are data points of ONE spring each. I reference 7.2 lbs / 16.5 lbs as the standard for AR10/LR308 since this is what Tubbs reported on their website. I also highlighted the EA1095 which I purchased from HeavyBuffers; I'm unsure if it's an actual Armalite component or their copy of that spring. I have also tested some of these springs in my carbine, A5, and rifle LR308 setups. Without going into detail on this post, I have these few conclusions: The Sprinco Orange was massive overkill. Ejection pattern direction didn't change but ejection distance cut 1/3-1/2. Maybe only try if severely over-gassed; it's $20 so maybe getting an adjustable gas block is smarter if you already have a good spring, proper gas port size, and correct buffer weight. The EA1095 is pretty much ideal for A5 and Rifle setups. There are some GOOD alternatives as well. The Strike Industries flat wire was extremely weak; I think it's best served in the AR15. The Griffin Armament +15% A2 spring was more like +35%! I'm not sure if that is a defect or not. I may call them. The KM Tactical 308 Rifle spring is also very weak; also a possible defect or I was sent an AR15 rifle spring. ALL M4-carbine tube springs were overkill (except the weak SI flat wire), and it does not seem like an efficient nor flexible setup. I have both A5 VLTOR and BCM MkII tubes. They both measure 7.75" internal. I don't care they're not 7 5/8" and not going to argue; I just wanted to make a standard for my measurements. And honestly, I 3D print custom shims for my buffer tubes to make all my AR bolts have 0.060-0.080" bolt catch gap. Buffer-bottoming depth varies based on how far the tube is threaded into the lower receiver, and every tube is different. Enjoy and pin if you think it will help. I'll update when I test new springs. Cheers, Dewey

A few weeks ago, I attended the Suppressor Day hosted by East Valley Tactical at Ben Avery with my father and son. My father won this in the raffle but gave it to me since I bought the tickets (lucky me!). So I just purchased a blem BCM upper and going to make my first 300BO build. I will be shooting this suppressed with subs once my can gets out of jail. I'm looking forward to this shorty! Barrel is Mos-tek 5.5" with a Micro gas tube length. Gas port is 0.111" so I hope it will cycle without the suppressor installed, but we'll see. Ready to Ship 300 Blackout Barrel 5.5" 1:5 Twist Zulu Profile, (mos-tek.com) Cheers, Dewey

Yes, by Lake Pleasent. Function tests at the new Church Camp Road range, then drove across the road SE to Saddleback Mtn Range for the long range plates. No benches, just shooting "plots". The Church Camp road has 100yd & 200yd plates with nice concrete bench rests w/adjustable stools, and also a pistol plate range. The benches were just added a couple months ago. I really enjoy going there. And if I need to print paper, I just drive down the road to Ben Avery. Win-Win.

Range Report: Yup. It works. With the KVP setup, I even started bleeding out the gas a few clicks, but I had a couple hold-open failures on the cheaper ammo, but no issue with hunting ammo. So I think I'm going to run it open for now and have full adjustment if I start seeing forward ejections or suppress it. KVP works for me! I had very random issues with the Armaspec Stealth spring system. It was just....inconsistent and unreliable even when gas block fully open. It sometimes worked, sometimes didn't, and I tried multiple bleed settings. It needed a couple quarters behind it as well to take up the slop. I'll see if Armaspec will exchange them for AR15 versions I can try in my other rifles. For my personal results, I don't recommend their system in the LR308. Using the Norma Tactical 147 FMJ ammo with my PA SLx 4-14x ACSS HUD/DMR FFP scope, the holdovers were dead-on out to 700yds! I started at 200yds and worked up, never missing a hit. I even had my son shoot at 700yds and hit 3 in a row. He was shocked. I'll have to sight it in for my hunting ammo, which will probably have more drop, but this ammo matched perfectly with the scope! Best of all, it's a free public range. Thanks again 98Z5V! I very much appreciate it!

I have drilled the gas port to 0.096", but I had to retrieve my FatWrench from my Bro-in-law to torque the gas block. I also purchased a borescope on amazon to confirm the port was lined-up correctly with 0.025" off the shoulder per Superlative instructions. The SA port is 0.120" and measuring the distance of the barrel gas port from the shoulder, I needed to space the gas port for good alignment. If I push the gas block all the way to the shoulder, the gas port would be partially covered. I have always installed it with 0.025" gap but just wanted reassurance. The borescope confirmed my math. Poor weather here in Phoenix (imagine that), so I'll go to the range later this coming week after the holidays to confirm functionality. I'll test both the KVP heavy spring/buffer and Armaspec AR-10 Gen3 Stealth Recoil system again.

Thank you for the response! I'll drill it out later this week and report back. KVP is a 2.5" long buffer. SS buffer with tungsten weights. https://kawvalleyprecision.com/product/kvp-ar-10-308-car-ss-tungsten-buffer-5-6-oz/ https://www.joeboboutfitters.com/Kaw-Valley-Precision-AR-10-308-Tungsten-Carbine-Bu-p/kvp-ar10-5.6.htm Standard M4 carbine tube. I buy the buffer from joeboboutfitters as you can get the entire Carbine kit or just order the buffer and add the heavy XP spring for $5. The spring is advertised as an extra power PCC spring, but the photos label it also as AR-10 spring. I'm 99% positive this is the spring that's in the KVP AR-10 kits, and it's sold separately on joebob advertised as the 308/PCC spring. It is definitely stronger/stiffer than the Armaspec stealth recoil system that I tried earlier. https://kawvalleyprecision.com/product/kvp-17-4-ss-pistol-caliber-carbine-xp-spring/ https://www.joeboboutfitters.com/Kaw-Valley-Precision-AR-10-6pos-Mil-Spec-Carbine-S-p/kvp-ar10-milspeckit-5.6.htm

Hello experts, After trying multiple, different 308 Faxon barrels with poor accuracy, I finally switched to a WC barrel and getting much better results. I do have the longer, correct-length gas tube but it is short-stroking with my Superlative Arms Adjustable gas block at full-open (with multiple different types of ammo), no last round hold-open, but ejecting at 4 o'clock. I removed the gas block and measured a 0.087" gas port. Gas block was properly aligned. Wilson Combat .308 18" Tactical Hunter (fluted SS) BARREL, .308 WINCHESTER, TACTICAL HUNTER, 18", FLUTED, STAINLESS, GLASS BEAD, 1-11.25 (wilsoncombat.com) .750" gas block shoulder .087" gas port Rifle+ length tube, ends middle of keyhole Kaw Valley Precision 5.6oz buffer and heavy spring kit, carbine tube w/PRS Lite stock SA Adjustable gas block Toolcraft 6.5CM "high power" dual-ejector DLC BCG Should I drill to 0.090" or 0.093", or just jump to 0.096" and adjust with the gas block? Thanks in advance! On a side note, I was initially using the Toolcraft standard DLC 308 BCG, but it was cratering or puncturing every single primer. Toolcraft swapped it for free to the "high power" 6.5CM DLC BCGs which have a smaller diameter firing pin, and it immediately fixed the cratering.