group sizes
 

What are REALISTIC expectations for group sizes @ 100 yards for a relatively modern in line muzzle loader?

It always depends on how good a shot the shooter is more than what the gun will do.

A modern scoped inline is capable of MOA if the shooters is.

Something like this, these are various inlines I have sighted in for my hunting buddies...

At 100 yards with a scoped inline from the bench? Very best five shot groups around 1.5". Normal average five shot groups around 3".

You should be able to get MOA or even sub MOA if you put in the time and effort for load development and find the best load your rifle likes. But even with only minimal experimenting you should be able to get 1 to 2 inches easy.

From a bench, good shooting conditions, a good powder / projectile combination, 3 shot groups....< 2 1/2" consistently, MOA occasionally. If you can't get a 3" group I'd change the load.

That's my experience. I don't claim to be the best shot at the range.

I've been in the 2 1/2 to 3 range. guess I'll tinker with my powder this weekend. How many shots do you fire before doing a complete cleaning? or better yet how many shots before it will affect your accuracy?

Depends on the powder you're using. Why not tell us everything you're using? Gun, powder, primer, and bullet.

There's the best answer so far.

I hunt with a clean barrel and clean between each and every shot when sighting in...It only takes a few seconds if you are organized...I use a spray bottle with rubbing alcohol in it, dampen 2 patches, run down, using both sides, then a dry patch then a patch lightly sprayed with WD-40, then a dry patch and I'm ready...

The secret is to not use patches that are too wet that might get that dampness into the breach plug...

All my groups were shot with FFF Goex...As you see 80-85 grs was the ticket...Bullets were either .430 Hornady XTPs in 240 or 300gr with the Harvester plain green sabot for those bullets...

Rifles were a Knight Original Disc, a Knight Bighorn, an Omega and an Optima, so brand of rifle had little to do with group size...