Vertical stringing/

[Buck 89]

What causes different loads to start vertical stringing?

 

[Immike]

Primers and shoulder pressure are a couple suspects high on the list.

 

[bheadboy]

when you say differeent loads, i am assuming you mean shooting 5-10 rounds of ammo loaded in the "same" way.

this said, + on the shoulder pressure, also, trigger hand grip pressure on the stock, cheek pressure variation, forearm position on rest, neck wall thickness variations, primer pocket tightness variations, flash hole inconsistances, powder load marginal low or on brink to beyond max,

mirage, paralax in scope, heat waves off bbl as it heats up, tail or head wind variations

to name a few

Bob

 

[Immike]

Hot loads will cause excessive recoil and create barrel flip. This is the rifle reacting from tight shoulder pressure and rising up before the bullet has left the barrel.

 

[Buck 89]

Thanks for all the info. It is the same load just a different day.

 

[kelbro]

I blame it on the heat. Or the cold. Or the moon phase. Or the barometric pressure. Or....

But it's usually me and my position, grip, cheekweld.

 

[Steve Blair]

What causes different loads to start vertical stringing?

[br]
At what distance?

 

[Romulus]

Shooting over a chronograph could help eliminate some of the suspects.

 

[Buck 89]

I was shooting 100 yards with three different loads and all three had a nice clover group. The next day they were stringing.

 

[Nomad47]

I was shooting 100 yards with three different loads and all three had a nice clover group. The next day they were stringing.

If the 'next day' was a cold day and if the cartridges were good and cold, the first shot would have considerable less velocity. And depending on how long each loaded cartridge sits in the fired (and warmed up) chamber, you could have quite a bit of velocity variation. Especially if using a temperature sensitive powder.
Like Romulus said, a chronograph would tell you if that is what is going on.

 

[Greyfox]

Assuming this is an accurate rifle and that you are shooting over wind flags, then your rifle is out of tune. Tune changes with temperature changes, so the same load on a day that is warmer or colder will be out of tune. You can change this by reducing/increasing powder or using a barrel tuner.

Of course, it could be the wind (mentioned above). If you have a strong tail winf or head wind, that can cause stringing. But, it is very likely the tune. I shot a match two weeks ago that started in the low 40's. The first two groups were in the teens. The temp went up to the mid 50s and I got over a bullet hole of verticle. The tuner took care of it, but unfortunately it was too late.

Rick

 

[Raythemanroe]

vertical stringing, I notice if I'm not holding consistently and using a good steady hold after trigger the breaks I can get some vertical stringing.. Follow through...