Actually, a synopsis of aseveral range sessions...

Got this in a trade, previous owner said it was shot less than 50 times. It's in near-perfect condition inside & out. If put back in the packaging it could pass for NIB. Came with factory nipple, Hot Shot nipple new in package, and a MagSpark 209 adapter nipple. Opted to use the Hot Shot as I'd prefer to use #11 caps instead of shotgun primers. Always thought scrubbing the primer residue off was the worst part of cleaning the inline I used to have.

All shooting was done using Remington #11 caps (only ones stocked locally), Goex fffg powder, & Hornady .530 roundballs. Patch thickness, type of lube, & powder charge were the variables.

60, 70, & 80 grain charges produced poor accuracy regardless of patch thickness (0.010-0.018") or lube (bore butter, deer tallow, crisco, olive oil). Nothing better than 3" to 3-1/2" groups at 50 yards. I badly wanted this rifle to handle roundballs well, and was getting worried that I might have no choice but to find some .54 conicals... big time overkill for kentucky whitetails. Well, lo & behold, with 90 grains & .018" pillow ticking, everything changed. This combo performed well with all lubes, though the best groups by a slim margin were with bore butter. First 5-shot group with this combo was <2" center to center. Shot another 5-shot group to test repeatability, this one <1-3/4" center to center.

Surprising to me for a couple reasons. First, with a 26" barrel (~2" of which is QLA), I kinda figured anything over 80 grains fffg would likely be a waste of powder. Second, the .018" patches looked fairly rough. Not completely blown by any means, but on the ragged edge. But I used the same strategy I use with my wife: don't argue with results, just give her what she wants & everybody's happy! If she wants 90 grains fffg, she'll get 90 grains fffg.

A few things I'm considering for the next session:
1- Try using felt over-powder wads or cornmeal filler. Patch/ball combo is fairly tight with the .018" ticking, so I'd rather not try thicker patching. On the other hand, protecting the patches a bit surely couldn't hurt since they're getting fairly beat up- might tighten up groups even more. I think this rifle/load is a prime candidate for wad or filler.
2- Using wads/filler, increase charge in 5-grain increments until things open up. I don't expect that it'll get any better from increased charge, but I thought 90 grains was a shot in the dark as well. Again... if she wants 105 grains fffg, she'll get 105 grains fffg!

No misfires or hangfires at all, everything was instant. And what a sweet trigger, 2 lbs 1 oz, zero creep/grit. That surprised me as well. A buddy of mine has a .50 New Englander that almost requires a two-hand pull. I suspect there's something going onin his lock, bridle screws too tight, etc., or it just needs to be cleaned & lubed. We're gonna check it out tonight. His rifle is a good shooter with prb as well, but he hates that trigger, and I don't blame him.