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Posted: 1/11/2012 12:35:00 PM EDT
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I am new to the AR but after doing some browsing I am looking at building a 7.62x39 AR. After doing quite a bit of research on here and searching through the wonder that is Google. I know the 7.62 requires a different bolt and barrel of course, which I am going to be getting through Doublstar. My only question that I have not been able to find is, Are the upper receivers themselves different? I have found a few people asking and threads but it seems that immediately it turns to why would you want to build an AR with that caliber lol. I know you can use the 5.56 lower and BCG which leads me to believe you can use any upper but the lack of info and 100% certainty worries me lol. Anyone that can shed some light and info would be appreciated. If you can not use a standard 5.56 upper what is different would be my next question? Sorry I am new to the AR world and trying to take it all in and learn as much as I can.
THANK YOU |
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Be sure to find out whether your barrel has M4 feedramps or not. Buy a standard AR upper that matches M4 ramps, or no M4 ramps.
My double star 7.62 upper and barrel did NOT have M4 ramps. If I was going to make a suggestion it would be that there is no way in hell I would get another 7.62 upper without M4 ramps. Reliability problems have been a nightmare with rounds tilting down and hanging up on the front of the upper receiver. I ended up doing a DIY feed ramp job with a dremel. Not pretty, but I was not willing to spend $$ on it, and it now pretty much works. But it sure is ugly looking as hell. You can believe what you are being told. 7.62 in a standard AR is a pain in the ass. There is a reason you are being told that, because people who have BTDT have found it out the hard way. I would do a lot of research, make sure you can find a source for mags, and choose wisely before going down this road. It made more sense when 7.62 ammo was dirt cheap. |
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Thank you very much makintrax for the reply. I had not thought of the DS not having the M4 feed ramps in the barrel, thank you for that info. Yea I have read quite a bit about feeding issues most point to magazine feed issues. I had saw that DSC carries SS magazines which I have been looking for reviews on them. I am looking at Henderson Defense NP3 coated upper and lower to do this build with this. That was the main issue with wanting to be 100% sure before buying the upper and lower.
Do you know of any good magazines that I should look for? I have read the FAQ for 7.62x39 on here it list a few but I think most are out of production. Was wanting to build one due to the fact of how readily you can find the ammo. Thank you for all the info so far |
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I got some C-products mags from 44mag.com (site sponsor BTW and excellent prices and shipping). I looked and can't find them anymore. Heard they went out of business and some other company was making the mags with their tooling?? Honestly not sure where to send you for mags. I was really never that happy with C-Products SS mags - to me they feel FLIMSY compared to GI 5.56 mags (which are not all that stout to begin with IMO).
Good luck with your build! |
| Don't let anyone scare you away from this caliber, i have one from AR Performance and it runs flawlessly and is very accurate. Mags are not a problem anymore now that ASC is up and running, I have not had any problems with mags in mine. I would suggest buying your parts from AR Performance, they have stronger bolts that are also designed to give you more firing pin protrusion to light off the cheap Russian ammo. |
| Same here, I had some minor feed issues with my ASC mags but they settled in quickly after loading them 3 or 4 times. I know it was the mags cause I ordered two batches of mags from different vendors, second batch of mags were 100%. My upper has M4 ramps, but I worked tham dowm a bit as well, sometimes the round would not come straight out of the mag and hit the flat space between the ramps so I rounded that off. If you read the FAQ and do your homework you can have a perfect setup the first time. My lower is a standard RRA lower, nothing to worry about there. Started with the standard buffer which works fine but later upgraded to a 9mm 5.4oz buffer which smoothed out the recoil and still works with my 5.56 upper. |
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My experience with 7.62x39 has been very good.
No feed problems, no broken parts. Much better performance on targets when compared to my best SKS experience. I use mostly surplus and a little Wolf without any issues. CProducts Magazines have run for me without any issues. I have 10 rnd for CA use and also the 30s for away trips. The nay-sayers had me worried when I first attempted the project. I could see that any semi-automatic can become a troubleshoot if you don't have things right, but that wasn't my experience with either of my Russian Surplus AR rigs. Once I saw how well 7.62x39 worked, I also got into 5.45x39 and have no regrets. |
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+1 my 7.62x39 AR runs like a champ!
2 must haves for this caliber: 1) ASC mags (formerly C Products) ammosc.com 2) A upper with good reviews: Bushmaster, Colt, Model 1, ARperformancen ar15performance.com Just do all the research you can on AR15.com in this section (AR Variants) before you decide on which brand to buy and you will read what works and what doesn't. But I just passed on the knowledge above #1 and #2 
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I'll chime in too since the thread has my favorite AlphaNumeric combination of 7six2by39
You do want M4 ramps in the upper receiver. You may even go so far as to polish them. I did mine and the gun runs wonderfully. 320, 480, 600, 800, 1000, 1200, 1500, 2000 grit sandpaper. I've run over 2500 through my 10.5" upper and am patiently waiting for my 30cal suppressor to be able to come home with me sometime in May perhaps. IMHO, your best bolts are coming from AR Performance or LMT. I'd figure thousands of rounds with either. A close 2nd would be YHM, Doublestar, M1S, Delton. ASC magazines are better than CPs in my opinion, as it appears spring strength is much better than the CPs were. If you find some CPs cheap (read $10-12) and they don't run, you could pick up some 30rd Wolff extra power mag springs for AK47s. I still download my magazines to 25rds anyway. I also run an H2 buffer on a carbine gas length. Nothing like slinging 123gr rounds at over 2100fps. It may be 20% slower than 62gr 5.56, but it is twice the bullet. I'll happily shoot that round for about $0.20 and enjoy it. |
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I want to THANK everyone who has posted and given information. This has to be one of the most informed post about this caliber with an AR I have seen. My biggest concern was just wasn't 100% sure if I could use any 5.56 upper (standard upper) I have read some info that says no while others say yes. Just to double check I can use an upper that was used for 5.56 for this conversion correct? I have a DS rifle that I think I am going to use the for this swap. After reading so much about ARperformance I will most likely go that route as I want to buy/build this rifle ONCE Lol. I will def be purchasing ASC mags with all the good words about them. Is there any change to the barrel nut? Just want to get all my info before I start to buy.
Thank you again for all the info Also just noticed all the 7.62x39 stuff on AR15performance is all Out of Stock :( Welp just got off the phone with them, they are out of stock of everything 7.62 just my luck lol aren't expecting any back instock until sometime March |
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Any AR15 stripped upper of quality manufacture will work. I've run my 10.5" on a LMT upper since May 2010.
Just got my barrel back from ADCO. They did the "behind gas block contour" to .700 and I went function testing tonight. Just ran 200 rounds through the gun tonight and it has been a marvelous performer. I got the Daniel Defense handguard too hot to hold....all in about 15 minutes worth of function testing. A couple failures to fire but this has been my experience with some 1974/5 Yugo M67. I'd recommend calling M1S or ARP to see if their upper receivers have M4 ramps. They really aren't optional, imho. Round count of my SBR is now 2730. ETA: any stock AR barrel nut works. I'd recommend a torque spec to at least 40ft lbs. I've run YHM, Troy TRX, Troy MRF, and Daniel Defense MFR handguards on this upper. Posted Via AR15.Com Mobile |
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Thank everyone for posting up and giving me all the info I needed along with the support. I am glad to finally see a thread that has people that are happy with there 7.62 rifles. I spent most of last night web browsing on parts listed in this thread. Bolts are few and far between it seems these days. LMT no longer makes them, MGI seem to have a bad reputation of breaking extractors I have found countless threads on these, and ARP doesn't have any in stock and wont until late March at earliest :( . I seem to read a lot of mixed things about Model 1 sales some have a lot of issues while others have none.
I am not too worried about the upper as i will either convert my Spikes or Doublestar upper which both have M4 feed ramps into this. Or just buy a new upper, but I would like to build it myself. Nothing like building one by yourself. Also what gas system to do most run with 7.62? I haven't read much on whether people are running carbine or mid-length gas systems? And on buffer spring do most stay with a Carbine buffer spring? |
ArmaLite 7.62x39 ramps:
AR Performance 7.62x39 ramps: 
Bushmaster 7.62x39 ramp: 
Model 1 Sales 7.62x39 ramps: 
These photos are meant just to show these suppliers' barrel extension ramps; i.e., the receivers shown are not from the same manufacturer. Also, the gun with the M1S barrel in a receiver with no ramps works just fine with 20 round frankenmags and C Products 10 and 30 rounders. |
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Quoted: Bolts are few and far between it seems these days. LMT no longer makes them Call them, chances are they still have stock left. They aren't listed on their website, but they may be available. That was the case when I bought my LMT bolt, but that was a while ago. |
| It depends on the stock you are going to use. I personally have found the standard carbine springs from Joeboboutfitters being the best for my little brother's rifle, buy a few. For us, it is best to start by scratch and build the rifle around the round itself. The m4 feedramps are a non issue as you can make your own feedramps and cater around the round and the magazine to the upper receiver and barrel extensson. We have a Del-ton full auto bolt carrier group as it will not headspace at all with my brother's upper. The MGI bolt is the best thing we have for the 7.62x39, 2000 plus rounds of Wolf, Winchester, Tula, and Yugo, no breakage at all. I assure you, it is a great bolt. |
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I just got a 16'' upper from M1S. It has the M4 feed ramps as pictured above. I've only had it out for one shooting session so far. Shot about 70 rounds. I had one jam early on, but it was b/c I was using 7 rnds in a standard 5.56 30 rnd mag. I also have the G-Tech/USA Frankenmags which run flawlessly. Time will tell how the bolt will hold up...
My experience with M1S was fine. I ordered it online. I had to get the AWB compliant upper with no threads on the barrel or bayonet lug. I also ordered the enhanced firing pin so I can use cheaper ammo. If I remember right, it cost me just over $500 shipped. It was on my door step within a week or 10 days. I'm happy with my purchase. |
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The MGI bolt/FP combo I had worked OK with the hard primered eastern european steel case ammo, but when its extractor broke at 1100 rounds MGI told me they wouldn't sell replacement parts. I prefer to not deal with MGI.
I use the AR Performance bolt with a standard firing pin or LMT bolts with M1S firing pins. I did use an M1S bolt for a while and it never gave me a problem. |
| i ordered my upper from Model1sales and the barrel is great, nice heavy barrel for the price. You will need to order the bolt carrier group for 7.62 and a charging handle, unless you just wanna take all that off another AR and just order the 7.62 bolt. i ordered the C products mag and had some issues feeding the cheap stuff, wolf, tull, etc. i can run about 6 rounds in a 10 round mag. but i picked up some remington brass 7.62 and it worked like a champ. model 1 said the steel cases don't slide as well as brass..... but now i'm loading my own ammo and running remington brass with Zombie Maxx projectile. the best of both worlds. |
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