Can powder brand be responsible for this much difference?

[wiscoaster]

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

Didn't have time to retry at shorter range.

 

[Flint62Smoothie]

There is an old saying in high power shooting, as that is done with open sights too ... "Light's up ... sight's up!"

I'd say it was the combination of light and the Swiss powdah which would impact lower on the target due to the faster velocity.

 

[Rebel bull]

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.

everybody jumps on everything but the biggest factor are you mounting the gun the exact same as last time ? I find as I'm entering my 7th decade that I have to work harder and pay more attention to my mount to maintain the level of accuracy I was getting before weather that's 1 day, week, month or longer, or even target to target. the first place I'd look at is my mount the powder isn't going to be off a foot just by changing brands. You also say nothing about group size?

 

[wiscoaster]

....are you mounting the gun the exact same as last time...

Yes.

....You also say nothing about group size?

No, because I drifted the front sight for windage correction in between shots, so there was no "group" to speak of. It's a little loose and must have gotten bumped since last time. Once I get zero set and confirmed, I'll peen it in tighter.

 

[CaptainVane]

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.

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.

 

[Flintandsteel]

I’ll add one thing. What do your spent patches look like?
There is no way that a .010” patch is going to seal in either a Rice, or GM(Kibler) barrel.
Double them up, and see what happens.

 

[Grenadier1758]

The simple answer to the original question is, "Yes". Coming up with right answer as to why the point of impact is dropping is far more complex and can have several different answers. Some may have to do with powder and others with the mechanics of shooting.

@wiscoaster, are you shooting from a rest or off-hand? Is the rest hard or soft with a deadening bag of sand or other material?

This leads back to @The Crisco Kid's observation of harmonics and the effect of barrel rise under recoil. It does seem odd that a more energetic powder will strike lower on a target than a less energetic powder.

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.

If you are shooting from a hard rest, the recoil of ignition will cause the barrel to rise off the rest. A sandbag rest will cushion the barrel and lessen the effect of barrel rise during recoil. These is also the effect of natural barrel harmonics under recoil. Resting the barrel at the null of the harmonic motion of the barrel will reduce the effect of movement of the point of impact at the target.

If you are shooting offhand, the more energetic Swiss powder will have a bit more recoil. That anticipation of recoil can result in dropping the muzzle upon firing

Resting the barrel at the muzzle on a long-barreled rifle will induce a slight bend upward to send the ball high. Resting the barrel at the entry point of the ramrod into the stock lets the muzzle drop to lower the impact point.

 

[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....

Yes sir

 

[azmntman]

Different rests will do it. If your rest withe swiss was softer there ya go. A hard bag or log will shoot high. Thats why I shoot out the window of the corolla as it is close to shooting conditions in the field. The rest is my hand steadied on the window frame. in the woods its my hand steadied on a tree trunk. In the blind it's my hand steadied on a shooting stick. Your issue is more than likely a combo of every post in here. You'll get it. But also remember rifleaifle may just ONLY like the Scheutzen. It may hate swiss. I recall member rifleman saying he has a few rifles that will not shoot swiss. I'd find the rifles favorite and then start all over, and not file anything until you have it figured out, an acceptable group size and then bring the group into the bull.

Keep us posted, we'll all be there some day!

 

[#BPBReloadingFFL]

Time in bore results in lower POI
IF the theory of shooting a bullet faster results in the POI being lower.
Then explain how a subsonic suppository, note 3 holes in paper @ lower left. VS 3 holes top left made by a projectile traveling at 2x the speed.

 

[Codger Craig Wilcox]

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.

You'll be there in spirit, though. One hopes...

 

[M. De Land]

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....

Are you shooting off from sand bags on a bench?

 

[TreeMan]

I’d never ever trust my shooting at 100 yards to determine whether I need to file on my sights. Wind, lighting and eyesight at 100 yards differs too much from one range trip to the next. I sight mine dead on at 50 and know my ball drops six inches from that at 100. If im shooting cloverleafs at 50 and six inch groups at 100 then it is those mentioned factors not my loading components.

 

[Flint62Smoothie]

... have also read that recoil doesn’t start until the ball leaves the barrel ...

That would violate Newton's 3rd Law of Motion ... for every action there is an equal and opposite reaction.

 

[Pete G]

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.

Hotter powder has less barrel time, therefore shoots lower. Same thing happens with a lighter bullet in a cartridge gun.

 

[Salty Cracker]

No suggestions that havnt been mentioned but a really interesting thread nonetheless.

 

[wiscoaster]

...
There is no way that a .010” patch is going to seal in either a Rice, or GM(Kibler) barrel.
...

0.010 IS just a tad loose; 0.015 is REALLY tight (requires mallet pounding to start), and doubled 0.010 is just near impossible, and I've tried all three, and noted no difference.

 

[wiscoaster]

Are you shooting off from sand bags on a bench?

....are you shooting from a rest or off-hand? Is the rest hard or soft with a deadening bag of sand or other material?
....

Caldwell rest on bench to stabilize forearm, clenched fist under toe to stabilize elevation and fine-tune windage.

 

[wiscoaster]

Lots of interesting points about how rifle is rested. Will have to cogitate on those. Thanks.

 

[bpd303]

I found some 0.012 linen at either Hobby Lobby or Joanne Fabrics, can't remember which now but it works very well strips cut at the muzzle.