Lyman Great Plains Rifle .54 cal. percussion

[Jerry V Lape]

I acquired my first percussion rifle for my son to use elk hunting.  I am very well qualified with flintlocks but don't know how to determine cap size based on the nipple.    Instruction manual on Lyman website lacks information on which caps as well.  How about some guidance please?

[flinchrocket]

Probably #11, most all the factory rifles I have seen use #11

[Birddog6]

It takes a #11 cap.  I can't remember the brand I used to like best, but I think it was a CCI or
a German cap. Think I have couple thou. in the ammo safe, will look later. Reason I liked them
is over the years I found a variance in #11 cap diameter. This cap I was using was made of copper
or copper alloy & I could put it between thumb & forefinger & lightly squeeze the skirt, and it fit
tighter for hunting. Some of the brass caps worked well, but if you tip the gun sideways or turn
it over, the cap would just fall off. Found this out one time as I was cocking it for a shot at a deer,
dang cap is gone 

[elkhart]

I use a #11 on mine. The half-cock throw on the LGPR is very short, does not leave enough room to fit a brass capper between the hammer and nipple. A leather capper works fine.  And I second the recommendation to pinch the cap.

Great gun, hope he gets his elk!

[Darkhorse]

I bought a Hot Shot nipple and just used what was recommended. American nipples like the TC used #11 caps. The foreign caps all took a specific size. It's been a long time since I had a percussion and my memory is fuzzy.

[Daryl]

Most nipples this side of the pond "take" size 11 nipples. Seems to me, most of Track's replacement nipples also 'take" size 11 caps.
I prefer Remington caps as that is what I have in #11's, but RWS and CCI work just as well.

[Chocktaw Brave]

Like others, I tend to squeeze the open end of the #11’s down slightly for a more snug fit. I have had them fall off the nipple as well.

[hanshi]

I have nearly 1,000 CCI #11 caps and some Remington #11.  But I have also used German caps and may have a few of the loose caps left.  Other than that there are a couple tins of #10.