Colin, I once cast a lead plug to try polishing a tight spot out, I stood a welding rod up in a 3" off cut from the same type of barrel and poured molten lead in, then used this to polish the other barrel thinking it would work on only the high spots where a mop would polish all dia's equally. I cant find a pic of it to show you.
I also agree with getting the lead in re-machined as BSA barrels often have a step into the rifling. I have machined the breech end on all my barrel so that when a pellet is loaded and the barrel removed no light can be seen around the pellet. It is quite precise to get it right so the skirt has a perfect seal in a smooth bore yet the head is engaged in the rifling with a very smooth transition from one to the other but well worth the effort!
When no air can escape past the pellet before it starts to move the fps variation is drastically reduced!
I still have that 3" off cut of .177 BSA barrel chamfered at one end to pour lead into if you want it?
HFT, for people with only 2 buttucks!
VooDoo TwoTwo The next chapter.
Last edited by Tench; 14th January 2016 at 10:09 AM.