Preliminary accuracy results with the Thumper Carbines

chorizo · Mar 20, 2023

Other than the fact I have 1500 musket nipples, no #11s and no place here has any for sale nor have they for 2 years.

I am also using Triple 7 not BP. Not underestimating, just not going to use them is all.

longcruise · Mar 20, 2023

chorizo said:
Other than the fact I have 1500 musket nipples, no #11s and no place here has any for sale nor have they for 2 years.

I am also using Triple 7 not BP. Not underestimating, just not going to use them is all.

Ok, now I totally get your reasoning and decision. May or may not make any difference, but you might get better ignition regardless of the cap used if you sprinkle a little holy black in the bore before the T7.

chorizo · Mar 20, 2023

longcruise said:
Ok, now I totally get your reasoning and decision. May or may not make any difference, but you might get better ignition regardless of the cap used if you sprinkle a little holy black in the bore before the T7.

Getting really good ignition right now. No delays from cap to boom. As I am using FFFg, it gets into the flash channel readily with just a thump of the butt on the ground (the stocks all have the t/c rubber butt pad).

That is another thing you can't get here.....nobody stocks BP of any type. You can only find sub. I am using Triple 7 FFFg for the ease of cleaning afterwards, the more vigorous energy of burn and ease of ignition.

Recommended to me by @Brokenbear and I am glad I made the switch.

Sandro_Ventania · Mar 20, 2023

chorizo said:
Well, the world balances itself....just as things go wrong, things go right. Today I had been anticipating my 22" 1:32 twist 54 cal barrel I sent to Mr. Hoyt 4 weeks ago. When the postal lady handed me my tube, it was too heavy for one barrel. Surprise, surprise, surprise....he did the 58 cal barrel 22" 1:32 twist I sent 11 days ago also. So now I am back in the 58 game. Got to mount sights and I am waiting on Williams to send those, but I got some shooting to do!

So a recap of guns:

24" 54 cal 1:38 mounted in Renegade stock
21" 54 cal 1:38 mounted in WMC stock
22" 54 cal 1:32 mounted in WMC stock
22" 58 cal 1:32 mounted in Big Boar stock

It could have a .62 cal.

Sandro_Ventania · Mar 20, 2023

chorizo said:
but I suspect it will not meet my 125 yard parameters as I won't be able to push the heavy bullets fast enough.

Ever heard of barrel Forsythe?
barrels for high-velocity shots in calibers .58 and above.

chorizo · Mar 20, 2023

Sandro_Ventania said:
Ever heard of barrel Forsythe?
barrels for high-velocity shots in calibers .58 and above.

No, I haven't. It will be two weeks before my next range time. Time to hand lap the two new bores and install sights.

longcruise · Mar 20, 2023

Sandro_Ventania said:
Ever heard of barrel Forsythe?
barrels for high-velocity shots in calibers .58 and above.

I believe the Forsythe barrels were extremely slow twist large bore meant for balls.

hanshi · Mar 21, 2023

Those targets show very good 100 yard accuracy and obviously you're a good shot. Good luck on your testing the loads.

chorizo · Mar 21, 2023

hanshi said:
Those targets show very good 100 yard accuracy and obviously you're a good shot. Good luck on your testing the loads.

Thank you, a very fine compliment indeed.

chorizo · Mar 23, 2023

Here are the Thumper Carbines in final form:

Top to bottom: 58 cal 22" 1:32 Big Boar stock; 54 cal 24" 1:38 Renegade stock; 54 cal 22" 1:32 White Mountain Carbine stock; 54 cal 21" 1:38 White Mountain Carbine stock

centershot · Mar 24, 2023

chorizo, a couple of questions; First, have you thought of using a Helicoil to repair the stripped threads?

https://www.mcmaster.com/helicoils/thread-size~1-4-28/
Second, when you cut those barrels back to carbine length did you find it necessary to D & T a new hole in the under-rib and barrel to keep the rib in alignment? I'm thinking I would like to have my .54 shortened to reduce the muzzle-heaviness!

chorizo · Mar 24, 2023

Yes, I have. I previously posted there is just not enough depth for them to work. I will just find me a new breech for it.

If anybody has one they are willing to part with, please contact me.

I didn't have to drill any new holes as there still are two left and that is plenty to hold it..

At 24" with FFFg you will get full powder burn at 22" Be aware you must use FFFg, even 90 grains of FFg just barely burns completely even at 27"

Use this calculator:

https://www.p-max.uk/cgi-bin/black_powder.cgi

Sandro_Ventania · Mar 25, 2023

chorizo said:
Yes, I have. I previously posted there is just not enough depth for them to work. I will just find me a new breech for it.

If anybody has one they are willing to part with, please contact me.

I didn't have to drill any new holes as there still are two left and that is plenty to hold it..

At 24" with FFFg you will get full powder burn at 22" Be aware you must use FFFg, even 90 grains of FFg just barely burns completely even at 27"

Use this calculator:

https://www.p-max.uk/cgi-bin/black_powder.cgi

Great calculator!
I am in awe of the difference the granulation of black powder makes. I had no idea the effect was so intense. For me, as it is the same black powder, the difference was minimal between a 1F and 4F.
Have you put her to the test yet? To see whether the calculation actually coincides with the practice?

chorizo · Mar 25, 2023

Sandro_Ventania said:
Great calculator!
I am in awe of the difference the granulation of black powder makes. I had no idea the effect was so intense. For me, as it is the same black powder, the difference was minimal between a 1F and 4F.
Have you put her to the test yet? To see whether the calculation actually coincides with the practice?

Yes. I velocity tested it with triple 7 and it corelates nicely

Freedom · Mar 25, 2023

Yes that's a great calculator! Thank you for sharing it.
I use 2ff Olde Eynsford, and the calculator using 3fff Swiss is within a few feet a second of the loads that I've Chronographed with my 58 Colonial and a round ball.

user 49399 · Mar 26, 2023

chorizo said:
Here are the Thumper Carbines in final form:

Top to bottom: 58 cal 22" 1:32 Big Boar stock; 54 cal 24" 1:38 Renegade stock; 54 cal 22" 1:32 White Mountain Carbine stock; 54 cal 21" 1:38 White Mountain Carbine stock

View attachment 208890

I like these. They remind me of German Jaegers with short barrel and large bore. Made for hunting.

chorizo · Mar 26, 2023

Banjoman said:
I like these. They remind me of German Jaegers with short barrel and large bore. Made for hunting.

They are loosely based upon that concept. Large bores, short barrel and fast twist. These are going to be hunting guns, not range or bench guns. Mix in Val Forgett's concept of small grain powder (FFFg) and heavy for caliber bullets and some modern vigorous burning BP substitute powder and there you have it.

chorizo · Apr 21, 2023

Well, like a phoenix, the 58 cal 24" thumper is back from the dead. I installed the new breech plug that @Skogmann sold me and it fits well and looks like a champ. It is mounted in the Big Bore stock. I migrated the 54 cal 24" to the Renegade stock and the 22" 58 cal to a WMC stock.

I now have 2 58 cal rebores to work with. This 24" 1:38 twist that I intend to use heavier than 510 grain bullets with and a 22" 1:32 twist with bullets in the 440 to 510 grain range.

The weather is looking to be nice after 1 May, so it will be back to the range to get the accuracy testing under way again.

Dirty Mike · Apr 27, 2023

chorizo said:
Well, like a phoenix, the 58 cal 24" thumper is back from the dead. I installed the new breech plug that @Skogmann sold me and it fits well and looks like a champ. It is mounted in the Big Bore stock. I migrated the 54 cal 24" to the Renegade stock and the 22" 58 cal to a WMC stock.

I now have 2 58 cal rebores to work with. This 24" 1:38 twist that I intend to use heavier than 510 grain bullets with and a 22" 1:32 twist with bullets in the 440 to 510 grain range.

The weather is looking to be nice after 1 May, so it will be back to the range to get the accuracy testing under way again.
View attachment 216415 View attachment 216416 View attachment 216417

How hard was it to get the breech plug off?

chorizo · Apr 27, 2023

Dirty Mike said:
How hard was it to get the breech plug off?

Very easy as it had been to hoyt for rebore recently and he had lubed it up with copper no seize when he reinstalled it

Preliminary accuracy results with the Thumper Carbines

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