just built my first AR, rounds jamming on feed ramps.

[tenringdriller]

I have an LRB lower which is manufactured by JV precision machine co. seymore CT, who as i understand machines many of the more popular brands of lowers. I checked them out thru my dealer and he said they make a decent product. As for my rear sight, if you look at where the carry handle mates to the upper there is a glaringly obvious mis-match...like 1/16 of an inch. I'm going back to my local dealer monday to switch it out with a different one and see if that makes a difference, also to test different mags/ammo, maybe pin my upper to a different lower and see if we can isolate the problem.

[tenringdriller]

ackspac: the rifle jammed on the first round ever shot through it...kinda puts some holes in your cheap ammo gum theory....the rounds exit the mag ok but bind up against the feed ramps, leaving copper on them...i tried to take pics of the ramps to post but alas, my camera sucketh.

[big shrek]

The problem sounds much like Drifter's, from another AR-15 thread.

I realize I'm getting to this party way late, but maybe this will help someone else not have the same problems. Or maybe I'm even later than I think and it's already been covered here.

I got 500 rounds of Wolf coated steel case marked only as 'Wolf .223' and had to wait to get on an outside range where I could try it after I discovered it was steel. More than one round every 10 seconds or so and it'll stick the empty in the chamber. I was warned but got carried away. Ooops. The empty will pop right out with a cleaning rod after it's cooled off. Filthy ammunition though. Half a grocery bag of used patches to get the crud out of the barrel and I'm concerned about the gas tube, but not sure what to do about cleaning the little bugger.

Another no-no for my rifle is Winchester White box from Wally World. Many of the cases in the batch I had measured several thousandths wider that they're supposed to be, checking unfired rounds after the fact, and that was my first adventure sticking an empty.

The rifle is a S&W M&P 5.56, and a gem to shoot with good ammo.

What I'll say I've told people for years...BREAK-IN WITH TOP QUALITY AMMO ONLY!!!
Pistols or rifles...only use the GOOD STUFF!!

It's like using Remington Golden Bullet .22lr or Remington Thunderbolt .22lr in a .22lr semi-auto...it should never be done until you've gone thru at least a 500-round break-in. Period.

Heck, I won't even USE it in a semi-auto .22lr anymore. I've learned better. It's inconsistant as all heck and dirtyer than anything else on the market. I've tested enough ammo to KNOW, the stuff sucks...but it's cheap, and people buy it in bulk...and some actually love it. But it's definitely not the choice I'd make for serious shooting. Plinking with a .22lr revolver...yeah. That's about it.

In this way, you aren't looking at your ammo in the equation if you are using top quality ammo...you are strictly looking for problems in the weapon itself. Mismatch in the upper/lower mating...machining tolerances off slightly...etc...

Good ammo costs more...but during break-in, it's more than worth it

[tenringdriller]

his problem is not the same as mine. never stuck an empty, they eject just fine, its when the bolt picks up the next round the nose of the bullet lodges in the feed ramp and kaput.

[at4rxj]

tenring, do you know what kind of buffer components (spring, buffer, and stock/tube) you have? I'm wanting to make sure you have the proper spring and buffer for your type of stock.

If this is happening fairly consistently, try a mag of hotter ammo (true 5.56 nato), assuming that your gun is chambered for 5.56 and not .223. I'm curious to see if that works. I had a buddy who's rifle would cycle the 5.56 fine, but jammed with the cheaper remington .223 loads... His gas block was canted. Once we straightened it out, it worked fine.

[tenringdriller]

now granted, I'm a newbie when it comes to ar-15, but I know my stuff when it comes to guns. the buffer and spring came IN my stock...so i can only assume that they are designed for it. my rifle doesn't have any problem cycling the action, the round gets pinched between the feed ramp and the bolt. even putting pressure on the forward release button doesn't move the round. the only way to clear it is to lock the bolt back, remove the magazine and shake the rifle till the round falls out. i'm pretty sure it's a feed issue, not a buffer spring issue...but i could be wrong....monday i'll pin it to a differnt lower and use different mags and different ammo and see if we can't find the culprit.

[tenringdriller]

was inspecting the rifle and noticed that there is axial play between the upper and lower, that is if i grab the carry handle with one hand and the pistol grip with the other and twist, there is play...is this normal? could it contribute to my issue?

[Aznative]

ARs have a little play between the upper and the lower. The big no no is to put a rifle barrel extension on an M4 upper receiver. Above you spelled out that you have rifle extensions which is fine as long as the upper is a rifle style upper.

[at4rxj]

The play, unless it's extremely excessive, will not affect anything operational OR accuracy related on the AR platform...

[Rifle_Shaman]

Originally Posted by tenringdriller

now granted, I'm a newbie when it comes to ar-15, but I know my stuff when it comes to guns. the buffer and spring came IN my stock...so i can only assume that they are designed for it. my rifle doesn't have any problem cycling the action, the round gets pinched between the feed ramp and the bolt. even putting pressure on the forward release button doesn't move the round. the only way to clear it is to lock the bolt back, remove the magazine and shake the rifle till the round falls out. i'm pretty sure it's a feed issue, not a buffer spring issue...but i could be wrong....monday i'll pin it to a differnt lower and use different mags and different ammo and see if we can't find the culprit.

"the round gets pinched between the feed ramp and the bolt"

Like the bolt on top of the case head, and not behind it? Just reminds me of a AK my buddy had, wouldnt run steel cased. That was an issue with a butchered gas system. Basically the steel case kinda deflected off the bolt face and jammed with the bolt carrier pinning it to the feed ramp. It was weird as hell. Jam it and take a pic, even a krap one will help us see whats happing.

[tenringdriller]

well I took it to the guy that sold me everything but the lower, and after an hour of swapping parts and manually racking rounds through it we deduced that it was the upper receiver....swapped it out and it functions fine so far....haven't had it to the range yet but we manually racked 2 magazines through it without an issue. Also, the new upper he gave me has a bull barrel and is free-floated....2 options that my defective one did not have...I will definitely continue to do business with this guy. thanks for all the suggestions fellers, i'll post a range report on this thread just as soon as i get out to shoot.

[Mullenite]

http://cgi.ebay.com/Magpul-Yellow-223-Rifle-Magazine-Follower-3-Piece_W0QQitemZ310173144875QQcmdZViewItemQQptZLH_D efaultDomain_0?hash=item4837c2972b

.....MAGPUL YELLOW 223 REM SELF LEVELING MAGAZINE FOLLOWER
Model: MPIMAG110YEL

No more jamming with Magpul magazine follower

[Pothole]

Originally Posted by tenringdriller

feed ramps look lined up and smooth, using aluminum mags with pmag springs and anti-tilt followers, wolf 62 gr steel case fmj .223 ammo

sounds like he's already got em

[tenringdriller]

OK, just got back from shooting and I'm happy to report that my weapon now functions flawlessly. It must have been the head spacing or the barrel extension on the upper. I ran 120 rds of el cheapo wolf steel case and not one jam! I ran the first mag thru as fast as i could pull the trigger just to try and get it to malfunction. After returning home and filed-stripping my weapon I realized that I hadn't even lubed up anything. Thanks for all your help and suggestions, looks like I got it figured out.