NickG32 Posted August 9, 2015 Report Share Posted August 9, 2015 I've got an Aero M5 set, rifle buffer,tube, and spring, Phase 5s version on the BAD lever. My problem is that I have an intermittent problem with the bolt not locking back on the last shot. Regardless of ammo type. Also I only run the Magpul mags. Kinda perplexed as to why sometimes it locks, sometimes it don't. Thanks for any help you can offer. Quote Link to comment Share on other sites More sharing options...
mrraley Posted August 9, 2015 Report Share Posted August 9, 2015 I have some questions ... You said "regardless of ammo type" ... what type of ammo are you using and what grain? With an empty magazine inserted to the rifle, Will the follower activate the bolt stop when you physically pull the charging handle rearward? What size are the buffer and buffer spring? More questions to come, pending outcome... Quote Link to comment Share on other sites More sharing options...
Robocop1051 Posted August 9, 2015 Report Share Posted August 9, 2015 First what MrRaley said... Also, Have you tried other magazines yet? Have you tried other bolt catches yet? Does the bolt lock manually? What BCG are you running with? How many rounds do you have through the rifle? What gas system are you playing with? Remember, as you are breaking in your rifle.... LOTS of lube in the action of the rifle. It helps to give the buffer assembly a little lube attention as well. Quote Link to comment Share on other sites More sharing options...
survivalshop Posted August 9, 2015 Report Share Posted August 9, 2015 (edited) All the above & does a std Bolt Catch work in the rifle ? Not the Phase 5 assembly ,a standard Bolt Catch assembly. One other thing , builders have been having problems with Aero's Buffer system that they sell , so what system you have may be important . Edited August 9, 2015 by survivalshop Quote Link to comment Share on other sites More sharing options...
NickG32 Posted August 9, 2015 Author Report Share Posted August 9, 2015 Yes, the bolt locks manually. I'm using a dpms rifle tube, spring, and buffer. Has a Red X Arms bolt carrier with a dpms bolt. Haven't tried to swap out for standard bolt catch, don't know if I ever would as I've trained myself to run an AR with a bad lever. Don't have any mags but Magpul and they lock the bolt back on an empty mag when cycled manually. It's got the sass barrel with the mid length gas sysrem. The ammo types are Fed. 168gr Sierra, Fed. 165gr tactical bonded, Freedom Munitions 168gr bthp, and some surplus Georgia Arms 150gr fmj. Cycles like a dream and is pretty accurate with the 168 Sierra, my only complaint is the bolt not catching on an empty mag about half the time. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted August 9, 2015 Report Share Posted August 9, 2015 Who built the rifle? Sounds like one of two things here - buffer weight, or gas system issues. Look at the gas system closely, first. Quote Link to comment Share on other sites More sharing options...
NickG32 Posted August 10, 2015 Author Report Share Posted August 10, 2015 I built the rifle. I've already checked the gas block/port alignment and also the gas tube. If it's a buffer issue, too light maybe? It's the standard dpms rifle buffer. What other options do you guys recommend? Quote Link to comment Share on other sites More sharing options...
98Z5V Posted August 10, 2015 Report Share Posted August 10, 2015 When it won't lock back, it's usually because the buffer is too heavy - BCG gets enough travel to eject a spend piece of brass, but not far enough to hit the catch. If you're using a standard buffer, and not a heavier buffer, then it's a gas issue - your gas port on the barrel is too small, usually. Quote Link to comment Share on other sites More sharing options...
DNP Posted August 10, 2015 Report Share Posted August 10, 2015 How many rounds have you put through it? Number your mags and see if it happens more with one than another. As said. Lube it well. Mine was iffy about locking back till about 200 rounds. I have a lower that's known to be touchy with PMAGS and I run a 16" rifle length system which makes it a really soft shooter. I haven't run many different types of ammo, but I don't seem to have any issues anymore. Just took some breaking in. Quote Link to comment Share on other sites More sharing options...
NickG32 Posted August 10, 2015 Author Report Share Posted August 10, 2015 Got 240 exactly as of two days ago. Got one 10rd and three 20rd mags. It happens mostly with the 10rd but I use it the most cause I shoot prone the most. I really don't know anyone around here I'd trust to enlarge the gas port if that's it. If it's a buffer issue, it's right on the edge of being right and wrong cause it's an every other mag full issue. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted August 10, 2015 Report Share Posted August 10, 2015 Take apart the buffer, remove one weight, insert a 1/2" diameter plastic spacer of equal length. Run it and see if that works. That's gonna tell you if it's the buffer weight - which is a gas port diameter issue with a standard-weight buffer. It's a shortcut, but a good test. Quote Link to comment Share on other sites More sharing options...
survivalshop Posted August 10, 2015 Report Share Posted August 10, 2015 Yes, the bolt locks manually. I'm using a dpms rifle tube, spring, and buffer. Has a Red X Arms bolt carrier with a dpms bolt. Haven't tried to swap out for standard bolt catch, don't know if I ever would as I've trained myself to run an AR with a bad lever. Don't have any mags but Magpul and they lock the bolt back on an empty mag when cycled manually. It's got the sass barrel with the mid length gas sysrem. The ammo types are Fed. 168gr Sierra, Fed. 165gr tactical bonded, Freedom Munitions 168gr bthp, and some surplus Georgia Arms 150gr fmj. Cycles like a dream and is pretty accurate with the 168 Sierra, my only complaint is the bolt not catching on an empty mag about half the time. What if that lever is interfering with the Bolt Catch function in some way, how else you going to know that if you don't try the rifle with a Standard Bolt Catch . Not saying thats the issue , but with out swapping it out to try , you may go through a lot of hoops & still have the issue . Stick with the simple stuff first . You say DPMS Buffer assembly , are you sure its all 308 Components ? Measure the spring & how many coils , Buffer length & weight . Some DPMS Barrels are known to have tight Chambers & or are rough & some need to be polished as to release the spent case , a rough chamber will slow the Extraction down & can cause the same problems you are having . Quote Link to comment Share on other sites More sharing options...
washguy Posted August 10, 2015 Report Share Posted August 10, 2015 Yep, you gotta try a standard bolt catch first...its a matter of trial and error... so to speak. In most of my 16" middy gas ports I open em up to a #44 or #45 drill bit size .0820 (45) or .0860 (44) if you cant get a 45 in the hole you are under-gassed . as for drilling em out...easy peasy....stick a wood dowel in the barrel so you wont drill thru to the other side if you are gonna use a hand drill, or set up your drill press so it wont drill too far. I have never ever had a standard DPMS buffer/spring fail in holding the bolt catch open. I have seen a rifle that was on the edge of too little gas work most of the time but when limp wristed...as in not shouldered tightly fail to hold back. :) Wash Quote Link to comment Share on other sites More sharing options...
98Z5V Posted August 10, 2015 Report Share Posted August 10, 2015 Yes, the bolt locks manually... Don't have any mags but Magpul and they lock the bolt back on an empty mag when cycled manually. Guys, he stated this already ^^^... Won't hurt to try a standard bolt catch, but his catch is functioning right now. I'm just sayin'... Quote Link to comment Share on other sites More sharing options...
washguy Posted August 10, 2015 Report Share Posted August 10, 2015 Guys, he stated this already ^^^... Won't hurt to try a standard bolt catch, but his catch is functioning right now. I'm just sayin'... Okie Dokie :) If his spring is a true ar308 spring and his buffer is an ar 308 and its working sometimes...then it would seem he needs just a touch more gas then.... or his bra is padded causing the problemo :) Wash Quote Link to comment Share on other sites More sharing options...
NickG32 Posted August 10, 2015 Author Report Share Posted August 10, 2015 Nope no bra, and I got the bruised up shoulder to prove I don't "limp wrist" the rifle. I am going to try removing a weight from the buffer to see if that helps. If it does, I may try to enlarge to gas port myself. Bought the buffer, tube, and spring from Brownells. It all came labeled as .308. Quote Link to comment Share on other sites More sharing options...
survivalshop Posted August 10, 2015 Report Share Posted August 10, 2015 Guys, he stated this already ^^^... Won't hurt to try a standard bolt catch, but his catch is functioning right now. I'm just sayin'... Pushing the Bolt Catch into lock manually is not the same as the Mag follower doing it . He has a non standard component in the mix , is why I asked to begin with . With the follower at the top of the mag , there is not much spring pressure to lift the Bolt Catch & it will not take much to keep the Catch from being raised far enough to catch the Bolt Face & it can slide right over it . <dontknow> But , hay , drill out the Gas port , but first I would take a measurement to see what it is now , before its made bigger . <dontknow> Have fun <thumbsup> Quote Link to comment Share on other sites More sharing options...
NickG32 Posted August 10, 2015 Author Report Share Posted August 10, 2015 When I say manually locking the bolt catch, I mean using the charging handle to manually cycle the bolt with an empty mag in the gun. It locks out every time that way on its own. I never push in the mag catch like you would have to without a mag in it. Quote Link to comment Share on other sites More sharing options...
shepp Posted August 10, 2015 Report Share Posted August 10, 2015 Nope no bra, and I got the bruised up shoulder to prove I don't "limp wrist" the rifle. I was wondering how you were going to take that ;) good job :D Quote Link to comment Share on other sites More sharing options...
Toolndie7 Posted August 11, 2015 Report Share Posted August 11, 2015 Just a guess here, but how well do the gas rings seal in the carrier bore? maybe not getting enough of a seal to really blow that carrier all the way back consistently? Quote Link to comment Share on other sites More sharing options...
JAY Posted September 27, 2015 Report Share Posted September 27, 2015 (edited) I have heard that sometimes the pmag followers have trouble engaging the bolt catch on some LR 308 models. I would suggest buying a steel magazine and try that before anything else. No need to spend a lot of money replacing different things when it may be simply a mag issue. If you look around for deals you can find deals on steel mags comparably priced to the pmags. Lancer mags are another good option but they are pricey. It seems to me if it was a gas system or buffer/ buffer spring issue you would also be running into FTF (failure to feed) problems. If it was really short stroking for some reason, it would not only happen on the last round in the mag. Edited September 27, 2015 by JAY Quote Link to comment Share on other sites More sharing options...
98Z5V Posted September 27, 2015 Report Share Posted September 27, 2015 I have heard that sometimes the pmag followers have trouble engaging the bolt catch on some LR 308 models.It's kinda the opposite of that - some mag catches won't always catch all followers, on different types of mags. That's a mag catch/bolt catch issue. Quote Link to comment Share on other sites More sharing options...
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