I have wrap around grips rubber, and shoot HV ammo, at 25 yd's bullseye, MKIII 5.5 slabe side. If I change to SV ammo and get a better pair of grips (I can shoot high 80's) will this tighen up my groups I have had days when I can put 6, to 7 in the ten ring most of the time I can keep all in the black 8 ring or better just need to step up. I shoot for 8 months and take off 4 well go to work no guns allowed thanks
Almost all quality standard velocity ammo will outshoot high velocity.
Some HV is respectable, by why beat up the gun.
As to the grips, I have no opinion.
Just use the one that feels good to you.