Sear-ingly Simple

pistol-180

Tooling Up For Better Actions

By Ted Yost

Achieving a better 1911 trigger has long been one of the basic modifications paying huge dividends in the shooter’s ability to perform better with his pistol. The main problem is trigger work on a 1911 can be complicated, and getting it wrong can result in real problems, ranging from annoying to disastrous. Properly done, a good trigger gives the desired pull weight, is safe and reliable and allows the hammer to fall consistently. This consistency is accomplished by establishing a proper engagement, or interaction of the hammer and sear each time the mechanism is reset. It involves a working knowledge of the effects of geometry on the parts’ relationships in addition to the simpler aspects of just stoning the parts square, and with the proper mating of surfaces and relief angles.

Whether the sear nose/hammer hook interface is a positive (captive) or negative (release) angle is also of critical importance. Hammer hook height becomes a serious concern — too much engagement, and you can feel the sear creep up the face of the hammer hook. Too little engagement, and you risk hammer follow. Once you add in the prospect of getting just the right balance of sear spring and trigger reset pressure, it’s easy to see why 1911 trigger work can be a frustrating exercise, even for the accomplished hobbyist and dedicated shooter.

An interesting new concept in the quest for a better 1911 trigger comes from Chuck Warner of Warner Precision in Rio Rancho, New Mexico. Chuck’s a real old school gunsmith with a gift for problem solving. In response to a need for a process the hobbyist could use to achieve a better, safer trigger with a minimum of tool expenditures, he developed his “True Radius” sear system. Like so many of the industry’s problem solvers, Chuck’s approach is to simplify the most difficult aspect of the job — prepping the sear.

pistol-1

The True Radius sear fixture in use. Note the sear inside of the jig (red arrow).
The stone shapes the face to match the jig.

pistol-2

Harrison’s True Radius action component set. Using high quality action parts
helps to assure good results.

Staying Centered

Chuck’s initial research showed of approximately 80 different hammers he tested, virtually all of them had hammer hooks cut square to the pin hole, and were of sufficient height and most importantly, were “neutral” — offering neither a closed or open engagement angle. With this as a starting point, work began on finding the right configuration for the sear giving the best balance of performance, safety and simplicity. Chuck found sear length is very important to the process, and the original print specification of .4045″ was the place to start.

The sear was stoned with a radius whose center was the sear pin hole. This ensures the point of contact with the hammer hook swings on a perfect radius, giving an absolutely neutral engagement. What this means for us is as the sear moves, there is no perceptible movement of the hammer. Trigger pulls are extremely consistent shot to shot, and safety is enhanced due to the ability to leave the hammer hooks a little taller. I cut a sear and tried it in a brand new Series 70 Colt. No modification to the hammer, all other parts were factory spec, and no modifications to the springs. The Colt sear, unfortunately was not long enough to cut, so I used an aftermarket sear. The result was a 1/2 pound reduction in trigger pull weight, with a very smooth, very clean break. A little further work I’m sure would have yielded even better results.

pistol-3

Prepped True Radius sear

Nothing Is Drop-In

No process is worth much if it can’t be repeated accurately time after time. Warner invented a multi-purpose fixture allowing the user to precisely stone the radius on the sear nose. It’s incredibly simple, to the point of being fool-proof. It’s very well made, from hardened steel, and includes well written instructions. The fixture has different settings for differing sear lengths, also serving as a “NoGo” gauge. If your sear cannot be stoned at the shortest setting, well then it’s just too short to work! You don’t have to worry about setting the sear up incorrectly because you can’t. Since the radius is cut with the sear pin as its axis, you simply can’t get it wrong.

In addition to the stoning fixture, complete sets of fire control components and individual sears are available exclusively from Harrison Custom.

One important thing to remember — any time you make a change in the fire control parts of a 1911, you must do a complete check of all safeties, as well as a careful function test of the pistol. Load one round and fire a few times before loading two or more. Chances are very good you will need to either re-fit or replace your thumb safety to fit a new sear. If you’re not familiar with this operation, seek the help of a qualified gunsmith. Don’t forget, nothing really just “drops-in” on a 1911. Everything affects something else!

My take on the True Radius Sear? I don’t think it will replace the two-angle system in my world as it’s what I’ve grown up with and become proficient at. I do think it has great value to the hobbyist who is looking for a safe, reliable trigger offering improved performance with less expenditure for tools — and a better likelihood of success.

For more info: www.americanhandgunner.com/index; Harrison Custom, Ph: (770) 419-3476, john@nullharrisoncustom.com.

Read More Pistolsmithing Articles

ahjf17_400

Purchase A Password To Read The Jan/Feb 2017 Digital Edition
(Includes FREE Download of PDF version of your desktop or mobile device!)

Purchase A Printed Copy Of The Jan/Feb 2017 Issue

Purchase A PDF Download Of The Jan/Feb 2017 Issue Now!

~