I finally got to go shoot my .510 lever action Marlin 1895. It has been highly modified by Mic Mcpherson. It weighs almost 10 lbs, has a 23 1/2" barrel, a full length ammo tube that holds 6 rounds, and all the metal parts are finished with robars NP3 finish. I fired 47 rounds through it this afternoon with 450 and 500 grain bullets. I used IMR 3031 powder and heavy jacketed bullets by Alaskan Bullet Works. The gun kicks a fair amount even at 9lbs and 14 1/2 oz. But it is quite doable and does not hurt to shoot at all. It does have a very thick Kick-eez butt pad. I had no problem with the 100 and 150 yard targets.I did not have anything else set up at a longer distance. The rifle just has iron sights on it. I was getting 2300 ft/sec with the 450 grain bullets and 2160 ft/sec with the 500 grain bullets. The gun cycled smoothly and was flawless. No signs of too high of pressure. No sticky extraction, no flat primers and no lengthening of brass after the shots. The 510 cartridge is a 50 alaskan cartridge, that has been lengthened by 23/100ths of an inch. That is as long as you can go in a Marlin and it still be reliable.I always enjoy taking out a custom gun and making sure that it performs the way it is supposed to. Besides 5284 ft.lbs of energy aint too bad for a lever action.