In my Marlin LXR 24" Bbl 45-70. I make & use the Lyman mold 330gr HP plain base.. . Cast from straight scrap wheel weights Brn 10.5 to 11.0 hardness. I use enough IMR-4198 to drive the bullet about 1650 fps. Out of this rifle it delivers excellent accuracy ( about 1.5" ) at 100 yd with a 2.5X scope. . This bullet has shown it's ability to not only take deer cleanly , but elk also within 150yds. Will easily shoot completely thru mature muley bucks even at acute angles. . It will do this with very reasonable recoil for a 45-70. As stated absolutely no need to hot rod the 45-70. If you wish to shoot the 400 gr or heavier bullets which I don't see necessary for deer, no need to exceed 1250 fps, If you do so recoil can become brutal. Remember, , squeeze the trigger. Best to you..
