Guys, this is getting more interesting as we go forward! My Encore had a trigger job already done on it when I got it as a rifle. I put a new hing pin in it; the one that has a screw on the opposite side that tightens it up. Plus, the pin itself was much tighter than the original so I now have a very smooth and tight pin. Today, I went to my friend who has a gunsmithing setup. I showed him my problem with blowback and after he decided I wasn't crazy, we got to measuring. The primer is flush with the rear of the plug so we then closed it and turned the plug out. Yep, it did turn out just a wee bit. Exactly 0.003". I think that's right. Anyways, I had thought of that solution before,but because the gap was so small, I didn't pursue the route we wound up taking. He had the shim stock I needed so we cut a three thousandth shim to go down over the plug to seat when the plug is screwed down. It seems perfect! Barrel closes and opens, no gaps anywhere. I just need to remember primers come in different lengths and they can effect that new set up. Now all I need is my other friend to fix the plug for the flame so I can shoot BH209 ! We'll work on that issue next week. He says he can do it and if I want, I will be able to shoot pellets,too. Probably never will again! I just wish BH 209 wasn't so darned expensive!
So, I also agree, Before buying a new barrel, try what you have by getting a new and tighter hing pin. A trigger job, if yours is not to your liking, is a plus. Don't know how much this helps, but I opened the forend to get a "free float" on the barrel.
I was glad to hear someone else has decided to weigh charges. After you first get the close volume you want. Weighing will get you lots better results; but don't forget it's really about improving a volume throw. I found the same thing, that 75 grains by weight is a great charge and is about 110(?) by volume. I also like the Barnes TMZ 250s and their sabots with this load. I think it's TMZ. Actually , it's Knights packaging of a Barnes boat tail bullet. That's the TMZ , right?