American Handgunner May/June 1978

The OMCA Preference for an Outside Hammer Sparkedthis Interesting Gunsmithing JobVER the past two years, the OMC0 Back-up has gained wide acceptanceas a second or off-duty pistol for the policeman,and as a first-line gun for otherswho can legally carry a concealed firearm.Produced by Harry Sanford of Auto-Magfame, this little stainless steel .380 is madeby Ordnance Manufacturing Corporation,a subsidiary of TDE Marketing Corporation(11658 McBean Drive, El Monte, CA91732). Its performance and featureshave been well-covered, in GUNS and inother magazines. When I first examinedone of these nistols. I was imnressed bvthe clean design, and such good featuresas the separate breech block, recessedsafety lever and trigger bar, and other finepoints.A few months ago a friend who owns anOMC Back-up commented that while hewas well-satisfied with the gun, he wishedWOODit had an external hammer. The manualsafety of the OMC blocks the sear, and italso has a grip-type safety, so carrying it"cocked-and-locked" is not all that dangerous.My friend, however, apparentlyhad been too long under my influence,and carrying with hammer cocked over alive round made him nervous. So, with theOMC, he just carried it with a full magazineand emntv , , chamber. If a serious socia1situation arose, he would have to cyclethe slide before the first shot. Since theBack-Up has a pivoting internal hammer,I suggested that it might be possible toconvert it to an external hammer. If so,the hammer could be gently let down on achambered round, and would need only tobe thumb-cocked for the first shot. Myfriend handed me the OMC and said "Tryit!"Making an entire new hammer mighthave been the best wav to go. but Ithought it could be done by just 'makingan extension piece, using the originalhammer. So, I drilled and tapped the topof the hammer to take a headless 6-48screw, and mated this to a small block ofstainless steel with a vertical measurementthat brought its top edge level with theouter top of the slide.Next, J cut a slot the width of the hammerand extension in the top of the slide,down the back, and continued the cut intothe back of the frame. The separatebreech block has several adequate bearingsurfaces for strength, but just to be extra-safeI left a small top bridge at the rearof the breech block, and cut the extensionpiece to clear this. The slide cut neatly removedthe rear sight notch, but the deeprounded groove ahead of the sight can stillserve as a "combat sight," and anyway,who's going to use this pistol for serioustarget work?The flat top of the hammer extensionwas deeply cross-grooved to match the topof the breech block, and the edges wereleft sharp to give a good thumb-grip. The' 1