Is your.69 cal a double? I'm asking because the quote from "Shooting the british double rifle" by Graeme Wright about average 3 inch group sizes at 50m is specifically about large(ish) bore doubles shooting patched round ball with black powder. I also assume he meant short barreled doubles of 24 or less inches, but that's just me. The author has been shooting hundreds of doubles doing research for many years etc so I believe him when he makes a statement like that regarding round ball shooting large bore black powder doubles. This comes from the third edition of the book chapter titled "Accuracy".

The Hawken is of course a single barrel rifle. If we are talking about single barrel rifles here I'm very much interested in finding out the barrel length of your .69 cal. (I assume Hawken is 28in). I never found anyone who could shoot such groups with barrels shorter than 26 inches. I'm still looking,but that is a completely different subject that interests me.

Those groups you report are very good, but it is possible to shoot like this with a 45 deg crown providing it is not sharp and free from burrs. I provide my example from few days ago below.

My single barrel muzzleloader (flinter no less -.54 cal Frontier shooting patched round ball in front of 80 grains of 3f) with a factory Pedersoli crown (looks like 45 degrees) smoothed by a method with a lead ball shot a 5 shot group around ~0.7 inch big at 100m(measured center to center as per modern practice).

So here is the target at 100m showing 10 shots when I was doing load development. I shot the 5 that are sprayed all over the target using a different patch thickness. Then I changed the patching material and I shot next 5 into one big hole. The large hole end to end is about an inch, center to center it is around .7.

No sand filled bags were used, but a wooden rest at a bench (the rear of the rifle was shouldered normally). I found I'm getting better groups this way with this particular rifle as it is very light weighting only 3.3kg (7.2 pounds) and long barreled (44 inches, 8 land very shallow rifling octagon barrel).

The rifle has a large buckhorn style rear sight mounted on the barrel a hand width in front of its center of mass and a typical leaf as a front sight.

I have another patched round ball rifle capable of shooting through the same hole at 50m and ragged 1 inch holes at 100m. However it is a small caliber. 38 cal. It is also a Pedersoli. Made in the 1970-s long thin octagon barreled (looks 40~44 inch) Plainsman caplock rifle I show the muzzle of earlier in the thread. That rifle uses a simple front post and a rear notch barrel mounted just in front of the center of weight. Interestingly it has a muzzle coned by the previous owner.

Still it was my most accurate muzzleloader at the time with which I recently won a local black powder rifle target contest shooting 26 shots(2 contests consisting of 13 shots each, without break or cleaning the rifle during a total of 26 shots) , in standing position (off hand - no sling, no support) at 50m. I managed all my shots hitting 8 or better (5 inches). It is not "national level" shooting but I'm pretty happy with it. Of course I had to use a looser patch/ball combo for the contest than one shooting best from the bench due to no cleaning requirement. However as this was off hand I don't think it made a difference.