Tuners poor boy trigger job

[cuba]

My PT 1911 came with a 16# coil spring and 20# main and my trigger broke at 3 1/2#, The hammer hooks were set at .20 and I tried the marker trick to make sure I was getting good engagement all I did was polish the sear and all the fire control mechanism after installing the 23# Main and did the poor boys trigger, the trigger got about 5 1/2# and when I would pull the hammer back it was pretty stiff but the hammer would fallow about 40% of the time, the strange thing is if I rack the slide back the trigger breaks about 4 1/4# and no hammer follow, I've installed the Travis Reduction System with FPS radius 1/32 14# recoil and the 23# and I've ran about 1,000 round with no hammer follow and the trigger is about 4 1/4, very happy, but today I was tinkering with dry fire and when I pulled the hammer back The trigger brook about 5 1/2# and had the hammer fallow I kept doing it and the same thing happened about 40% hammer fallow with a heavy trigger but when I would rack the slide and try it the trigger became lighter and 0% hammer fallow can anybody tell me whats causing this to happen the 1911 functions differently when I rack the slide vs when I cock the hammer, thanks in advance for your help.


Cuba

[DnPRK]

Adjust the tension on the sear spring.

[Jolly Rogers]

Posted by Cuba:

My PT 1911 came with a 16# coil spring and 20# main and my trigger broke at 3 1/2#

And you were trying to do what exactly here?
Joe

[cuba]

DnPRK
should I increase sear spring or decrease it is that the leaf thats to the left or center?

[cuba]

Jolly Rogers
I installed the Travis Reduction System and changed out the 20# Main spring with a 23# it reduces the muzzle flip by also changing the FPS to a 1/32 Radius end which uses the Main spring to reduce the recoil by shifting the energy to the mainspring.


Cuba

[LaserSpot]

When you thumb the hammer, it goes back further than when you rack the slide. I don't know why it wouldn't catch the sear, could there be a problem with the notch in the hammer? It sounds like the sear isn't engaging the same way.

I've found that an 18# recoil spring seems to reduce recoil. Could you provide a link to the "Travis Reduction System"? What is "FPS"?

[cuba]

Laser Spot
FPS is Firing pin stop The Travis Reduction System was the original JMB design that has not been used since 1918 installing a stronger recoil spring will actually beat your gun to death this system actually requires a max 16# recoil spring with a minimum 23# main spring which virtually reduces the battering to your firearm I'll attach a forum that explains all about it.and a picture of the different radius profile that is attached on this forum on the heading EGW Firing pin stop on the Gun smithing section
http://forum.m1911.org/showthread.ph...5&page=9&pp=10

[cuba]

Dn PRK
Just went out side and fired 100 round with out a hitch I did increase the sear spring(made the trigger harder) but while dry firing no more trigger fallow.

Cuba

[LaserSpot]

cuba, this is an interesting modification. I think it's designed to make the gun cycle faster for action shooting games, not reduce recoil. Someone said that the recoil feels stronger and more abrupt, but it comes back on target faster. Is that how it seemed to you? Does the small radius FPS make it hard to rack the slide?

I suspect that the reduced muzzle flip is because the sharper recoil encourages you to grip it harder.

[cuba]

Laser Spot
your right that it make the slide a bit harder to rack but a 1911 was designed to be carried cocked and locked so the slide being harder to rack for me is not an issue, as far as recoil I think it does reduce it at least for me I do feel a more pronounced snap on my palm like when you shot a 40SW, think about it. if it slows the speed of slide recoil about 25% and keeps you on target that means there is less recoil, and by reducing your recoil spring you weapon is going to last longer, increasing your recoil spring actually batters your barrel lugs, this system makes your brass fall about 2 feet away from your right foot, I've attached a youtube video of some one shooting with this system and tell me if you think theres less recoil now understand this man is shooting a 1927 model 1911 not a race gun he's a cop and that's his duty gun.
http://www.youtube.com/watch?v=IWLRx5lzCoY
http://www.youtube.com/watch?v=5A2fC...eature=related

cuba

[LaserSpot]

If there's more snap, that means you're getting higher slide recoil velocity, not lower. The extra power mainspring isn't doing much. I don't think it will hurt anything if you have a shock buffer in place. You may have a point about returning to battery; the shock buffer doesn't help when it's going forward and a stronger spring will slam the barrel legs a bit harder.

The guy in the video is shooting pretty fast, but I don't see any way that this mod could reduce flip.

[Jolly Rogers]

Posted by Cuba:

Jolly Rogers
I installed the Travis Reduction System and changed out the 20# Main spring with a 23# it reduces the muzzle flip by also changing the FPS to a 1/32 Radius end which uses the Main spring to reduce the recoil by shifting the energy to the mainspring.


Cuba

I got that part and I have my 1911s set up that way for over a year now...
Why did you play with a 3.5 # trigger???
Joe

[cuba]

Joe
My 1911 came with a reduced 20# main and when I changed the set up with a 23# main spring that has increased the trigger pull not by much I think it's 4 1/4# and thats not bad for a self defense weapon specially with the Travis reduction system that keeps me on target with less recoil and which will make my gun last longer.


Cuba

[Jamie B]

If it ain't broke.........

This is why professional gunsmith's make the money that they do.

[1911Tuner]

Seems that there's a little misunderstanding on the mechanics of the small radius firing pin stop and what it does.

First:

I think it's designed to make the gun cycle faster for action shooting games, not reduce recoil.

It's not designed to reduce recoil. It's purpose is in delaying the slide. It does so by reducing the mechanical advantage in overcoming the mainspring by placing the contact point lower on the hammer.

"Speeding up" the slide is a physical impossibility. Force is what makes the slide move. There are X units of force available when the gun fires. In order to speed the slide's rearward velocity up, more force would be required...just like the only way to increase the bullet's velocity is to use more force.

The sharper felt recoil is due to the more immediate transfer of the slide's momentum to the frame through the mainspring. Once the hammer is cocked, and the mainspring's resistance has been overcome...which only lasts for a brief instant...the slide is moving slower...not faster.

Because 90% of what we perceive as recoil in an autopistol comes from the slide impacting the frame, the lower slide velocity means that the slide isn't moving as fast when it hits the impact abutment.

Because the action/recoil spring constitutes the other 10%...the slower compression of the spring further alters the felt recoil by slowing the spring's push against the shooter's hand.

The recoil system is a closed system that is separate and apart from the gun...which is made up of the slide and barrel. Once it's in motion, it sets up an equal/opposite event of its own. As the spring compresses, it pushes forward on the slide and backward on the frame.
The slower the slide compresses the spring, the softer the push on the frame. Simple action and reaction.

You don't actually feel much recoil from the ballistic event in an autopistol. The "gun" moves on a rail. The frame is really no more than a gun mount, and there's no solid connection between the gun and the mount. Recoil in the gun is transmitted to the mount through springs. The mainspring's transmission is immediate, but is over quickly. The slide only moves a 10th of an inch before the bullet exits. At bullet exit, the ballistic action/reaction event is over, and a 120th inch of compression just doesn't provide a lot of push against the frame. By the time the slide impacts the frame, and you actually detect muzzle flip...the bullet is long gone, and there is no more ballistic recoil.

Cuba. .020 inch hammer hooks are a bit short for the Poor Man's Trigger Job Hammer followdown from inertial trigger bounce is more likely with hooks shorter than .023 especially if they're squared. and I much prefer .025 inch undersquare hooks and a small breakaway angle on the sear. That point was made clear in the instructions. If you're going to use .020 squared hooks, I strongly suggest using a sear jig and making sure that it's done correctly.

[LaserSpot]

It's not designed to reduce recoil. It's purpose is in delaying the slide.

I still don't quite understand the purpose; is it to solve a problem, or improve performance?

I can see a theoretical benefit if you're shooting heavy 10mm, or thousands of rounds of 45 +P. Have you had problems with broken bottom lugs or slide stops in regular 5" 45 ACP pistols?

[Jamie B]

Actually, the answer is both.

I learned of it several years ago by reading some posts by our own Tuner.
I was having problems with my SA Micro .45 not properly feeding.
A return to SA resulted in no fix for the issue.

I corresponded with Tuner @ THR.org, and wound up fitting one to my SA.
All of the feeding issues disappeared, as the slide was slowed enough to allow the fresh round time to engage the slide upon return.

The gun has run perfectly for the last 4 years.
It runs like a beast, and I have never had any issues with feeding.
I was even able to slightly increase the poundage of the recoil spring.
I run a 20# mainspring in all of my 1911's.

I have always been very grateful in Tiuner's help with fixing this gun!

Jamie

[1911Tuner]

It doesn't have anything to do with the lugs, Laser. Lower lugs break for other reasons.

Its function is in delaying the slide. Slide delay is accomplished no matter what the radius is. The smaller radius...and the reduction in mechanical advantage in cocking the hammer...just delays it a little longer.

The delay from the hammer and mainspring comes at the instant that the slide under maximum acceleration by the equal/opposite reaction of the cartridge firing, and the slide loses speed and momentum because of it. Once the momentum is lost, it can't be regained...so it's moving slower from that point. The slower the slide is moving, the slower it compresses the recoil spring and the softer it hits the impact abutment. All these things
change the way the gun cycles.

Another benefit is that it allows the use of a lighter recoil spring without increasing slide to frame impact. The lighter the recoil spring, the less force backward on the frame.

Several years ago, Ned Christiansen was able to use an 18-pound recoil spring in a Delta Elite by installing a stop with a 1/16th radius and a 25-pound mainspring. He found that a shock buffer lasted a little longer than with the standard setup using a 22-pound recoil spring in the same gun...firing full-power 10mm ammunition...and he reported that the gun was much more user-friendly.

[LaserSpot]

I was having problems with my SA Micro .45 not properly feeding.

This sounds like a good fix. I've always heard that 3" 1911's are hard to get running reliably. If the slide velocity is too high, it probably bounces off the frame (or the shock buffer) and closes even faster. In the micro, the reduced slide travel must not allow much time for the next cartridge to rise.

I was even able to slightly increase the poundage of the recoil spring.

I thought this was supposed to let use you a lighter spring. Did you try the heavier recoil spring before changing to a small radius firing pin stop?

[1911Tuner]

This sounds like a good fix.

It's actually a good thing to do to any of them. Even 5-inch guns can experience a bolt-over base misfeed if they're oversprung, or the magazine spring isn't up to the task.

If it is a "fix" for anything, it was done a hundred years ago by the man himself. The original firing pin stop radius was 5/64ths...changed to 7/32nds by Colt on request of the US Army after the troops complained about the slide being too difficult to hand cycle with the hammer down. All I did was take it a step further and reduce the radius to a 16th...or less for some guns.

If you'll have a look at an older High Power stop, the shape is more squarish than on modern 1911s.

[1911Tuner]

Laser...This is a very old fluroscope photo of a 1911 firing. Study it for a few minutes, and things will clear up. Notice by the link's position that the slide has moved approximately .075 inch, and The hammer hasn't cocked yet. The bullet is just nanoseconds from exit.

I'll comment in the next post.

[1911Tuner]

With the present 7/32nds radius, the slide moves apporximately .100 inch at bullet exit. Remember that figure. It'll be important later.

Momentum is a function of mass times velocity. Momentum will be conserved unless it encounters an outside force. Anything that fights the slide's movement...friction...springs...the hammer's mass...all constitute outside forces that are trying to bring the slide to a stop. If any of those things change, the slide's available momentum likewise changes.

Once the bullet has left the system, there is no more force available to accelerate the slide, and the slide continues rearward on the momentum that it conserved during that brief period of acceleration...while the system was still closed and action/reaction is in effect.

By reducing the FP stop radius, its point of contact on the hammer is placed lower...increasing the level of force required to cock the hammer. This robs the slide of speed and momentum, and once that momentum is lost...it can't be regained without a new force to accelerate it...and there is no new force available. So, the slide now has a little less momentum than it would have had with a 7/32nds stop.

Now, we get into the part that very few consider. Time.

By applying a greater outside force...and even a little change makes a big difference...we give the bullet more time to escape the barrel relative to the slide's position.
So, with the small radius stop...the bullet escapes and removes the accelerating force earlier in the slide's travel...while the slide is fighting to get past the speed bump imposed by the hammer and mainspring...further reducing the time that the accelerating force bears on the slide...which further reduces the slide's momentum.

The effect is rather like using lightly loaded ammunition...except that the bullet doesn't slow down. It's still accelerating toward the muzzle at full speed.

How much more time is unknown, but I'd estimate it at about 20-25% more...or having the bullet exit at ..075-.080 inch of slide travel instead of .100 inch. On paper, that's not a lot. Dynamically...during the gun's cycle...it's pretty signifigant.

If that causes your head to hurt...just wait'll we get into the main delaying force. Its effect is far more signifigant than the mainspring, slide to frame friction, and the recoil spring combined. The recoil spring actually has the least effect of all on slide delay. The recoil spring's main function is in returning the slide to battery.

The main factor in slide delay in a locked-breech pistol is the bullet itself. Stew on that awhile. The photo above will come in handy.

[Jamie B]

I thought this was supposed to let use you a lighter spring. Did you try the heavier recoil spring before changing to a small radius firing pin stop?

I pulled the original thread, and did use the lighter recoil spring - sorry!!
Remember that this is a 3" .45, so the spring rates are higher.

I had corresponded with Tuner about all of these ideas, and proceeded with his blessing. As usual, he was spot on!

Here is the original thread: http://www.thehighroad.org/showthread.php?t=155972

jamie

[LaserSpot]

If it is a "fix" for anything, it was done a hundred years ago by the man himself.

Didn't realize that; was this a change from the prototype before it was issued, or was it one of the later 1911A1 changes?

I'm not having trouble understanding the mechanics of this modification. By putting a few extra pounds of force on the slide, it may take a couple extra milliseconds for the slide to retract the first tenth on an inch. This could be good for accuracy if it creates more consistency at the point when the bullet exits. You are also greatly accelerating the initial rearward movement of the hammer; this is somewhat similar to a roller-delayed action.

As far is feeding and ejection issues go, I think the rearward velocity of the slide at the back of it's travel is what matters the most. If it's hitting the buffer too hard, it could "bounce" and close too fast. I don't really see what difference it make if it was slowed down by the recoil spring, or the hammer and main spring. I realize that a heavier recoil spring will drive the slide forward a little faster; maybe this is more significant than I think.

If this system allows you to use a lighter recoil spring, it should put less stress on the slide stop pin and the barrel feet when the action closes. On the other hand, the stronger mainspring puts more stress on the hammer, sear, and firing pin. I'm not sure which part is more prone to breakage, so I don't know if this is a good trade-off.

What I've really been trying to figure out is where the best real-world application for this is. The SA Micro and the Delta Elite are both good cases for it.

The OP is apparently hoping to reduce muzzle-flip. I note sure how this mod would help as you still have conservation of inertia. Maybe the pistol has a bit more rotational inertia with the slide in the forward position. The mod would transfer more recoil to the slide and users hand while the slide is still in the forward position. This could result in more straight-line motion with less rotation, but it may also be insignificant. I still suspect that the sharper-feeling recoil may encourage a stronger grip, thus reducing muzzle flip.

I found a slow motion video of a bullet exiting the muzzle. If you look at the full-length guide rod, you can tell how much the slide has retracted: http://www.youtube.com/watch?v=EFhGgYq3XOE

Dylan

[LaserSpot]

I pulled the original thread, and did use the lighter recoil spring - sorry!!

OK, that makes more sense!