magnum caps with BP, good/bad/no matter?

[Enfield58]

#11 standard cap - 6.53 cc of gas at 3,024 degrees F when fired.
#11 magnum cap - 7.59 cc of gas at 3,717 degrees F when fired. < That's why my shotgun goes bang more than it did with regular percussion caps!
U.S. #2 musket cap - 14.36 cc of gas at 3,717 degrees F when fired.
#209 shotgun primer - 21.98 cc of gas at 3,024 degrees F when fired.
#200 rifle primer - 11.68 cc of gas at 3,024 degrees F when fired.

Magnum caps vs. standard [Archive] - The Firing Line Forums

 

[Frontier's]

never noticed a difference between any cap brand, magnum or not.

 

[Howard Pippin]

I have a friend who bought a CVA percussion 50 about a year ago, and when we first set out to shoot it, he had his own supply of caps, powder, and accessories. He would put one of his caps on and he would have to shoot It twice to get them to go. I had never ran into this before, and I thought perhaps it was just a weak hammer spring. Then I got to wondering if it was just the caps, so I dug out mine, which turned out to be magnums. Upon inspection they appeared to be slightly larger in diameter, so I said let's try it. Well, don't you know they worked every time, apparently the problem was the regular size didn't seat far enough on, where the larger primer did. Mine happened to be Remington brand, I don't know what brand his were. The nipple that was on his rifle was an odd thread to what I had in stock so I couldn't change it to see if it made a difference. When he want to Town next time he just bought some Magnum caps.We didn't notice any difference in the noise or position of the hits on targets between the two different caps. I didn't check them with my chronograph to see if there was a difference in speed. He was shooting black at about 50 grains.
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[Boomerang]

He would put one of his caps on and he would have to shoot It twice to get them to go.

Sounds like maybe he was using #10 caps.

 

[Howard Pippin]

Sounds like maybe he was using #10 caps.

No, I checked his container and it said number 11 but it didn't say Magnum as mine did. When you placed one of each side-by-side With one of mine, you could see a definite, though slight difference in size. I think his might've worked if he would've shoved them on firmly with his thumb or something which I don't think he was doing. I noticed the same number 11 Magnum caps are loose on my new traditions 50, and I think I will experiment a little and see if he will loan me some of his regular 11's.
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[GREENSWLDE]

I haven't used CCI caps for years after an ignition problem with a Live pigeon gun. Found some Fiocci caps marked for "Muzzle Loading Guns"that fitted old F4 nipples Not foiled and were corrosive But "BIY" did they work. Don't think I've had a cap misfire since. I bought a load and still have a good stock. We also had Plastic caps for Kids toy revolvers that came as a 6 shot ring. They would clear a cap miss fire with no problem. They were beyond any Magnum but soon disappeared from the market as "Nannie" thought they were too Dangerous for children!! OLD DOG.