I just came across a great deal on an old Ruger Security Six this afternoon. The gun's finish was worn as it had been carried a great deal but it was in excellent mechanical condition and shoots well. The only problem is that the factory wood grips are so tiny that the gun is really uncomfortable to shoot. Is there an aftermarket grip (preferably rubber) that will fit this gun that's bigger? I know there are tons of choices for S&W revolvers but I have little experience with Ruger revolvers. Any advice?

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or ..both under $10

The Hogue rubber-fingergroove grip went on my 'snubbie' Security-Six and feels/functions very well.

Ruger first introduced the Security Six with a slender grip and grip frame, which was unpopular.  They then modified the frame a bit and added slightly different grips.

If your Security Six serial number starts with a 150, it’s one of the earlier ones.  You’re going to find it very difficult to find replacements.  Your best bet, other than custom made grips, might be just to add a Tyler Grip Adapter.

If your Security Six serial number starts with a 151 or higher, grips should be pretty easy to find.