Velocity Data - .58 Caliber Green Mountain Barrel

This one is kind of interesting guys.

On Saturday I shot a bunch of 5-shot groups to gather velocity data for my .58 GM/TC Hawken. For consistency, I used weighed loads that were the equivalent of 105 grains volume in my TC U-View powder measure. I shot GOEX FFg, GOEX FFFg, Jim Shockey Gold FFG, Triple Seven FFG, Pyrodex Select RS, and Pyrodex P.

Here's the gun.



Here's the data chart.



Here are the targets.













The Pyrodex P absolutely DESTROYED the patches. I found one wrapped around one of the wire "v" shooting guides on the chrono. All that was left to it was a wad of threads. That accounts for the total loss of accuracy and wide variance in velocities. However, I'm pretty sure that on the third shot on this target I failed to seat the ball after short starting it. (Got distracted swatting flies and wiping sweat.) Fortunately, it did the barrel no harm.

I was quite surprised to see how close the velocities were between GOEX FFg and FFFg, and between GOEX and T7 in this barrel/caliber/load volume.

Interesting data. I would have expected more velocity all across the board from these loads. Well done and well presented.

Thank you Sir!

Very interesting.

The GOEX 2Fg and Pyrodex Select velocities are fairly close to the velocities Lyman published in their BLACK POWDER HANDBOOK & LOADING MANUAL, 2nd ed.

They didn't test the other powders you listed.

I haven't shot any of it but the low velocity you found with the JSG supports the data that I've seen published in the AMERICAN RIFLEMAN which indicated that much lower velocities can be expected if it is used.

Thats a really good post. I enjoyed the data

Thanks for the time and trouble it took to post the info. Very intersting. I have a .58 with a 34" barrel and now I know roughly what kind of velocities I can expect with different powders.

I think it's really funny that the jim shocky stuff had the lowest velocities. HA HA HA! Bill

I feel the same way about Jim Shockey's powder as I do about his fake inline muzzleloaders and "canned hunts" He needs to learn to hunt with real traditional muzzleloaders loaded with real BP.

Does anyone want to take a crack at explaining the horizontal spread with T7?

There was no cross-wind. If the group were more "rounded" I would blame it on the powder. But with all five shots on the exact same horizontal plane as the GOEX and Pyrodex loads, all I can figure is that I got a little sloppy with the sight picture for that shot sequence.

zrifleman said:

I feel the same way about Jim Shockey's powder as I do about his fake inline muzzleloaders and "canned hunts" He needs to learn to hunt with real traditional muzzleloaders loaded with real BP.

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Jim is a nice guy. Don't be to hard on him. I'd take his job if I could.

My results persuction GM 32" 58 cal. 1-70 105 gr fff goex using the same chrono.

1561 fps with lubed leather op wad

1629 fps with lubed fiber op wad

in this barrel the op wad increased velocity

enjoyed your chrono data..keep up the good work!

Did you recover any of the patches fired with those 5 shots that landed horizontally? I am suspecting that you were getting holes, or burns in the patches with that powder, and charge.

Of course, you could be also right, and it was just fatigue setting in that made you a bit careless in how you mounted the gun on the bag, and fired those shots. If you focus on the target, rather than on your front sight, you will move the POI, usually UP.

Good job of recording data, BTW. :thumbsup:

Did you recover any of the patches fired with those 5 shots that landed horizontally? I am suspecting that you were getting holes, or burns in the patches with that powder, and charge.

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No, I was not able to identify those patches Paul. There were too many patches on the ground to determine for sure which one came from the T7 loads, and all that I looked at were fine. The only reason I was able to identify the badly blown Pyrodex P patch was because it hung up on the chronograph.

I have shot horizontal strings like that before and have a mild suspicion that it may be related to my eyeglasses. I wonder if it's possible that viewing the sights through a slightly different part of the lense is changing the sight picture?

Jim Shockey may be a nice guy but he is poor representative for the muzzleloading world. He promotes inlines (notice I didn't say muzzleloader)and fake blackpowder. I would like to see a television show with a muzzleloading hunt using a traditional rifle and real blackpowder. Apparently there is no money and no sponsorship for it from gun companies.

You are correct there's no money in it. I love all firearms.

Next time, pick the patch up after Each shot. Use the range when its not crowded with other shooters to do this work. Then you don't have to wait to close the firing line to go down range a pick up the spent patches.

I hate to sound like a nag about patches, but they tell you so MUCH information when YOU DO pick them up after each shot, you simply save Lots of time and money by doing so. If I am using fabric that has been sitting in my range box for more than a year, I pick up the spent patch to make sure its not weakened with age, or tearing. That is How important checking your spent patches are.

If you don't have it, Get Dutch Schoultz' BlackPowderRifleAccuracy System, for under $20.00. Its the best investment you can make in learning how to work up loads for any gun, quickly, and with as few shots as possible.( cheap).
http://www.blackpowderrifleaccuracy.com/

You will learn the " OLD Way " we zeroed loads by using POI and condition of patches to tell us what was happening in the barrel. Today, everyone can own his own chronograph, and use that to speed the load development process even more. When I got my chronograph, and shot some test loads over the machine, it confirmed everything I thought was going on using the old time way of building a load. The only really new information was MV, and SDV. Both are very useful in diagnosing problems with any load, for any reason. :hatsoff: