OK - My typical Field Pistol load for a .22 Hornet in a 10" T/C is a CCI SR primer, 4.6 gr's of WW231 in a RP case under a 55 gr. Hornady FMJBT that gives me 1" to 1-1/2" groups at 100 yds - fine for IHMSA. I will start using WW296 (8.5 gr's) for the rams though. Damn ringers - the rams need that extra oomph the 296 gives !

ANYHOW - my buddy suggested that a pistol primer would be better for use with the 231. I made five up with exactly the same components and powder - except I used CCI SP primers.

I shot 10 (SR primer) rounds to warm up the barrel. I got a a 3/4" and a 1/2" group at fifty yards. I then shot the (5) rounds with the SP primers. I got the most perfect horizontal string I ever did see! Elevation was damn-near perfect (right on the center line), but each shot was almost an exact 1/2" apart left to right.

I chrony'd these too - not that much of a difference than the SR primers.

This was not a wind thing. This was not a sight thing either as I had a 3-9x Bushnell set at 6x on the KL rail for the days' load testing. It HAD to be the primer difference - at least in my mind it does! I went back to rounds with the SR primer - no problemo - nice groups.

Anybody else experience this? IS this all primer ya think ??

Thanks. I'm eager to hear some theory AND experience responses from y'all !

Anything you can't explain try again three times under the same conditions. Most of the time you can see if it was a fluke of nature or something else. Then you can start trouble shooting.
Just my opinion.

Oh Dino ... when ya gonna stop foolin' 'round?

Try Lil'Gun From 12.0 grains to 13.0 grains and the Remington 6-1/2 primer ...

Dino 32HR,
I loaded Hornet with a 24"BSA Hunter using Speer 40g SP's H110 & Rem SR Pimers.The groups were ,as we say over here 'like wild womans shite'and in the order of 1.5-2".I found an old issue of G & A which mentioned an old boy who used SP's due to a drought of primers.Results were so good he stuck to them.In the BSA the 1st group of 5 shots(CCI SP's)measured .42 including a flyer.After 5 groups the worst was .6",3 years on the accuracy is the same but the rabbits now have a nervous twitch. Cheers Rob T.

Quite a sticky wicket here ! It's evident that SP's will have an effect in SOME barrels - like Rob's rifle likes 'em. My buddy's 10" T/C likes the SP's too - for 53 gr HP flat base Sierra's. However - he can't even begin to shoot a 55 gr FMJ-BT in his barrel; they don't stabilize, even though his barrel has the same twist as my T/C barrel. He gets 4" - 5" groups with the 55 gr'ers where I get about 1" with them, same powder, same weight, same primers!

Damn T/C barrels - they really do each have their own personality !

BUT - back to the original question - what causes a horizontal string??? I've read about vertical strings, but can't find anything on the horizontal ones !

Help !?