311410 & Bullseye in .308 Win

[Jim]

I set out today to find the bottom of the pressure window for a Lyman 311410 over Bullseye in my new Mossberg .308 Winchester bolt gun. I started with 5 grains of BE and used large magnum rifle primers for the spark plugs. I've got almost 2Ks of the LMRs and as this is going to be toward a subsonic load, I figured I'd go ahead and use 'em up.

The 5 grain load gave a good report and a recoil but certainly not anything substantial. 4 grains wasn't much less. At 3 grains, I could tell the report was a bit quieter and the recoil got down to about like a 22 magnum. 2 grains reported a bit softer still and the recoil dropped to about like a 22 LR.

I went back in the house and made up a 1.5 and was prepared for the inevitable stuck boolit. I was very surprised that it fired! I made up a 1 grain load and it fired, too!

When I fired the test shots, I took the rifle out in the front yard and propped it on the wood fence. I have the top of a 55 gallon drum hanging in front of my berm which is 75 yards from the front steps.

I think the first shot hit the gong, but I couldn't tell. I could definitely hear the boolit hit the gong with the 4 grain load, although the report and the clang were very close together. There was a bit more time between the shot and the strike of the boolit with the 3 grain load. The 2 grain and the 1.5 grain load both hit the gong, also. I don't know where the 1 grain load boolit went. I'm guessing it just fell to the ground before it got to the gong.

That 1.5 grain load strike actually made me chuckle. Pop................clang!

I used my Graphlox to lube the boolits. The alloy is 1/3rd WWs and 2/3rds range lead with about 2 to 3% lead free plumber's solder added.

I didn't expect any leading at those low velocities, but I checked anyway. Except for the residual black from the graphite, the bore was clean as a pin.

The next step is to start at 2 grains and work up. My intention is to go up at about a grain at a time until I start seeing pressure signs. Then I'll drop back and work up at about .2 grains at a time in 3 shot groups looking for accuracy.

I'll let ya'll know how it goes as it progresses.

[TCLouis]

Thanks Jim

This gives me some ideas where to head with the 7-08 if the owners father wants to follow my plan, for Fam-Fire otherwise they are on their own!

[Jim]

At what distance are you planning on doing your accuracy testing?

50 yards. The purpose of developing these loads is so Janet can shoot my centerfire bolt guns without the heavy recoil of standard loads. My range here on my property is limited to 50 yards.

[felix]

Excellent procedure to use, Jim. Treat these loads as you would for the rubber bullets of years ago for indoor use. You might also consider including a toilet paper slice (1 layer loosely) over the powder to allow shooting a sharp angle downwards, like for swimming pool shooting off of a diving board to retrieve boolits for measurement. That's my personal technique for "slugging". ... felix

[Jim]

Actually, Felix, I've done some of my screwball testing with Bullseye and found it to be very 'user friendly' toward this kind of experimentation. I've fired rounds flat, about 80* or so up at a tall tree and almost straight down. No bigger than a 7.62X51 case is and lighting the charge with large magnum primers, I haven't had a bit of trouble.

As for recovering the fired boolits, I've been thinking about that and have an idea I'm going to experiment with in a few weeks. That's another story for another thread, though.

I just came back from the range testing for 'top of window' pressure. I loaded these same 311410 boolits lubed with Graphlox over charges of Bullseye from 7.5 grains to 10 grains in .5 grain increments. No pressure signs. I feel very sure I'll find a load suitable for recreational use for Janet somewhere in that window.

Also, the Graphlox seems to be holding up. I'm pretty sure 10 grains of Bullseye is pushing that 130 grain boolit much faster than I did with my experiments in the .223. I checked the bore carefully when I got done and it looked good. I pulled a tight patch through it and very little black came out.

I doubt I'll get any further testing done until next week. I'm going out of town this weekend, so it'll be Monday at the earliest before I can get some loads worked up for group shooting.

[6.5 mike]

Interseting Jim, I'm getting ready to use the same boolit & powder in a gallery load for my 30-40 Krag hi-wall thanks to Larry Gibson's advice.

[jaysouth]

Excellent procedure to use, Jim. Treat these loads as you would for the rubber bullets of years ago for indoor use. You might also consider including a toilet paper slice (1 layer loosely) over the powder to allow shooting a sharp angle downwards, like for swimming pool shooting off of a diving board to retrieve boolits for measurement. That's my personal technique for "slugging". ... felix

I don't have a swimming pool, but a deceased family member left behind several cases of Depends Guards. A cast bullet over 2-3 grs. Bullseye would penetrate about 8-10 of the pads. Each case would soak up dozens of 'test rounds' fired at both ends of the case.