Nitro Conversion Inconsistency.

[enfield2band]

First of all, some links to a few pictures of my Ruger Old Army nitro conversion revolver which allows me to load the gun with the cylinder in place rather than having to remove it to load using a small press which is normally the case on UK conversions or purpose made muzzle loading nitro revolvers.

https://i.imgur.com/33xXWRNl.jpg

https://i.imgur.com/p5SEooyl.jpg

https://i.imgur.com/8L92G2el.jpg

https://i.imgur.com/p5SEooyl.jpg



I tried increasing the load in small increments from 5 to 6 grns of Herco at the range today. The heavier loads grouped higher, but still suffered from the presence of some unburnt powder with the occasional light discharge. A definite improvement this time though as the 5 grn load grouped into 4" at 25yds unsupported with the fewest light discharges. I will now try a faster powder and some .460 ball to see if things can be further improved.

Regards
Brian

I think I know what your problem is.

You do not compress blackpowder but you do need to compress smokeless to achieve good ignition. Blackpowder is consumed almost immediately on ignition, which is why it is classed as an explosive and it will explode when unconfined. Smokeless powder will not, it only burns with a very fierce flame. It needs to be held back for a fraction of a second because it generates pressure very quickly but needs time to do this.

An example of this is from when I used to reload shotgun cartridges and may help you understand it better.
For a shotgun cartridge to function correctly so it gives a clean powder burn the crimp, (or rolled turnover), has to hold the powder back long enough for it to start generating pressure. Sometimes if a paper cartridge case was used too many times the paper at the mouth would become soft and the crimp would not be tight.
What happens is that on ignition the shot and wads start to move before the pressure has built up and the powder charge funnels up the barrel with just the outside portion burning. When it gets out of the barrel into the atmosphere it burns rapidly and goes "bloop". Hence the term a "Blooper" (You may not of heard of this now paper cartridges are rare). The shot usually falls to the ground well short of its intended target and has no energy. Because a clean burn has not been achieved there is usually a lot of residue left in the barrel.

Centrefire ammunition works differently so the powder does not need to be compressed. The resistance of the bullet in the case neck and the resistance of the bullet passing through the rifling have the same effect of holding back the charge.

I would look at using a wad under the ball so the powder needs to be compressed when the ball/bullet is pressed into the chamber. The tighter fitting bullet will obviously help as well.
I would also try different primers and check the nipples are clear with no unburnt residue or burrs that can impede the jet of flame into the powder charge.