Higher Impact

[Jerry]

With fixed sights who raises the point of impact by increasing the powder charge? Just thinking. Jerry

[snapper]

Of course.   Also lower the point of aim by reducing the charge.

fleener

[Kurt]

This past spring, I worked on a .50 caliber to find an economical, accurate load and found a 60-grain charge worked well. A week ago, just as a thought, I'd try it again with a hunting load of 80 grains. That raised the impact by about 3 inches. 50 yards.

[Scota4570]

IF accuracy is the same why not? 

However, I have found that most rifles have a load that shoots best.  Changing the charge enough to raise or lower the point of impact would negatively effect accuracy. 

[Daryl]

Many guns with the slower rate of twist shoot well with a range of powder charges, from relatively light, to heavy loads.
My .69, with it's 66" ROT does well with from 82 or 85gr. 2F GOEX on up to 200gr. GOEX.
I settled on a load of 165gr. for hunting & sighted for that with he express sights. The stanging sight was dead on at 100 meters, first leaf, 150meters and second leaf at 200 meters. The third leaf was zeroed at 300 for the steel plate we used to shoot at rendezvous. No one who shot that rifle at that plate, missed it. As the charge was 165gr. 2F, I would get no one to shoot it twice.
 For plinking, as in shooting trail walk, I settled on 85gr. 2F GOEX. This proved to be slight more accurate than my previous load of 82gr. 3F, especially at 100 meters.
I use the same "accuracy" loads in my rifles no matter the range. I just hold accordingly as the range changes. This "goes" for my .50 longrifle at 85gr. 2F and 40gr.3F in the .36 SMR.

[alacran]

The problem lies in finding the best load for a muzzleloading rifle. It takes a long time to shoot 25 shots with a ML rifle. If you are working up loads you are being methodical with everything you are doing.
I talked to a good friend that is an exceptional black powder cartridge shooter and though not a as slow as
MLs, working up loads is still slow. He tells me he settles on a load when it performs the same group wise on three different days.
My friend has spread sheets going back many years describing all the conditions of every shot he has ever shot.
When he started shooting MLs he was frustrated by how long it took to develop consistent groups. Of course, there is a big difference shooting open iron sights and aperture sights.
With ML's with primitive sights, if it takes 2 to 3 hours to shoot 25 shots, your light is going to change quite a lot. The wind may change quite a lot also.
That is the problem. I don't believe you are ever going to find the best possible load for a muzzleloading rifle in one day.
Since most of my shooting is offhand, I do almost all my load development offhand. I keep tweaking it over a period of matches.

[Jeff Murray]

My 50 caliber flintlock has a 1 in 66 twist.   It will shoot with good accuracy loads from 65 to 105 grains of Goex 2FF.   I found over many days of testing that loads that produce around 1750 feet per second in muzzle velocity produced the best results, regardless of powder type.  That seems to be the sweet spot for consistent velocity with minimal variation in velocity shot to shot for this barrel.  Interestingly, Elephant powder produced the lowest standard deviation between shots but required 10 more grains of 2FF to achieve that result and the 1700+ muzzle velocity.  To address the OP's original question, I did increase the powder charge when reaching out to 100 yards by 5 grains.  I always sight in a new rifle from the bench so I can better find out what the barrel is doing rather than what I am doing with the gun.  I am not as steady or consistent as a bench rest.  Its not easy getting old.

[Daryl]

I suspect balancing good powder burning pressure and cleanliness of shooting as in more of the 56%solids of combustion leaving the barrel, might be more important than an exact vel. This is getting technical.
Much depends on the lubricant and patched ball fit in the barrel, I think than an exact vel. It is quite possible that various "combinations" will have a vel. ceiling.
My .40 and .45, when using the VERY slippery LehighValley Lube, both shot best at 2,240fps. When using the normal for me trailt walk water based lube, they shot best at 1,700fps, very close to your findings.
My shot to shot vel. variations are usually under 10 fps. I chock that up to the snug combinations I use. Close shot to shot variations are necessary for accurate shooting at any range past about 25yds.
The longer the range, the more critical becomes close shot to shot velocities.

[Leatherbark]

It is my experience that lowering the powder charge sometimes causes the point of impact to be higher at a shorter distance when it is not far below the regular charge. For instance, you are trying to hit a "X" at 25 yards and you already hitting a little high and reduce the powder charge by 5 grains thinking it will lower the POI and all of a sudden, the impact is an inch higher than what you were already shooting.  I seem to experience this at short range. Maybe it is more barrel time for the ball, but it only seems to do this with small changes in the charge at short range.

  Something interesting for what it is worth, in Sam Fadala's black powder loading manual books, many of his loads marked "T" for target shooting show 45,50 and 54 calibers with the "T" marking almost all have a muzzle velocity in the neighborhood of 1400 to 1500 fps range and use 70 grains of 2F or 50 grains of 3f to achieve this.  I know. His guns and his shooting, but it would be a place to start if one were new at this.