View Full Version : DPMS ar in 7.63x39

05-07-2011, 7:19 AM
I have a M4 that I built using a DMPS upper. The only problem that I am having is that when shooting cheap Russian ammo like wolf ect. a few of the primers are being stuck but not going off? This is only happening about 10 out of ever one hundred rounds fired or ruffly 10% of the time. That same ammo that would not shoot in the AR shot fine out of an AK. I know this thread is worthless without pic's sorry my camera was left at my Aunts house. I have heard a few different things mentioned that other have done to solve this problem like stronger buffer spring, elongated firing pin,ect, but I have heard mixed reviews on some of these. Please feel free to post what has worked for you guy's and girl's as I plan on shooting this type of ammo out of this rifle. Thanks in advance!

05-07-2011, 7:25 AM
I know most 5.45x39 uppers come with an extra power hammer spring for the harder surplus primers. From what you describe, it sounds like you need that spring for the 7.62x39 you're shooting.

Full Clip
05-07-2011, 7:29 AM
Yep, new hammer spring.

05-07-2011, 7:31 AM
sorry type-o I don't have a 7.63x39 it is a 7.62x39 which brand hammer spring would you recommend?

05-07-2011, 8:53 AM
Wolff(2 f's) extra power hammer spring http://www.gunsprings.com/index.cfm?page=items&cID=2&mID=1&dID=79

05-07-2011, 10:49 PM
I just assembled a 7.62x39 AR, after much research I went with a wolff extra power spring and a Model 1 sales enhanced firing pin being that I'm planning on primarily using Russian ammo, after firing over 800 rounds out the rifle I've haven't had any failure to fires using wolf, and brown bear ammo.... HTH.

Fred R.

05-08-2011, 12:27 AM
Hey Fred R is the Model 1 sales enhanced firing pin come standard on their 7.62x39 uppers? I am thinking of getting the car awn... don't see it as an option

05-08-2011, 12:38 AM
replace your firing pin with a 7.62x39 from M1 SALE, had the same problem, after the replacement no more FTF

05-08-2011, 9:55 PM
Hey Fred R is the Model 1 sales enhanced firing pin come standard on their 7.62x39 uppers? I am thinking of getting the car awn... don't see it as an option

Not sure about the Model 1 7.62x39 uppers coming with the enhanced firing pin or not but the Upper I received from Alpha shooting came with a regular 223/5.56x45 firing pin and from what I've read most other 7.62x39 uppers come with regular firing pins... there's a noticable differance between that firging pin and the enhanced 7.62x39 firing pin. It's on their website here FIRING PIN (https://www.model1sales.com/index.cfm/fuseaction/product.display/product_id/1158/index.cfm) but I called in the order as I've heard multiple accounts about them having security issues on their site with card numbers getting stolen. Also get the wolff extra power hammer spring, takes all of 1 min to replace and is only like $2 bucks and is extra insurance when dealing with russian ammo and light primer strikes.

Fred R.

05-09-2011, 6:01 AM
I cut .012" off the sholder/stop of a regular pin and now have no FTF with yugo or handloads.