huge velocity differences !

[JeffB1961]

watching the video above , all shots with 100 grains by volume of 777 ffg ... and was amazed at the velocity differences !
most had close to or over 100fps difference in 3 shot groups .
the 250 grain conivore didn't break 1100 fps even though the 300 grain diid almost 1700 fps or better and the 330 grain PB ELR broke 1600 and 1700 fps .
really didn't expect 250 grain bullets to shoot 500 to 600 fps slower than the 300 and 330 grain bullets using the same powder charge from the same gun .

what are the possible reasons for these differences ?

 

[MrTom]

Heavier bullets create enough initial drag to burn the powder better.

 

[JeffB1961]

so we should shoot heavier bullets if we want higher velocities ???

 

[michiganmuzzy]

so we should shoot heavier bullets if we want higher velocities ???

I like that idea. Go big or go home… my shoulders gonna hurt tho

 

[JeffB1961]

i'm not doubting you folks , but i guess i'm missing something ' Ethans results with the carnivore and borelock both weighing 270 grains had a 700 - 800 fps difference in velocity .
Smackdown Carnivore 1069, 1052, 1025 FPS
BORLOK 1863, 1900, 1792 FPS

i do realize they have different sabot designs .
is it possible something is not quite right with the carnivore sabots ?
the carnivors FPS being so far off from the rest is what keeps me thinking what the heck .....
i apologize if my ignorance offends anyone , i'm just trying to grasp in my mind what is happening .

 

[CatamountRob]

so we should shoot heavier bullets if we want higher velocities ???

No.
My guess is that it’s a loose fit in the bore.

 

[JeffB1961]

this morning i read that Ethan replied to several folks in comments that he thought the chrono might have been reading the sabot on the carnivore and that they typically hit 2000 fps in his other test .

 

[snapbang]

Something is wrong. The powder company publishes data and it all shows an increase in velocity with a decrease in projectile weight. If this were not true I think we would have heard about this decades ago. There are some things in life that don't make sense once in a while but Ill go according to the powder company published data. Yet I know they fudge the velocity a bit to make velocity look a little better.

 

[ElDiablo]

In all my tests, lighter bullets shoot faster than heavier bullets with a given powder charge. All else being equal, that is what one would expect. It certainly appears that there is some mysterious issue here that is upending things.

That’s pretty common in muzzleloading! Solving the mystery is part of the fun.

 

[Swamp]

I'm not knocking the guy trust me, I like his videos on bullet comparisons. But, he did so many things wrong to test velocities for consistency. One, he was pouring loose powder down a dirty bore without a drop tube. This alone will make a HUGE difference when comparing velocities. He was not swabbing between shots. How consistent was he with his bullet seating pressure? I can on and on, but this is not a good test for looking at velocity comparisons.

For true velocity comparisons, you have to be VERY CONSISTENT on everything you do before pulling the trigger and looking at the chronograph.

 

[ILoveMuzzleloading]

I'm not knocking the guy trust me, I like his videos on bullet comparisons. But, he did so many things wrong to test velocities for consistency. One, he was pouring loose powder down a dirty bore without a drop tube. This alone will make a HUGE difference when comparing velocities. He was not swabbing between shots. How consistent was he with his bullet seating pressure? I can on and on, but this is not a good test for looking at velocity comparisons.

For true velocity comparisons, you have to be VERY CONSISTENT on everything you do before pulling the trigger and looking at the chronograph.

Thanks Swamp, you are right -this isn't a super precise test. I don't take it as knocking at all, I truly appreciate it.

To provide some background, I get asked to do these videos by folks that, from my understanding, are just going hunting a few days a year. They aren't using drop tubes, they are measuring by volume and they aren't cleaning for a follow-up shot.

My main goal for the test was to see the accuracy with the same load out of the same gun, but I always get questions about speed so I try to include the chronograph. Perhaps on this round, it was so inconsistent it is detracting from the purpose?

I'm humbled the video is even being discussed, thank you all. I really enjoy learning from the forum.

 

[Swamp]

Thanks Swamp, you are right -this isn't a super precise test. I don't take it as knocking at all, I truly appreciate it.

To provide some background, I get asked to do these videos by folks that, from my understanding, are just going hunting a few days a year. They aren't using drop tubes, they are measuring by volume and they aren't cleaning for a follow-up shot.

My main goal for the test was to see the accuracy with the same load out of the same gun, but I always get questions about speed so I try to include the chronograph. Perhaps on this round, it was so inconsistent it is detracting from the purpose?

I'm humbled the video is even being discussed, thank you all. I really enjoy learning from the forum.

Ethan, I love your videos and its great that you take the time to do them for us. The original post made it sound like this was a velocity comparison test, and thats how I took it. so if that was wrong I'm sorry. Finding how things work out for a particular rifle is what makes this sport fun. I go into all kinds of details to try and squeak out the best I can in all my shooting. I really enjoy the videos you make, and please keep doing them.

Make yourself a drop tube if you don't have one. Buy a piece of brass tubing and flare one end. I put mine thru a powder funnel used for modern cartidge reloading. It works amazing, and will keep consistent powder charges down in breech.

 

[JeffB1961]

thanks for replying Ethan . i'm very new to muzzleloading and i enjoy your videos also and this one , even though my question was off track for the videos intended purpose , it did provide me with useful info going forward .
please keep doing what you do , and thanks again sir . jeff

 

[Swamp]

thanks for replying Ethan . i'm very new to muzzleloading and i enjoy your videos also and this one , even though my question was off track for the videos intended purpose , it did provide me with useful info going forward .
please keep doing what you , and thanks again sir . jeff

Jeff, I think it was me who kinda drifted off on what the video was intended for. I'm sorry for any confusion, and if I came across arrogant to you and Ethan. My apologies to both of you! I love everything and everyone on this board, as well as individuals who take the time to make videos for our learning, and viewing pleasure. Sorry guys!

 

[rangerod]

I have to suspect a faulty chrono.

 

[Ninering62]

I like that idea. Go big or go home… my shoulders gonna hurt tho

I like using the max charge the gun will take & find a bullet that will give me the accuracy I want with that charge. And, yes, my shoulder pays for it, but I'll keep it up until my body can't handle it any longer.

 

[Ninering62]

Jeff, I think it was me who kinda drifted off on what the video was intended for. I'm sorry for any confusion, and if I came across arrogant to you and Ethan. My apologies to both of you! I love everything and everyone on this board, as well as individuals who take the time to make videos for our learning, and viewing pleasure. Sorry guys!

Respect! Good on ya Swamp.

 

[JeffB1961]

Actually it was me . I was wanting to know why there was such a big velocity difference . Replaying his video and not seeing a significant drop in the hundred yard shots it looks to me like there wasn't a huge velocity difference between them so Ethans comment about the chrono reading the sabot and not the carnivore seems most likely .
But im new so .......

 

[bobcat_trapper]

There is something wrong with the chrono. The 250gr bullet will have a higher velocity. With the same grain powder charge. Wasnt the test at 100 yds?

 

[JeffB1961]

just asking BC ...... but why would the chrony read seemingly somewhat accurate with the other bullets but be consistantly so much slower/wrong on the carnivores ? the bore driver was the only other bullet that has a sabot that detaches after firing .... is it possible that the bore driver sabot was still intact with the bullet when it went through the chrony ? or maybe the chrony needs cleaning from ML powder residue collecting on the sensors ?