Rolling Triggers

[ong45]

Is a rolling trigger when there is very little secondary angle cut into the sear?

How long does this setup last compared to the standard crisp trigger?

James

[ErikW]

Back To Top because I found this in a search and nobody has replied to it.

I can't answer myself, other than to suggest talking to Michael Voigt, the rolling trigger guru.

[PaulW]

A rolling trigger is where the sear angle is cut in such a way that the sear "rolls" off the hammer hooks. It actually cocks the hammer ever so slightly as the sear is disengaging from the hammer.

This is different from a "normal" trigger job as ideally you would want the hammer hooks and sear to be square to each other and have a nice clean break as the sear realeases.

Actually I bet there is more rolling triggers out there than perfectly square ones.

[dajarrel]

Do these "rolling" triggers involve a roller or bearing or are you talking about rounded surfaces that actually "slide" past on the way to hammer release?

dj

[ErikW]

No bearings. It might be that it got its name due to the feeling of rolling, not the actual geometry of the hammer-sear relationship.

[mcoliver]

How does the rolling feeling differentiated with trigger creep?

I'd like to think my trigger is setup to roll and not creep.

[Skywalker]

I'd like to think my trigger is setup to roll and not creep. 

If your trigger is creeping, that's a procedural penalty...

[Flexmoney]

I think our host has talked about the voo-doo needed to set up a trigger to roll...without adding in extra creep and such.

Sounds like FM...and not too many smiths that would know how to do it right (or want to).

[bountyhunter]

How does the rolling feeling differentiated with trigger creep?

I'd like to think my trigger is setup to roll and not creep.

The term "creep" is usually reserved for triggers where the sear "jerks" in steps across the hammer hook as you pull the trigger, as opposed to sliding smoothly across it.

The trigger in my CZ deflects the hammer to the rear significantly as the sear moves, but the pull is still glass smooth. That kind of trigger is very easy to shoot accurately, the jerky ones are not.

[owen]

The Olympic guys play with rolling trigers quite a bit. What they are looking for is basically a long(ish) smooth pull. Think of a DA revolver, but only 2 pounds. The idea is that you get to steer the gun with the trigger a bit more...it gives your brain time to fix your alignment screwups.

[Dan Burwell]

I remember our host talking about it here before. I remember him saying that when done properly the hammer will not cock, the radius has to be cut on the same arc as the sear moving away from the hammer hooks. I thought he also said it will last much longer than a traditional setup and there is a little creep but it is hard to feel when the trigger is under 1.5#.

Hopefully our host will respond to this thread and tell us his dark secrets on the rolling trigger.

[Duane Thomas]

I talked to Bruce Gray on this matter a few days ago. According to Bruce, one advantage to the rolling trigger is that you can have far more sear/hooks engagement, thus a very long lasting trigger pull BUT still have a light pull weight, compared to that "glass rod" light trigger break that's commonly achieved by lessening sear/hooks engagement therefore doesn't last very long without upkeep.

[diehli]

So Voigt's good at these trigger jobs? About how light are we talking? 12 ounces?

[bountyhunter]

I remember our host talking about it here before. I remember him saying that when done properly the hammer will not cock, the radius has to be cut on the same arc as the sear moving away from the hammer hooks.

The hammer deflecting rearward slightly may not be 100% necessary, but it is good insurance against "hammer follow". If you look at the angles of the sear and hammer hook faces as the hammer is coming forward, a "no hammer deflection toward the rear" setup would mean they come together about "square". If you put a bit of positive angle on the sear as it comes into the hammer hook, that will tend to pull the sear in towards the hammer pivot effectively "locking" it in. The portion of the sear face nearest the hammer contacts first, and the hammer hook face rotates it inward. (If it is a 1911 sear, it will have two faces: a "primary" cut and a "secondary" or "relief" cut. The primary face cut is the one that has to capture into the hammer hook face).

Remember the hammer has inertia coming forward, so if the sear face angle starts to go slightly the other way, the hammer hook face starts to look like a "wedge" and can bump the sear out of the way from it's foward momentum: result is hammer follow where the hammer falls th the half cock notch because it didn't hold when it hit on the FC notch.

I think the smoothest roll is obtained with a "radiused" sear face where it rotates smoothly as the sear moves to drop the hammer (and the hammer does not move forward or rearward). But, you have to make sure and keep good sear spring pressure to prevent hammer follow.

[blackdragon]

From what I understand, an older koenig hammer has longer hooks that can be shaped to creat this rolling effect. Fred Craig installed one on each of my guns. It enables me to get on the trigger quicker, with out the infamous A.D. Hope this helps

Ivan

[Dan Burwell]

The Great One and I were fortunate enough to be trained by the god-like Jack B. He never used jigs because the tolerances on every gun and its corresponding trigger parts are different. Often, to get that perfect 16 oz. trigger job with .020" hooks, you have to work the sear "at an angle" on the stone to get the sear to exactly mate to the hammer hooks. The theory - the sear angle must be set so as the sear moves out across the hammer hooks the hammer should neither cock nor de-cock. (This is in complete contrast to the typical gunsmith's methods that have been used since the early days of the 1911.) When I worked for SVI, I worked with Sandy to redesign his sear face so it does just that. And I know the EGW sear is pretty close to that as well, as George does a lot of Doug Koenigs work, and Doug is one of the few who knows how to do a trigger job. (He learned from me and Robbie.)

Random thoughts:

I can't think of how to say this... Rotate the sear on the sear pin, and if the radius on the end of the sear's face matches the circumference of the circle described by the rotating sear, the angle will be very close to being perfect. I set up some sears angles on a bench grinder to accomplish this an they were very close, but still required some final hand polishing.

In the beginning, it helps to rig up a dial indicator to a bench vise so you can measure any cocking or de-cocking of the hammer as you press the trigger. Later, after a few years, you'll develop the ability to feel this, or to see it by carefully looking at the hammer as you pull the trigger. And you have to learn to brace your finger against the trigger guard so you can really control the trigger press.

A trigger set up like this does have a lot of trigger "movement," but you can't "feel it move" precisely because the hammer isn't cocking or de-cocking during the trigger pull.

A trigger set up like this is very safe and will last a very long time because its function is dependent on full "engagement." (.020" if the hooks are .020") Using SVI parts, I'd often have a trigger run perfectly for over a year at 16 oz. using this method.

If the sear is not cut so there is no cocking or de-cocking of the hammer, you will feel it as "creep."

gotta go for now...

be

Didn't get to finish this yesterday... Once you move into the 14 to 20 oz. range it is imperative that both hammer hooks contact the sear evenly. You check this by wiping the sear nose with a BLUE Sharpie marker, (don't waste your time with any other color), reassemble your pistol, snap it a few times, and disassemble and examine the sear nose. Seldom will any sort of "jig-cut" sear face have both sides touching the hammer EVENLY. This is what I was talking about in the earlier post when I said you may have to "work the sear at an angle." This is the really tricky part of getting the perfect trigger, and you can only learn it through quite a bit of experience, and, typically, ruining a bunch of sears.

The easiest thing is to just drop in an SVI hammer, sear, trigger, and titanium spring and go shooting with a 2 lb trigger.

be

Erik had bumped this thread back to the top but I thought it nice to have Brian's exact words here.

enjoy

[diehli]

Interesting. I wonder what people are doing on reliable 12 ounce triggers. Guess they've got something right.

[bountyhunter]

Interesting. I wonder what people are doing on reliable 12 ounce triggers. Guess they've got something right.

I'm betting they hold the trigger DEAD tight back when they drop the slide for loading to prevent an inertia trip and also protect the sear face from bounce damage. But, some folks get REALLY upset if you drop slide with the trigger back, even if the muzzle is pointed downrange.

[diehli]

Interesting. I wonder what people are doing on reliable 12 ounce triggers. Guess they've got something right.

I'm betting they hold the trigger DEAD tight back when they drop the slide for loading to prevent an inertia trip and also protect the sear face from bounce damage. But, some folks get REALLY upset if you drop slide with the trigger back, even if the muzzle is pointed downrange.

Interesting conjecture... but no. I've seen this guy repeatedly drop the slide on an empty chamber without issue. AFA being a Safety Moron ®, I seriously doubt he placed 4th at the Open Nats doing stuff like that.

Anyway, back to the topic: how long can one expect a superlight non-rolling trigger set up to last? What about with hardchromed parts?

What difference in pull length are we talking about here? Obviously a soft break rather than a crisp one, but at the lighter pull weights, does it simply feel like take up?

[diehli]

Got to dryfire a gun right after MV did a trigger job on it yesterday. Smooth break that could barely be felt. The hammer just released. It was at 12 ounces before he decided to up it just a tad. I'll have it done on my Open gun.

BTW, look for him to be shooting a 6-inch Limited gun at the Nats.

[Flexmoney]

BTW, look for him to be shooting a 6-inch Limited gun at the Nats.

Is that legal???

[bountyhunter]

but no. I've seen this guy repeatedly drop the slide on an empty chamber without issue.

As to whether dropping a 1911 slide on empty is "an issue", I know a parade of gunsmiths who say it should never be done for a number of reasons which include sear face chipping as well as stressing the lower barrel lugs. Most forums that deal with 1911's have posted threads regarding why this should not be done, and the technical explanations as to why and what is potentially damaged. If the person in question wants to drop the slide empty on his own gun, I would not argue with him. Most competitors would smack anybody who did it to THEIR gun, however.

I did not imply that anybody who holds a 1911 trigger back to protect the sear when loading is a "safety moron". It used to be standard practice on a tricked out 1911, many would not appriove of the action because it can be dangerous if done carelessly. On the other hand, an inertia trip on a 1911 with a light trigger is also dangerous.

For the record: some experts (Michael Plaxco in Shooting From Within) say the proper way to chamber up the first round in an auto loader is to lock the slide back, insert the mag, hold the hammer down fully with the strong thumb from under the slide and then trip the slide release lever with the weak thumb to prevent a possible inertia trip or sear damage. I'll wager that would not go well with the RO's at most ranges. So I guess safety is in the eye of the beholder and the hand of the shooter.

[MoNsTeR]

Is Mr. Voigt doing these trigger jobs on a commercial basis, or does one have to be a friend of a friend?

[diehli]

It seems that it's commercial, though I'm not sure what his turn around is. The one he did was done on the range, so it shouldn't be too bad providing he's actually sitting someplace with your gun (getting him to sit is the hard part). I'd post the price that he quoted me, but I don't think it would be appropriate... it's a good-deal cheaper than many of the major IPSC and non-IPSC 'smiths, though a good number of them include some parts in their trigger jobs.

[MoNsTeR]

This article linked from the November Brownell's WebBench has some great diagrams of the sear/hammer relationship and how to cut conventional angles.

http://www.brownells.com/aspx/NS/GunTech/N...x?p=0&t=1&i=545

Can anyone describe the engagement surfaces of a rolling trigger with the assistance of these diagrams? Particularly Figure 9, which shows how a conventionally-cut sear and hammer mate. How would Fig. 9 look if we were looking at a rolling break instead of a crisp break?