Can powder brand be responsible for this much difference?

[wiscoaster]

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....

 

[Frontstuffer070]

Swiss is a bit more energetic than Scheutzen, but a foot low? That's quite a bit. In my Kentucky I have had POI changes with different brands of powders but nothing that extreme. Before I took a file to my sight I would try again and reverify with the Scheutzen if you still have any that is. If not, being swiss is a more powerful powder back the charge off a bit and see what happens.

 

[Hammond79]

I believe it absolutely could be the powder. As previously mentioned Swiss is "hotter" than Schutzen.

However, how long has it been since you shot last? If it's been a while and if you are using prelubed patches maybe they dried out or rotted lessening the gas seal. That's another possibility.

 

[wiscoaster]

....

However, how long has it been since you shot last? ....

It's been a while, but I'm using the same patches (0.10 cotton) lubed with spit. When short-starting the seal seems pretty damn tight, and no change from last time, best as I can recall. I don't really care much for those prelubed patches for the very reason you mentioned.

If the Swiss powder is "hotter", shouldn't the ball's trajectory be flatter, given the same load? ie, should hit higher, not lower? I'm probably missing something, ballistically-wise.

 

[stikshooter]

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....

Absolutely, joys of having a chrono ! Way more energy and then factor in not only brand but projectile (BHN) hardness effects will do it too/ fresh patch or same with lube as previous day?/Ed

 

[Uncle Miltie]

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.

 

[wiscoaster]

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,cand of course the wind.
Several variables to consider.

No, flintlock. Same time of day, no wind. Yes, variables make a difference. As far as I know, the powder was the only material variable. Thanks for different angles to consider.

 

[The Crisco Kid]

If the Swiss powder is "hotter", shouldn't the ball's trajectory be flatter, given the same load? ie, should hit higher, not lower? I'm probably missing something, ballistically-wise.

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.

 

[TDM]

Swiss is definitely hotter than Schuetzen. So you would think you would print higher. But maybe @The Crisco Kid is correct.

 

[#BPBReloadingFFL]

Something else is wacky. I can change powder manufacturers,grinds and product and have never had a 12" difference in POI.

At most 2-3" at 100 yards off hand.
Using the same powder charge

 

[wiscoaster]

Something else is wacky. ....

No kidding. Suggestions?

 

[oldwood]

If you are using a bright front sight blade , and are shooting out in sunlight , a penumbra , (glare) on top of the front sight , will make you shoot low. Go out on another day , shoot from under a covered range , or in shade , rifle will be normal. Consistency rules the day. In my case , I use steel sight blades , and in sunlight , a touch of cold blue on front , and rear sights cures the problem.

 

[Absoroka]

This does not involve either of the powders you are using but might offer something to ponder. Several years ago when GOEX was very difficult to find, I tried some Elephant black powder. It gave excellent results in terms of standard deviation in velocity but required around 15% more powder by volume to match the velocity of the GOEX. when it comes to "drop" at various ranges, all other things being equal, a .495 round ball with a muzzle velocity of 2000 fps will drop around 6.5 inches at 100 yards. Reduce the velocity to 1800 fps and your drop at 100 yards is 8.1 inches. If you were sighted in at 100 yards for the slower velocity, the faster velocity would likely hit low at the same distance. If you can find access to a chronograph, you may be able to answer your question.

 

[SDSmlf]

It's been a while, but I'm using the same patches (0.10 cotton) lubed with spit. When short-starting the seal seems pretty damn tight, and no change from last time, best as I can recall. I don't really care much for those prelubed patches for the very reason you mentioned.

If the Swiss powder is "hotter", shouldn't the ball's trajectory be flatter, given the same load? ie, should hit higher, not lower? I'm probably missing something, ballistically-wise.

Are the groups similar?

I have found significant changes in POI with handguns of the non-blackpowder variety when shooting the so-called magnum calibers. Using the same bullet with the same POA the faster loads will hit significantly lower than the slower loads to a point. Have seem more than 12” at 100 yards with more than one handgun/caliber. Always attributed to the time the bullet was in the barrel as the gun would rise from recoil. Before I would panic or CHANGE ANYTHING I would want to confirm POI with both powders.

While some (AKA the bride for example) may call it hoarding, the situation above is why I purchase powder in 10 to 25 pound lots, patching material in multiple yard sizes, cast my own bullets from 25 to 50 pound lots of lead and purchase percussion caps for when I use them in 1000 count minimums is to avoid variables occurring all that often. Above not always possible, but remains a goal. The left overs will be part of what some former coworkers of mine called ‘one hell of an estate sale someday in the future’. While I would cringe at though of my stuff being sold off for pennys on the dollar, I don’t plan on attending the sale.

 

[Steve Wagner]

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.

Good call. I know it isn't directly apples to apples, but I have extensive reloading experience with unmentionables over a chrony, and with no sight adjustment, higher velocity loads invariably strike lower on the target. Counter intuitive and it leads many without a chronograph to believe that they are losing velocity with more powder. SW

 

[bpd303]

Like SDSmlf, I have seen different POI's with the same brand of powder but different lot numbers. Mostly Goex as that has been my go to powder for more years than I care to count.

 

[kyron4]

Try shooting at 25 or 50 yards and see what you get there ?

 

[#BPBReloadingFFL]

No kidding. Suggestions?

Sun, glare on sights

 

[wiscoaster]

If you are using a bright front sight blade , and are shooting out in sunlight , a penumbra , (glare) on top of the front sight , will make you shoot low. Go out on another day , shoot from under a covered range , or in shade , rifle will be normal. Consistency rules the day. In my case , I use steel sight blades , and in sunlight , a touch of cold blue on front , and rear sights cures the problem.

Sun, glare on sights

Ya know what, I think you guys are right on. In fact, I was laying in bed this morning wondering about whether front sight glare could make that much difference and was planning on asking that when I got online to the forum this morning, only to find you guys had already answered me. Because.....the range I zeroed the rifle at I was shooting from a covered bench, and the range I was shooting at yesterday I was exposed to the bright sunshine. A variable I hadn't considered. If I get a chance, I'll have to get back to the range with the covered benches and try again.

I think some patina on the front sight blade might help, no?

 

[reddogge]

Try a 20% less load of Swiss. Also, try the Schuetzen again.