22 OF OF OF 22 22 - Jeffersonian

PISTOLSMITHINGAlex HamiltonTHE INSIDE SCOOPON PISTOLSMITHINGTECHNIQUESDrop-in PartsMyth Or Magic?Right up front I have to tell you, as a custompistolsmith, I have no love for drop-in parts foreither pistols or revolvers, with the exceptionof a spring kit or two. However, even spring kitscan get the novice in dangerous trouble if he doesnot understand the mechanics and geometry of theinternal works. One excellent attribute of drop-insis they allow you to save a little money and helpyou sorta personalize your pistol with some minorgunsmithing. But always be sure there is a real lifegunsmith close by who can get you out of trouble.Just guessing here, but I would speculate the dropin1911 pistol grip safety is one of the top sellingdrop-in parts for any handgun. I am a huge fan of aproperly installed, graceful, functional Brown highrise grip safety. There are others, but I find them bigand bulky. Drop-in grip safeties like the one shownwill cut down on hammer bite from a long spurhammer, but as many of you have found out they arenot exactly drop-ins.The grip safety, when at rest, has an arm blockingthe rear of the 1911 trigger bow keeping it from contactingand disconnecting the sear from the hammer.When the safety is squeezed, the trigger block armmoves up and away from the trigger bow allowing thetrigger to push the sear off the hammer. If the triggerblock arm is too long it will have to be precisely fittedfor safety, but if it’s too short the safety will not workand will have to be welded and re-cut for proper fit.To test proper operation of your grip safety, pull thetrigger without pushing the grip safety in and watchthe hammer. If the hammer moves even the slightestthe grip safety is not doing its job and will have to beproperly fitted by a competent gunsmith. The “moneysaving” drop-in will end up burning up all the moneyyou believe you initially saved.A definite “danger zone” when it comes to drop-in bits.If you “install” a drop-in safety, conduct a check tomake sure it’s working. Read Alex’s article tofind out whatthat test is.A neatlyfitted gripsafety canbe a thingof beautyand highlyfunctional.MatchOr Not?Drop-in match barrels for the 1911 are a very popular item,but you must understand what a true match barrel isbefore spending those Ben Franklins. A true match barrelinternally is nothing more than a quality standard “run ofthe mill” barrel with internal dimensions cut to SAAMI specs.The bore is not tighter nor is the chamber any different than aregular barrel. It’s the outside dimensions that need to be fit,in order to create match grade performance. And it needs tobe perfectly fitted to eliminate all barrel movement when yourpistol is in battery.A drop-in match barrel will have only slightly oversizeexternal dimensions and will make the barrel lock up only“somewhat” tighter in battery. A drop-in must be looseenough to drop into all or most of the 1911s out there, so itwill never be able to give you the true match-grade accuracyshooters demand. The same facts apply to drop-in “match”bushings. If the bushing is so loose you can turn it with yourfingers, the loose tolerance translates to vertical stringing andmisses on the target.A drop-in thumb safety is where you will really get intotrouble, so be very careful when installing this importantpart. After installation push the safety into the safe positionand pull the trigger. If you see the hammer move or after thesafety is pushed off the trigger feels lighteryou have a serious safety problem andwill have to take your gat to a competentgunsmith for fixing.Use Your BrainDrop-in trigger jobs are sold by anumber of companies and normallyinclude a lighter sear spring, disconnector, hammer andsear. You will pay around $160 for the parts and will morethan likely end up taking your pistol to a quality gunsmith toget the creep out and sharpen the pull. To fine-tune the pullwill cost another $85 to $150, but the gunsmiths will reallyappreciate working with those new, high quality parts. If youare simply looking for a ten- or 20-percent better trigger thedrop-in kits could be your cookie, but always be careful inthis area if you flunked geometry.There are many drop-in parts you can install without creatinga safety problem or extra expense. Items such as some modelsof laser sights, scope mounts, rings and scopes, magazine wells,etc. are usually a safe bet. But even the mag wells need to beblended and fitted to the edges of the magazine opening so justbe careful how you spend your money on anything with theprefix “drop-in.” Be careful out there, don’t hurt yourselfand know when the job is beyond your skill level.*30 WWW.AMERICANHANDGUNNER.COM • MARCH/APRIL 2010