Sarugo

My thought was that since my bolt wouldn't lock back with the gas port fully opened that I may be slightly undergassed on account of a small gas port.

Thanks again everyone. Currently my rifle is mostly disassembled and I’m waiting on some new gas block screws(stripped ‘em) and a JP extractor. Once I receive those parts I plan to do the following… - Install new extractor - Remove one of the two O-rings from the extractor spring - Notch the buffer tube and install it one more turn - Remove the buffer retainer(if this works I will buy an offset one) - Round off my ejector - Open my gas block fully - Switch from H3 buffer to an H2 buffer - Clean my bore and chamber gently with a wire brush I’ll then take it to the range for a day and report back. Last two questions… when I drop a live round in the chamber and gently seat it with a finger it doesn’t fall out freely, I need to shake the rifle a bit(nothing crazy) and the round falls out of the chamber. Does this sound like a correctly sized chamber? Also, with my bolt disassembled it closes easily on a live round. Does this mean My headspace is likely okay?

Thanks for the photos, I’ll round off my extractor corners a bit on the belt grinder. Also, after measuring with better tools my gas port hole is actually somewhere between .078”-.08”, not .094”

Hey all, Appreciate the replies. @edgecrusher the buffer tube is 7.75” internal depth. As you can see in the pic below the installation puts it a bit behind the lower receiver lip so functionally it’s actually closer to 7.875”. Some pics without the buffer/spring installed are linked below. My calipers battery died, but as best I can tell gas port is roughly .094” diameter. No spring on my firing pin. @98Z5V do you have a photo of a correctly rounded ejector? After removing the gas block I don’t think I’m leaking much gas. Also I had the block set up directly against the shoulder and after double checking the measurements(pardon the painters tape) that appears to be the correct location, no gap necessary here. I’ve got a new extractor in the mail, I’ll get that offset buffer retaining pin and and lastly I’ll round off my ejector for the next range trip. I plan in spending a full day at the range troubleshooting. Are there any useful tests I can do to help diagnose while I’m at the range?

Thanks 98Z5B, Lower is an 80% from righttobear.com. Also of note, it’s the firing pin retaining pin that is bent. The buffer retaining pin looks fine… but it is leaving marks on the buffer face(shown in pic above) so I guess something is wrong. Any quick/easy fixes for this or is a new lower needed? I believe the gas system is a rifle length +2, but I’m not positive. Odin Works sells the barrel, gas block and tube as a set. See photo below of inside of the receiver. Thanks for the gas block advice, makes sense. Sam

Hello all, New to the forum. If this is the incorrect location for a technical troubleshooting post, apologies. Thanks in advance for everyone’s replies. About me and about the build in question: I’ve built a few AR 15s before, but never an AR 308, this was my first one. Relevant parts are as follows… Aero M5 upper, Odin Works 6.5CM 22” barrel with tuneable gas block and XL gas tube, Ballistic Advantage BCG, Vltor A5 buffer tube, H3 buffer(came out of a previous AR15 build), Sprinco Red buffer spring. Didn’t have upper vise so I delicately clamped the upper btwn 2 pieces of wood for the barrel install, needed to use shims for Aero’s barrel nut and they got kinda crumpled but I used ‘em anyways, barrel extension was a sloppy fit so I bedded it with stainless shims and green loctite. Torqued to 70 ft/lbs. Took it to the range for the first time yesterday… spoiler alert… it went poorly. I preset the tuneable gas block to almost fully closed. Fired one round of 140g Hornady Atypical soft point and to my surprise the round extracted and ejected(bot did not lock open),upon inspecting the brass the primer had sort if prolapsed(pic below). I continued to fire more of this same round while gradually opening the gas block… got more prolapsed and even pierced primers, but the bolt never locked open on empty, even with the gas block fully open(the bolt locks open just fine manually). In the 20 rounds I experienced a few failure to extracts and a few very weak ejections. I also had the bolt jam closed twice on a live round and once on an empty chamber. I switched to 147g Hornady match and with that round the primers looked just fine after firing, but I got multiple failure to extract and the bolt still wouldn’t lock open. Fired about 30 rounds total Back home I disassembled to rifle to see what I could see, some notable things are as follows…. Firing pin retaining pin was bent and looks like it took a beating, buffer has some marks on the face from hitting the buffer retaining pin, lots of pierced primer bits fell out of my bolt upon disassembly, BA apparently used 2 o-rings on the extractor spring(could be a manufacturing error or intentional) which made the extractor absurdly stiff, firing pin has some carbon that I can NOT get off with solvent and scrubbing(never seem this before), one bolt lug has a small nick, extractor seems pretty rounded off. I have not had the bolt/barrel extension headspaced and I know I should do that. Any thoughts or diagnostic tips that y’all could offer would help greatly for my next trip to the range. From my basic understanding of AR malfunctions I am confused by the combo if malfs that I’m seeing here. Again, any “if this then that” type diagnostic tests that I could run in the field would be of great help. My bet is the guilty party is either Colonel Mustard with the double o-ring in the library, or Sam with the shotty amateur build in the garage.