Can powder brand be responsible for this much difference?

[Grenadier1758]

@bpd303, make sure that linen is 100% linen from flax. Linen will hold together much better than 100% cotton. Make sure it's a tight weave. I have successfully used linen patches in a rifle that shredded cotton patches, but linen patches held together. After about 3 years of shooting linen patched balls, I could use cotton patching.

I do admit that I need a short starter and use a mallet and starting nub to start the ball for my precision target shooting as all the best shots in my gun club. I use the #40 cotton drill from JoAnn's Fabrics.

I agree that 0.010" thick patching will not fill the grooves in the deeply rifled barrels.

 

[wganz]

You may not be missing anything. A faster load spends less time under recoil in the barrel. That means the barrel will rise less before the ball leaves the muzzle which will make it strike lower. A slower load spends more time in the barrel before it exits which will make it strike higher. Longer distances will be different, of course.

He is correct on that point.
Another thing might be the barrel harmonics in that the barrel vibrates differently with the different burn rate could change the muzzle orientation when the ball exits the muzzle. Add in that the bedding also impacts this thus 2 otherwise identical kits will not react the same.
Emphasizing the importance of load development & consistency.

 

[olskool]

my first thoughts were sights sun and glare. it will affect you every time. even at 50yds it makes a difference, but much more of a difference at longer yardage,,,,,,,,,,,,,,,,,

 

[LRB]

Previously when I shot my SMR I had noted in my shooting log that it had been zeroed at 100 yds. I shot it again today and amazed to find that it's now hitting around 12 inches low at 100 yds. I'm using the same load, same ball and same patch. The difference is that previously I had loaded with 3F Scheutzen, and today I loaded with 3F Swiss. Everything else the same but the powder brand. Is it possible the different brand of powder would be responsible for this much difference in elevation trajectory? (Unfortunately I didn't take along my file, so nothing to be done about it today). Thanks for your input....

Anything that gets changed can and most often will change POI. That goes for all guns. Especially out at 100 yrds.

 

[wiscoaster]

Update: I had a nice day yesterday to take the gun back to the same range where I had originally zeroed the sights - the range with the covered benches. Shooting from a shaded bench brought the point of impact back up about one-third of the distance to center, but didn't completely account for the offset. Since I'm going with the Swiss (lots on hand) I decided to rezero and had taken along a file to do that in the field. Got that about half done before running out of time and energy. Will have to make another trip. Will also patina the brass front sight. Thanks for all the new knowledge shared in this thread.

 

[Mike in FL]

Is it a percussion rifle and did you change caps?
The powder can certainly make a difference, but at 100 yards with open sights so can the light, and of course the wind.
Several variables to consider.

I don't have any percussion rifles, but can the brand of caps affect POI?

 

[Uncle Miltie]

I don't have any percussion rifles, but can the brand of caps affect POI?

It sure can, especially Magnum (hot) caps.

 

[beardedhorse]

On a full stock I could bend a piece of index card and trap it between the barrel and stock, creating a shader to avoid any glare on the front sight. Unless the powder had moisture a 12 inch difference seems like a big deviation. Maybe bench it at 25 and 50 yards to check drop and tightness of groups.

 

[büchsenmacher64]

Previously when I shot my SMR I had noted in my shooting log that it had been zeroed at 100 yds. I shot it again today and amazed to find that it's now hitting around 12 inches low at 100 yds. I'm using the same load, same ball and same patch. The difference is that previously I had loaded with 3F Scheutzen, and today I loaded with 3F Swiss. Everything else the same but the powder brand. Is it possible the different brand of powder would be responsible for this much difference in elevation trajectory? (Unfortunately I didn't take along my file, so nothing to be done about it today). Thanks for your input....

If you chronograph the two powders Swiss will shoot 300fps faster than Scheutzen. That's huge.

 

[wiscoaster]

If you chronograph the two powders Swiss will shoot 300fps faster than Scheutzen. That's huge.

Well, I don't know what any of the actual inputs are for my rifle, but just for grins I ran ballistic charts for 1500 fps vs. 1800 fps with 200 yd zero, 0.5 BC, G1 drag (totally inappropriate for RB) and 100 gr projectile, and came up with an elevation difference of three inches at 100 yds.

Interestingly, that number accounts for about another half of the remaining from the original offset. And if my muzzle velocity input guesses are way too high, that number will be even bigger.

 

[Nav]

You have to remember that a .32 ball has about 1/4 the BC of a .22lr (.50 is about half). EVERYTHING is going to make a much bigger difference than even rimfire. @100 yards there is already about ten inches of drop even with a stout charge moving at 1,450FPS MV. It looses about half it's velocity in the first hundred yards.

https://ctmuzzleloaders.com/ctml_experiments/rbballistics/web_apps/rb_ballistics.html

Plug your data in and weep.

 

[büchsenmacher64]

Well, I don't know what any of the actual inputs are for my rifle, but just for grins I ran ballistic charts for 1500 fps vs. 1800 fps with 200 yd zero, 0.5 BC, G1 drag (totally inappropriate for RB) and 100 gr projectile, and came up with an elevation difference of three inches at 100 yds.

Interestingly, that number accounts for about another half of the remaining from the original offset. And if my muzzle velocity input guesses are way too high, that number will be even bigger.

I bought a bunch of Scheutzen and Graf's, which is Scheutzen in a Graf's bottle, and that's what I practice with. I use a lighter load of Swiss when I'm hunting so wiping between shots isn't as critical. That stuff is really clean. Very good powder but about $10 a lb more.

 

[wiscoaster]

....

Plug your data in and weep.

I hear ya!!

 

[wiscoaster]

The final lesson to be learned from this instance is: when trying to replicate performance with a black powder muzzleloader one needs to document all applicable variables. All I had done previously was to document in my "iron sights" log, which I use to document hold vs. print at 100 yds for my various milsurp rifles, and in which I had logged for my SMR "POA/POA" - meaning it had shot to point-of-aim for elevation and windage (ie I considered it "zeroed" at 100 yds), but nothing else about replicating that performance. This might be sufficient for a cartridge milsurp, where most applicable factors are either constant, or of very little effect, and for which I don't diddle with the iron sights anyway (and most are non-diddleable, and ruin them as collectible if you do). But this is not sufficient for a black powder muzzleloader, where the difference in ambient conditions or brand of powder can make a big difference.

 

[CaptainVane]

Hey Crisco.
I tend to side with your thought, but (the infamous but) I have also read that recoil doesn’t start until the ball leaves the barrel.
Somebody should do a slo mo utube video.

After extensive research, i concur recoil starts the instant the bullet starts to move. Utube videos confirm.