What are the largest, heaviest grips available for the LCR? I hope to improve reliability for Crimp Jump (ammo falling apart) by adding as much weight as possible to my 9mm LCR. This is a range gun only. I really wanted a 9mm SP-101, but they are unobtainable. I have a J-Frame with 10 oz Pachmayr Decelerator grips and its like shooting a full size revolver!

If it s factory ammo - change brands!
If its handloads - you need to evaluate how you're doing the taper crimp on the case.
To me the 9mm doesn't have an excessive amount of recoil since case volume and strength preclude ultra velocities with the cartridge and hence the higher recoil - just my $0.02!

I suggest you read this thread at Ruger Pistol Forum
Crimp jumping

Thanks, I understand that you need to test your ammo and crimp. I just want to get bigger grips to improve reliability across the board with random store bought ammo.