Well went and shot today with my 8mm mauser and my 30/30. 30/30 loads were 9.6 grains of unique with a 165 plain based bullet. 8mm was 11 and 12 grains of unique with a lee cast bullet ( 170?) un-gas checked as I do not have a sizer or checks for them yet. at 50 yards the 30/30 shot ok about 2 inch groups and the 8mm was about the same with the 11 grains of unique the 12 grain loads were all over the place. I am done with the plain base loads for one reason with the 30/30 I had to raise the peep sight again as high to compensate for the low power loads. I want something more flat shooting so I do not have to change my sights from cast to jacketed. I do not mind some kentucky windage if they shot fairly close but these shot real low due to the low velocity loads. As far as the 8mm went it shot ok at 50 but then got leaded up so it did not shoot well after 20 rounds so I will have to shoot gas checks with them also, but then I was warned here and other places that un-checked would not shoot the best. One grain between 11 and 12 ( unique) sure opened up those groups. I guess maybe 10 grains would have been a better place to start or even 9? Same with the 30/30 I should have maybe tried 7 0r 8 instead of 9.6 but that is what I had a dipper for so I tried it. Should have dragged out the powder measure and scale.

Unless you try to duplicate the jacketed velocity, you will find there is a change in one step of the rear sight elevator. I shoot cast at about 1100 to 1800 fps in the 30-30 and this seems to hold true for all loadings.

Thanks, I should have mentioned I have a peep sight on mine and it is one of the cheaper williams so it does not have click adjustments. I guess I will have to mark it for jacketed and cast loads or keep a notebook on where I have to set it. That goes for both guns they has the same sight the Winchester came with it used and the 8mm is what the gunsmith installed. Jim