Vertical dispersion

[270windude]

If you have a gun that shoots roughly half inch wide groups with an inch and a half vertical dispersion what are some likely reasons? I’ve seen some wild velocity spreads shooting accurate at shorter ranges but also thinking distance plays a part here. I have not shot long strings through the chrony but am considering it now. The range I’m referring to is 50 yards. I was shooting from a seated position using a short shovel stuck into the ground as a rest. I had the foremost part of the forend of the stock rested on the shovel. Right now I’m thinking I need to play with different holds and check my velocity spreads better. It is a new spring so hoping that if it is indeed related to velocity that it will settle down or I can somehow help the situation.

 

[scratchcoobster]

Springers don't generally respond well to being placed directly on a rest, particularly a hard or firm rest. The best method is to cradle the fore end in the palm of your hand with your hand positioned on the rest (such as a sand bag, or other softer rest). This way the recoil will be reduced and shot accuracy will be improved. Vertical displacement is often a result of the rifle barrel jumping up off the rest and affecting the shot angle up or down. Try this out and you may well see an improvement in your groups.

 

[270windude]

So the vertical may be hold related is what you’re saying... i Unfortunately didn’t play too much with holds as I was more focused on pellet selection. That’ll be my next outing I think. Shoot a 10 shot string through chrony and try different holds. Based off of my current thinking I’ll only try front supported hold vs rear and full rest. Won’t mess with the butt end, I just keep it light enough on my shoulder to keep it propped up. Probably won’t use my hand for an “artillery hold” yet but some sort of wood block with a soft towel for the gun to rest on.

 

[Michigander]

I find the balance point, mark it with a piece of painter's tape, and rest the rifle just forward of the tape. The rest should be padded, but not bouncy. I am usually shooting off a set of Stoney Point sticks that I have padded by wrapping the rest areas with some cloth. Try to be consistent as possible with positioning on the rest. This has given good results on all my springers so far.

 

[bandg]

And if it's a break barrel, clean the breech area well and check for consistent lockup.

 

[Duckfish]

Big bag of rice, inside a big zip lock baggy. Cut the sleeve off an old flannel shirt stuff the baggy in, and presto, a very good rest for a springer.