Everyone pretty much knows what a crisp break is. The roll trigger is very popular amoung bullseye shooters and other precision shooters. The best way i can describe it is a very consistent / smooth creep with consistant pressure. No building to a let off..
With practice you know when it is going to release. There are long, medium and short roll triggers. Personally i shoot short roll triggers in my bullseye pistols. Fairly easy to do with the TR sear jig.

 

That is the best description I've read yet. Well done.

 

Thanks jglenn. The explanation sounds pretty clear. I think I need to experience it to really understand it. Like you said, everyone knows what a crisp break is. All my 1911s are very crisp. We have several bullseye shooters at my club. I'll have to see if someone will let me dry fire their bullseye 1911s.

BTW, why do bullseye shooters like and not other shooters?

 

BTW, why do bullseye shooters like and not other shooters?

BE is about accuracy, more than speed. It is hard to anticipate the exact moment the sear will break with a rolling trigger, than with a crisp trigger. Anticipation is the enemy of the "surprise break". Hence a rolling trigger makes it possible to smoothly squeeze the trigger as a "process", rather than break it as distinct event. Bottom line, a rolling trigger reduces the tendency to flinch and to pull the slights off the target with increasing trigger pressure. It encourages a good follow through by making it part of the process.

A short rolling trigger can be a good thing; even though it feels a bit odd. Too long a roll and fatigue will set in, long before you drop the hammer. Then you could be tempted to speed things up by mashing the trigger.

 

The roll trigger is based on the "true radius" sear, which guarantees a neutral sear/ hammer engagement. The sear nose is cut at a radius with the radius center at the sear pivot hole. This maintains a constant distance between the sear pivot point, and the point of contact between the sear nose and the hammer hooks. As the sear moves out of engagement with the hammer, the hammer does not move at all.

There is a small amount of movement of the sear (and trigger) as it disengages from the hammer. This is the "creep" stage of the trigger pull. With conventional flat faced sear noses, the engagement will typically be either positive or very slightly negative.

If the engagement is positive, the movement of the sear will force the hammer backward slightly, producing a heavy trigger with noticeable creep. The trigger force needs to increase gradually up until it breaks. This is the safest trigger though.

If the engagement is slightly negative, the movement of the sear will allow the hammer to move forward slightly during disengagement. This accelerates the transition through the creep stage and reaches the break point with no additional trigger force. The trigger break feels crisp. This is also potentially dangerous if the engagement is too negative.

The neutral engagement of the true radius sear provides some safety in that the hammer is not trying to force the sear out of engagement as it would be with negative engagement. It also eliminates the "rough" feel of positive engagement creep.

Note though, that the creep stage involved is only on the order of about .020" of sear and trigger movement. The differences can be subtle.

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If you all think that the True Radius sear was developed for roll triggers you are off base. A roll trigger can be had with a conventionally prepped sear or with a True Radius sear. It has more to do with the amount of engagement of the hammer/width of the sear face/break away angle and the condition of the mating surfaces.

 

It's true that there are other ways of achieving a roll trigger, but it requires that the sear nose faces and angles be precisely cut to provide as neutral engagement as possible. The engagement will never be perfectly neutral with flat sear nose faces, but can approximate neutral engagement enough to achieve a roll trigger.

The true radius sear guarantees the neutral engagement necessary for a roll trigger.

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As noted the TR jig simply makes it easier to do.. roll triggers have been around for quite a while. Way before the TR jig..

 

Why do BE shooters prefer them? Shooting at 50yds with one hand is a challenge for most anyone..trigger control is paramount. The roll trigger simply allows you to start the trigger pull before you ever get on target and continue in a controlled manner as you settle into your minimum arch of movement( how still you can hold). Waiting to pull the trigger till you have settled on the target is a great way to jerk the trigger. BTDT.

With all that said the all time record BE match score is 2680 out of 2700. Shot with iron sights and most likely a hard trigger ��

 

I've shot high power, small bore and a few other disciplines over the years..BE is by far the best way to learn trigger control.

 

Found the True Radius fixture website. It includes a drawing of the geometry. Now it makes sense.

One of the panelists on the modcast commented that he has had a life long problem with flinch, and that the rolling trigger helped him.

 

Link to the website??? I'd like to see the drawing of the geometry.

 

Let's see if this description helps also. A roll trigger allows you, the shooter to feel the sear travel or move for the entire length of the hammer hooks. That is the "feel" of the roll.

 

KC:

Very nice looking Trigger Kits!

http://kcskustomcreations.com/roll-trigger-kit/

As someone that completed Chuck's Advanced 1911 Fire Control Workshop, it's great seeing this in your information:

We now have our own dedicated manufacturer for our hammer. And we gave it a very unique shape spur just to add a bit more to the fun of making your own parts. The “Battleaxe” was born at Camp Perry 2013 and now a full set of parts complete the process. I approached Chuck Warner about his true radius (TR) sear. Through conversation with Chuck he agreed that his sear would be the perfect compliment to the roll trigger kit, and that is the sear used today.

:rock:

 

This one is hard to explain. I'll take a stab at it, but can't find a good graphic that helps.

A rolling break longer hammer hooks and very little secondary/relief cut with a blended transition between the primary sear angle and secondary/relief cut.
You can vary the rolling break short to long by altering the length of the hammer hooks and engagement is pretty much neutral (no discernible hammer movement).


A crisp break has a more defined primary to secondary sear angle with the sharp transition between broken over slightly (as opposed to blended)
and a slight positive engagement (hammer moves back a bit prior to release).

Many trigger jobs use a blend of the above factors. True Radius is a nice working blend with good longevity.

 

A crisp break has a more defined primary to secondary sear angle with the sharp transition between broken over slightly (as opposed to blended)
and a slight positive engagement (hammer moves back a bit prior to release.

I disagree with the statement as the “slight positive engagement” is not necessarily true. It can be possible with an improperly angled primary sear angle. The blueprint spec sear primary face works out to be a negative angle where the hammer release point at the sear primary/secondary transition is microscopically lower than the full cock location. This sear treatment can offer a crisp break when dimensions are carefully crafted. And in truth it is a negative sear hammer fit.
Joe

 

My 1911s and BHPs have crisp trigger breaks. My Glock 26 has a short rolling break. I shoot the Glock more accurately and prefer the short, rolling break.

 

BTW folks, K.C. offers a roll trigger kit that is a bit unique. Used by quite a few BE shooters....

 

I assumed from the title that someone had developed a rolling contact trigger for a 1911 similar to the Trigger-Tech trigger I have in my AR, it has a very small carbide roller between the hammer hook and the sear and feels great. I was trying to figure out how they could get all that into a 1911.

 

Word is TT is working on a 1911 version.

 

Bet it was a struggle back then BBBBill . You have been poking around 1911 innards a while!
Joe

 

Young and stupid. Had no idea what I was doing.