lateral dispersion of shots

[Grizzlypeg]

I'm shooting off a bench with a Rem 700 heavy bbl and Aics stock using a front rest and rear bag. I'm getting the majority of my groups with the shots lined up as to elevation, but the maximum dispersion in the group is always laterally. Some of that could be wind, as 10 mph at 100 yards will supposely produce up to .7" of lateral movement. I suspect most of it is me. Any suggestions? Is it trigger control or follow through? Can we rule out the rifle and load, if its all lateral movement?

A really typical group of 5 shots would be 1/4 to max 1/2" of up and down movement, but often 3/4" laterally.

 

[ultimate_monkey]

Is it just random lateral or consistently to one side or the other of your POA ?

 

[rnbra-shooter]

Some of it *could* be wind. What sort of variations in wind speed were you experiencing during your string? Do you have any wind indicators available? (flags, spinners, pieces of surveyor's tape, etc)

I used to find that with less-than-perfect trigger control when shooting off the bench, that my groups could be mostly horizontal. It might be a bit of this. I wouldn't see my shots as being off-call when I was shooting, but I was not satisfied that I was breaking good unrushed unflinched shots, and I'd get groups half an inch high but an inch wide.

It is also possible that there is something wrong with your scope. If the front lens is a tiny bit loose, or if there is a bit of movement in the erector tube (aiming mechanism) inside your scope, this sort of thing is possible.

It could be the rifle; it is possible for some odd bedding problems to produce something like this.

It could be you. Are you an experienced at shooting sub-1/2" groups from the bench, are you able (with other scopes/rifles) to shoot rounder groups than what you're getting with this scope/rifle? If you can't count on yourself (yet), do you have available a more experienced bench shooter who might be able to try out your scope+rifle+ammo and see if he can produce the round sub-1/2" that are presently eluding you?

 

[Grizzlypeg]

I do not count myself among the rank of those who shoot group after group of 1/2". Never pulled that off. I tend more towards hoping that if I fire ten shots, they stay under an inch. The rifle on the rest and on the rear bag seems real steady elevation wise. I struggle with lateral movement and try to really concentrate on the smooth pull of the trigger and follow through. I'm trying to develop an accuracy load for shooting F-tr, where I will of course be shooting prone instead. The bench seems a little easier to shoot from for developing the load and shooting consistently.

As an added thought, there is probably a reason why benchrest shooters have heavy benches, rests, well selected bags to match their setup and light triggers. The under 1/2" game isn't easy.

 

[GSoD]

Is it a factory barrel? I'm just asking because I had coincidentally found .7" as the average grouping (usually more lateral than vertical) for my factory barreled Rem700 with a moderate level of reloading.

IMO, whatever you're doing it is something minor. Could be as small as not using a small enough target dot or not getting your eye back to exactly where it was on the previous shot.

 

[maynard]

As an added thought, there is probably a reason why benchrest shooters have heavy benches, rests, well selected bags to match their setup and light triggers. The under 1/2" game isn't easy.

That's because you are not using a Savage/Remington/Stevens in a tuperware stock and shooting Winchester white box ammo. Those guys can shoot 1/2 MOA all day long

How heavy is your trigger? Try putting more finger on the trigger. Use the middle pad of your trigger finger on the trigger, it makes for a straighter squeeze.

 

[Mystic Precision]

Try this - shoot 3 3rds groups with a 5 min break in between, and measure the average.

Could be:

wind
YOU
Barrel heating up.

Put up flags and track where each shot lands. Is there a pattern?

Many shooters simply get tired and loose form as the shot count increases. Getting a good boot in the shoulder and muzzle blast fatigues shooter far faster then they might think.

See if this changes your results.

But you only average 3/4" at 100yds. That might still hold sub MOA way out there and that is plenty enough fun for LR plinking.

Also, try shooting at 200 or 300yds. Might surprise at how the rifle now shoots.
Jerry

 

[c3pppo]

I find that doimg a few dry fires, concentrating on making sure the crosshairs don't twitch when I pull the trigger, is very usefull before and during my shooting session. Gets me in tune with the trigger and the overall feel of the rifle, and always helps me tighten up those pesky lateral excursions.