RS vs P and general questions on pressure

[John McCorkle]

I've seen several guys state they substitute P powder for RS in muzzy stuffers such as hawken ECT.

I know it causes higher pressure but not sure how to know how to look for signs of pressure in a muzzleloader. Beyond that there are so many gun from so many manufacturers now that have not had a single standard "chamber pressure" to base load recommendation off of, that making these recommendations now would be super specific to the make of gun. How do you know what is safe and what is pushing it?

What substitution can be made with P vs RS and how do you know if it's too much?



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[mooman76]

P will likely be only slightly higher. I wouldn't worry about it too much. It isn't like smokeless powder.

[longcruise]

P will likely be only slightly higher. I wouldn't worry about it too much. It isn't like smokeless powder.

Ditto. It's comparable to 2f and 3f BP. you can use recommended charges for any rifle interchangeably between the two.

[arcticap]

If substituting P for 2F or RS, an equivalent load may be 10% less to obtain similar velocity.
One indication of pressure might be if the hammer blew back enough to reset it.
A hammer reset can simply be due to the nipple having an extra large flash hole, or a weak mainspring, and not necessarily an indication of anything dangerous at all.
But no one wants to put unnecessary wear and tear on moving parts.

It's not easy to rupture a barrel even if a person tried to overload it with powder.
It really requires a barrel obstruction of some sort since a powder charge of 3-4-5 times the max. load may not even bulge a barrel.
The powder gets blown out of the barrel before it can all ignite.
The weakest link in the system is what would fail, usually nipple threads, the mainspring, a lock part or the stock will develop a crack.
The important things are to protect the nipple threads by cleaning and greasing them, and to not over-tighten a nipple to the point of stripping the threads, and to prevent corrosion which can also weaken threads.

Some individual barrels can have problems, but in general I'm referring to modern octagon or heavier round barrels that are built in industrialized nations.

[rodwha]

^

Nicely put.