tazman
04-22-2014, 10:18 PM
Last week I got my hands on a new/old stock Lyman 356634 135 grain tc mold. I promptly cast up 150 of them and ran them through my lube sizer. Since they were the same weight as my NOE 135 rf I figured they would load the same or at least be close.
Boy was I wrong.
Poorest grouping so far. Terrible. 8inch group at 25 feet and some were hitting sideways. Definitely not good.
Checked the fired brass and saw no pressure signs. Pulled some of the boolits from the loads I didn't shoot and they were the proper size. Checked the powder charge and it was right on the money.
Then I looked at the boolits and the loaded rounds and the problem became obvious. The bearing surface on the tc is much longer and the nose is shorter. I had to load it to a much shorter oal to get it to chamber.
At this point I am certain I was over charging the boolit for my pistol. By my measurement there is .100(1/10th of an inch) more boolit inside the case with the tc than with the rf. I knew I was using a very light load with the rf and assumed that it would be workable with the tc. I am just lucky the firearm handled the load without any harm.
This post is more a warning for someone who may get in a hurry and make improper assumptions about a particular combination than for any informational benefit. I messed up and got away with it. Maybe by posting this I can save some one else a worse problem.
I have loaded the same boolit with a suitable starting load and work up sequence for this weekend. I will see how it goes this time.
Boy was I wrong.
Poorest grouping so far. Terrible. 8inch group at 25 feet and some were hitting sideways. Definitely not good.
Checked the fired brass and saw no pressure signs. Pulled some of the boolits from the loads I didn't shoot and they were the proper size. Checked the powder charge and it was right on the money.
Then I looked at the boolits and the loaded rounds and the problem became obvious. The bearing surface on the tc is much longer and the nose is shorter. I had to load it to a much shorter oal to get it to chamber.
At this point I am certain I was over charging the boolit for my pistol. By my measurement there is .100(1/10th of an inch) more boolit inside the case with the tc than with the rf. I knew I was using a very light load with the rf and assumed that it would be workable with the tc. I am just lucky the firearm handled the load without any harm.
This post is more a warning for someone who may get in a hurry and make improper assumptions about a particular combination than for any informational benefit. I messed up and got away with it. Maybe by posting this I can save some one else a worse problem.
I have loaded the same boolit with a suitable starting load and work up sequence for this weekend. I will see how it goes this time.