Startleing results..30-0 + Unique

[Throckmorton]

Had time off yesterday so took the old Marlin to the range,along with some plinker loads...10 grains Unqiue under a 170 grain gc boolit.
As usual,they shot great..I shot so-so <grin.
Then I 'discovered' some 9 grain loads and decided to shoot them up.

WOW
at 85 yards they dropped over 6" low,and patterned like buckshot !

Has anyone else experienced this big a difference? I was amazed .

Changed back to the 10gr loads,and accuracy was right back where it was...punching bulls eyes every shot

gonna have to experiment with some loads in between just to see what happens.

[Mk42gunner]

I read the thread title and thought it said thirty grains of powder. I was expecting a spontaneous gun disassembly story; glad that wasn't what happened.


Robert

[Throckmorton]

DOH !!!!

fixed it.

[twildman]

Two possibilities come to mind:

1) Insufficient velocity to stabilize

2) Iffy ignition of that little charge.

If the latter is true, then flashover detonation may be on the cusp of occuring; for pete's sake use the 10 grains!.
Terry

[NickSS]

I have used the 9 gr load with a Lyman 311041 boolit in my 94 Winchester and the only problem I ever noticed was a slight key holing at 200 yards. It shoots fine at 100. I went up to 10 gr to get rid of the key holing.

[Throckmorton]

Twildman
fyi, the 9 grain charge is WELL within published specs in LYman's , so why yell at me to use the 10 grain load? don't you trust your load books?

also,fyi,by ear,the charges were igniting just fine.

[NHlever]

Actually, the thing I suspect here is a problem that I've had with a couple of Marlin barrels. If there is a large spot / area in the bore, the boolits usually need to be run faster (more pressure), and work best if they have long bearing surfaces. I had one old Marlin that would shoot 170 gr. jacketed bullets into small groups at 100 yards, but would tumble 100 grain plinkers at 25 yards. How large are you sizing the boolits........ I'm thinking that as large as you can go, and still easily chamber would be good. See what size boolit will fit easily in a fired case to get an idea where you should be. Otherwise, I have had very good luck with loads from 7-10 grains of Unique in various 30-30's over the years, and have gone lighter.

[Papa smurf]

I can go all the way down to 6.0 of Unique (no gas check 7.5 and under) with no problem.
Your problem may be boolit size ----as in too small. ---------------------Papa

[35remington]

I wouldn't give the "flashover detonation" theory too much credence with a 9 grain charge of Unique in the 30-30 case.

[atr]

I've used 8 gr of Unique with 170 gr in my 30-30 very successfully. The drop you mentioned doesn't surprise me. But I've never had that buckshot pattern you described.