I loaded them in 38 Special over 3.5 gr. of Bullseye and fired about 150 rounds thru a 66-5. It was a mess, all six chamber mouths were leaded so bad I could not push a .354 pin gage thru, the forcing cone was leaded up quite severely. I cleaned the gun up, it was a job of work to get all that out. Tried the same load in a 30 year old Ruger, almost as bad. I loaded some up over a max charge of H-110 in 357 cases and went back to the 66-5, that time it worked quite well, a few traces of lead but nothing like what the low pressure rounds had left behind. I tried other calibers and found that the Laser Cast bullets need to be pushed pretty hard to get good service from them.