Just out of curiosity I intend trying some 4227 in my CPA Stevens in which I usually use 2F.
Some sort of starting load would be appreciated that is safe in this action.
By the way I would appreciate it if no one mentions this to anybody I know as I'm in a black powder club that frowns on this sort of thing.
Mike.

I would use 4227 and a chronograph loading to get your velocity to about 1250  fps more or less. I think 1100 is too slow for good results at distance, 1400 is too fast for a plan base bullet. Between the two you should find a good load. 

My 38 cal CPA is a 38/55 and use 17.5 grs of 4227 . Considering your 38/56 case is bigger 17.5 ought to be a good starting load.

The CPA action is safe with any reasonable 38/56  load. They chamber for cartridges with much higher pressure than the 38/56 however the limiting factor is more brass than action.   

Boats

I would load with 4227 to the same velocity as your BP load then test.

My guess is, bullet varables the same, no difference in group size unless. BP load groups shot with inconsistent bore condition. 4227 groups shot with inconsistent mount.  Run both properly propellant should make no difference.

No one is going to agree with me though.

Mick You are right smokeless is not going to need any wiping between shots. Your BP routine sounds very good. 

Thing about 4227 or any powder that does not fill the case powder position makes a difference. I prefer to mount the gun exactly the same way every shot, vs. using some sort of filler to keep the powder orientated.

Noting your group sizes.  To my eye they are very realistic and probably are the limit of real performance with a rifle that has a round forearm and regular butt stock shot off a simple rest and using sights with less resolution than the high power scopes seen in true bench rest

Holly Grail in Single Shot Bench Rest is 250 at 200 yards.  10 shots touching 3/4 Moa center ring. Depending on bullet size 1 moa  rifle can touch a 3/4 moa ring 10 times

With few exceptions rifles that shoot 250's are wide forearm angled  butt stock bottom specialist guns using very high power scopes in heavy  rest, and handled by experienced shooters. Not to say others can't shoot 1 moa at 200 it's just the guns configuration makes more difference by far than the propellant. And the shooter makes the score.

Sum is position rifles are very limited by their configuration when shooting bench rest.

I like 4227 it’s as good as any smokeless powder better than most. I also like using Black Powder but fact is I shoot a whole lot more smokeless than black because it’s so much easier.  Limit my BP shooting to matches that are BP limited

Boats

Mick that scope will tighten things up for sure.

Even so way your gun and mine is stocked is going to affect groups off the bench.  Dozen years ago I played with bench shooting using my BPCR CPA.  At the time rifle was 10 years old and had a good benchmark performance.

Put a 12x scope on groups tighten up.  Bought a CPA # 5 barrel with a wide flat bottom stock & proper mechanical rest. Right away horizontal tightened up because the gun did not twist as much on recoil. Still had vertical stringing due to the slanted bottom of the butt stock riding the rear bag. If you look at top bench shooters guns rear is parallel so it comes back straight.

I never changed my rear stock and sold off the # 5 and rest. Thing I learned is don't expect bench rest groups from a position rifle.

By the way friend told me bench ASSRA is scored center of the bullet hole. So benchmark great goup is 3/4 moa 

Boats

Boats
I'm about to re load the 38/56 with the 4227, I was considering just leaving everything the same as my BP load, CCI BR2 primer, powder and two .060 LDPE wads in the case mouth. The Paul Jones Spitzer seated approximately .160" ahead of the case mouth.
I intend to start with 18 gr of the 4227, the bullet weighs 325gr in 20-1. What I was wondering was whether I need to put the wads in the case mouth at all as such a small amount of powder in such a large case will just lie in the bottom of the case and not spill out on loading if I keep the rifle level.
Any advice from yourself or anyone else with an opinion would be welcome.
Mike.

Boats
Thanks for that, no sense in re inventing the wheel when someone has done it all before.
I may run the load across my Chrony to see how it compares with my usual 62 gr load of Wano PP for velocity.
Mike.

Chris
I don't think leaving the wad out of the case is going to cause me any problems with spilling powder into the rifles chamber owing to the large capacity of the 45/70 case that was formed to make the 38/56.  However I was also wondering if I should put a thin card wad in the bullet seater to protect the base of the bullet from the blast ?.
Mike.