Diagonal stringing?

[BsChoy]

I have been pairing down powders and was running my last batch of test 223 ammo yesterday and noticed something. With H4895 in my 223 I was getting a very normal circular 100 yrd group. But with the last three test batched of RL15 in the same gun with the same bullet and primers I am getting diagonal stringing?? A tightly grouped string but still a string over an inch long compared to the circular equally tight H4895 at under an inch....is this normal/possible with just a different powder? The seating depth was identical btw and the cases were all virgin Winchester full resizied out of the bag and trimmed to the same length...thanks in advance

Chris

 

[The Bushmaster]

You might look at barrel heating...RL-15 might burn a bit hotter...

 

[taliv]

i ran into that this past weekend. i think the target i was using, and impacts changing my sight picture, changing the shape of the black aiming circle

 

[JollyWhiteGiant]

If the barrel isn't hot then check your action screws. loose or screws tightened unevenly can cause this as well. make sure both are tightened to as close to the same as possible.

 

[dakotasin]

yes, very possible w/ just a powder change. when i run into stringing like that in my rifles, it has meant the rifle doesn't like one of the components. since powder is the easiest for me to change, i just run a different powder and all is fine again.

if you are bent on using that powder, try a different bullet, or maybe switch to magnum primers.

 

[FLORIDA KEVIN]

I seem to remember reading that vertical stringing was sign of irregular ignition ! seems it could be that or inconsistant powder measuring ? it sounds as though your QC for reloading is too good for a measuring defect , so i would think you are near a limit for the powder you are using ?

 

[BsChoy]

My action screws were at the same torque and nothing had been changed between the 4895 group and the RL15 group...I shot them 1 after the other with the barrel cooling completely between each. I want to think its just the powder...thank the lord that was the last of my RL15..

 

[JollyWhiteGiant]

I just make it a matter of habbit, if something isn't right it takes me just a minute to make sure everything is tight and right. never know when a small problem could be exagerated by other things (different pressure wave possibly).

But maybe your rifle just don't like that powder.

 

[GooseGestapo]

It's probably the bedding of the action with the stock and unequal pressure on the forend.

I've had quite a number of rifles that have done that. Most have been cured with freefloating the barrel and glass bedding the action.

Even with powders/loads that didn't string, but gave "round" groups, the round groups were much improved by the "accurazing" of the rifle.

One such expample was a Rem. M7 in 7mm-08. With the "round groups" and after the bedding, freefloating, and a trigger job, groups went from ~2" to submoa. Some of the stringing loads quit, but then, some combinations are still down-right abominations. The very light barrel on this gun is exceedingly finicky.

 

[jacobhh]

Last time I had diagonal stringing it turned out to be
the cheap scope I was using finally gave up which was
frustrating because everything was tight, but that was
a 30-06 and it was pretty bad ( over 2" ).

I'd be curious as to what bullet you're using. RL-15
appears to be good under 70 gr. and H4895 over 70, of
course your gun has it's own personality.

 

[BsChoy]

The bullets were 60gr vmax's...The barrel is free floated from about an inch infront of the chamber and I did bed the recoil lug and "savagenut" area. This gun is very sensitive to seating depth and I have had to play with that more than anything...My scope if a 2.5 yer old Burris FFII 3-9...one reliable scope in my opinion and dead accurate adjustments