FF vs FFF Lyman Manual?

[newkid]

Can this be right? On page 260 of the "Lyman Black Powder Handbook and Loading Manual" (2nd Edition), it shows that in .54 with a 32" barrel and 1-60" twist, shooting roundball, they get consistently higher velocities (grain for grain) with Goex FF vs FFF.

Thanks

 

[Stumpkiller]

Wouldn't think so.

But it's hard to argue with what folks measure vs. what we think.

 

[BrownBear]

I hadn't noticed that, but without unfolding my chrono I'm not in a position to debate it. I do notice that they report the same kind of thing for Pyro RS (and Select) versus Pyro P, while reporting what we think of as "normal" behavior for Goex Clear Shot, so I doubt it's a typo. If it really worries you, I'd send an email or place a call to Lyman.

I probably never noticed because I'm not worried about absolute velocity delivered by my loads so much as safe pressures.

For me the more important measures are accuracy and ease of use. The 3f shoots so much better in my guns than 2f, that I simply don't care about velocity differences of less than 100 fps. On top of that 3f fouls a whole lot less than 2f.

 

[newkid]

I guess the reason I find it hard to believe is because last year I shot 80 grains of FF, and this year I decided to up the power a little and went to 90 grains of FF. Based on what I read here, I also bought some FFF and tried 80 grains. Based on the accuracy, efficient ignition and less fowling I'm very happy with the FFF and don't plan on switching back. But the reason I looked it up in the manual was because the FFF at 80 grains seems to hit my metal spinners with more authority then even 90 grains of FF. I've never had .54 caliber round balls dimple the steel like my FFF load does. It actually dimples the steel deep enough to knock the paint off on the back side of the spinner plate sometimes, that's a first. So I assumed I had to be gaining a reasonable velocity, which is why I looked it up. My gun is a TC Renegade with a 30" TC barrel with 1-66" twist.

Thanks

 

[BrownBear]

Yeah, that really is interesting!!!

Do you have access to a chrono? That's the only way to clarify it.

I also found it interesting to compare the pressure readings for the same charges of 2f and 3f in the manual. We are always admonished to "reduce charges by 10-15%" when substituting 3f for 2f, but above 80 grains of Goex the pressures are virtually the same for 2f and 3f, and in some cases even higher for 2f.

That .535 ball with a .015 patch is a really tight load in my Lyman barrels, so I doubt there's any kind of gas leakage going on.

Stranger and stranger, the longer you look at the #s and think about what's going on.

 

[Zonie]

With the 3Fg loads consistently showing lower velocities it makes me wonder if they somehow mis-printed the information.

In all of the Lyman data I charted it shows that the 3Fg powder produces higher velocities than an equal load of 2Fg.

Another thing that is strange about the 3Fg chart is the barrel pressures.
While the 3Fg does show higher pressures for a given powder load when compared with the 2Fg it isn't significantly greater. For instance in the 100 grain loads the 2Fg shows a pressure of 6,200 PSI while the 3Fg 100 grain load shows a pressure of only 6,000 PSI. IMO, there is no way the 3Fg powder would produce lower breech pressures for a given load.

It looks like Lyman reversed the 2Fg and 3Fg data.

Even assuming they reversed the powder designation the data looks strange to me.
The same barrels test loads for the Elephant 2Fg and 3Fg shows increases in pressure which are more like I would expect to see. The 3Fg powder loads consistently show higher velocities and breech pressures than the same 2Fg powder load.

Although it's comparing apples and oranges, the .54 caliber 28 inch barrel with a 1:48 twist shows data which also agrees with the idea that a given load of 3Fg produces higher velocities and breech pressures than a comparable load of 2Fg.

The bottom line IMO is the data for the 2Fg powder should be listed as data for 3Fg powder and visa-versa.

 

[newkid]

Yes, I actually have a chrono, but I've never used it for my muzzleloader. I've been hesitant to use it for the muzzleloader because I wasn't sure how to set it up so that the patch and the over powder wad wouldn't play havoc with the readings. Basically, I've been too busy (and lazy) to dig it out and blow the dust off it. Also, since it's so close to season, and I'm happy with my current load combination, I don't want to do too much experimenting lest I lose confidence in my load. Experience (archery) has taught me that this is a bad thing when season starts.

Thanks

 

[paulvallandigham]

If you set the screen up 20 feet or so from the muzzle of your gun, you generally won't have any problems with patches. A Heavy felt, or OP wad may go over the screen, however. Consider substituting a loose filler, like corn meal for these sessions with the chronograph. They won't travel to the screens. The same happens when hornets or wasp nests are used as a filler.

And, if you try Jim Rackham's suggestion of using OS card instead of OP wads, and poke an off-center hole in each OS card, the cards will separate and flutter to the ground within that first 15 feet.