The little 3-holed disk surrounding the firing pin for the left barrel of my Searcy .500 NE has become loosened, and I'd like to tighten it properly. Is this the tool I need?

http://www.midwayusa.com/produ...itori-b-ss-b-99-b-78

Also, if I back it out all the way, are there any springs to watch out for? (don't want to lose anything)

That ad doesn't say what spacing the pins are. Either call and find out (after you measure yours) or build one/

I do believe that it is. Same one I have.

It looks like it would work. I have one I use for my Searcy doubles that I got from Brownell's. It is called a "Firing Pin Bushing Tool" and is listed as part "590-017-003". Brownell's also sells Replacement pins for the bushing tool. They come in a 3 pack and are part "590-017-203". I have used this tool on two of my Searcy doubles, and it works. I always carry this tool, replacement pins, and extra firing pins to Africa with me. I have never had to use it, but it is there "just in case". If you back it all the way our, you will find the firing pin in a cone shaped spring. It is not going to go flying out of the striker hole, so no worries about that. The spring just keeps the firing pin correctly aligned in the recess.
I just checked Brownell's using the part number for the search, and the tool shows up as being on back order. It is also a Menck tool, so my guess is that it is the same one Midway has in stock.

Does that tool work on your new .375 from Butch, too, Dave?

Regards, Tim

It works on my .470 and my 450/400, so I am assuming it will also work on the .375 Flanged as well (whenever I get it, that is!).