Help - why recoil management issues don't show up in 100 yard groups

[Deleted calshipbuilder]

I shoot a mix of tactical, long range, and F-TR. For the past year I've had - what I believe to be - recoil management issues. I'm getting vertical stringing at distance when shooting my 308 with GMM 175 and M118LR - I have not tried anything heavier. I also experience it with muzzle braked 300 norma mags (15-20lb rifles). I do not have the same issues shooting 243, but every once in a while will get a high right flier.

I've read the excellent post on taming the 215 berger in F-TR: http://forum.accurateshooter.com/threads/taming-the-215-berger.3872414/

I shoot a mild load in my 300 Norma, 2930 fps with a 215 berger, 84.5gr retumbo, CCI 250, COAL 3.550. I have decent SDs (high single digits), and my 5-10 shot 100 yard groups are consistently 1/2 moa or less. My scope tracks as it should (multiple tracking tests). But I can't keep it together at distance.

Example from last weekend with my 20lb norma, on a 12" disk at 777 yds, I make a first round impact, then miss high, low, high right, impact, low, low... repeat for 5 impacts out of 40 shots in light winds. At SAC valley with my 308 late last year, same thing - I did ok at 800 - a few 8s, but mostly 9s and 10s at 900, It started to fall apart, and at 1000, all over the place vertically - 6 high, 10, 8 low, 8 high, impact, 7 low...

Why is it that I can hold consistent 1/2 moa groups with these rifles at 100 yds - but completely fall apart at distance? I'm beginning to think the worst thing I ever did for my shooting was to switch from 308 to 243. What is it about recoil management that this problem doesn't show up at short range.

Thanks for any help you can give me.

 

[Fast14riot]

What do your groups look like at 300 yards?

 

[Pablo]

Sounds like conditions are getting you, unfortunately nobody has access to a tunnel a thousand yards long to check lr rifles in. If this stuff is going on at a group shoot competitors will often say that something is going on out there, in either the wind or mirage that is causing fluky conditions. Happens all the time in 100 and 200yd BR matches, usually the winner is the guy that understands what's going on, oh, they don't usually talk too much about it either. LOL

 

[dkhunt14]

I don't believe it's recoil management. I think the loads are falling apart. For 1000 yard BR I never test under 400 yards. I had a Dasher that would shoot ES of 2 to 3 and groups in the 0's at 100 yards and it wouldn't shoot under 13 inches, all vertical at 1000. I have seen this many times with lots of guns. Matt

 

[dmoran]

Similar to Matt's input, often what I see at 100 does not act/react the same at 1000.
Strong believer that both the load and the rifle are best when tuned at the desired distance.
Donovan

 

[Willie]

Could be parallax, rifle, load, scope, mounts or shooter.

 

[SheepDog]

No matter where the error comes from it is multiplied by the distance. What long range shooters would consider unacceptable ammunition fluctuations don't even enter into my hunting loads. I am only shooting to 200 yards and if my ammo is off a half inch at that range it isn't going to make any difference to the animal I harvest.
If the recoil is unpleasant to you it could just be the differences in muscle tension between shots. I only have to shoot once so I don't have to worry about anything but buck fever.
At my age it would have to be some buck to cause that.

 

[Deleted calshipbuilder]

What do your groups look like at 300 yards?

I'm not sure, but I will get that on paper soon.

Sounds like conditions are getting you, unfortunately nobody has access to a tunnel a thousand yards long to check lr rifles in. If this stuff is going on at a group shoot competitors will often say that something is going on out there, in either the wind or mirage that is causing fluky conditions. Happens all the time in 100 and 200yd BR matches, usually the winner is the guy that understands what's going on, oh, they don't usually talk too much about it either. LOL

At the F-class match in December, no one else had the vertical issues I did.

I don't believe it's recoil management. I think the loads are falling apart. For 1000 yard BR I never test under 400 yards. I had a Dasher that would shoot ES of 2 to 3 and groups in the 0's at 100 yards and it wouldn't shoot under 13 inches, all vertical at 1000. I have seen this many times with lots of guns. Matt

I would love it if thats the issue. Earlier this spring I had no problem with that 12" plate. The load was slightly hotter (86.5gr) didn't group as well at 100, and SD was 15ish, but I was hitting consistently. I'll load some of these up again.

However going back to my 308, which had similar vertical dispersion issues - I was shooting proven factory loads (M118 & GMM 175).

Similar to Matt's input, often what I see at 100 does not act/react the same at 1000.
Strong believer that both the load and the rifle are best when tuned at the desired distance.
Donovan

The problem with my shooting is I need a load that's consistent from 600 to 2000 (these are the distances at the NF ELR match I just dropped out of, and Sacramento f-class matches are from 300-1000).

Could be parallax, rifle, load, scope, mounts or shooter.

But which one and how do I tell?

No matter where the error comes from it is multiplied by the distance. What long range shooters would consider unacceptable ammunition fluctuations don't even enter into my hunting loads. I am only shooting to 200 yards and if my ammo is off a half inch at that range it isn't going to make any difference to the animal I harvest.
If the recoil is unpleasant to you it could just be the differences in muscle tension between shots. I only have to shoot once so I don't have to worry about anything but buck fever.
At my age it would have to be some buck to cause that.

The recoil doesn't bother me much, at least consciously... i hear you on hunting, I'm very happy hunting hogs with my Savage 99, but I've got an addiction to impacts at long range, and I need a hit.

 

[Fast14riot]

I'm betting that the vertical is being lost in the close range tuning, I asked what it looks like at 300, because that's where the vertical may start to become visible. Tune at 300+

 

[BenPerfected]

I don't believe it's recoil management. I think the loads are falling apart. For 1000 yard BR I never test under 400 yards. I had a Dasher that would shoot ES of 2 to 3 and groups in the 0's at 100 yards and it wouldn't shoot under 13 inches, all vertical at 1000. I have seen this many times with lots of guns. Matt

Matt, with 1.5"-2.0" (5) shot groups @ 500 yds in light winds, what would you expect the results would be @ 1000 yds?
Ben

 

[shoot4fun]

Matt, with 1.5"-2.0" (5) shot groups @ 500 yds in light winds, what would you expect the results would be @ 1000 yds?
Ben

Wouldn't it be lovely if your 1.5" @ 500 always translated to 3" @ 1,000?
I have been shooting one match in particular for several years that has no sighters, and targets placed at 600, 800, 900 and 1,000 yards. I've developed some great loads on my 500 yard range that could shoot sub 1/2 MOA at 600 and 800 but started to dissolve at 900 and became big old "steamers" at 1,000 yards. It has led me to believe that the forces of physics and ballistics magnify themselves greatly at certain points downrange and do ugly things to that "perfect" load.

 

[dkhunt14]

Matt, with 1.5"-2.0" (5) shot groups @ 500 yds in light winds, what would you expect the results would be @ 1000 yds?
Ben

I believe it is capable of 3 to 4 inch. What these people dont understand is sometimes it will shoot smaller MOA at 1000. Seen it many times. Typically my good heavy guns will shoot 1/2 to 3/4 inch 10 shot groups at 100. They will shoot 1 to 1 1/2 inch groups at 400 and it shot the world record 10 shots in 2.815 inches. So MOA doesn't always hold. That gun shot a lot of small 4 inch targets at 1000. You need to find the load that doesnt fall apart. Matt

 

[dkhunt14]

Wouldn't it be lovely if your 1.5" @ 500 always translated to 3" @ 1,000?
I have been shooting one match in particular for several years that has no sighters, and targets placed at 600, 800, 900 and 1,000 yards. I've developed some great loads on my 500 yard range that could shoot sub 1/2 MOA at 600 and 800 but started to dissolve at 900 and became big old "steamers" at 1,000 yards. It has led me to believe that the forces of physics and ballistics magnify themselves greatly at certain points downrange and do ugly things to that "perfect" load.

That load isn't perfect if it won't shoot at 1000. The right load doesn't fall apart and tends to shoot through conditions. Ask any 1000 yard BR guy. When you shoot 20,000 to 30,000 shots on paper at 1000 you tend to see what others don't. My gunsmith and his buddy used to go to Shippensburg to test. They shot plenty of 2 inch groups at 800. He told me they tend to fall apart at 1000 and shoot big. I am talking 85 to 100 pound heavy guns that track and heat doesn't hurt them becuase of 1.450 diameter barrels glued in a block. Matt

 

[shoot4fun]

That load isn't perfect if it won't shoot at 1000. The right load doesn't fall apart and tends to shoot through conditions. Ask any 1000 yard BR guy. When you shoot 20,000 to 30,000 shots on paper at 1000 you tend to see what others don't. My gunsmith and his buddy used to go to Shippensburg to test. They shot plenty of 2 inch groups at 800. He told me they tend to fall apart at 1000 and shoot big. I am talking 85 to 100 pound heavy guns that track and heat doesn't hurt them becuase of 1.450 diameter barrels glued in a block. Matt

Exactly what I am saying. Good loads don't prove themselves until out past the 800 yard mark.

 

[XTR]

I didn't read all of the posts, but of those I did I think you are all missing that he's shooting factory ammo. FGGM and Lake City 118LR.

They are not up to snuff to shoot to 1000. The reason that F TR shooters (and others) obsess over chrono info and load to get very low ES numbers is because at 1000 yards it matters a whole hella lot. Factory ammo can't get there.

Spend some time with JBM but here are some numbers for thought.

Assume your average MV for the 308 is 2650.

your drop from a 100 yard zero:
200yds = 5.2"
600yds = 124"
1000yds=526"

Now, if you get an extreme spread of only 25FPS your impacts are
±0.1" at 200 yards
±1.5" at 600 yds (that's top and bottom of the X ring)
± 6.5" at 1000 yds. (that's in the 9 ring a lot)

Now assume that your factory load is probably more like an ES of 75FPS and you fall completely apart at range:

±0.2" at 200 (still can't see it)
±4" at 600 yards (you are getting high and low 9s at 600)
±18" at 1000 (that's 8 ring vertical and now you have no ideal where it's going to hit)

Take into account that a 175SMK launched at factory velocities starts is going transonic at about 800 and is subsonic by 1000 and you're doing well just to hit the target.

 

[Deleted calshipbuilder]

I didn't read all of the posts, but of those I did I think you are all missing that he's shooting factory ammo. FGGM and Lake City 118LR.

They are not up to snuff to shoot to 1000. The reason that F TR shooters (and others) obsess over chrono info and load to get very low ES numbers is because at 1000 yards it matters a whole hella lot. Factory ammo can't get there.

Spend some time with JBM but here are some numbers for thought.

Assume your average MV for the 308 is 2650.

your drop from a 100 yard zero:
200yds = 5.2"
600yds = 124"
1000yds=526"

Now, if you get an extreme spread of only 25FPS your impacts are
±0.1" at 200 yards
±1.5" at 600 yds (that's top and bottom of the X ring)
± 6.5" at 1000 yds. (that's in the 9 ring a lot)

Now assume that your factory load is probably more like an ES of 75FPS and you fall completely apart at range:

±0.2" at 200 (still can't see it)
±4" at 600 yards (you are getting high and low 9s at 600)
±18" at 1000 (that's 8 ring vertical and now you have no ideal where it's going to hit)

Take into account that a 175SMK launched at factory velocities starts is going transonic at about 800 and is subsonic by 1000 and you're doing well just to hit the target.

M118 and FGMM actually do pretty well with SD in my Surgeon actioned custom (26" Krieger with GAP reamer), and my Dad's GAP Crusader. See attached. He has not experienced the vertical issues I have had with his rifle. I think I need to shoot his a bit more.

The 300 norma is my hand loads

 

[seymour fish]

M118 and FGMM actually do pretty well with SD in my Surgeon actioned custom (26" Krieger with GAP reamer), and my Dad's GAP Crusader. See attached. He has not experienced the vertical issues I have had with his rifle. I think I need to shoot his a bit more.

The 300 norma is my hand loads

Ok, have you shot a ladder with it at 100 yes. Has anyone else shot it and had same problem

 

[338 Mollett]

I had a hard time weaning myself off of those big cases,what did the trick was shooting them in a match.The no.5 shooter from the St.Mary's Girl's School for the blind beat me with a sling-shot .Live and learn,good luck!

 

[Bart B.]

Even if all bullets leave at the same speed, the small spread in their BC due to tiny unbalance issues as well as different air density and subtle cross winds, groups subtended angles at 100 yards open up 5% to 10% every hundred yards further down range. It gets worse as extreme spread in muzzle velocity increases.

That assumes no positive compensation for velocity by barrel whip and the angle bullets leave at.