Robocop1051's 7.62X39 Project

[washguy]

"I'm still shocked how thin the Troy/VTAC rail is"

Robo...thats why I use the Troy trx on my 308's...you can really get a grip ! <thumbsup>  Wash

[imschur]

Very nice....I dont have one of these...hmmmmm

[archangel]

that is pretty sweet.  what kinda ammo you planning on shooting? brass or steel cases?

[Robocop1051]

It has stainless extractor so I can devour steel ammo.

I put a revised parts list in the O.P.

[unforgiven]

Way to go brother Robo,like that look.I like the stock got a couple 8)

[Robocop1051]

Horrible day shooting AGAIN!!!

Took this little hottie out for her virgin run. I bought a box of Herter's 122gr FMJ and a box of Herter's 154gr SP... I know this is garbage ammo, but I want this gun to be able to handle cheap garbage or it defeats the purpose of the rifle.

First few rounds of 122gr went fine. Only doing one or two rounds in the mag at a time to check the lockback. Everything seems semi normal. I'm not locking after every shot, but these parts might need to wear in a bit better too. She is running pretty damn wet at this time. I finish my 20 rounds of the 122gr and move over to the 154gr. She doesn't like the SP's at all. The soft lead tip just gets mashed in the chamber. I get 2 or 3 to finally chamber and they are binding up super fierce. At one point I started using the forward assist to seat the rounds. Even once they were seated I wasn't getting any ignition from the primer. I looked at the ejected cartridges and saw that there were no marks on the primer at all.

Back to the truck to play doctor. I remove the BCG and tear it down to pieces. The first thing I notice it that it is REALLY dirty. For only 20 rounds of ammo, it was REALLY REALLY dirty. I noticed several very small brass circles falling out of the bolt and carrier as I continued my field strip. I stole this next picture from the web, but it shows exactly what came out of my BCG;

Next I removed my firing pin. At first I saw the retaining pin was bent, but I thought nothing of it. Then I saw that my brand new firing pin looked like it had been in the gun for years. It was totally burnt and blackened. I immediately noticed it was bent and the tip was crushed. I then noticed that the retaining rim was also crushed;

More of the little brass dots kept falling out. I think I had near 15 at one point. I went back to where I was shooting and located some spent casings. That was when I found the root of my problem. Almost all of my primers had popped and I was having a severe blow back from the cartridge. The little "dots" were like cookie cut outs from the firing pin.

When I got home I took the bolt apart and found more of the "dots" crushed under the extractor, freezing it into position. One of the "dots" worked its way into the extractor spring and destroyed it. Luckily I have a LOT of those little buggers, and it was easily replaced

I broke out the Simple Green and cleaned all the salvageable parts really good. The bolt appeared to be OK still, the carrier was fine too. The extractor got a new spring and everything was reassembled. The parts are soaking in their full synthetic bath now, waiting for the proper firing pin.

I have already shot out an email to MGI regarding their "Enhanced Bolt and Firing Pin".

To be continued...

[unforgiven]

                                              :o <munch>

[Robocop1051]

Looks like I may have found a solution HERE if MGI fails to help me out in a decent amount of time.

[edgecrusher]

I was shooting wolf black box in my colt x39 when shooting it with no problems with blown primer cups, give that a shot. I was also using a titanium firing pin, might even have an extra.

[Robocop1051]

I called and spoke to MGI again today. They advised me that their tech was out sick and hasn't had the opportunity to check my part yet. The nice gal I spoke with on the phone reassured me that they had my part and "it looks all mangled up." It was in her opinion that the parts were very likely to be replaced. I hope to be able to share more news soon.

[.308LiteHunter]

I called and spoke to MGI again today. They advised me that their tech was out sick and hasn't had the opportunity to check my part yet. The nice gal I spoke with on the phone reassured me that they had my part and "it looks all mangled up." It was in her opinion that the parts were very likely to be replaced. I hope to be able to share more news soon.

I 've been thinking of building a x39 upper and I'm interested to hear if you got your MGI bolt running reliably or if you are using a different one?

[Robocop1051]

That rifle is still running an MGI bolt. It's running flawless now.

[Robocop1051]

Also check out Cason Engineering. It looks like they are making a bolt similar to the old LMT enhanced bolt. They claim several thousand rounds of full auto fire.

[.308LiteHunter]

Also check out Cason Engineering. It looks like they are making a bolt similar to the old LMT enhanced bolt. They claim several thousand rounds of full auto fire.

That is a pricey BCG. Have you heard anything good or bad about the Liberty Gun Works bolt, internet rumors say it's made by Cason?

 

What did you think of the Cobra Tactical barrel you got, I was thinking pretty hard about their 16" Hbar in x39. I'd be real surprised if it shoots as accurate as they claim, but I just want to shoot cheap stuff anyway.

[Robocop1051]

Cason does make the BCG, that's why I suggested them.

You get what you pay for. I wasn't expecting much from a 7.5" barrel in the first place.

If you want an inexpensive complete setup, check out the Stoner combo package on Brownells.