Made it to the range this weekend and put a DPMS chrome lined, M4, 16” 1/7 twist upper to the test with 8 different rounds. Rifle was mounted on an old Bushmaster lower, w stock trigger and an EOTech, (same as RRA M4 upper test) was mounted to the flat-top. Firing was done after 100+ rounds of Winchester Q3131A had been run through the upper. Rifle was cleaned thrice, once after 10-15 rounds, again after 60-70 and finally at around 100 rounds, with an additional 5 rounds fired for spoilers.
Please note: this is a pre-ban upper and it was mated to "as stated" my old Bushmaster lower, which, UNLIKE my RRA and CR6724, has NO tweaked/aftermarket trigger, (just 10-15 thousand rounds fired) so my groups are not what I’d hoped for, as several of the strings show trigger pull errors. After shooting the RRA 2 stage, (over the last few weekends) suspect I’ll be getting another one for the Bushy.
Temperature was 85-89 degrees, humidity was 46% and wind was NNW at 10mph, which had little effect at the range I was shooting.
With the long ranges closed, my groups shot on 2 targets at the 100 yard line, got contaminated as I returned to the 50 yard line after groups had been fired and some numb nut, ignored my binocs and mags, laying on the bench and used my targets for his varmint AR, (my fault for getting up and moving, but I was trying to cover 2 areas at once, so I don’t blame him, and as range was closed, for no good reasons from 200-600, place got crowded).
All rounds are fired from a sandbag rest at the 50 yard line, 5 shot groups:
First up was my 77SMK load, which I zeroed the rifle at 50 yards with:
Second and winner of the 8 loads, my 64 grn, Win PP load, which w/ a decent trigger I’m betting will make one hole:
Third, my Hornady 75 grn, AMAX load:
Fourth, my Hornady 75 grn, HPBT Match load:
Fifth, old reliable Win. Q3131A, bought from Eric the “Ammoman”
Sixth, IMI 62 grn, M855
Seventh, Win. 45 grn, HP, sold at Walmart in the 40 round “Value Pak”
Note: Black dot, when viewed through the EOTech red-dot was a bit hard to see for this round, so blame me w/ this, as this round is very accurate in my other M4s and appears to shoot in the 1/7, without slingin’ it’self apart, (which was why I tried ‘em…).
Eighth, was Win 64 grn Power Point Plus, outta the box:
There were no malfunctions/FTF or FTEs at anytime with the DPMS upper and bore cleaned up spic & span w/ no effort.
This upper was purchased from CMMG here on the EE and fit and finish was fine, (barrel parkerization is a little on the light colored side, but upper on whole is very fine as I'm not pickey, if it shoots, and seems it does).
Note: I never touched the EOTECH "after zeroing" was done, seem'd very suprising to me the consistency of this upper w/ a wide variety of weight rounds, it's a winner.
Mike, Great range report! My wife just informed me that the UPS truck just dropped mine off![:D] Heh, heh, heh... I have an ARMS SIR #50 and an EOTech 552 waiting to go it, I can't wait to get it all together!!! Edited to add: Now my wife is torturing me and sending pics...[;)] [img]http://a0.cpimg.com/image/12/42/19794450-fbed-02000180-.jpg[/img] [img]http://a9.cpimg.com/image/11/42/19794449-a16c-02000134-.jpg[/img]
Interesting report and thanks !! (I've gotta get some new ink cartridges then I'm gonna print this one off and file.)
Glad to see this. I put together a rifle using a CMMG/DPMS barrel and a [url=http://www.georgiaprecision.com/cart/items/CompetitionComponents.htm] marked upper[/url] from Georgia Precision. I really wanted the marked upper, just for authenticity's sake, so I opted out of the complete upper offered by CMMG. I went to the range last weekend to sight in my KAC 300m BUIS. Used BH 77g, and things went quite well. Although DPMS has apparently warned against it (see [url=http://www.ar15.com/forums/topic.html?b=2&f=30&t=139931&w=myTopicPop] this[/url] thread), I then ran about 100 rounds of SA surplus - 55 grain? - through it, without a single hitch. I was quite proud of it, as this is my first home-built AR. I plan to sight in my TA01NSN this comming weekend.