1911 extra power firing pin spring

[Koda94]

I'm not a gunsmith, but years ago I must have thought I wanted to be.... I'll make my case then ask my questions.

I fell in love with the 10mm in the 90's and got a new Delta Elite (series 80) with the intent of using full pressure loads. Back then I recall reading about frame cracking in early productions.... yada yada, so I went and installed a Wilson Combat Shok-Buff Recoil System with its FLGR using the 18.5# recoil spring. The kit came with 1 extra power firing pin spring which I never installed. Its fired plenty of Corbon 135g, 180g BTSP and Winchester 175g loads flawlessly.

Fast forward to today, I don't shoot the gun much anymore but would like to get back into it when the ammo hype dies down. I recently picked up a box of Buffalo Bore 180g JHC but have not fired it yet. Anyways, I was reading about using heavier recoil springs and learned that using heavy recoil springs require using heavy firing pin springs to prevent inertia discharge from slide return. ooops, I never installed mine.

So should I? Remember, I have not had an issue... yet

Why not install extra power firing pin springs regardless of the recoil spring used?

Any answers and lectures appreciated.

[Scorch]

I build 1911s in my shop (not that that makes me an expert), and I never use them. The slide is slowed down by stripping the cartridge off the mag, so why worry? I would worry more about battering the frame, so measure your recoil spring and replace if it is more than 3 or 4 coils shorter than a new one. Or just replace it and feel safer.

[g.willikers]

On the other hand, changing firing pin springs is easy and quick.
Why not put the stronger one in and see if the gun runs ok, with the ammo.
If it does, an extra measure of safety has been added, without cost.

[4V50 Gary]

Guns work as they were designed. Guns don't work as well when some aftermarket products are thrown in.

Put in a heavier recoil spring means slowing down the unlocking and shortening the lock up period. Reliability issues may arise in extracting, ejecting or feeding. Putting in a heavier firing pin spring means that the hammer will have to overcome that extra stiffness.

If you're going to do it, be sure to test it with the loads you intend to use in that gun. Going to another load or to factory ammunition may yield less than reliable results.

[polyphemus]

The main spring works hand in hand with the recoil spring and it is designed to balance the recoil force,so changing specs one way or the other would
require compensation from the other parts.To different extent all the springs
in the pistol work together and are designed for the .45 ACP pistol ball force.
The standard GI spring combination is tried, true and it works other weights
might also work this being a great tribute to the M1911's excellent design.

[Dixie Gunsmithing]

What you may run into, with a heavier firing pin spring, is the failure to ignite some primers, according to the brand, and design. The hammer spring has enough pressure to drive the hammer, with enough force, to counter the standard firing pin spring, so changing it to a heavier one might mean changing the hammer spring to a slightly heavier one too, to balance this out.

The recoil spring can be sized to the load, and buffers can help with high-load rounds, but that's about it. The problem you have with this, is that of the breech locking lugs on the barrel getting battered, along with their mating recesses in the slide, and more stress on the link pin, and link.

The above is the same reason I won't shoot hot rounds in my Browning Hi-Power, as it can damage the lugs, so I shoot standard 9mm ball ammo. The 1911 falls under a similar category, just that you have a link and pin thrown in.

[Koda94]

Thanks for the replies, so far I have not read anything that indicates I should add a heavy duty firing pin spring. In fact, there might be an argument for not considering it... unless I wanted to calibrate the guns entire spring operation to a more specific load (not necessarily within the intent of my purpose or use of the gun)?

One thing my google-fu is having a hard time finding is the stock/factory recoil spring weight? (not certain how that would be calculated with its dual spring). What I am guessing is the 18.5# Wilson spring I put in there might not be a huge increase and thus why I've never had any problems.

One interesting thing I did find on Google was a good note in Wikipedia on the original Delta frame cracking issue was because of a bridge in frame material above the slide stop cutout, which Colt quickly removed. Mine is removed.... so I never had anything to worry about in the first place.

http://en.wikipedia.org/wiki/Colt_Delta_Elite

[1911Tuner]

It seems that there's a little basic misunderstanding of the locked breech, recoil operation. At the risk of becoming a pariah, I'll try to clear up a few things.

First, the extra-power firing pin spring is about making the gun more drop safe. I've tried the springs in several pistols, and have never had an ignition failure, even with "hard" GI primers...as long as the pistols were run with standard mainsprings that were in good condition.

Second...the "recoil" spring does little to delay or slow the slide during the recoil phase, which is very brief...and it has nothing to do with the timing of the vertical barrel disengagement...or "unlocking" if you prefer. The link takes care of that. There's often, if not usually, a confusion between "time" and "timing." Time is a function of speed and distance. Timing is mechanically fixed and the timed event will occur at its appointed place in the cycle, regardless of the speed of the cycle. Technically, the barrel doesn't "lock" until the gun fires. It engages vertically, but locks horizontally with the lugs in opposition under shearing forces.

The hammer mass and mainspring have a greater effect than the recoil spring on delaying and slowing the slide during the recoil phase...and even that is small compared to the bullet's effect.

Neither does the recoil spring have any effect on lug battering or preventing/forestalling it. That's done by opposing forces in the system when both bullet and slide are being accelerated in opposite directions, with the bullet exerting a forward drag on the barrel...and resisting the slide as it drags the barrel backward.

The recoil/action spring's primary function is returning the slide to battery. Whatever else it does is incidental and essentially irrelevant. I've demonstrated this by repeatedly firing a Colt LW Commander without the recoil spring. There was no early unlock. There was no frame or slide abutment damage. Nothing at all changed other than having to return the slide to battery manually. This demonstration requires a FLGR and plug. The standard guide rod will tilt and tie up the slide, possibly doing damage...in case anyone wants to try it.

Study this photograph and take note of the way the upper barrel lugs are forced against those in the slide. Also notice the link's position. The slide has moved about .070 inch and the base of the bullet is within about an inch of the muzzle. The recoil spring has compressed a very small amount...about .070 inch shorter than its static position...adding very little resistance above preload, which is about 8 pounds with a 16 pound spring. That's not a lot...certainly not enough to make a huge difference in the slide's acceleration during the recoil phase.

Understand also that "recoil" is only in effect as long as the bullet is present and being accelerated. Once the bullet exits, recoil ends, and all movement of the slide and bullet beyond that is due to conserved momentum.

Finally, take note of the bones in the shooter's hand, and the distinct lack of muzzle rise in the gun. What we perceive as recoil in the autopistol...muzzle flip...comes mainly from the slide impacting the frame.

[1911Tuner]

And here is the photo referenced above. A picture is worth a thousand words. In this case, it's probably worth 10,000.

[Dixie Gunsmithing]

1911Tuner, I did not mean that the recoil spring had anything to do with the battering of the lugs, that's from the pressure of the load being fired, and was the reason I said "but that's about it". If it has anything to do with it, it is not very much if at all. The recoil spring is really there to keep the slide from slamming into the frame with too much force, over recoil, and return it to battery. The barrel lugs take their battering from the lug play and the amount of pressure applied between the breech face of the slide, and the barrel, trying to move the two apart. Thus, the higher the load, the greater the separation forces. Hot rounds in both the 1911 and the Hi-Power can ruin the lugs, especially the Hi-Power.

As far as timing, though, a heavier spring will cut back the time it takes for the link to move past center, and the barrel to drop, but it is only a very minute amount, since there's not much spring compression while this happens. It still doesn't have anything to do with lug wear, though.

On replacement springs, or heavier ones, there have been a few times, on varying models of guns, where the spring would cause the firing pin to not indent the primer deep enough, and cause a mis-fire. I always warn about this, whether it may happen or not. I've had to order replacement, factory, springs to install, back into place of the over-power springs, because of this.

[polyphemus]

" At the risk of becoming a pariah, "
That is not going to happen any time soon.Anyway the slide has to overcome
the recoil spring resistance to further compression to reach the end of rearward
travel,so if its purpose is essentially to return it to battery then it would seem logical to think that anything in terms of weight would do the job.
As it is there's considerable energy absorption which leads me to think that it
does more than that and it is closely matched to work with the mainspring
to properly cycle the the pistol.

[Dixie Gunsmithing]

polyphemus,

The barrel and slide are locked together during the first amount of slide recoil, and it's not much, about 1/4" or so, until the lugs start to disengage from the slide. This happens after the link swings up, actually digging the lugs into the slide frame, and then they start to drop again, as the link passes center. The recoil spring, though, isn't compressed much, yet, and it's tension isn't that much. However, the bullet leaves the barrel, lickity split, and the barrel and slide stay locked together while this happens, so the spring can control this time, but minutely. In other words, it can keep the slide stationary just a few milliseconds longer, than it would without a spring, as the spring pressure would effect the mass of the slide during inertia on recoil. This, especially, since the spring is under pre-load from the barrel busing, already compressing it some, when it is in place. In other words, the spring is not completely uncompressed when the gun is at rest, and is supplying an opposing force to the slide.

The idea of a heavier firing pin spring, to a lot, is to keep the mass of the firing pin from to wanting to travel forward, due to inertia, than with a weaker spring, over a heavier recoil, forward and return, (but the factory spring is purely a safety measure to keep the firing pin away from the primer, when returning to battery, or dropped, and the recoil inertia could only send it against a fired primer). The problem is, though, that when the hammer strikes the firing pin, with the force put to it by the hammer spring, is if it has enough force to indent all primers fed to it, as the weaker spring would allow. The hammer imparts movement against the firing pins mass, creating inertia at the firing pin, and then the pin compresses its spring. The heavier the spring, the less power forward.

[polyphemus]

ok two issues,there doesn't seem to be any advantage to installing a heavier
firing pin spring and possibly the opposite.
As to recoil spring-slide,barrel interaction aside- I understand that the cap keeps
it under tension and the bushing holds the cap,but my point was that once the slide is traveling rearward it must overcome the recoil spring resistance and then
the main spring so the two are somehow balanced to provide smooth automatic
action.I am quite sure that the standard recoil spring weight was not a random
spec and was arrived at after much testing,anyone that has ever stripped an
M1911 knows it is pretty hefty,so there must be good reason for that.

[Koda94]

two part reply, first:

First, the extra-power firing pin spring is about making the gun more drop safe. I've tried the springs in several pistols, and have never had an ignition failure, even with "hard" GI primers...as long as the pistols were run with standard mainsprings that were in good condition.

I've heard this before, this is why I am wondering why not install an extra-power firing pin spring regardless of other springs?

second part:

Second...the "recoil" spring does little to delay or slow the slide during the recoil phase, which is very brief...

I think 1911Tuner has a good point about timing, but I'm still confused about dampening the recoil/inertia of the rest of the slide travel rearward. Once the barrel drops, isn't the rest of the job to dampen the inertia to a manageable level to avoid frame damage? Returning the slide to battery is regardless because that's gonna happen with any spring strong enough to strip the next round from the magazine?

I would think that ideally; the recoil spring, the mainspring, hammer mass, and the slide/barrel weight would all be packaged together for proper function for a specific range of bullet loads (power)?


Putting it all together:

Isn't there a reason extra-power firing pin springs are not installed from the factory in the first place? Would the reason they are not installed from the factory in the first place is because they have to be weak enough to let the mainspring overcome it when the hammer drops, and the mainspring power/strength is set to the function of managing slide inertia for a specified power load of ammo? (stock GI hardball ammo for .45 and 200g/1300fps for 10mm?)

[Dixie Gunsmithing]

The heavier recoil spring, and any dampener used, is to keep the slide from not only slamming back harder into the frame, but to control the amount of power the hammer is hit with, during recoil, and to dampen the hit to the barrels bottom at the breech, when it falls, and comes into contact with the frame, at the front of the magazine well. This also reduces shock to the link, takedown lever pin, and the link pin.

In theory, with the heavier recoil spring, the slide would shut closed with more force than with a weaker recoil spring. In doing so, and observing Newtons law, that once something is in motion, it wants to continue in motion, the firing pin would keep going as soon as the breech closed, and possibly set off a primer on a new round, if a spring was not placed onto the firing pin. Since the closing is more forceful, then, in theory, the firing pin spring should be strengthened to stop this.

A good test would be, after installing the heavier recoil spring, to take a spent cartridge, and glue a piece of cigarette paper over the old primer. Place the case into the gun, pull the slide all the way back, and let it slam shut. Take out the case, and see if the firing pin protruded enough to either mark, or poke through the paper.

[James K]

Things got a bit off track, there. The concern is about a pistol with a loaded chamber being dropped so it lands on its muzzle. When that happens, the firing pin can creep forward with enough force to fire the chambered round.

That does not happen, or happens only very rarely, with the original design, since the slide moves back against the recoil spring and absorbs most of the shock.

But when a full length guide rod is installed, the shock is not absorbed and accidental discharge from firing pin "creep" becomes much more likely if the gun falls on its muzzle. That was the case with the original discharge in California which led to the requirement for firing pin blocks or some other way to prevent firing pin creep.

One way to prevent, or at least reduce, cases of firing pin creep is to install a stronger firing pin spring, making it harder for the firing pin to move forward. That is why a stronger firing pin spring was included with the full length guide rod, to be used where required by law or when the gun owner felt the need for it.

Jim

[Hunter Customs]

Isn't there a reason extra-power firing pin springs are not installed from the factory in the first place? Would the reason they are not installed from the factory in the first place is because they have to be weak enough to let the mainspring overcome it when the hammer drops,

Koda94
I believe the standard mainspring was rated around 23 pounds, so I don't believe your line of thinking is correct.

After reading this thread I have to assume no one here has ever experienced firing pin drag. Firing pin drag is evident when the primer of the fired round shows an oblong indention instead of the nice round indention from the firing pin strike.

I believe the main reason for the extra power firing pin spring is to retract the firing pin faster to help in eliminating firing pin drag.

For what its worth I set guns up with mainsprings as light as 15 pounds and extra power firing pin springs; never experienced any difficulty in lighting off the rounds fired in the guns.

Best Regards
Bob Hunter
www.huntercustoms.com

[Koda94]

Originally Posted by James K

Things got a bit off track, there. The concern is about a pistol with a loaded chamber being dropped so it lands on its muzzle.

this is a good point but actually my OP was about inertia discharge when the slide returns to battery. I did mention my pistol was a series 80... which has a firing pin stop. As far as I know, the firing pin stop is disengaged as long as the trigger is still depressed which is probably the case until after the slide returns, and so inertia discharge is a valid concern. As for landing on the muzzle end of the FLGR I would think the pin stop would eliminate any discharge. Correct me if I am wrong. Where I think we may be getting off track here is that we are talking about full pressure 10mm, not 45acp.


There is some good discussion about the operation of the 1911 here in this thread, but overall I have not seen any case to argue changing anything in my pistols setup. Like I mentioned its worked fine for years. As far as I understand one installs a heavy recoil spring to prevent frame battering and nothing else. But I also read a convincing article about the subject of inertia discharge in this article:

http://www.realguns.com/archives/020.htm

(scroll about midway down)

I guess my question is not easy, and I do understand this is a forum not a class. My only concern here is to prevent inertia discharge in my 10mm using an 18.5# recoil spring. I just want to make certain I have not gotten lucky so far.

Originally Posted by Dixie Gunsmithing

A good test would be, after installing the heavier recoil spring, to take a spent cartridge, and glue a piece of cigarette paper over the old primer. Place the case into the gun, pull the slide all the way back, and let it slam shut. Take out the case, and see if the firing pin protruded enough to either mark, or poke through the paper.

+1 Dixie, I will look into this.

[James K]

I was actually trying to respond to the point of why the heavier firing pin spring was included with the FLGR kit. Might it be needed to prevent firing pin creep with a heavy recoil spring? I don't think so, but you can always chamber a primed but unloaded case and let the slide slam forward several times. If the primer shows any marks, it might be a good idea to install the heavier FP spring.

Jim

[Koda94]

John, I see now. Firing pin creep threw me off a bit, is it the same as inertia discharge?

The fact that the package included an extra heavy firing pin spring is why I am debating installing it, because when I read the realguns article the light finally clicked as to why it was included.

The fact that I've (so far....) never had a problem is why I'm asking if I should even bother. The Wilson kit's heaviest recoil spring was 18.5# and I still cant find any info on the OEM Delta 10mm springrate to compare. Consider that the Wilson kit was made for .45 not 10mm, and many 10mm fans (from what I read) install recoil springs starting at 20lbs. What I suspect is going on is my Wilson kits 18.5# recoil spring is not that much heavier than the OEM Delta dual spring, so no problems. But if I had put this kit in a OEM 45acp to fire hot 45acp then it would be necessary because maybe the Delta has a heavier firing pin spring than a OEM 45?

I think the solution is to do the test. I only have a spent case, but no cig paper.... it could be a while before I stop by a cigarette store I don't smoke.

[1911Tuner]

The barrel and slide are locked together during the first amount of slide recoil, and it's not much, about 1/4" or so, until the lugs start to disengage from the slide. This happens after the link swings up, actually digging the lugs into the slide frame,

Uhhhh.....

No.

The barrel starts to link down at about .100-.110 inch of travel. At 1/4 inch of rearward travel, it's all over with. Go back and look at the photograph.

And the link doesn't lift the barrel as it swings forward unless the barrel is long-linked.

And, while the mainspring weight/rate was never specified in the original blueprints...the specs did happen to work out at 22-23 pounds. The same goes for the "recoil" spring. Specified only in wire diameter and number of active coils...and it works out to around 14-14.5 pounds at full compression, and 13.5 at full slide travel as installed in the gun.

And back to topic...

The purpose of the extra power firing pin spring is exactly what JamesK and I said...to make the pistol more drop-safe. It has nothing to do with the slide velocity as it goes to battery.

[Jim Watson]

I never heard about the FLGR safety gimmick.

I have used the firing pin springs provided by Wolff along with their new recoil springs in all guns, all mainspring weights with no misfires... except the time the firing pin spring broke and a piece of it dragged against the firing pin.

[polyphemus]

"The purpose of the extra power firing pin spring is exactly what JamesK and I said...to make the pistol more drop-safe. It has nothing to do with the slide velocity as it goes to battery"
Absolutely correct,the slide can not provide in and of itself enough energy to the
firing pin to cause it to detonate the primer,which touches on that mythical
firing pin drag malfunction,cartridge fires,instantly pushing pin back helped by
the spring and rearward motion of slide.Any suggestions of said pin lingering
long enough to cause a drag mark on the primer are far fetched.If the pin
remains off the breach face after fire it is most likely due to something other
than a weak spring,an obstruction of some sort yes but not a weak spring.

[RickB]

The fact that I've (so far....) never had a problem is why I'm asking if I should even bother. The Wilson kit's heaviest recoil spring was 18.5# and I still cant find any info on the OEM Delta 10mm springrate to compare. Consider that the Wilson kit was made for .45 not 10mm, and many 10mm fans (from what I read) install recoil springs starting at 20lbs.

The stock Delta Elite recoil spring set-up is dual springs, the outer one of standard "1911" dimensions, around a smaller, shorter spring, both mounted on a guide rod of smaller than normal diameter, with a plastic insert in the head performing some "buffering" of the slide impact. The two springs have a combined rating of 23#.
I like to use a heavier-than-stock, 25# mainspring, to redistribute the load and allow a lighter recoil spring for the same overall effect.
It has also been popular to fit a firing pin stop with a smaller-than-normal radius on the heel, to reduce the slide's leverage on the hammer. I've always used the part made by EGW, which required creating the desired radius on the part's square edge. A new option from Harrison Design has a small radius already applied to the heel, and the added benefit of a small angle above the firing pin hole, to help ensure that the contact point is down at the base of the hammer.
http://shop.harrisoncustom.com/hd-20...iring-pin-stop

[Koda94]

Originally Posted by RickB

The two springs have a combined rating of 23#.

This is a much appreciated reply. If true, then installing the Wilson 18.5# spring actually made my gun worse off and I never should have installed it, I obviously did not do my homework correct back then. It also explains why I never had a problem with any inertia discharge, or would had need to install an extra power firing pin spring.... logically Colt would have matched the springs accordingly.

So I tested this by re-installing the original spring kit and compared the effort of retracting the slide (this is the best I can do, by feel). By feel, the stock Colt dual spring "feels" a tad heavier... but its close, I have no way to accurately tell.

So moving forward, my saga is empirical evidence of the old adage 'if it aint broke don't fix it'. I'll leave the stock spring kit in.