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View Full Version : DPMS 3G1 Upper Review



Fried Chicken Blowout
22 September 2011, 19:23
As part of my reentry into 3-Gun matches, I've bought a bunch of new gear. One piece of that gear is my new upper, the DPMS 3G1 upper. Prior to this, I've had little respect for DPMS, but I know better now. Lets start out by saying that I got a smoking deal on this upper. Its from Midway USA with the $50 coupon that they've been running. It arrived in 3 days from the time I ordered. It came complete with BCG. The barrel is a 1:8 twist with a stated 5.56 chamber. The barrel is a heavy profile that is extra heavy under the hand guard. A Jerry Miculek brake made by DPMS. It has a rifle length gas system and an aluminum gas block.

The whole upper is pretty heavy, especially compared to the upper it replaces. I sold the upper from one of my M&P15TS rifles to pay for this upper. I have two of the M&P15TS rifles so it wasn't too much of a sacrafice to sell one of the uppers and use the lower for this build. I'm headed to New Mexico to compete in the upcoming Thunder Beast Arms Team Challenge match, where I'll be required to engage targets up to 450 yards. I figured an 18" upper would be better suited for this over my existing 14.5" upper. So after receiving this upper I began load development. Being that I had already developed my load for a long range 24" AR, I went ahead and use the same 75gr Hornady BTHP bullets but changed up the powder to save some money for the high volume shooting.

I ended up with an outstanding load. The 75gr Hornady BTHP bullet was placed over 21.2grs of WC846 (Win 748) Surplus Powder and CCI 450 primers. This load shoots fantastic... I have not shot it over a chrono but I expect a light 2300 FPS as I was focused on low recoil and a match for the recital in my Burris Tac30. With this load I've been able to make 550 yard shots on prairie dog sized steel targets with the drop markers in my scope. The load shoots fast and reliable without any issues. Plus as evidence of the accuracy of this load, I shot a 0.275" MOA 3 shot group today with this load as my first group back to the range from changing out the gas block.

Intially this upper came with an alluminum gas block that had two set screws that held it in place. As normal, I figured I could improve things... So I ordered an adjustable gas block from JP Enterprises. This was their low profile gas block with three screws that clamp onto the barrel and hold it in place. After installing the new gas block, I headed to the range to test it out. What I found out was that the upper needs pretty much all of the gas to cycle the bolt. I ended up opening up the adjustment screw all the way to get the upper to cycle. I was dissipointed to say the least. I'm sure that after a proper break in and some hotter ammo, I could have closed the gas port some and got a little lighter recoil, but being that I'm headed to a high round count match that is costing me some money, I didn't want to take any chances... So off came the adjustable gas block and back on went the factory one. I locktited everything in place and headed back to the range to confirm my zero before my first 3-Gun match on saturday.

My first 3 rounds at the range got me a 0.275" MOA group at 100 yards. Very impressive... The reliability with the facotry gas block has been 100%. So far I can highly suggest this upper. The recoil is almost nonexistant and the accuracy is just crazy. My lower has an EMOD stock, and CMC trigger to round it out. Can't wait for my return to 3-Gun shooting this Saturday. If I can come up with anymore information about this upper after the match, I'll let you all know...


http://gallery.me.com/jason_alicia/100686/IMG_1462/web.jpg?ver=13167410830001


http://gallery.me.com/jason_alicia/100686/IMG_1467/web.jpg?ver=13167410880001


http://gallery.me.com/jason_alicia/100686/IMG_1461/web.jpg?ver=13167410920001

Here's a shot of my 3 round group... The two extra rounds are from my mixed brass 55gr plinking reloads that I was checking against my LC brass 75gr Hornady loads. You can see the differance in the accuracy of the mixed brass loads, the 3rd round of that group is off the photo to the top. I was able to repeat this same tight group after adjusting the zero on my scope, so I'm happy to say that this upper is a sub 0.5MOA upper for sure. I'm very happy with it. My only warning is to tighten up and locktite the gas block in place prior to shooting. When swapping out the factory gas block for the failed adjustable on, I noticed that it was very loose....

http://gallery.me.com/jason_alicia/100686/3-20SHOT-20GROUP/web.jpg?ver=13167432170001