Finally Jug Choked the 7 bore

[11Bravo]

The Underhammer is perfect for hunting. That's why I built 2, years ago when I stopped with the flintlock. Numrich kits, one 45 and the other 58, but with the 58 I had H&H make a progressive rifled mini 58 barrel for it. Such a simple design, 3 moving parts and no doubt the fastest lock time of the MLs. Great job on yours

 

[BS]

Looking goid.
Tried Skycheif load yet?

Sort of, Instead of a nitro card, I used 2 over the shot cards and no card over the shot, just 1/3 or 1/2 of a cushion wad, dry.
Hoping that the cushion wad just vaporizes over the shot.
Just needs some more fine tuning!

 

[BS]

Todays:

2 Cards, H Cup w/150 shot, Card

4 Cards, 150 shot, Card, Lubed Wad with Moose Milk

4 Cards, 150 shot, Card, Lubed Wad with olive oil

4 Cards, 150 grains shot, 1 Card

The Lubed wad over the card did help.

I need to soak some wads on Olive oil overnight.

What do you use for fiber wad lube?

30 yards with Hard 7.1/2 shot.

 

[LawrenceA]

Currently I am using beeswax/olive oil patch lubes on wads.
Have done no testing

 

[BS]

Did some re-testing, before the rain.

4 cards-150 grains of 7.1/2 shot-card-cushion wad soaked in olive oil.

Happy with the first target, then I shot the second.

manure..........this gun can do this!

I am happy with this.

Then I shoot this:

Look at the shot count!

This gun has been hiding it's potential.

With the .875" bore, I need to try 2 lubed cushion wads over the shot.

Maybe that is the 'secret' to this pattern??

 

[BS]

Have not been able to duplicate the last target.

As soon as the shop warms up, the choke will be an extra full!

More is better, right?

 

[LawrenceA]

More is better, right?

Not necessarily. Traditionally Full choke is supposed to mean any further restrictions makes no difference to the pattern. If more choke tightens the pattern then it was not really Full choke to start with.
Remember the old rhyme:
Little powder lotsa lead shoots far kills dead.
Lotsa powder little lead kicks hard wide spread.

Try a little less powder first maybe?

 

[BS]

I now have Full choked jug bore and it does pattern tighter than the old Modified.

But I am not sure if this large bore that .040 restriction is full.

Anyway it patterns tighter.

Also remembered that the breech plug was originally 1/4" x 1.1/4". That would blow the center out of a patch on a round ball.

Opened it up to 5/16" that helped,[patched round balls] but it made for inconsistent results with birdshot loads.

The venturi, 'jet' effect was causing .......... problems with unbalanced pressure on the first card. Very inconsistent patterning.

So, I coned the breech plug 3/4" taper 1" long. Patterns are consistent!!!!!

Also found my can of 1F............cannot tell if it is better, but you would think so.

The breech plug change made the biggest difference.

Wonder how many other scatter guns have a similar problem with a poorly designed breech?

 

[BS]

All home made, I spent two weeks with a long rod and Sunnen Lapping stones and fuel oil honing the tubing smooth. I put .002 choke in it, thought it might help with round balls.. Thinking about putting in more choke for a tighter pattern. Lot of work! [Jug choke] Do I do another .010 or go .020?
Old RB target.
View attachment 71654

I need to try this again and see it anything changed much.
I have 3"s of taper and 4"s of straight, back side has a little taper. [.040 restriction]

 

[BS]

Holey manure!!!

Love it when a plan comes together.

Been doing some searching and reading about jug choked loads.

I add 2 1/16" larger diameter lubed felt wads in-between the first two nitro cards.

Shot, the 2 over shot cards.

30 yards, not 30 feet!

I divided the sheet inti 1/4s to make it easier to count.
120-84
63-25

Now to do some fine tuning. Reducing shot amount and messing with wadding.

 

[LawrenceA]

well I'll be Damned!!!!
Think you may be on to something!
Looks like an 80 yard turkey load.

Curious. Where is the centre of the pattern?

 

[BS]

I may be shooting high left.

 

[LawrenceA]

I may be shooting high left.

Yes you may

 

[TGJaeger]

You will really want to have that monster sighted in before taking a turkey....just a bit low and the breast meat will be pre-masticated for you !

 

[BS]

If the pattern stays the same, I plan on reducing the amount of shot.

I am trying a gas seal made out of milk jug.

It is folded over, forming a cup, with a smaller nito card inside.

 

[Britsmoothy]

If the pattern stays the same, I plan on reducing the amount of shot.

I am trying a gas seal made out of milk jug.

It is folded over, forming a cup, with a smaller nito card inside.

View attachment 73564

View attachment 73569

Oooooh plastic with black powder!
But hey, its your party and quite innovative

 

[BS]

"Oooooh plastic with black powder!
But hey, its your party and quite innovative "

I will also try leather, But, I need to know if it works!

 

[LawrenceA]

I will also try leather, But, I need to know if it works!

I cannot remember where I read it but recall reading that leather was the best.
I do know they use milk bottle and tetra pack cardboard, with the foil and plastic, for wads in BPCR for a gas seal so there must be some use/benefit.

 

[BS]

UPDATE:

The plastic seals, well, not fond of them.

150F-2Nitro-135#7.5-Card at 30 yards

I found patter improvement with a heavy walled pvc drop tube.

The .840 OD fits nicely.

I use it for the powder and the shot.

If I did the calculations right, I have an 84% pattern at 30 yards.

Velocity should be just under 1000 fps.

Next is less shot.

Why am I testing 7.5 shot, cause I have a bag and a half of them.

84 % mainly in a 26" circle.

 

[Britsmoothy]

UPDATE:

The plastic seals, well, not fond of them.

150F-2Nitro-135#7.5-Card at 30 yardsView attachment 75994

I found patter improvement with a heavy walled pvc drop tube.

The .840 OD fits nicely.

I use it for the powder and the shot.

If I did the calculations right, I have an 84% pattern at 30 yards.

Velocity should be just under 1000 fps.

Next is less shot.

Why am I testing 7.5 shot, cause I have a bag and a half of them.

84 % mainly in a 26" circle.

Lol. Shot, plucked and shredded all in one go. Now if you could just get it to cook it as well you've cracked it