Known gun, known scope, known shooter - most of the time. How would you diagnose these hunting hand loads?





Where would you start the tinkering process? Seating depth, powder choice? Details of the load:

243ai
85 TSX
Winchester brass
CCI
IMR4831- 46.5 grains

Personally I would up the powder.

Looks like a solid 1 3/4" group to me...

Runout or randomness.

Or bedding

I wouldn't doubt that's a bedding problem.

Looks like a mechanical issue to me.

Or maybe a barrel that likes to be dirty.

I'd start here.

First off, there's no specifics on the rifle. It's only "known" to the OP. What does "known shooter most of the time" mean? A rifle is a mechanical device. If it is set up right, it's going to be a "known shooter" all the time. Providing you are using good ammo. The weak link is the nut behind the butt. Like I said, op is very vague: There's a lot to this equation the op is leaving out...

Let's fill in the imaginary blanks here:

1. Rifle used: Remington 700
2. Rifle not glass bedded. Or if so, not glass bedded properly (action stressed)
3. "known scope": Leupold of some sort....Maybe Vortex?
4. Dies not set up properly. Ammo produced exhibiting high TIR.
5. Factory pressure point at forend tip.....

Now let's start dissecting the load in question......

1. How far off the lands????
2. TIR: Runout????
3. What "CCI" primer?
4. New brass? Once fired?
5. Is that an optimum powder for the cartridge and bullet combo?
6. Is that an optimum charge wt.??

Cooper 243ai, known shooter that bugholes 87vmax
Leupold VX6

Brass 1x shot and fire formed
Neck sizes with Lee collett die
Bullets seated with Hornady 6mm seater
CCI large rifle primers
IMR4831 charge chosen from 6mm Rem data. Not a max load, not a min load.

85 TSX seating depth chosen with the sharpie. Getting nice squares.

My gut says try a different propellant. Gun is a heck of a shooter, just wanted the TSX as a hunting round to compliment the 87Vmax plinking round.

Seat the TSX 0.050" off the lands and try again. Then 0.100" and 0.150". One of the above will show more promise than the others.

IMR4350 is also a good bet.

Is that just the cold barrel first shot? Or first shot out of a mag even if it's a second or third group?

I load for the same rifle, .243 A.I. Cooper,?? are you stuck on the 87 gr. for every thing you do?

I am having great results with 105 gr. scenar, and 41.5 gr. of IMR 4350, not a hot load.

But I don.t do much plinking just hunting, Deer, speed goats, Coyotes,and some other critters.

Just a thought, do what works for you that's what I do.Rio7

If it's the first shot of the day with a clean barrel, then stop cleaning it.

Dirty barrel. Hasn't been touched in 50 rounds.

1st shot, cold barrel.

Good bed job.
Play with seating depth.
Play with different powders.
Play with different bullets.
Be happy with whatever gives you the best results and all the shooting you did in the mean time.