I was able to take the gun out last week with Hornady 147gr ELD Match and 140gr Hornady Black (both factory loads). The groups with the stock trigger were averaging 1.5-2” at 100yds. That is just not acceptable to me personally. This morning I dropped in a Larue trigger, cleaned the barrel and loaded up some 140gr ELD M, starting at 36gr H4350 as per Hodgdon’s starting load and working up in .5 increment up to 38.5gr. As you can see, it did not start out well at all. The factory ammo sight-in group was abysmal. By the time I got to 38gr, the groups started to look much better. I think I am going to load some more at 38gr and try that one again.

I also loaded some 123gr ELD’s at 42gr and shot a 7shot group. That one is the lower left group. It seems this gun likes the lighter loads better.

I’m a fairly decent shooter, but this gun is kicking my butt. What kind of groups are you guys getting? This gun is all factory built except for the trigger and Toolcraft BCG.

quote:

Originally posted by usncorpsman:
What kind of groups are you guys getting?

I haven’t done any handloading for the cartridge, but I get very good groups with the Hornady 147 grain ELD Match from a Tikka.
Some groups posted on pages 2 and 3:

https://sigforum.com/eve/forum...935/m/7470031074/p/2

Did you make any scope adjustments as you moved from one group on paper to the next?
What were the shapes of your prior groups with factory ammo?
*****

My 6.5CM AR10 has Black Rain receiver set, BCG, and rail. Krieger barrel. I started piecing it together as an F-U to our state legislators during one of their attempts to ban ARs. I intended to use it for semiauto only PRS-type matches, but such matches never really took off. I don't have all that many rounds on the rifle -- unfortunate, as it shoots well.



No pictures of groups on paper or steel. The only groups I've measured and documented were during its first outing -- after maybe 10-15 rounds for barrel break in, MV testing, and scope sight in. I used leftover Hornady AMax for this.
Amax 140 -- 5 rounds in 1.12" at 100 yards. Then 5 rounds in .88" at 100 yards. I stacked 3 or 4 rounds on top of each other, then pulled one or two in each group. There's a lot of mass and gas moving around in an AR10. Much harder to follow through and control the recoil cycle than with a bolt action. I need a day with my A-game working to shoot an AR-10 well.

Amax 120 -- 10 rounds in 1.12" at 100 yards. Most of the rounds were stacked on top of each other, but a couple pulls.

Most of the shooting I've done with this rifle is mimicking fast-paced PRS-type stages. First is to set 3-5 steel targets more of less in a line, at distances from 350-600 yards. Dial the elevation for one target, hold over/under for the others, and put 8-10 rounds on different targets quickly.

Second is a traditional PRS timed tie breaker stage. 3-4 steel targets at roughly the same distance of 400 yards, separated left-right by 50-75 yards each. Bounce back and forth between the targets quickly, one shot per target.

This rifle absolutely excels in rapidly engaging multiple targets. I suspect there have been a few "..W..T..F.." responses from neighboring ranches when they hear rapid patterns of bang & ting.

When I assembled my 6.5 Creedmoor a couple years ago, the Hornady factory match ammo I bought shot pitiful groups as well. My disappointment could not be overstated. I started with a Sharps Jack 308 receiver set, my main parts are JP Enterprise; barrel, break, handguard, bolt & carrier, captured recoil spring, PRS II stock, Geissele Super dynamic Enhanced flat bow 2-stage trigger, Atlas bipod, Leupold Mark4 8.5-25x50 ER/T scope etc.

However when I started loading my own everything turned around, I was shooting 2” groups at 300 yards with 123g HPBT pills at 300yards. I can look up my exact load data if you need but I looked up load data online and my powder charge was in the middle of min and max load.
If our weather holds I’ll load some fresh, get to the range and shoot some new targets as it’s been 2 years since I’ve been able to shoot do to health issues.

My m5 Aero is has a 22 inch 6.5 cm barrel. It shoots well. If I recall correctly it grouped at .75” to 1.25” with 140 grain eld match factory rounds. I don't reload 6.5 since factory has been good for me. I am relying on memory as I haven't shot this gun in a while. My long range buddy can't play anymore since he got married.

I dug up more notes on 6.5CM, both my bolt action and the AR10.

I have only shot factory ammo through both rifles, mainly Hornady. Hornady loads with the following bullets have all shot under 1 MOA out to a few hundred yards -- 120 GMX, 120 Amax, 140 Amax, 140 ELDM, 147 ELDM. I haven't shot 123 ELDM. I've shot with competitors for whom it works well in 6.5 Grendel.

In my experience the higher MV of the 120 grain bullets is offset by their lower BCs. The BC of the 147 ELDM bullet is overstated -- so much so that the 140 ELDM performs better at distance. I've seen 147 BC issues play havoc with 3 competitors using 6.5 PRC in ELR competitions -- their impacts were so low that they tossed the data from their ballistics calculators after the first day, and shot by extrapolated actual results on subsequent days. But the 147 ELDM flies true and is accurate.

My 6.5CM AR10 has only shot Hornady factory 120 Amax, 140 Amax, and 140 ELDM. It shoots well with all three types. I suspect my Amax ammo has long been consumed.

I have a 6CM AR10 that is almost a match to the 6.5CM AR10 -- but with a Bartlein barrel instead of a Krieger. I shoot the 6CM AR10 a bit more accurately. Could be the barrel, but I suspect its the reduced recoil of the 6CM. Here's the 6CM Black Rain.


In March 2020 I shot both rifles back to back. Winds were funky over the two different weekends -- one day 5-15 mph from my 4-7 o'clock, and the other 5-15 mph from my 3 o'clock. It seemed like the 6CM got the better deal each rotation, with the winds being more steady. Vertical variations tended to be an inch or so less with the 6CM, but the gusting while shooting the 6.5CM resulted in stringing shots across the width of the steel plates. This was the refrigerator trophy picture of the day with the 6CM. 2.38" vertical and 4" horizontal at 525 yards. Hornady 108 ELDM.


I walked down to repaint the target, shot again with the 6.5CM, and the horizontal stringing was across the whole plate.

At 410 yards the 6CM held 2.75" vertical with 108 ELDM and 2.25" vertical with 105 HPBT Black. Again, the 6.5CM 140 ELDM had slightly larger vertical variation, but with more horizontal stringing.

At 340 yards the 6CM held verticals of 1.62", 2.00", 2.12", and 3.25". I wasn't thrilled with the pulled shot on the largest group. The 6.5CM had verticals under 3" from what I recall.

******
I suggest trying again with factory Hornady 140 ELDM. Clean the barrel before shooting. Make sure you're warmed up with another rifle and shooting well.
Confirm that your technique with the other rifle is solid by using dot drills, and by getting up off the rifle between shots.

[QUOTE]Originally posted by fritz:
Did you make any scope adjustments as you moved from one group on paper to the next?
What were the shapes of your prior groups with factory ammo?
*****
Factory ammo averaged about 2”. It could be a new barrel that needs break in. I adjusted the scope after the second group to hit more POA.

To eliminated some variables, I removed the FH and will shoot it with a bare barrel with thread protector. I had a gun that was MOA with a bare barrel and all over the place with a FH. I’ll post results tomorrow.

Thank you guys for all your help.