Mike - great advice. Thanks for having the patience and for taking the time to share it.

I've been using Old Eynsford for both today and yesterday's loads. On day 1 I tried 137gr of OE in 3Fg with 300, 340 and 370gr bullets. All used the same beeswax and crisco lube wad between the powder and the bullet. On day 2, I used only 340gr projectiles, at 0.504", with 130gr FFg and 130gr FFFg. Same lube wad. All 5 loads shot high at 30 yards. Excluding shots where I knew I didn't do my part, average height over POA was 3-4" high and 2-4" right. Dispersion across these loads was fairly consistent at approximately 3.5" between left and right barrels. If I did my part, left barrel shot 1-1.5" groups. Same for right barrel. But I didn't always do my part!

To reiterate re bullet weight, today I shot only 340gr bullets, 0.504" diameter, since that weight did the best on day one, and that's what Eley's Express Bullet in 500 weighed, back in 1892.

Sight picture has been top of front bead level with horizontal plane of rear sight. My eyes are 57 years old, but both yesterday and today the light was good on both sights and the target, with zero wind to mess with. Temps in mid 60s. For reference, with a decent scoped 22LR at this distance I'm shooting 1/2" groups for 5 with Walmart ammo, or better, depending on caffeine, last night's IPA count and hours of sleep.

My next step is to paper patch the bullets. I would be happy to try a more energetic black powder if one is readily available. If not, then after patching I'll try a nitro-for-black load, as this rifle, and the Dickson beg to be used in the field and current accuracy isn't great, even for whitetails on the east coast.

Please keep the advice coming. PM if you think I'm being stubborn (please)

Chris

(and on a very different note, since you flew, you might appreciate a quick story about another pilot. Tomorrow, April 1st, would have been my father in law's 86th birthday. He was born in a very small town in Western Maryland called Accident...who else can say they were born on April Fools in Accident. He went on to fly T38s as a pilot instructor in the mid 60s and was one of the youngest pilot instructors at the time. He last flew in an F16 on a courtesy flight out of Hawaii when he was 65. Great guy. Miss him. He passed in January.)