Gunboards Forums banner
1 - 19 of 19 Posts

·
Registered
Joined
·
21,212 Posts
Discussion Starter · #1 ·
Yesterday a novice shooter arrived with PSA AR 10, 20" barrel, Vortex scope and LCLR 175 gr BTHP issue ammo. He had a 100 yd zero and wanted to shoot 1000 yds. We assigned a spotter and we got him onto a 12 inch diameter cluster of skeet birds (1.2 MOA) and his "build" AR 10 was holding 1.2 to 1.4 MOA accuracy at 1000 yds which is darn good for a build by a novice. Obviously the stainless steel barrel on his PSA upper was a great barrel. His Vortex Crossfire had the elevation to make 1000 yds which is unusual as most all Vortex scope require a 20 MOA mount but the shooter was on at 1000 yds so never say never.

How much better could this build shoot with a more experienced shooter and better optics ? Good question but for a novice with his first build, the end result was impressive results for a short 20 inch barrel. That we had no mirage nor winds yesterday certainly had a positive impact.

AR 10 accuracy like that would be hard to replicate with heavily tuned M14 National Match rifle so all I can think of is CNC machining is making closer tolerance AR 10's these days.

This is the first PSA AR 10 type 308 Win rifle that I've seen , we never see any AR 10's show up at 1000 yd line . There are lots of AR 10 type rifles by different makers so they must sell rather well but I have not seen a Tsunami of buyers going after them. I may be at the wrong place to see that happening , certainly it seems most of the issues with AR 10 platforms have been sorted out.

Anyone got AR 10 accuracy to report ?
 

·
Registered
Joined
·
196 Posts
Had an SR-25 years ago configured in what later became the Mk.11 Mod.0 which shot just under one minute - except it reliably threw the first round out of the group. In fact I would stop enroute to call-outs (it was my LE SWAT sniper rifle) and fire that first round into the ditch (rural area) so that I went into the hide with a gas-chambered round. Lottsa Ar's are sensitive that way, probably due to the difference in chambering velocity between hand-cycling and gas-cycling. A later Sr-25 carbine (16") was maybe an inch-and-a-half gun (no free float) but it and many other .308 AR's with barrels at or less than 20" would and will go transonic before 1k yards, resulting in tumbling bullets. Had an LR-260 that was a three-quarter minute rifle with bullets it liked, but was very squirrely, often corking primers even with factory loads (which the .260 gas guns are notorious for - see Zediker). Current DPMS 24" bull .308 is reliably at .8" for three rounds including the first hand-chambered round, in carefully assembled ammunition.
 

·
Gold Bullet member
Joined
·
9,495 Posts
Had an SR-25 years ago configured in what later became the Mk.11 Mod.0 which shot just under one minute - except it reliably threw the first round out of the group. In fact I would stop enroute to call-outs (it was my LE SWAT sniper rifle) and fire that first round into the ditch (rural area) so that I went into the hide with a gas-chambered round. Lottsa Ar's are sensitive that way, probably due to the difference in chambering velocity between hand-cycling and gas-cycling...
I experience the same phenomenon with my Swedish AG42b Ljungman. The first round chambered is always outside the rest of the group. I have been able to mitigate this effect somewhat, i.e. reduce the spread, by using slow powder that allows a higher charge density i.e. case fill. I suspect powder tamping is the culprit.
 

·
Registered
Joined
·
21,212 Posts
Discussion Starter · #5 ·
Leon, a friend of mine...he lurks everywhere to seize the chance to say something about Swede rifles.
What are you doing here Leon, this is modern rifle talk at 1000 yds. Yeah before you volunteer more SWEDE trivia
here, we all know the 6.5x55 Swede is a great caliber so go back to Swiss Forum.
 

·
Registered
Joined
·
21,212 Posts
Discussion Starter · #6 ·
Had an SR-25 years ago configured in what later became the Mk.11 Mod.0 which shot just under one minute - except it reliably threw the first round out of the group. In fact I would stop enroute to call-outs (it was my LE SWAT sniper rifle) and fire that first round into the ditch (rural area) so that I went into the hide with a gas-chambered round. Lottsa Ar's are sensitive that way, probably due to the difference in chambering velocity between hand-cycling and gas-cycling. A later Sr-25 carbine (16") was maybe an inch-and-a-half gun (no free float) but it and many other .308 AR's with barrels at or less than 20" would and will go transonic before 1k yards, resulting in tumbling bullets. Had an LR-260 that was a three-quarter minute rifle with bullets it liked, but was very squirrely, often corking primers even with factory loads (which the .260 gas guns are notorious for - see Zediker). Current DPMS 24" bull .308 is reliably at .8" for three rounds including the first hand-chambered round, in carefully assembled ammunition.
Did you shoot 1000 yds ?
 

·
Gold Bullet member
Joined
·
9,495 Posts
Leon, a friend of mine...he lurks everywhere to seize the chance to say something about Swede rifles.
What are you doing here Leon, this is modern rifle talk at 1000 yds. Yeah before you volunteer more SWEDE trivia
here, we all know the 6.5x55 Swede is a great caliber so go back to Swiss Forum.
LOL. I also shoot a Savage MSR 10 LR .308. I do not have this first round flyer problem with this rifle. It has a gas block regulator with unusually fine adjustment, and this may be the reason. I have it set to just where it cycles reliably, so it is definitely not overgassed.

BTW I had to send this rifle back to Savage after its first range session because the bolt head lugs were showing abrasion and battering. The bolt head was replaced.

Re: "...we all know the 6.5x55 Swede is a great caliber so go back to Swiss Forum." Ah yes, the "Guns of Swederland."
 

·
Registered
Joined
·
332 Posts
AR10 rifles sell pretty good. Not nearly as well as their little brother but there is a market. I am an 01 dealer that sells a LOT of PSA products. (Think 60 or so on a good weekend). I personally own an AR10 PSA rifle with an 18 inch stainless barrel. My range only goes out to 200 rds , but that rifle will hold 1-1.5 MOA at that range with my handloads using 175SMKs. Just a note....DPMS is now owned by PSA.
 

·
Registered
Joined
·
196 Posts
Did you shoot 1000 yds ?
Oh, yes, often. Our agency ran police sniper schools for many years. We took them to a thousand, not because many police sniper incidents demand that, but because it increased their confidence tremendously, and it was a valuable diagnostic tool (e.g. trigger control, breathing, and follow-through issues that would not manifest at 100 yards, or even 300, become apparent at 1,000). As an aside, one of our graduates holds (last I knew) the US police sniper distance engagement at over 600 yards. I like to think that part of the reason is because he shot that distance and well beyond at our school.
 

·
Registered
Joined
·
21,212 Posts
Discussion Starter · #10 ·
Oh, yes, often. Our agency ran police sniper schools for many years. We took them to a thousand, not because many police sniper incidents demand that, but because it increased their confidence tremendously, and it was a valuable diagnostic tool (e.g. trigger control, breathing, and follow-through issues that would not manifest at 100 yards, or even 300, become apparent at 1,000). As an aside, one of our graduates holds (last I knew) the US police sniper distance engagement at over 600 yards. I like to think that part of the reason is because he shot that distance and well beyond at our school.
Sir,
What was accuracy of SR 25 at 1000 yds based on your experience at the range ?
 

·
Registered
Joined
·
196 Posts
Sir,
What was accuracy of SR 25 at 1000 yds based on your experience at the range ?
That particular rifle would hold 1.2 minutes at a full 1k. I believe it could have done a bit better, but this was long enough ago that the state-of-the-art bullet was the Sierra 168 Matchking. We didn't get onto the 175's until later. Also the range is notorious for its crosswinds (I've literally seen 90 grainers out of a fast-twist .22-6mm drift six feet at a thousand - onto the adjacent target frame in fact). Then there is the limited ability of the shooter; I have to hold my mouth just right to shoot into a minute at a thousand with anything.
 

·
Registered
Joined
·
21,212 Posts
Discussion Starter · #12 ·
My experience is 168 gr loads don't hang at 1000 yds out of bolt rifles with 24 to 26" barrels. The boat tail is such on the 168's that they are unstable by the time they get to target line , and in the last decade running the 1000 yd line here at Quantico, no one with a 30 caliber rifle has found 168's worth a hoot at 1000 yds. The bullet weight for 800 and 1000 yds is 175 gr BTHP minimum for 308 Win caliber rifles.
 

·
Registered
Joined
·
546 Posts
My experience is 168 gr loads don't hang at 1000 yds out of bolt rifles with 24 to 26" barrels. The boat tail is such on the 168's that they are unstable by the time they get to target line , and in the last decade running the 1000 yd line here at Quantico, no one with a 30 caliber rifle has found 168's worth a hoot at 1000 yds. The bullet weight for 800 and 1000 yds is 175 gr BTHP minimum for 308 Win caliber rifles.
Not a long range expert, but based on what I learned before going to the 1000 yard line, I shelved my 168s in favor of 175s.

I was shooting Lapua 175gr Scenar-Ls in a Savage Model 10 with a 24" barrel, and they were supersonic at 1000. My partner was shooting Bullets 1st 175gr SMKs from a Savage Axis 20", and they went subsonic before making it to 1000, so there are other variables as well. Based on my calculations that day, I had just about 100 yards more before mine would be subsonic as well.

It's mostly about the bullet's Ballistic Coefficient.

A 168gr 30 cal is less efficient than a 175gr, and loses velocity and stability before making it out that far.
 

·
Registered
Joined
·
196 Posts
My experience is 168 gr loads don't hang at 1000 yds out of bolt rifles with 24 to 26" barrels. The boat tail is such on the 168's that they are unstable by the time they get to target line , and in the last decade running the 1000 yd line here at Quantico, no one with a 30 caliber rifle has found 168's worth a hoot at 1000 yds. The bullet weight for 800 and 1000 yds is 175 gr BTHP minimum for 308 Win caliber rifles.
I've seen an awful lot of bullet holes through the bull at a thousand with 168's, but they're not to be relied upon. We found that rifles with long and/or fast barrels mattered, and that some rifles could do it on a hot summer day but not a cold winter one. Had an entire team clear off the line weeping in frustration when their 16" suppressed gas guns couldn't push 168's much past 700. Lot of factors influence the choice of bullet for police snipers, but for long range I cheerfully agree the 175's are mo' better..
 

·
Registered
Joined
·
37 Posts
Oh, yes, often. Our agency ran police sniper schools for many years. We took them to a thousand, not because many police sniper incidents demand that, but because it increased their confidence tremendously, and it was a valuable diagnostic tool (e.g. trigger control, breathing, and follow-through issues that would not manifest at 100 yards, or even 300, become apparent at 1,000). As an aside, one of our graduates holds (last I knew) the US police sniper distance engagement at over 600 yards. I like to think that part of the reason is because he shot that distance and well beyond at our school.
Yesterday a novice shooter arrived with PSA AR 10, 20" barrel, Vortex scope and LCLR 175 gr BTHP issue ammo. He had a 100 yd zero and wanted to shoot 1000 yds. We assigned a spotter and we got him onto a 12 inch diameter cluster of skeet birds (1.2 MOA) and his "build" AR 10 was holding 1.2 to 1.4 MOA accuracy at 1000 yds which is darn good for a build by a novice. Obviously the stainless steel barrel on his PSA upper was a great barrel. His Vortex Crossfire had the elevation to make 1000 yds which is unusual as most all Vortex scope require a 20 MOA mount but the shooter was on at 1000 yds so never say never.

How much better could this build shoot with a more experienced shooter and better optics ? Good question but for a novice with his first build, the end result was impressive results for a short 20 inch barrel. That we had no mirage nor winds yesterday certainly had a positive impact.

AR 10 accuracy like that would be hard to replicate with heavily tuned M14 National Match rifle so all I can think of is CNC machining is making closer tolerance AR 10's these days.

This is the first PSA AR 10 type 308 Win rifle that I've seen , we never see any AR 10's show up at 1000 yd line . There are lots of AR 10 type rifles by different makers so they must sell rather well but I have not seen a Tsunami of buyers going after them. I may be at the wrong place to see that happening , certainly it seems most of the issues with AR 10 platforms have been sorted out.

Anyone got AR 10 accuracy to report ?
why do you have to be Da Vinci to "build" an accurate AR 10? also PSA is supposedly a low tier supplier
 

·
Registered
Joined
·
21,212 Posts
Discussion Starter · #16 ·
why do you have to be Da Vinci to "build" an accurate AR 10? also PSA is supposedly a low tier supplier
We're talking that ...AR10's that are accurate at long range and the dude last weekend with the PSA AR 10 clone was doing it. Does it matter made his rifle if its holding at 1000 yds ? I don't own any AR 10's so I don't have a dog in brands of them but if I had the loose change, I'd like a HK MR762 LRP ... a mere 7,249 bucks and I'd bet 1000 yd accuracy comes with it.
 

·
Registered
Joined
·
74 Posts
Yesterday a novice shooter arrived with PSA AR 10, 20" barrel, Vortex scope and LCLR 175 gr BTHP issue ammo. He had a 100 yd zero and wanted to shoot 1000 yds. We assigned a spotter and we got him onto a 12 inch diameter cluster of skeet birds (1.2 MOA) and his "build" AR 10 was holding 1.2 to 1.4 MOA accuracy at 1000 yds which is darn good for a build by a novice. Obviously the stainless steel barrel on his PSA upper was a great barrel. His Vortex Crossfire had the elevation to make 1000 yds which is unusual as most all Vortex scope require a 20 MOA mount but the shooter was on at 1000 yds so never say never.

How much better could this build shoot with a more experienced shooter and better optics ? Good question but for a novice with his first build, the end result was impressive results for a short 20 inch barrel. That we had no mirage nor winds yesterday certainly had a positive impact.

AR 10 accuracy like that would be hard to replicate with heavily tuned M14 National Match rifle so all I can think of is CNC machining is making closer tolerance AR 10's these days.

This is the first PSA AR 10 type 308 Win rifle that I've seen , we never see any AR 10's show up at 1000 yd line . There are lots of AR 10 type rifles by different makers so they must sell rather well but I have not seen a Tsunami of buyers going after them. I may be at the wrong place to see that happening , certainly it seems most of the issues with AR 10 platforms have been sorted out.

Anyone got AR 10 accuracy to report ?
All my serious work was done with bolt rifles, I have shot 5 different AR 10's. I gave up on the 7.62x51 nearly 50 years ago. Don't get me wrong I believed at the time and now still it's one of the best specialty rifleman general purpose cartridges out there. In the field I was just either going too far or in too close.

My experiance with the AR10 is that they all would struggle to replicate the results you write about. This in my opinion was an exceptional set of circumstances, luck, combined with good ammo, a good build and a good shooter. Most AR 10's I shot were 2" shooters, I never took any past 600 but, 1 rifle did a bit better but I thought it lacked reliability. I haven't shot an AR10 for nearly a decade, I respect the M1A but would not buy one.

I have 3 generations of AR 15's in my family and I can attest that you're correct, the machining has improved over time. My AR A2 (nearly 40 years old) is about a 3/4" shooter with 69 grain match at 100 yards and carries that out to 300 in good wind conditions. I never seem to get good wind with it when I'm on longer ranges.

My AR15 M4E in 6MM ARC is a true 1/2" shooter so far all the way to 600 in light wind. I'm now looking for 2 quick release scope mounts one for an LPVO and another for a precision scope the place on it. This rifle was bought as a general purpose rifle not a competition rifle, as far as I'm concerned a real value for my buck.

I believe a modern AR10 would benefit from the modern machining techniques.
 

·
Registered
Joined
·
1,492 Posts
except it reliably threw the first round out of the group.
That is your "Cold Bore" shot. We would start a logbook and plot the hit locations of each cold bore shot. You can then build a group and adjust your zero/scope dope accordingly for the cold bore.

It is the shift in zero of the rifle due to heating of the bore/barrel.
 

·
Registered
Joined
·
1,492 Posts
The bullet weight for 800 and 1000 yds is 175 gr BTHP minimum for 308 Win caliber rifles.
There is a valid reason why M118 LR is 175 grain.
 
1 - 19 of 19 Posts
Top