What twist is that barrel?
Also, how many miles have you driven that barrel? Is it possible the grooves are just full of lead? What do you clean it with?
The idea to remove the QLA to shoot conicals is a good one. I read some gunsmiths charge as little as $50 to remove it.
Oh, sorry, meant to put that in ... it's a 1-48" twist. It's predecessor shot both PRB and 560 grain conicals fine with the same twist.
I shot it quite a bit trying different conicals. At that time I'd clean it first with TC #13 to get the powder out, then scrub it with Hoppe's lead remover solvent, then go back and do it again with the TC solvent and boiling water to get it hot, then "season" the barrel with bore butter patches so it wouldn't rust.
About 4 years ago I gave up on conicals and just shoot PRB. There's no sign of cutting clear through the patch, neither friction nor flame. Decidely worn. About perfect so far as I can tell. No leading.
I do my cleaning now with TC #13 solvent, then hot water, then "season" with bore butter. 'til Saturday I hadn't shot it in over a year. Before leaving home I ran a dry patch down the bore. There was not one iota of rust or lead. What I'm doing in that sense **works**. Real happy with that part.
