So I talked my dad into building ARs with me by telling him we don’t do enough ‘father / son bonding’ projects
We got our parts and had our build / range (my house) day yesterday.
Unfortunately, I am having some major feed problems.
The problem:
When manually cycling or after firing, many times the projectile jams on the feed ramps and gets some nice deep grooves cut in both sides of the bullet. If I pull the CH and let it rip again, it usually chambers fine. I don’t think this is a gas related issue, since it happens just as often if I’m manually pulling and releasing the charging handle. see video below. It does seem like this happens most often from the left, but still happens on the right sometimes.
Things I’ve tried / done:
3 different types of ammo (both 5.56 & .223)
2 different mags (magpul, hexmag)
Upper receiver and barrel both have feed ramps, and they look to be perfectly lined up etc
Mag drop test was a success
I verified 37 coils on my buffer spring, which I understand is the right number.
I cleaned and lightly lubed all the normal things, including a minimal amount from a rag on the buffer spring
I put about 40 rounds through it hoping it was just a little break-in thing. Didn’t change.
I’d do an RMA with PSA, but you can try polishing the feed ramps (which could void your warranty, keep that in mind.)
It looks dry by looking at your photos, but maybe it wasn’t at the time of firing… but that gouge in the bullet, makes me feel something isn’t within spec or not aligned.
These issues are either from your BCG or feed ramps, if you’ve ruled out ammo/mags
That detail picture of the bullet going into the chamber looks like the bullet is going not on the feed ramp, but the slot to the left of it. It might be an issue with perspective of the camera skewing how it appears, so can you send a picture looking from the back of the upper receiver when removed from the lower directly into the chamber/barrel?
My thought is that either the magazines aren’t properly controlling the feed angles (up/down or left/right) which is possible, but honestly you’re using fine mags. Or as @JosPri said, something is out of alignment.
shooting regular ammo, nothing out of the norm, definitely apply more oil. From what I can see they are aligned, but it looks like I can see where it is getting caught on the left.
Okay, I just scrubbed it out with a brass brush… will apply more oil around there try again shortly.
Just thought of this, and I’ll have to wait for my dad to be back around, but I should have tried his upper just to rule out all lower and/or mag related things
Yeah no worries, first builds always have these learning curves
Try his upper if you can and see the results. I’m almost sure it is your upper, either it is too dry or a feed ramp issue. You can always polish the ramps to get rid of any burs.
Worst case scenario, you create a ticket with CS and they’ll get you squared away
Also, how easily should this slip up the ramp like this? Left side really wants to catch, even at a pretty extreme angle… right side not so much. (this is with a fresh virgin round btw, not one of my gouged ones)
OK, yeah, those look perfect. BTW, great pictures and post overall. Having such a well written, detail filled post makes all this a joy to read.
Something keeps bringing me back to that picture you have of the feed jam. It seems like the magazine might not be correctly aligned vertically or is canted forward. Could be the magazine? Upper? Lower? Mag catch? I did my best to recreate the angle of your picture on a rifle of mine I know works with a PMAG G3 and it looks like my magazine might be higher and definitely doesn’t cause as much of an angle. In your picture the brass has a gap towards the base of the case. I retracted and locked the bcg back after letting it slowly ride the cartridge forward.
Thanks for the kind words! I’m very new to this, and very aware of that fact, so trying my best to not be an idiot
One more picture I just took after seeing yours… this was after cleaning and making it wetter than a nun on a bender. First attempt, jammed. I locked the bolt back and took the pic where it’s stuck.
Angle seems completely expected to my untrained eyes
Sounds like RMA it is unfortunately. I think I see where it could be polished down a little bit, but I don’t really want to do that, this being my first one etc.
Any experience with the PSA RMA process? What’s the turnaround typically?
I’ve never experienced the process, but from what I’ve heard - PSA is very good about making it right, and if you run into trouble, the moderators here are also awesome and can help you out.
well that doesnt look like the issue, and i checked mine and cant push the mag in any farther with the mag release pressed.
Like suggested or mentioned I would try swapping the uppers and if that takes care of the problem, I would put your upper back on and swap the Bolt carrier group.
Either way, Palmetto will take care of you and get it fixed. Years ago I had a rail with a noticeable curve in it, they swapped the whole upper out no questions asked.
Yeah, that new jam picture looks fine, despite it not working. Maybe the cartridge was just further forward in the one that looked like it had too much of an angle. Good idea to test with a different upper. I take it there’s not another lower you could test with, is there? Agree that breaking out the polishing or grinding tools probably isn’t a great idea on a new upper. You might fix it, but why take the chance.
As for the RMA process, it’s a couple of days. Nothing too crazy. Shipping roundtrip plus a few days, or thereabouts. I don’t think I’ve ever read more than one or two bad customer service stories, and those sounded like the customer might have been more twisted than the part getting replaced.
