Hello 22rimfan,
Since 1996 I have fire 4,480 cast bullets in my 30/30s. I shoot a lot in Marlins and Contenders.
I have found that, if you use gas checked bullets, my barrels never lead up. I only clean them when accuracy goes away. That may be in 200 or 300 rounds. It certainly makes shooting a lot more fun when you dont have to clean the guns every time you shoot them.
If a barrel gathers lead, I will clean it and free it of lead. The new cleaner CR10 does a great job. I follow up with a lead cleaning cloth. And even steel wool wrapped tightly around a brass brush of the caliber.
I fire lap the barrel with lead bullets impregnated with LBT diamond lapping compound. Ill load the bullets with 5 to 6 grains of Bullseye, WW231 or other fast powder. All you want to do is launch the bullet out the barrel. I have done this with rifles valued up to $4,000. I dont own a $4,000 gun. It belonged to a well to do friend. It was a Remington Rolling Block 45/70. I usually fire lap all barrels and revolvers too. Why wait until I find out that it leads. However, CZUSA rifles dont need fire lapping. 99% of the time, the lapping improves accuracy to an unbelievable degree.
I can shoot cast bullets up to 2200 feet per second and never get leading. However, I dont usually shoot cast bullets or jacketed bullets at that speed.
Shooting cast bullets between 1500 and 1800 is prime time. Low recoil and great practice.
I have shot commercial cast bullets and they generally work fine. I have had better accuracy with my home cast, lubed with Alox/Bees Wax mix and gas checked.
Last Thursday, I was shooting Saeco #281 (150 grain bullet) bullets cast from a 4 cavity mould our of my 7X57 Mauser CZ Rifle. Had a great day. I shoot at the 500 meter rifle silhouette range in Sloughhouse, California. It is only 17 miles from my home. My 7X57 Mauser will get out to the turkeys at 421 yards (385 meters) and hit turkeys quite regularly. Win an outrageous amount of hold over, I can hit rams at 500 meters. I set them back off the rail so that if I hit one, it will fall over. Last Thursday, I hit 4 in a row. Lucky?? Well, yes.
My Marlin Cowboy with the 24" barrel and a 150 grain bullet will reach the 500 meter Rams. I elevated the rear of the scope mount . I can only shoot with the cross hairs right on at 200 out to 500. I can't get down to 100 yards even using all the mil-dots in the scope. My load is the Saeco #316 30 caliber bullet with 12.6 grains of Blue Dot.
The 30/30 is one of my all time favorites with cast bullets. Every gun I own or have owned has shot cast bullets. Since 1996 I have shot 40,501 cast bullets.
Harold Clark