ar-10 accuracy, what is to be expected from a factory upper?

tangolima said:
Gas plume is the exiting gas at the muzzle? How is it different for the last round? The gun doesn't know it is the last round till the bolt returns and stopped. The bullet must be tens of yards away from the muzzle if not more.
Click to expand...

Smart gas. :)

It is how the gun moves differently (due to improper recoil management) that affects the plume. Do a dot drill at 100 yards, fully loaded and free recoil, you can measure the difference.

At 550, with my .308, the difference between free recoil and fully loaded bi-pod is a few inches.
 
MarkCO said:
Smart gas. :)



It is how the gun moves differently (due to improper recoil management) that affects the plume. Do a dot drill at 100 yards, fully loaded and free recoil, you can measure the difference.



At 550, with my .308, the difference between free recoil and fully loaded bi-pod is a few inches.
Click to expand...
But there isn't anything different, recoil management, bipod loading or whatnot, for the last round than the other rounds. That's unless the shooter anticipates it.

-TL

Sent from my SM-N960U using Tapatalk
 
tangolima said:
But there isn't anything different, recoil management, bipod loading or whatnot, for the last round than the other rounds. That's unless the shooter anticipates it.

-TL

Sent from my SM-N960U using Tapatalk
Click to expand...
Theres an easy way to check for that. Dry fire before the first round, and before the last.
 
tangolima said:
But there isn't anything different, recoil management, bipod loading or whatnot, for the last round than the other rounds. That's unless the shooter anticipates it.
Click to expand...

The vast majority of gas gun precision shooting experts disagree with you. I'll admit, it took me a while, some additional wisdom from others, and some testing to understand it enough to know there is a difference.

Here is the rub...most shooters are not good enough to be able to measure the difference with their guns at 100 yards and when you get out to 200+, the other variables of the environment obscure the data collection.

I'll not tell you to "trust me", but it is a very real thing, albeit a small factor for very good shooters and irrelevant for mediocre shooters.
 
I'm not saying it is not real. I saw that at times but not very conclusive.

But the mechanism you have described is just above and beyond my comprehension. I haven't come across the idea of steering a bullet in-flight with gas plume. A very mediocre shooter I am, still need a lot of work on zen.

Thanks for your info. It is a perspective to contemplate on.

-TL

Sent from my SM-N960U using Tapatalk
 
Easy way to test the last round flier theory. Load one extra round in the mag than you intend to shoot and see what happens. Just don’t forget to keep count.
 
"...load one extra round..."

hey that's a novel idea. i have some 30 round mags that will hold 31 rounds...
but all joking aside, (knowing that it wasn't all jokes) there are many things that can and do affect the shot placement, not the least of which is the trigger nut.

and i wasn't trying to start a debate about whether to use wd-40 or not... so to speak.

just asking for a few honest real world openions about what to logically expect out of a new cheap ar-10 would sub-MoA be unreasonable or quite within reach for most hardware... that was all i was asking, and yes i know you can get a shooter out of any brand and you can get one that blows paterns rather than groups... even out of well reputed hardware... so thanks to all for all the feed back.
 
We just need to fool or convince the rifle that it isn't the last round. :). Perhaps better to convince the shooter there is one more round in the magazine, so that he won't flinch for it.

-TL

Sent from my SM-N960U using Tapatalk
 
I have a Les Baer .308 semi-automatic (AR10 style) match rifle. I have shot five-shot groups that are 0.38 (nearly a single hole) from a sanbagged rest with Federal match ammunition at 100 yards. The ammunition was the Federal Gold Medal Sierra MatchKing .308, with 175-grain bullets.

The testing of the gun was done in the tunnel at the gun club I belong to so that wind drift was not a factor. The scope on the gun was a U.S. Optics 5-25 x 50mm diameter optics scope with a first focal plane reticle.

The Les Baer gun has a Les Baer-designed "Enforcer" muzzle brake EDM machined into the barrel. With the scope on the rifle, a 20-round magazine, and a bi-pod, the gun weighs close to 13 pounds. Between the weight of the gun and the muzzle brake, the recoil is less than a .243. Flinching is not a problem with the gun.

The only preparation of the ammunition was to check it on a Hornady 050076 ammunition concentricity tool and ensure that all of the bullets were centered in the cases.

I have shot targets out to 1,000 yards with the gun. Six hundred-yard shots are quite easy. It is by far, the most accurate gun I have with targets under 800 yards. Over that distance, the custom 30-338 that I have is more accurate, but that has more to do with the bullet weight and velocity and less effect by wind than the inherent accuracy of the 30-338.
 
Last edited:
what should be expected from a cheep factory ar-10 in 243 win. ... well with good hand loads i can consistantly get sub MoA, i went to a pay to play range last saterday, and shot a 5 shot .48 MoA group at 100 yds, the wind was from 6 o'clock and gusty with a slight variance side to side so my 200 yards group opened up to 1.02 MoA and that was as far as they had range for. so i have to rely on my 424 yd range on my drive way. for any longer stuff. but all in all the short answer is "all i did was lap the chamber and install an adjustable gas block. the was simple load tuning. and i am well pleased with my $425.00 ar-10 243win using 107gr smk pills, with 42.7 grs of rl-19 powder, and cci 200 primers, in winchester cases. like i said, the answer to my question "what should one xepect..." expect at least sub MoA it might take a little playing with things to reach it, but it is reachable ImO.
 
georgehwbush said:
what should be expected from a cheep factory ar-10 in 243 win. ... well with good hand loads i can consistantly get sub MoA, i went to a pay to play range last saterday, and shot a 5 shot .48 MoA group at 100 yds, the wind was from 6 o'clock and gusty with a slight variance side to side so my 200 yards group opened up to 1.02 MoA and that was as far as they had range for. so i have to rely on my 424 yd range on my drive way. for any longer stuff. but all in all the short answer is "all i did was lap the chamber and install an adjustable gas block. the was simple load tuning. and i am well pleased with my $425.00 ar-10 243win using 107gr smk pills, with 42.7 grs of rl-19 powder, and cci 200 primers, in winchester cases. like i said, the answer to my question "what should one xepect..." expect at least sub MoA it might take a little playing with things to reach it, but it is reachable ImO.
Click to expand...
I concur. My ar-10 in .243 win is definitely bottom of barrel material. With tinkering it hovers around 1moa. If I do everything right, it can go better than 1moa with 10-shot groups. It is a 24" light weight (thin) barrel, and it tends to cold bore shift. I reckon a 20" heavy barrel may do better in consistency.

-TL

Sent from my SM-N960U using Tapatalk
 
You must log in or register to reply here.
Back
Top