can't get the Mustang to group????

[wabi]

Been juggling loads in the Lyman Mustang and just can't seem to get good performance. Seems like every time I think I'm close to finding out what it likes the groups start getting fliers. I thought it was going to like 250 grain Barnes Expanders, but today it shot poorly (over 2" @ 50 yards) with them. I tried the 285 grain Barnes, and two were almost touching then the third went 1" high (again @ 50 yards). I pulled the harris bipod off thinking it might be part of the problem, but still couldn't get good groups. I've tried Pyrodex and Jim Shockey Gold with charges from 80 grains to 120 grains and bullets (sabots) from 240 grains to 300 grains. Even tried 3 different leadbullets (Lee REAL - Lee Mini - T/C Maxi) and they won't group well either. I swab between shots to keep the bore conditions the same, so I just can't figure why usually 2 shots will be very close and one will be an inch or two out.
I'm down to questioning the possibility my scope may have developed problems. It's an older Leupold (M8-4X). I pulled the scope when I cleaned tonight, and I'm going to try it with the fiber optic sights sometime soon.

[frontier gander]

Does it have a free floating barrel? With my winchester, 2" with any bullet @ 100 yards was normal, once i floated it, Any bullet that shot over an 1" @ 100 was odd. Is the mustang a break open? i never really looked at it so im not sure if free floating the barrel is even an option.

[wabi]

It's a hammerless break-open design. That's why I thought it might be the bipod throwing things off.
I've even considered removing the forend and trying a group!

[frontier gander]

You could always give that a go. Ive seen the forends on other rifles that were break open, throwing off the groups. I personally would give it a try without the forend on and see how it does.

[sabotloader]

wabi

I think you have the right thought... remove the scope and shoot the iron sights...

I would set up a target at 25 yards and shoot several shots @ the target looking only for grouping - if you are satisfied there then move back to 50 and repeat the process. If you are not satisfied @ 25 then you might need to pursue another path with Lyman...

Use a mild charge - 90/100 grains and a 250 or there abouts grain bullet. What sabots are you using? - make sure you let the barrel cool between shots - for me that is the hardest shooting in the summer heat.

This should not be a problem but take a real good look at the crown on the muzzle of the barrel - even use a mag glass - make sure the crown is uniform all the way around the barrel.... with mass produced barrels a little thing like this can really affect your groups...

Again - make sure you give time for the barrel to cool - nothing screws a group more than putting a sabot in a warm barrel.

Good luck....

[Semisane]

Well wabi,looks like we ought to start a "Finicky Mustang" club. On average the best 100 yard groups I'm getting are right at three inches - plenty good enough for deer, but..... dang!

So far thisgun is showing no inclination to being a one hole shooter.

This is what I've learned so far.
-It likes 300 grain bullets more than 250s.
- It likes 110 grains or more of T-7, or 120 grains or more of Pyrodex. I get flyers with lighter charges.
- It likes CCI primers over all others.
- Shooting off a bench, you must rest the gun right in front of the breech hinge, not on the center of the forearm.
- Tension of the forearm screw is important. Mine shoots best if I tighten the stud as tight as I can with my fingers, then back it off one full turn.

This stuff is almost like voodoo - you gotta believe for the spell to work.

OOPS! One more thing. It likes crush rib sabots.