PDA

View Full Version : Cap size question


skinsman
September 26, 2010, 08:49 AM
This forum has been good to me for a new BP shooter, I shot for the first time, and it was a blast. I had one issue, after about 4 shots the last 2 caps seems to have wiggled loose. Is this normal? Or even though the caps seem to fit good maybe I have one size to large? Thanks.

GNLaFrance
September 26, 2010, 11:36 AM
You must be shooting a revolver, right? What is the make and model? Bought new or used?

The two common sizes of cap are #10 and #11. #10 caps are slightly smaller than #11 caps. If you're using #11, get some #10 and see if they fit better. They should fit snugly, that is, you should have to press a bit to get it all the way down on the cone of the nipple. WARNING: Do NOT push the cap onto the nipple with your finger or thumb. If the cap sparks from the pressure, the powder in the charge hole will make an ugly mess of your finger or thumb, not to mention send the ball out the side of the frame. Get a good quality capper or use something like a Popsicle stick.

If the caps split when you press them down, then the nipples are too big. Take them out, chuck them into a drill and slowly and carefully sand or file them down, checking frequently, until the caps fit snugly.

Besides being a pain in the butt, a cap falling off means the nipple is open and when the cap under the hammer fires, it could send a spark into the other nipple and set off the charge; this is called a "chain fire". It's usually not harmful to the gun, but it is scary and can be dangerous.

Hawg
September 26, 2010, 12:20 PM
If you're using #11 caps you can go to #10. If you're already using #10 you can try different brands. You can also pinch them together slightly before you put them on. Caps are impact sensitive, not pressure sensitive and wont go off from finger seating.

Rifleman1776
September 26, 2010, 03:18 PM
HH said it. Caps sizes do vary brand to brand.

mykeal
September 26, 2010, 03:30 PM
Sorry, Hawg, but if he's using Remington No. 11's, going to Remington No. 10's doesn't mean he'll be getting a smaller cap. It MAY (or may not) fit further down the cone, and thus appear to be a better fit, but it's not smaller.

Cap size numbers are utterly and totally meaningless. Once again, here's the data, measured from at least 20 samples of each brand and 'size':
http://i122.photobucket.com/albums/o254/mykealsm/Guns/CapSizes.jpg
Remington No. 10's are not the same size as CCI No. 10's, nor are the No. 11's the same size. Furthermore, Remington No. 11's are actually smaller than Remington No. 10's.

To make things even more interesting, there's absolutely no standardization in the size of the nipple cone that the cap fits on.

Finding the right size cap is essentially a crap shoot. You can dress the nipple cone to fit whatever brand and size of caps you happen to have on hand, but you don't get 3 decimal place precision for 4 cents in today's world, so good luck on the next batch being the same size.

GNLaFrance
September 26, 2010, 04:12 PM
Caps are impact sensitive, not pressure sensitive and wont go off from finger seating.

One of the pards on CAS City, "Cuts Crooked", set off a cap with thumb pressure. Here's the thread where Cuts tells his story and shows a pic of his injury.

http://www.cascity.com/forumhall/index.php/topic,1620.0.html

Hawg
September 26, 2010, 05:44 PM
Yeah but i'm betting there's more to it than he's telling. I've personally taken a wooden dowel and put all the pressure I could on one and couldn't make it go off.

GNLaFrance
September 27, 2010, 04:14 PM
Yeah but i'm betting there's more to it than he's telling. I've personally taken a wooden dowel and put all the pressure I could on one and couldn't make it go off.

I'm looking forward to you showing up on CAS City to present your opinion and argue your case.

Hawg
September 27, 2010, 06:52 PM
I'm looking forward to you showing up on CAS City to present your opinion and argue your case.

Why? Would just be my word against his.

mykeal
September 27, 2010, 08:47 PM
This has been 'discussed' on other forums (besides the vaunted CAS City); Mr. Cuts Crooked is the only person to ever make this claim that I've seen. Hawg is absolutely correct about the chemical nature of the material used in percussion caps - it's only impact sensitive, which means the force time history must have at least one sharp edge.

I'm not saying one should not use caution; that's prudent any time you're working with explosives, but I don't believe carefully applied thumb pressure has any likelihood of igniting a percussion cap. You can believe whatever you want.

And no, I'm not going to go to CAS City and start an argument - I don't really care one way or the other what the members of that forum believe on this subject.

GNLaFrance
September 27, 2010, 09:25 PM
In that case, I hope you two won't be upset if I continue to believe the story as told by Cuts Crooked. After all, he was there and we weren't.

denster
September 27, 2010, 09:26 PM
I'm inclined to agree with Hawg and Mykeal. I've used far more force with the haqmmer or a push stick than anyone could ever exert with a thumb and have never set off a cap.

shortwave
September 27, 2010, 09:31 PM
As Hawgs suggested, want your cap to fit a bit more snug, squeeze the opened end of cap a bit till you get your desired fit.

Also, I'm not a believer of normal thumb capping pressure igniting caps.
Just don't hammer the cap on :rolleyes:.

Roaddog
September 29, 2010, 07:22 AM
The cap should be # 10 for a revolver and should fit tight to avoid chain fire. That said, I know there is a difference in cap brands. I would stick to #10 and check the different ones before going to #11.

Hawg
September 29, 2010, 05:46 PM
The cap should be # 10 for a revolver and should fit tight to avoid chain fire.

Most do take 10's. I've had a few that took 11's and have one that takes 9's.

rosewood
September 29, 2010, 06:45 PM
I had trouble getting caps to fit my dragoon so i picked up some ampco nipples, now my #10 caps are a perfect fit. I assume those of you who squeeze your caps are not using a capper, is this so? Also someone had mentioned chucking a nipple in a drill and using a file on it, how do you prevent stripping the threads?

mykeal
September 29, 2010, 09:27 PM
You don't attach the chuck to the threads; you attach it to the larger diameter just above the threads. You run the drill slowly and don't use a lot of force on the file.

Noz
September 30, 2010, 09:12 AM
Rose wood, I chuck the threads into the drill with out using a chuck key, hand tight. I run the drill at low speed and lightly touch the file. I have not damaged the threads on any nipple yet.

Pinching caps is a useless operation. Get nipples that fit.

arcticap
September 30, 2010, 12:27 PM
Also someone had mentioned chucking a nipple in a drill and using a file on it, how do you prevent stripping the threads?

I didn't use a drill and just carefully dressed the nipple by hand. :)

andrewstorm
September 30, 2010, 02:43 PM
I had the same problem,thumb pressure,and the correct cap,for my r.o.a.s that is cci 11 mag,pushed hard with thumb,while pointed in a safe direction,once you find the correct cap,and everything is clean,you shouldnt have any more problems,:cool: