Questions Regarding Powder Loads

[rodwha]

I have read conflicting info in forums concerning the need to reduce 777 loads by 15% of max for safety. I have asked Hogdgon's twice, but have not received a reply. There site only states the need to reduce loads to achieve similar velocities of such loads (BP).

Is there a general load reduction for using 3F instead of 2F (.50 cal)? Traditions stated to reduce max load by 5 grns, whereas Lyman's stated to reduce 20-30 grns depending on the weight of the projectile.

I intend on using 3F 777 in both my ROA and which ever .50 cal side lock I end up with.

I'm also a bit confused with the compression of 777. Is it to be compressed much like BP or Pyrodex? I read what articap posted and read what 777 states (firm).

 

[mykeal]

777 must be reduced 15% to achieve performance equivalent to a given real black powder load.

There is no safety issue involved - it's all about performance.

For example, let's say you have a 50 cal plains rifle and have determined that you get the best groups using 70 grains of 2f real black powder. If you wanted to switch to 777 you would load 70 x .85 = 60 grains (actually, 59.5 grains but let's not get too silly here) of 3f 777. That should give you muzzle velocities and energies with the 777 that are close to what you would get using the real black powder. Performance as measured by group size should also be close considering that the muzzle ballistics are equivalent.

This does NOT imply that using 70 grains of 777 would be unsafe, UNLESS the gun's max load rating was 70 grains of real black powder. 70 grains of 777 would be equivalent to 70 x 1.15 = 80.5 grains of real black powder. You could certainly shoot 70 grains of 777 in any gun that had a max load rating over 80 grains of real black.

Now, moving from 2f to 3f and vice versa: quite separately from the issue of 777 vs real black, one should consider adjusting a given load if changing granulations. 3f powder, whether it's 777 or real black, theoretically produces from 5% to perhaps as much as 10% more pressure (and thus muzzle velocity and energy) than the same volume of 2f powder. The actual number varies with the load, local humidity and for all I know the phase of the moon, but it's somewhere in that ballpark. If it's really important to get EXACTLY the same performance when switching granluations the only way to achieve that is to experiment with various loadings.

With respect to compression of 777, it's been my experience that 'heavy' compression of 777 results in inconsistent and inaccurate results in revolvers, single shot pistols and long guns. The same is not true if 777 is loaded 'firmly'. How do you tell what 'heavy' and 'firmly' mean? Here's my description: 'heavy' means you put your weight into it; you try to pack the powder into as small a space as possible using force. 'Firmly' means you push down hard enough to assure yourself that the projectile is seated directly on the powder and not being prevented from seating by a bore restriction or some other problem. You are simply seating the ball, not trying to achieve some specific reduction in powder volume.

 

[rodwha]

So if the manufacturer states a max load of 80 grns 3F I shouldn't use more than 68 grns of 777 as more would be unsafe?

I'm very interested in Lyman's Deerstalker and Pedersoli's Country Hunter. I am also considering Tradition's Deerhunter. Can anyone with either of these share their hunting loads along with 100 yds groups?

 

[mykeal]

So if the manufacturer states a max load of 80 grns 3F I shouldn't use more than 68 grns of 777 as more would be unsafe?

Technically speaking, yes, the manufacturer would say it's unsafe. Personally I'd round it up to 70 (measuring 2 grains of powder by weight isn't reliable). To go a few more above that I would not say is particularly unsafe, but I would classify it as abusive. And it's highly unlikely to be your most accurate loading.

I have limited experience with those guns, certainly no ballistic data, so I can't help you there.

 

[J-Bar]

I have used 777 interchangeably with Pyrodex, Goex, and Schuetzen in modern blackpowder guns. I admit I am an idiot. I don't worry about over compression, I don't worry about reducing loads. For Cowboy Action Shooting, I just want it to go bang, and I am not worried about hair-splitting accuracy that a long-range silhouette shooter would be concerned about.

If I were shooting 150 year old guns or damascus barrelled shotguns I would be more precise. But I am shooting Uberti 1851s, Pietta 1860s, Ruger Old Armies, and SKB shotguns, made of modern steel, and I am using 18 to 25 grain powder charges in the revolvers under pure lead balls, and 50 grain charges in the shotshells.

In my experience 777 does not contain uranium. At the charges I am using, I am not going to get a mushroom cloud out the barrel. I use it like I would any other brand of black powder or substitute. It's black powder for crying out loud, not Bullseye!

And it is working just fine for me. I am not encouraging anyone to disregard a manufacturer's recommendations. I am just relating my experience.

You guys who bore out a cylinder to get more powder volume, and then try to pack a 300 grain conical on top of a 50 grain handgun charge are on your own!!

 

[crazysccrmd]

I spent last weekend putting 45gr of 777 under a round ball in my ROA. With firm compression I still had excellent accuracy.

 

[J-Bar]

I spent last weekend putting 45gr of 777 under a round ball in my ROA. With firm compression I still had excellent accuracy.

Thanks!

It's comforting to know I am not the only crazy one around here!!

 

[rodwha]

J-Bar: "...I am using 18 to 25 grain powder charges in the revolvers under pure lead balls..."
In essence aren't you reducing your loads?

 

[rodwha]

I would certainly push it in my ROA as well. It can more than handle it. I'd be more concerned with the longevity of a rifle though.

 

[arcticap]

I have read conflicting info in forums concerning the need to reduce 777 loads by 15% of max for safety. I have asked Hogdgon's twice, but have not received a reply. There site only states the need to reduce loads to achieve similar velocities of such loads (BP).
Is there a general load reduction for using 3F instead of 2F (.50 cal)? Traditions stated to reduce max load by 5 grns, whereas Lyman's stated to reduce 20-30 grns depending on the weight of the projectile.

Compared to the same volume of Goex, Swiss powder weighs about 10% more and produces correspondingly faster velocity, and which is nearly as fast as 777. Yet rarely to never does anyone here expressly state a disclaimer to reduce a powder charge of Swiss by 10% each & every time that a specific black powder load is mentioned or recommended in a post.
Quite frankly I don't think that the 10% - 15% difference of Swiss 2F or 3F verses an equal volume load of any Goex granulation or 777 really ever matters.
We almost always state the reduction for 777 even though that 15% difference alone isn't nearly enough to blow up a barrel that's in good condition and that has been proof tested.
I think that we all inform folks about it not really for safety but just to make them aware that some powders are more potent. Just like most folks often mention about brass frame revolvers being weaker than steel.
But I can't really say that there's ever been a case where if a person wasn't aware about reducing loads of certain powders that it would cause a serious safety issue.
I dare to say that every modern muzzle loader is designed to withstand much more than a 15% greater powder charge than any manufacturer recommends.

 

[J-Bar]

J-Bar: "...I am using 18 to 25 grain powder charges in the revolvers under pure lead balls..."
In essence aren't you reducing your loads?

I am using those loads for competition, to reduce recoil, and gain speed between repeated shots. I am not afraid of using full charges of any blackpowder or substitute including 777 in any of my guns. I've done it, I just don't care to waste powder while trying to shoot fast in competition.

My point is, I don't think one has to be afraid of the extra oomph in 777 in a modern gun. I don't compress any blackpowder load as hard as I can. Get the ball or bullet in contact with the powder charge to eliminate dead space...there is no point in mashing the hell out of any of this stuff.

 

[mykeal]

I spent last weekend putting 45gr of 777 under a round ball in my ROA. With firm compression I still had excellent accuracy.

'Accuracy' is a relative, and somewhat elusive, term. CAS shooters, for instance, consider themselves and their weapons (including the loads) to be accurate if they hit a steel 10"x10" target from 20 yards. Chunk gun shooters look for groups in the tenths of inches at much greater distances. What is your standard of excellent accuracy?

 

[crazysccrmd]

'Accuracy' is a relative, and somewhat elusive, term. CAS shooters, for instance, consider themselves and their weapons (including the loads) to be accurate if they hit a steel 10"x10" target from 20 yards. Chunk gun shooters look for groups in the tenths of inches at much greater distances. What is your standard of excellent accuracy?

Good point. It was hitting about 3" groups, two handed standing from 25yds.

 

[rodwha]

My standard for "acceptable" accuracy with would be within 6" with 4" preferable out to as far as I can keep that. With a rifle I'm hoping a 100 yd 0 would keep a group like that to 125 yds. The energy of a conical or bullet in a sabot ought to be enough that I wouldn't need lots of velocity.

My standard for the ROA would also be a group like that out to at least 15 yds with as much horsepower as I can muster with as heavy of a bullet/conical as I can use if it's used as a defensive (wounded hog) sidearm.

If it's for hunting I would hope to get a good that type of group out past 25 yds if possible. I'm not so sure it would have enough energy using RB for hunting anything over 125 lbs (on the hoof) out to 50 yds. Maybe a conical would.

I am looking for 45 Colt ballistics or better.

I wouldn't fear pushing the limits with 777 in a ROA.

 

[zimmerstutzen]

for getting the same POI as when shooting with black, yes reduce the 777 by 10%.

As for safety, unless you are already playing with charges already near dangerous maximum black powder loads, I don't think there is much concern.

However, not all guns are alike in strength and some imported/produced over the years are dangerous even with just a moderate load of black.

There are some guns that I wouldn't shoot any small amount of powder.

That said, the stuff is igniting inches from YOUR face. In a modern gun, the risk should be quite minimal.

For some reason, most shooters sooner or later have to see whether more is better and play with max loads. Or they hear, Uncle fred shoots 200 grains of Super Whupbutt powder in his modern in-line. Lets see what that does in this 1970's Chinese import gun. Fatal mistake.