My first AR: 7.62x39 with Superlative Piston kit - Learning from failure...

[NQNPIII]

I have both CPD and ASC mags. both are reliable. admittedly, my ASC mags are well worn-in, and all the edges are smoothed out, so that the round strips out of the mag and up the feed ramp reliably, effortlessly. I didn't grind down the front edge, that's a pointless old-wives tale.

I think key is smoothed feed ramps that don't gouge the cartridge case, bullet tip, and and also smoothed mag feed lips so that the cartridge can pop up, out of the mag as the bullet tip on the feed ramp tips the cartridge upwards towards the chamber. Newly manufactured mags, still have a sharp edge on the mag feed lips, that gouge into the cartridge case, and prevent it from tipping upwards.

that's been what i've found. YMMV.

When you have a 30rd mag and all you can force into it is 14 they are turds. The body has a taper to them that hangs up the follower. I talked to them more than once. I got an RA and sent them 22 mags back. Called 2 months later and they hadn't even looked at them. They claimed at the time, "we test all of our mags before we ship them. Bullshit! They sent me the replacements the originals would load 30. The replacements had the taper problems.

The rounds nose dive. "Turn the spring around. We do that with all the new ones, that will fix the problem." Once again bullshit. The followers look nice. That's about it.

The ASC's I originally bought gouged the rounds. I saw no reason to polish their turds. The replacements were total garbage. Customer service is crap.

[Pressingonward]

Got my rifle back together. It now has a YHM clamp-on gas block, DD gas tube, Rubber City Armory BCG, and a DD front sight.

Unfortunately, my handguard (UTG Pro) interferes with the gas block on the bottom, and I don't think I can clearance either of them enough. It'll work for now, but it's no longer free-floating.

I really like the look of this handguard, and others like it that have an interupted top rail (like the Aero Atlas S-one), but I need 1.45"+ internal diameter to clear this gas block. Anyone know of a similar looking rail that might have a larger ID? I could swap the gas block instead of course, but thought I'd look at rail options first.

Hoping I get a chance to get out and shoot this week, but it'll probably be next weekend realistically.

[rpoL98]

i had a similar issue with a Daniel Defense clamp-on gas block, rubbed on the bottom inside of the rail. I cut out a rectangular hole on the bottom of the rail to clear the gas block, about 1/16" clearance all around, and then mounted a short aluminum pic rail across the opening for bipod mounting, might've been a 7-slot section. you'd never know that the rail was clearanced as such. I got all the benefits I wanted: slim rail, clamp-on gas block. Turned out to be a good shooter. It does mean that rail is forever married to that barrel, gas block combo.

[Pressingonward]

Not a bad idea. For now I want to keep this rail intact in case I end up building another upper with the piston kit I still have (it's one of the few rails I was able to dig up that clear the piston kit block), but if I end up selling that kit then there's no reason not to chop up this rail...hmm

[rpoL98]

i did hesitate at the thought of cutting out the hole on the rail, but then I looked at the DD RIS II which is similarly clearanced for the bayonet lug of the A2 FSB. and then I thought, after all, in my case also, it is a UTG rail (keymod Pro slim-line rail). They make nice slim rails, i use them on several builds, now discontinued (keymod). and it was a Criterion HBAR chrome-lined barrel. so it was a quality combo, worth making the sacrifice for.

or you can go to a fatter rail. but the slim rail is nice. not bulky.

[georgeib]

If you PM me your address, I'll send you a low profile set screw gas block I have laying around. You'll just need to move your gas tube over to it. Clamp on gas blocks are not recommended for any sort of hard use rifles anyway.

[rpoL98]

If you PM me your address, I'll send you a low profile set screw gas block I have laying around. You'll just need to move your gas tube over to it. Clamp on gas blocks are not recommended for any sort of hard use rifles anyway.

@georgeib
hey, thanks for the offer, but i do have set-screw GB's laying around a-plenty. I wanted to use a clamp-on for this particular application, and ante'd up for the DD version. thanks again.

[georgeib]

@georgeib
hey, thanks for the offer, but i do have set-screw GB's laying around a-plenty. I wanted to use a clamp-on for this particular application, and ante'd up for the DD version. thanks again.

You got it. Offer stands for the OP as well if he wants it.

[Pressingonward]

You got it. Offer stands for the OP as well if he wants it.

That is very generous, I appreciate the offer, but I prefer the clamp-on style in order to ensure there are no point stresses induced on the barrel that might impact accuracy.

Really doesn't matter for a non-precision gun shooting crap ammo, but I'm an engineer, I can't help myself lol. I've seen several people recommend against the clamp-on style for a hard use rifle, but I have a hard time seeing how they could possibly move if installed properly. The clamping force is very high, and the only real risk is the screws backing out, which is the same risk as the set screw style, and can be mitigated with high temp threadlocker. Of course, I'm new to this so maybe I'm missing something?

[rpoL98]

i understand that thought process. in another forum, a guy replied that after shooting his set-screwed GB barrel, he bore-scoped it, and if that theory held water, you'd see copper build-up where the set-screw deformed the barrel into the bore. results were that there was none, no copper build up, no indications on inside of barrel bore of deformation. could be that the set-screw deformation is just at the exterior barrel surface. just food for thought. anyways...