Patch Report

[roundball]

As a piece of general info, when I was experimenting with .62cal PRB loads yesterday, I was using some OxYoke prelubed .020" plain cotton patches (not pillow ticking) and was suprised at how strong they were...using as much as 90grns Goex 2F, the bottoms got lightly browned from the fire but that was all...excellent patches.

 

[musketman]

Good to know in case pillow ticking becomes as hard to get a locally sold black powder...

What about the weave of the all cotton patch, did it separate on the fired parches?

How bad did the ends fray?

 

[roundball]

Good to know in case pillow ticking becomes as hard to get a locally sold black powder...
What about the weave of the all cotton patch, did it separate on the fired parches?
How bad did the ends fray?

Nothing unusual...if anything, a little less fraying than normal...could easily be reused, still had plenty of lube in them, etc.
As a piece of general info, when I was experimenting with .62cal PRB loads yesterday, I was using some OxYoke prelubed .020" plain cotton patches (not pillow ticking) and was suprised at how strong they were...using as much as 90grns Goex 2F, the bottoms got lightly browned from the fire but that was all...excellent patches.

 

[guncobbler]

Neat picture of the patches. If you look closely at the stain pattern the all look a little square. I'm sure this is due to the fabric weave but maybe its a testiment to Roundball being a square shooter

Kind of interesting the pattern tho. There is the dark center where the patch is exposed to the flame. Then a lighter ring where I suppose the patch is caught between the ball and barrel. Then there is another dark ring. Why is the outer ring dark? GC

 

[CoyoteJoe]

If you pick up patches which were cut at the rifle's muzzle you will find they are not round but square with rounded corners, just like the stain on those precuts. It's just a fact of geometry that you cannot form a flat circle into a round cup shape even with some stretching of the fabric.
The inner stain is scorching from the heat and the outer ring is powder fouling from contact with the bore.

 

[paulvallandigham]

Two things contribute to the outer ring being black: Friction with the barrel, and some gas blowing by as the ball is expanding on firing. The gas will tend to burn the fabric a little, before the ball expands enough to cut off the blowby. Which contributes more is your choice.

 

[roundball]

Kind of interesting the pattern tho. There is the dark center where the patch is exposed to the flame. Then a lighter ring where I suppose the patch is caught between the ball and barrel. Then there is another dark ring. Why is the outer ring dark? GC

I wondered at that also...wondered if it occurs when the patched ball goes through the .030" larger expansion chamber of the jug choke...a little flame gets to it then it's out the muzzle

 

[musketman]

Then there is another dark ring. Why is the outer ring dark? GC

In my opinion, that is the exact point where the patch grips the ball and the rifling, if you were to place an unfired roundball in the ring, it would be exactly where the patch pulls tight around the circumference of the ball...

This is the friction point, so it's going to pick up extra heat, barrel fowlings and even lead...

 

[roundball]

Then there is another dark ring. Why is the outer ring dark? GC

In my opinion, that is the exact point where the patch grips the ball and the rifling, if you were to place an unfired roundball in the ring, it would be exactly where the patch pulls tight around the circumference of the ball...

This is the friction point, so it's going to pick up extra heat, barrel fowlings and even lead...

You're right...I looked at it backwards...the whole time he was saying 'dark ring' I was thinking/looking at the light gray ring just outside the dark ring... :redface: