[Hellgate]

It is easy to shim nipples. Take soft fine steel or bronze wire and coil it around a nail or screw shank about 10 times to make a spiral the diameter of the threaded shank on the nipples. Then with wire cutters snip them off and you end up with a pile of what look like lock washers. I then I take a small hammer and flatten them on the vise pounding surface or an anvil to the desired thickness. They resemble small open ended washers. Slip one onto the shank of the low nipple and screw it in. I use anti-seize lube or heavy lithium grease on the threads so I can get the nipples back out. If the nipple is too high, pound the shim flatter or find some finer wire. If it still isn't tall enough, use two shims or get a thicker piece of wire to start over with. I've done this on several guns and have had no problems with it. If you have too high of a nipple then the hammer face gets battered and may not fire the other nipples or it will get burrs on it that may lift spent caps off the nipples and drop them into the action.