Heavy springs and now shooting low

[tek4260]

I finally got around to shooting a couple of my 45's that I installed #26 mainsprings in and both shot about 6" lower than they did with the factory springs. Still noodling it but haven't came up with a reason why yet. It must be the way I am gripping it and squeezing the trigger. Less lock time = less rise from trigger break until it fires with the way I grip it I guess.

Still, 6" @25 yards is a lot.

[subsonic]

What happens when you dry fire? SA hammers are heavy. Does the gun dip when the hammer smacks the transfer bar?

[tek4260]

45 Blackhawks, 4 5/8". It did this with both 325 LBT's over 23gr of H110 and the Ruger only Mihec over 24gr of H110.

There was a change in my OM Super cut to 4 5/8" though it was much less drastic. With that particular revolver, I changed from 300gr SWC to Mihec 300gr HP's so I attributed the change to the different boolit.

My groups were doing strange things as well. The first 3 shots would make a large 4" triangle, then the last 3 would cluster nearly touching in the center of it. The order was the same. Low, high, left, then 3 in the middle of that cluster. Did the same for four 6 shot groups from 2 different revolvers(8 groups total)

It has to be my grip. Just hard to believe that I repeat the same pattern over and over from what I saw with the groups.

[44man]

45 Blackhawks, 4 5/8". It did this with both 325 LBT's over 23gr of H110 and the Ruger only Mihec over 24gr of H110.

There was a change in my OM Super cut to 4 5/8" though it was much less drastic. With that particular revolver, I changed from 300gr SWC to Mihec 300gr HP's so I attributed the change to the different boolit.

My groups were doing strange things as well. The first 3 shots would make a large 4" triangle, then the last 3 would cluster nearly touching in the center of it. The order was the same. Low, high, left, then 3 in the middle of that cluster. Did the same for four 6 shot groups from 2 different revolvers(8 groups total)

It has to be my grip. Just hard to believe that I repeat the same pattern over and over from what I saw with the groups.
It is you. The hammer hits harder and you are not holding the gun tight so it dips the gun. You have no control. the gun does what it wants too. Get a GRIP. The hog leg has to be held, roll is not allowed. Hold it just short of shaking. If you are strong enough to hold it even tighter, it will be better.