R4
4 in. Revolver (.38/.357/.41/.44) Fits most 4 inch medium- and large-frame revolvers including:

Astra All Double Action
Charter Arms Bulldog Tracker, Bulldog Target, Police Bulldog
Colt Diamondback, Three-Five-Seven, Trooper
Dan Wesson Model 8-2, 9-2, 14-2, 15-2, 22
EAA Windicator
H&R All Double Action including: Models 504, 525, 532, 586, 622, 642, 686, 732, 733, 826, 829, 830, 832, 833, 900, 901, 904, 905, 922, 925, 929, 930, 980, 999
High Standard All models: Sentinel Series, Kit Gun
Iver Johnson Model 55, 57, 67, Bulldog, Rookie, Sidewinder
Llama All Large Frame including: Comanche, Marshall
New England All .22 LR and .32 H&R Mag.
RG All Double Action
Rossi All Double Action
Ruger GP-100, Security Six, Service Six, Speed Six
Smith & Wesson All J-Frames including: Model 30, 31, 34, 43, 51, 63, 651
All K- and L-Frames including: Model 10, 12, 13, 17, 18, 15, 19, 33, 48, 53, 64, 65, 66, 67, 386, 547, 581, 586, 681, 686
All N-Frames including: Model 20, 21, 24, 25, 27, 28, 29, 57, 58, 520, 625, 629, 657
Taurus Models 65, 66, 80, 82, 83, 84, 94, 431, 441, 607, 608, 669, 689, 741, 941