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

[turnburglar]

"prepping" the bore on that rifle is a massive waste of time. I have yet to clean my 6.5 creedmoor barrel in 6-700 rounds and its holding sub moa. If anything copper fouling helps with accuracy.

Next time you go out, dump 3 full mags into the berm. If it cant do that its not reliable enough to trust your life on. Buy a 556 upper, mags, and m193 and be done.

[rpoL98]

Not sure about lubing the buffer spring, couldn't hurt! I don't.

i put a light coating of synthetic wheel bearing grease on the inside of the buffer tube (as far as my index finger can reach), and on the buffer spring.

Also, on the buffer itself, a few passes with a file over the end of the roll pin to make sure the ends are flush with the buffer surface, not sticking out. helps reduce the cheese grater sound.

[NQNPIII]

Nobody has asked you.............what brand mags are you running? LRBHO, and feeding is certainly affected by which mag you are running.

I just found out C-Products Defense is now Duramag. I will not buy their 28rd mags. Why? They rattle like hell. That noise is not a good thing at night.

[Pressingonward]

I have some 20 round and 30 round C Products Duramags. Did C products and Duramag used to be separate companies or something?

I haven't noticed any rattling from the mags, but I'll pay closer attention now to see if they do rattle at all.

[NQNPIII]

I have some 20 round and 30 round C Products Duramags. Did C products and Duramag used to be separate companies or something?

I haven't noticed any rattling from the mags, but I'll pay closer attention now to see if they do rattle at all.

The 28's rattle at the bottom. I don't own any 28's. At a friends gun shop I picked up a loaded one and he showed me how noisy they were.

I think at one time there was something called a "Duramag" that you could swap followers and it was an expensive "soup to nuts one size fits all" mag. They were so-so on reliability and were very expensive.

[anarchocap]

Did C products and Duramag used to be separate companies or something?

There was some litigation between the original C-Products company and ASC over magazine subcontracting and C-Products lost their assets due to the decision and bankruptcy. Basically the story was that ASC wasn’t making the mags the way C-Products wanted (an extremely small company) and they were using their design to sell their own mags as well.

What happened was that C-Products created a new company CPD (C-Products Defense) to manufacture magazines themselves and improved upon their original magazine design that ASC no longer had access to. ASC sells old C-Products designed mags.

In order to try and further distinguish between the old design and the confusion surrounding ASC ownership of former assets, they changed the name of their magazines to Duramag.

[Pressingonward]

Thanks for the mini history on C-Products - good to have the backstory.

I've gone out a couple more times and my rifle is now shooting reliably (other than one fail-to-fire that I'll get to). For my experimentation session back in December, I loaded a single round in a mag, shot it, and repeated that to see how often the bolt would lock back. With the standard buffer and standard spring, the bolt locked back 50% of the time (shot 10 rounds total in this config, one round at a time). Ejection was at 1-2 o'clock.

I then put in the H3 buffer, and the bolt locked back 100% of the time for 10 or 15 shots (don't remember exactly). Ejection at 1:30-2:00 o'clock, and felt recoil was reduced slightly. When I ordered the lightweight buffer spring from Tubbs, I also ordered his standard 36 coil spring at the same time. I decided to try the standard spring in place of the mil-spec I was using - still with the H3 buffer. I can definitely feel the increased resistance over the mil-spec when I pull the charging handle back, and it goes into battery with more authority - gives me a bit more margin if I accidentally ride the charging handle part of the way back before releasing it fully. Also reduced the "sproing" noise that I was getting with each shot - now I only hear it on the last round. Didn't have much if any effect on the gun while firing - still cycles perfect and has about the same recoil. All in all, I'm glad I swapped it.

Edit: Big thanks to NQNPIII for suggesting that the bolt was moving too fast to allow it to lock back with the standard buffer. You were right on the money and I appreciate it!

Yesterday I went out again. Weather was good, about 40-45 degrees out with minimal wind and no rain. Decided to shoot prone and see what kind of accuracy I could get. I was shooting at 45 paces, which should be 45-50 yards. I bought a grippod to use as a cheap bipod, but neglected to bring a picattiny rail section to attach it to, so I ended up using a shopping bag stuffed with Goodwill clothes as my rest, which worked, but wasn't particularly stable. Nonetheless, I was pretty happy with the results. I pretty consistently shot 4 MOA with a variety of ammo, shooting 5 round groups. Had a couple 6 MOA groups, and my best was a little over 3. Tried to post a target picture here but it says I've reached my storage limit - I'll have to look into that and post it later.

I think the rifle is capable of shooting a tighter group, but I was having some trouble getting my eye to focus properly, and couldn't resolve where I was aiming as accurately as I would have liked to. When I get some spare cash I'll probably pick up a cheapish used scope to play with. In the short term I need to focus on basic weapons manipulation and shooting standing, sitting, behind cover, etc. (more realistic self-defense scenarios).

Out of the ~100 rounds I shot yesterday, I had one fail-to-fire on a brass cased PPU FMJ round. It has a tiny punch mark on the primer instead of the nice big dimple on all of the cases that fired correctly. I've read about light primer strikes, I'm guessing that's what this is? I don't quite understand how I could get such a tiny punch mark on this round - wouldn't the firing pin leave a big dimple whether or not the primer ignited?

[georgeib]

Did you try firing the round a second time?

[NQNPIII]

All 3 of my x39's have the standard 5.56 buffer springs. Not sure what you mean by "light weight." Next time I take my rigs to the range I want to try a .308 spring.

With the light strike on the primer? I have several cases of Wolf "Mil-Spec" that a few of the primers are set too deep.

[Pressingonward]

Did not try firing the round again - will do that next time. I don't think the primer is set any deeper than any other round, but I'll measure it when I get a chance.

The lightweight buffer spring (that I bought but never tried) is less spring force than a milspec. It's advertised as being for 300BO and other rounds if you're undergassed. Now that I know I'm not undergassed, I don't need it. I am running the Tubbs standard 36 coil spring. I hear he also has a 42 coil .308 spring that people really like - there's a thread on here that's been pretty active recently.