Trigger hump vs. sear height modification for creep...

[ChrisATX]

So, by my understanding there would be two ways to get rid of trigger creep. The first would be stoning the second stage to be shorter. The second way would be to shorten the height of the sear face.

Which way is correct or more preferred?

[gnoahhh]

I'll chime in on the side of leaving the trigger geometry of the '03 Springfield alone. It works, is safe, and was well thought out 100+ years ago. The most I have ever done was to gently polish interfaces taking care not to mess with engagement/geometry. I submit that if one desires a crisp one-stage pull that one install an aftermarket trigger.

[ChrisATX]

It works, is safe, and was well thought out 100+ years ago.

I don't want a crisp one stage trigger. I want a good 1903 Springfield trigger.

And the need to swap multiple parts until a proper fit, feel (no creep), and operation was achieved was also recognized long ago:


WAR DEPARTMENT TECHNICAL MANUAL
TM 9-1270

ORDNANCE MAINTENANCE

U.S. Rifles, Cal. .30, M1903, M1903A1, M1903A3 and M1903A4
20 January 1944




28 Rifle As A Unit.

c. Trigger Pull

(1) Trigger pull for rifles in service must be greater than 3 pounds but should not exceed 6 pounds.

(4) “Creep” is any movement of the trigger that can be felt by the finger after the slack has been taken up and before enough pressure is applied to release the sear. Creep should be eliminated as much as possible, whenever found, as it prevents the proper squeeze of the trigger, which is essential to the proper firing of the rifle.



47 Receiver Group.

f. Trigger

(1) Burrs on bearing and heel of trigger should be removed with a sharpening stone, care being taken not to remove too much metal. A loose trigger pin, especially if it allows side play, should be replaced.

(2) When creep, as defined in paragraph 28 c (4), is found in a trigger, or when the trigger pull does not fall within the prescribed limits, examine the sear nose and sear notch for burrs or rough surfaces. All burrs should be removed by stoning and all surfaces which are not perfectly smooth should be polished by stoning. Sharp corners and edges should not be rounded off. Should this procedure fail to produce the desired degree of smoothness in the action or the desired correction in trigger weight, the heel of the trigger and the point at which it comes in contact with the receiver should be inspected and any roughness removed by stoning. Should the action still be faulty, it will be necessary to interchange the parts until a combination of cocking piece, sear and sear spring, trigger, and mainspring is found which will correct the difficulty. The probable importance of these various parts in the perfection of the trigger pull is in the order given. A number of parts should be tried in their various combinations until a satisfactory pull is obtained. The shapes of the coking piece sear notch and sear nose and the strength of the sear spring should always be such that the sear invariably rises to its full height and the trigger returns to its forward position on a cocked rifle when the trigger is released.

[Parashooter]

So, by my understanding there would be two ways to get rid of trigger creep. The first would be stoning the second stage to be shorter. The second way would be to shorten the height of the sear face.

Which way is correct or more preferred?
Depends on the objective. Reducing sear height shortens the overall length of trigger movement before release and also increases overtravel. Reducing the rear hump maintains original length of movement and overtravel but shifts the second stage nearer the release point. Maybe a simple graphic will help -

1=1st stage, 2=second stage, /=release, o=overtravel

1111111111222/o - original pull, long 2nd stage
11111111112/ooo - shortened sear
1111111111112/o - reduced rear hump

[ChrisATX]

Depends on the objective. Reducing sear height shortens the overall length of trigger movement before release and also increases overtravel. Reducing the rear hump maintains original length of movement and overtravel but shifts the second stage nearer the release point. Maybe a simple graphic will help -

1=1st stage, 2=second stage, /=release, o=overtravel

1111111111222/o - original pull, long 2nd stage
11111111112/ooo - shortened sear
1111111111112/o - reduced rear hump

Thanks Para. That's a really great explanation/visualization.

[Fred]

Wow, Thanks Parashooter!

[chuckindenver]

remove one coil from the rebound spring.. and give it a try