Rifle started as an Eagle Arms stripped lower purchased in 2006. Geiselle trigger, Armalite lower parts kit, AR10t 20" 1:10 complete upper, Magpul MOE stock, and SWFA SS 10x mil/mil on armalite 1 piece base all added last year.
I did the barrel break in last summer and finally got around to shooting some groups and measuring velocities last weekend. All shots were taken at 100yds off of sand bags. I shot 3 - 3 shot groups for 6 different types of ammo. Here are the results with speed in ft/s and groups measured center to center and converted to MOA.
Fed GMM 175. 308
Avg speed - 2495, SD 12, ES 33
Groups 0.6, 1.0, 1.5
Black Hills 175. 308
Avg speed - 2461, SD 40, ES 121
Groups 1.5, 1.2, 2.1
LCAAP XM118LR 175. 7.62
Avg speed - 2584, SD 12, ES 40
Groups 0.8, 1.15, 0.55
Fiocchi 175. 308
Avg speed - 2435, SD 17, ES 58
Groups 1.3, 1.2, 1.6
Black Hills 168. 308
Avg speed - 2531, SD 11, ES 34
Groups 1.6, 1.0, 1.6
PPU 168. 308
Avg speed - 2515, SD 10, ES 29
Groups 1.4, 1.7, 1.7
I had 4 malfunctions - 3 failures to load the next round or "short stroking" and 1 failure to lock back after the last round in the mag. All were with LCAAP XM118LR.
I have more shooting to do before I can really judge the accuracy of each type of ammo with my rifle. I should also say there was a swirling 10mph wind while I was shooting.
Does anyone have an explanation for why the xm118lr wouldn't cycle well? It was clearly the hottest load of the bunch but the rifle acted like it was short stroking. It would eject and go back to full battery but wouldn't always pick up the next round on the way forward.
Also, how do my speeds compare to others out there? They seemed a bit on the low side (except the xm118lr) to me but I've never chrono'd anything before.
Now I'm on the fence about ordering a big lot of the XM118LR.
Like the accuracy you got but cycling issues won't cut it. What year was the headstamp on that stuff?
First of all, welcome Jdizzle, and thank you for such a well written range report. A lot of quality info there. Two thoughts: Did you use multiple magazine? If so were you using the same mag all the time with the M118LR? If so it might be a mag problem. Second, what kind of Buffer were you using? A rifle or a carbine sized one? But that wouldnt select out for the M118 so that is probably not it. Mine eats everything I put through it so far, including most of what you were shooting, maybe someone else has some thoughts.
One other thought: As your rifle is still within the 200 round break in period, it might just take some time to loosen up. As the hottest load, it might be causing more friction and a less constant force on the BCG. If so that should disappear with break in.
It could be related as well to the burn rate of the powder in the M118lr. That is Reloader 15, and I would not think that would be a problem compared to the other loads.
I used the same mag for all the shots. I have the full length buffer and after last weekend the rifle has 191 shots through it so I am still within the break in period. I really want the 118 to cycle well because it had good speed and so far is giving the best groups (obviously from a small sample though).
Thank you for the performance data and well written report. :thumbs:
That's quite a range you have there! I'm shocked / impress how solidly the shooting lanes are constructed. I see because of its design the sky screens had to be placed outside the enclosure. That must have been a bit of a challenge to align correctly...
jdizzle3id wrote: The head stamp on the xm118lr is 13.
I used the same mag for all the shots. I have the full length buffer and after last weekend the rifle has 191 shots through it so I am still within the break in period. I really want the 118 to cycle well because it had good speed and so far is giving the best groups (obviously from a small sample though).
How much lubrication are you using on the bolt carrier group? Generally during break in, it isn't a bad idea to run the BCG pretty wet.
Also, what sequence did you try all the different loads? Did you come back at the end and try the M118 after the other loads? I am thinking it might have been a temporary obstruction of the gas tube while you were shooting the M118 that cleared itself out. If you alternated loads, that would destroy that theory.
I like the M118LR a lot. I haven't found any better though Federal Gold Medal Match is close.
Like Night Force said, that is an awesome shooting range! A lot of concrete! Keep us informed on this issue, we all like to learn.
jdizzle3id wrote: The head stamp on the xm118lr is 13.
I used the same mag for all the shots. I have the full length buffer and after last weekend the rifle has 191 shots through it so I am still within the break in period. I really want the 118 to cycle well because it had good speed and so far is giving the best groups (obviously from a small sample though).
How much lubrication are you using on the bolt carrier group? Generally during break in, it isn't a bad idea to run the BCG pretty wet.
Also, what sequence did you try all the different loads? Did you come back at the end and try the M118 after the other loads? I am thinking it might have been a temporary obstruction of the gas tube while you were shooting the M118 that cleared itself out. If you alternated loads, that would destroy that theory.
I like the M118LR a lot. I haven't found any better though Federal Gold Medal Match is close.
Like Night Force said, that is an awesome shooting range! A lot of concrete! Keep us informed on this issue, we all like to learn.
I have been running the bolt and buffer soaking wet. The sequence was interesting in that the 118 was to be the 3rd string of groups and I stopped shooting it after the first 3 rds because of 2 failures to pick up the next rd and 1 failure to lock back(3 failures in 3 rds). I then shot 27 more rds (3 more types of ammo at 3 groups each) without a failure. Then I shot the final 2 groups of 118 and had 1 failure to load the next rd on the 4th shot.
On a different note, I am not a member at the range in the picture but was a guest. I have surmised there must be a long time member there with a concrete business as they seem very concrete happy there. The range is very well maintained and what I consider very expensive to join. They do have a 500m range opening up soon that may compel me to join.
You are doing everything right, so either your rifle just Does not like M118LR, or there is something going on with that lot number. I am starting the process of fine tuning an M118LR clone reload, so it will be interesting to see how it performs.
All content of this site is copyright 2003 - 2017 AR-10(T)™, AR-10™, are trademarks of ArmaLite, Inc.® AR10T.com is NOT endorsed or affiliated with ArmaLite, Inc.®
About AR10T.com
AR-10(T) is a community focused on rifles, optics, scopes, gear, accessories, and components used by the professional operator and skilled marksman. Enthusiasts, shooters, and gunsmiths alike contribute to our gallery, articles, and reviews Thank you for visiting!