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View Full Version : Range report - DPMS 7.62x39 carbine + C products mags



westcliffe01
05-08-2011, 08:42 AM
This is probably old news for many, but I finally received my Nikon Monarch 1-4x20 scope and got it mounted Friday. I purchased the carbine length AR15 styled DPMS 7.62x39 rifle in late January and went through quite a hassle with the FBI before they finally allowed me to take possession.

Just yesterday I received notification in the mail that my cpl permit was approved, so just have to pick it up in person..... Glad that I didn't have to go through any more hoops on that one, I must have gotten everything cleared up with NICS when trying to do the rifle transfer...

So I also located a really great range, the Sharon Valley DNR range. It is only a few minutes from my house, yet I had no idea it existed previously. The place is professionally run, has several different ranges available from 25yd to over 100 yd as well as a shotgun range. The 25, 50 and 100 yd ranges all have undercover shooting benches to work from (concrete with a 1/2" rubber pad on top).

I took both of my new acquisition out to sight in, the savage 24 222/20ga combo rifle with a Redfield 2-7x33 (Coyote gun) as well as the 7.62x39 DPMS.

The DPMS rifle was absolutely useless, since it would not feed from the C products mags. This was loading just 6 rounds at a time into the 30 round magazine... It was hard enough to get the first round to chamber and the slide would stop without stripping off the next round virtually every time.

To get sighted in, I finally removed the magazine and hand fed rounds into the breach, it was that aggravating. Personally, I find it hard to believe that a company like DPMS would sell a weapon system that is so completely non-functional. They must have gotten a lot of negative feedback, since they have stopped producing the 7.62x39 version and are in the process or re-designing them. Apparently I have to do my homework better before buying....

The weapon was actually sighted in pretty good and the grouping was acceptable (3/4" at 25 yds) considering the hassle screwing around with getting each and every round chambered. When I got home I scrubbed the bore with copper remover and then set to work on improving the magazines.

The feed lips were a large part of the problem, since they were shaving brass from every round (I was shooting brass cased Yugo ammo from wideners). I spent a couple of hours with a chainsaw file, dremel with sanding wheel and a steel rod wrapped with emery paper smoothing out the release of the cartridge in the forward direction. The front edge of the magazine was too high and caught the edge of the cartridge once I had the shell sliding forward without hanging up on the feed lips. I am not going to touch the feed ramps in the receiver at this point, since in my opinion these magazines are junk to begin with, but after the rework I had improved their ability to feed to about 90% from near 0%.

I think the next step is to make a new magazine follower for each mag. I think the original follower is too short, so it tends to hang up easily and I also think that there needs to be more pressure on the front of the cartridge to lift the nose of the bullet as it feeds forward. Basically, the feed lips of the mag are nearly parallel to the bolt, where they need to angle up very slightly to get the nose of the cartridge to point up the feed ramp instead of square into it....

Next round of testing is today and I will move on to 50 and 100 yds, since I am on the paper and about 2" high at 25 yds (as it should be).

I am considering the purchase of an MGI lower receiver with AK47 magwell
https://www.mgi-military.com/store/index.php?product_id=40&type=&category=10
https://www.mgi-military.com/image_upload/19467673512.jpg

This seems to be the most reliable way to solve the magazine / receiver design issue. Does anyone know whether the balance of my rifle will bolt right up ?

westcliffe01
05-08-2011, 06:20 PM
Well, after the work spent "improving" the magazines yesterday, as well as removing the rough finish (park ?) on the bottom surface of the bolt carrier, and liberally lubricating the bolt and bolt carrier, todays session at the range was much more successful.

Of a total of over 120 rounds, I had 1 misfire (good dent in the primer, but no bang) and 1 round which had the bullet knocked about 1/8" into the case when it hung up feeding. The balance fed fine and I was able to focus a little on shooting the gun.

Trigger is pretty heavy, I would like to lighten it some. I think I need to find a way to increase the length of draw some, perhaps a replacement stock ? Does anyone make spacers that fit under the butt pad ? I have the scope moved as far forward on the rail as it will go, but it is still a bit close.

I started at the 50 yard line, got the scope dialed in again, since I moved it forward after yesterdays work at 25yd. Then moved on to 100yd. I found 4x magnification a bit low with the black target background with the red center just over an inch in diameter. One of the other guys on the range suggested I try a white target with a small black aiming point, so that is what I will do next time. As it was, I could just see the faintest smidge of red if I had the cross-hairs centered.

All shots I fired once I had the scope re-aligned were within the "9" ring of the target, which was 5.5" in diameter, though the majority were grouped a little high and to the right in a grouping about 3" in diameter.

If anyone in the vicinity has C-products mags that are causing issues, I will be willing to help out, since it seems I did something right....

I bought 2x 5 round mags and another case of the Yugo ammo from Wideners, so I have more mag rework in my future. The Yugo ammo is good stuff. Only 1 misfire so far and it has an altogether different recoil to 223, that is for sure ! Kicks up a lot of dirt behind the backstop too..

Is it legal to hunt whitetail in MI with lead core copper clad FMJ bullets ? From what I can tell 7.62x39 can't be relied on to expand, even the hollow points, unless it is at point blank range, so I would like to use this ammo to hunt in the northern part of the state if possible.

Tyler
05-08-2011, 06:40 PM
Good to hear you have solved some issues... As far as the scope, it is not the length of pull of the gun that is throwing you off, it is the position of the scope... I reccommend one of these...http://www.midwayusa.com/viewProduct/default.aspx?productNumber=529396


That will allow you to move the scope farther forward... Also, there are one peice mounts available as well ranging from 80-a couple hundred dollars. One of the cheaper ones.... http://www.midwayusa.com/viewProduct/default.aspx?productNumber=199560


Hope that helps.

westcliffe01
05-08-2011, 09:21 PM
Tyler, excellent advice on the stoner 1 piece scope mount. Thank you. knowing where to find all the pieces clearly takes some time and experience.

It looks like there are rubber pads that can be added to the back of the A2 stock. http://www.midwayusa.com/viewproduct/?productnumber=778143&cm_mmc=Froogle-_-Gunsmithing%20-%20AR-15%20Furniture%20and%20Accessories-_-PriceCompListing-_-778143

Tyler
05-09-2011, 10:05 AM
You can do that too, but I prefer to keep the same shooting position between Iron sights and scopes, so I just moved my scope forward.... It works great. I used the YHM 1/5 inch rail riser (the first link) and some medium height rings, and it gave me perfect eye relief and a comfortable cheek weld.

westcliffe01
05-09-2011, 06:47 PM
I'm pretty tall at 6'4, so I do find the A2 stock a bit on the short side and I certainly think that an elastomeric pad on the stock will make firing the rifle more comfortable. I prefer to keep things simple, which is why I selected a rifle with the A2 stock in the first place (less to go wrong).

I haven't fired a rifle since 1987 and the last time I was in a war zone. I was much younger and the rifle a lot heavier (9.5lb for the 223 Galil), and I on the other hand only weighed in at 140lbs... So I was just a little surprised at the recoil from the light weight dpms carbine. I can start picturing why one has to "man up" to shoot the 308 bulpup designs...

I don't have iron sights and am pretty useless at shooting with them due to my eyesight, so that was never a consideration for me.

Tyler
05-10-2011, 05:43 PM
Sweetness, go with whatever is better for you. I am 6'1" and actually prefer a shorter stock. I like to shoot with my nose VERY rear the charging handle. It is all in preferences, so figure out what works for you and run with that!

Avid
05-11-2011, 04:36 PM
Nice detailed report, but I also have/had a Nikon Monarch 1-4x20 scope that I had to send back 2x because 2 different scopes could not hold the zero with a .223 AI. Sounds like you got a good scope from the start that will hold a 7.62x39 recoil from the get go.