I got the hankering to try out Lasercast bullets last year for my marlin 45-70. I seem to be constantly debating with myself whether or not I want to use lead, mostly because I don't want to have to deal with leading and I don't really need the penetration. At most I may be able to hunt black bear, and the Rem 405 gr SP should be fine for them.
Anywho. I went and bought 100 405gr .459" lasercast. I covered them with liquid alox per directions, then loaded them up with 40 gr Re7 and went to the range. I was less than pleased with the results. I can normally get less than 2" groups with the Rem bullets, these seemed to be all over the target (100 yds).
Should I try increasing the powder charge and see how they perform?
With the Remington bullets I normally use 49 gr Re7, and sometimes 40 for a nice plinking load.

What do you think?

Had the same thing happen. My encore barrel is a Shilen but has a 1-14" twist. Talked to some experienced lead heads and they suggested that I reduce my charege from 40gr Rl 7 to 38 gr. That did the trick. I can now hit a coke can at 100yds with ease. The theroy was because of my fast twist the lead was getting pealed off as it went down the bore. Something to do with the hardness of the lead. Give it a go.

I'd also slug the barrel, and see that the bullet is the right size, .001-.002 over bore size.