Long Ogives Fast Twist What Powders?

[MOOSE 4 GOD]

Hey Guys:

Got a TC PRO HUNTER 7MM REM MAG. After several attempts I have one bullet that is awsome. H4831 with a Speer 115 gr. hp this thing out to 200 yds. will shoot 5 shots a quater will cover. Now for the help I need a 1n9 twist barrel 28" long Hornadys 154 Interbonds, Speer 160 gr. SBT, and Combine Tech 150grs. will not stabilize at 100 yds. I've tried R-22, R-15, IMR'S 4831, 4350, 7828. H-4831. starting loads to just under Max loads, Mag. and Large primers. Now I found This gun with the 115 gr. hp likes a running start to the lands as a matter of fact .50 Thnds. I also have tried this with all the boat tails with the long ogives and can't get it under 1.75 at 100 yds. Oh yeah one more thing All the long bullets I have tried from .05 to .50 from the lands and all in between. I have even tried Hornadys 154 Round nose that is a flat base like the 115 hp. Withe these heavier bullets should I try a faster burning Powder in this twist rate barrel. Any help would greatly Be apperiacated.

Thanks so much For Your Time
Benny {THE MOOSE} Moses [COLOR=darkblue][FONT=courier new][B]

[Rocky Raab]

Ben, I'll answer here in lieu of your email.

There shouldn't be any reason why a 1-9" barrel won't stabilize bullets in the 150-160 grain bracket. Are you certain they are unstable, or do they just shoot into 1.75" groups. Unless te holes are oblong, it isn't a stability problem.

Those are the correct powders for the 7mm Mag. I wouldn't go to a faster burn rate powder at all. What I'd do first is to settle on a single off-lands depth (in this case, try .050") and back down on the powder charge to about 5% less than book max for whatever powder you choose. Work up a little at a time and see if the groups don't shrink a bit. Once you find the best potential load, then jiggle the seating depth a bit either way.

For most game, and certainly for most big game, a 1.75 or 1.5" group at 100 yards is more than sufficient. That'll still anchor any deer/elk out to 300 yards, I promise.

[MOOSE 4 GOD]

Rocky:

Trust me I've even tried 5% to 10% charges less than the starting loads with bullets .05 off the lands to starting loads with a single type powder to col. lengths listed even to .50 off the lands. Even tried the theory 80% case volume for accuracy. I do stick with one powder at a time. On paper you can tell they are not stablized. The flat base Speer 115 gr. hp in the Speer book has a starting load of 68grs. H4831 and it is a tack driver. I'm beginning to think that maybe this gun likes flat base bullets. I have a savage 110 I've had for 23 years that will shoot a 1.75 with these 154 gr. Interbonds at 150 yds. I thought that this TC BULL BARREL would do a little better. Well thanks so much for your time and when I get that perfect load I promise you will be the first to know. I'm a little anal when it come to my TC'S as I do have a fondness for them.

Thanks Again For Your Time
Benny

[HPBTMTCH]

Moose, like rocky says a 1 in 9 twist 7mm will stabilize bullets as long as 180 gr. VLD`s. If you shoot it at 25 yards and it does not make round holes then there may be a problem. Long olgive bullets do take a little time to "go to sleep" as some would say. Try this, take the target out to at least 200 yards, and 300 yards would be even better, and shoot some groups. In some rifles it will shoot almost as good a group at 300 yards as it does at 100.

[Rocky Raab]

Ben, wth loads that light, you may in fact be shooting them too slow to properly stabilize. Barrel twist and muzzle velocity are both resposible for stability - the bullet has to go fast enough to spin fast enough.

I've usually found best accuracy at about 5% under maximum charges.

One final caution: going under the START level loads with very slow powders can be very dangerous. I've personally seen it happen with H4831 in the 7 Mag. Nobody knows why exactly, but a much-reduced charge of slow powder can occasionally produce extremely high pressures.

Don't do it.

[MOOSE 4 GOD]

HPBTMTCH, and Rocky:

Thanks. I have found that at 150 yds. the holes on these bullets are better. Rocky I have never went under much starting loads but in my question I said I've been from one extreme to the other with powder. From starting loads to max loads. Our Church had a mens outing shooting clays with our shot guns and they had a 300 yd. target for rifles. They were clays taped on pallets. I took some 154 Hornady Interbonds that were tearing holes in paper at 100 yds just to shoot them up for the brass. These bullets where loaded with 66.0 gr. R-22 and rem mag primers. This bullet COL touching the lands is 3.400. I had it seated to 3.325. Out of 3 shots not letting the barrels cool I hit the first 2 clays and the 3rd fell off.

Maybe I'm just a little to worried and this gun is made to reach out there. After all it is 28" long and a Bull Barrel. My range I shoot all the time only goes to 150yds.

Again Thank You Both so Much
For your Kindess and Understanding.
Benny