F + ff = 1 1/2 f ?

[indian joe]

I measure compression from top of powder with wad to case mouth with wad lightly hand seated then from case mouth to compressed difference is the amount of compression.

Thats what I would expect as normal process - the point I was trying to make in my post to Leadpot is that powders with different poured density (Swiss as compared to plain GoEx fr instance) will be getting different amount of actual compression with the same amount of plunger travel - that is what happened with my small comparison.
If we use a press with compound leverage its very hard to feel the difference when we do it.

[indian joe]

Joe, your post is so true. Look what Goex did to Olde E 1.5Fg to run the velocity up ...
Swiss 1.5 (250.205)
12 mesh – 0.27% retained
14 mesh – 5.24% retained
20 mesh - 92.59% retained
30 mesh - 0.10% retained
Through - 0.72%

Olde E' 1.5Fg:
20 mesh - 98.163% Hold
30 mesh - 0.612% Hold
40 mesh - 0.000%
50 mesh - 1.224% Hold
60 mesh - Trace
80 mesh - Trace Passed

John
The OE is straight FFg according to all the stuff I can find and really the Swiss is a little less tidy, mostly FFG with some FG admixture.
All else being equal the OE should be the better bet
I grade my own powder very strictly (shake the c..p out of it) my process would not pay in industry but it gets nice even powder
Fg = 12-16
FFG = 16-20
FFFg= 20-40
FFFFg = 40-100
If we need more FF then I move the goalpost a little between that and FFF
Also used the same screens and process when we used to source 4FA in bulk

[Lead pot]

CG gave as good of a answer as any. compression is what it is.
I have no set amount of compression for any of my loads or powder. I do what I call a ladder load. I start with zero compression and increase the powder load one grain per three rounds fired of each or just two rounds at times. When I see the group at it's best that is the amount of compression for that powder or bullet.
Swiss most use very little or no compression but I find two different amounts of compression that works with Swiss and other brands. There is no one rule that works well for all calibers/bullets/primers/and so on. You have to spend a little or a lot of time behind the butt plate to get the best and it's not just a finding a good load but also developing your skill and this means a lot of time behind the butt plate.

Kurt

[indian joe]

You have to spend a little or a lot of time behind the butt plate to get the best and it's not just a finding a good load but also developing your skill and this means a lot of time behind the butt plate.

Kurt

That last bit is the kicker - I have yet to arrive at the place where I am shooting as good as the gun or the load
Used to do ok with muzzle loaders and I always believed there is a pretty strong connection between amount of powder burnt and results on the target.
Have to say hanging out here the last year has probably halved my group size with a couple of guns I like to shoot.

[GONRA]

".... big press with its compound leverage would not give the same reaction on the handle end..."

indian joe - GONRA put a Looong Handle on my Big Lee Press
(used for Range Bass Case Prep with STP Oil Treatment Case Lube)
to deal with these (RELATED) issues.

>>>> Get it: LOOONG HANDLE <<<<

[country gent]

I find when testing / working up loads in the above described manner it is interesting to watch the chronographs numbers especially ES and SD not just velocity. Starting at the no compression no airspace point and working up 2grn at a time the ES and SD numbers start to drop and get more consistant as you step up the compression. Most of my loads run around 12 fps ES for 10 round strings a couple have hit 8 or 9 fps. What gets interesting is after you go by this they will get bigger to a second point where they again become very consistant. Ive never looked for a 3rd point.

I currently weigh charges and drop into cases with a 36" drop tube. This gives a consistant powder stack in the case to start then add the heavy wad and compress the rest of the way with a die. What I have seen is the drop tube tends to do better with the lower part of the charge, when I pour a charge out after just the drop tube the bottom 48" or so is packed in snug enough it need a small screw driver or other tool to break it up to pour out. When compressed the entire charge needs this done. Compression should be consistant thru the charge with the die but due to friction and stacking it may not be.

One other thing to remember is black powder dosnt increase velocity in the same way smokeless does. a 1 grn increase is actually very little velocity increase