Dozen years ago I made a serious run on breech seating 38/55 with black powder for offhand work in my CPA. Idea was a trip out West & some BP Schuetzen matches. Had used the rifle in BPCS with some success. Switched buttstocks for a hook plate & added a palm rest. 

Found a couple of things . To get acceptable Schuetzen accuracy the gun needed absolutely clean barrel shot to shot. Many days, dry conditions, the leade had to be brushed first few inches with a short rod, then wiped the full bore one wet one dry.  I did not aways brush, sometimes not needed. Did stay consistent in a shooting session using the same routine start to finish.

Difference BPCS to Schuetzen was the paper target showing what was going on. Silhouette easy to overlook how far out a miss was, and be satisfied when the critter was knocked over. 

This changed my mind on blow tubing too. Never used the blow tube again. Black Powder is a very good propellant if the bore is clean. Clean depends more on ambient conditions than we think. 

Boats

Mick I almost never  shoot bench rest. About the only time is to use up ammo after a offhand match. That CPA with fixed smokeless and iron sights will put as many as I care to shoot in 4 inches at 200 yards muzzle rest, rifle held in my shoulder and elbows. It’s a practical 2 MOA Rifle. Scope full machine rest shorter runs it will probably shoot 1 moa, can’t say sure..  My standard is with a dirty bore after a 40 shot match with additional sighter shots. That’s what I have to do in shoot off’s and the only standard that counts using it like I do.

When I Shot it with BP it would do the same except when the bore was fowled it would throw flyers 3 - 4 inches or more out of group. Flyers went away with a perfect clean bore shot to shot and no difference in performance  black powder vs smokeless. I never noticed the flyers on steel targets. Painfully obvious on the ASSRA 200 yard offhand target. 

Way back when, the top shots muzzle loaded Schuetzen rifles with black powder. Good smokeless powders available they went to breech seating. Reason was no need to deal with fouling 

Martini I bet if you recorded ambient humidity as part of your range notes it would give a clue to what’s going on. When I Shot a lot of muzzleloader ramrod feel seating bullets could be considerably different day to day. Depending on not only humidity wind drying too. 

Carbon ring can be difficult to remove and if not completely removed it will just continue to build up. JB has worked well for me and you should also stay on top of it best you can as it will also start filling in the grooves and yet even more difficult to remove and accuracy will greatly suffer from it. I have seen this take place more than once while using smokless powder and the carbon will get as hard a glass if not kept an eye on. 

JLouis

I have an original Ballard #2 cast action in .25-25 Stevens, and so I am only using real black powder...Swiss 3FG so far, and plan on trying Olde Enysford in future.  So far I have only used fixed, using original Ideal 98gr. seated with only base band in case.  SPG lube.  I too found a hard fouling ring ahead of chamber.  I finally started loading a 1/16" thick grease wad of SPG over a 1/32" beeswax wad on top of powder charge.  I found for match accuracy, I needed to push 1 barely damp patch thru bore after each shot..bore left damp, chamber patched dry.  Patch came out with what looked like a hard crust of fouling..but squeezing between thumb & finger gave a very soft greasy feel.  I still haven't worked out all the loading details, and plan on giving breech-seating a try this year.

calledflyer wrote on Apr 10^th, 2018 at 7:45pm:


You could say the same about single shot rifles in general.   Most shoot bolt guns and jacketed bullets for a reason.

When I shoot black powder in my schuetzen rifles I wipe the bore completely clean after each shot.  I use several patches.  Then I have a very lightly oiled patch that I pass down the bore before each shot.  This seems to work best.  I've always found it much easier to develop an accurate smokeless load than a BP load.  For accuracy, I have no doubt at all that smokeless will in general beat a BP load.  Even so, I enjoy the BP more.  Maybe just because it's a little different than what most are doing.

Chris.

Might try altering your seating depth. 

JLouis

Iget the fouling and hard seating after the 1st shot, and am wiping with 2 moist patches between shots.  No fouling buildup, this is from single shot only.
Obviously, those 2 patches are not enough to get that fouling ring out, it is pretty stubborn.