Mainspring, recoil spring, and EGW firing pin stop...AKA "The System"

[sublimaze]

I read with great interest the thread re: recoil reduction: http://forum.m1911.org/showthread.php?t=13060&highlight=amazing+recoil+reduction

I'm interested in trying it but I have a few questions. My gun is a full sized NH Talon w/recon frame. The gun has a 19# mainspring, 17# recoil spring, extra power firing pin spring, and the standard radius fps. I've also looked at Wilson's and Ed Brown's websites and they use the same set-up.

I understand that 23# ms ,16# recoil spring, and small radius fps are a system. Could NH, Wilsons, and Browns be built around the above mentioned set-up(19/17) and therefore if I change to 23/16 could I upset their factory "system"? All three of those brands have great reputations for toughness and reliability after all.

One thing that I'm concerned about is that the small radius fps seems to concentrate all its force on the hammer right along the radius, whereas the standard radius seems to spread the force out a bit better. In terms of reliability and longevity, isn't it better to spread out the force?

I understand that JMB's original system was ~16/23 and small radius stop. When they changed to current standard radius fps, did they leave recoil spring and mainspring alone?

One last question, does the extra power firing pin spring and 9mm firing pin that NH, Wilson, and Brown use complicate matters at all with regards to perceived recoil and reliability?

Great forum by the way!

[niemi24s]

One thing that I'm concerned about is that the small radius fps seems to concentrate all its force on the hammer right along the radius, whereas the standard radius seems to spread the force out a bit better. In terms of reliability and longevity, isn't it better to spread out the force?

The force the FPS exerts on the hammer cannot be spread out on the hammer by any FPS contour. Whether the radius is large or small, it meets the flat face of the hammer at a single point across the face while it's cocking the hammer.

Theoretically the contact area between the two during hammer cocking is very, very, very small and independent of the radius. A line tangent to a circle meets the circle at a single point - at least according to some dead guy named Euclid!

[Hawkmoon]

The difference in the small-radius firing pin stop lies not in the contact area, but in lowering the point of contact closer to the rotational axis of the hammer. That means a reduced moment arm (less leverage) in terms of the slide pushing on the hammer. The amount of effort needed to move the hammer is a constant (for whatever spring is used), so if you reduce the moment arm length you increase the amount of force that has to be exerted by the slide.

Using up more of the slide's energy to cock the hammer reduces its velocity, and lessens the residual force with which the slide impacts the receiver.

[1911Tuner]

Not to mention that a small radius...albeit not as small as I've been using...was Browning's original intent. It was specified as .078 inch, which works out to 5/64ths. I go about a 64th smaller.
The "New/Improved" radius is nominally 7/32nds.

When considring all this...remember that the slide doesn't cock the hammer smoothly, and the hammer doesn't remain in contact with the slide. The hammer is slammed back, and rebounds off the grip safety...and falls back to the center rail of the slide, past the full-cock position. When the slide rides forward, it drops the hammer hooks back onto the sear.

[sublimaze]

[QUOTE=niemi24s]The force the FPS exerts on the hammer cannot be spread out on the hammer by any FPS contour. Whether the radius is large or small, it meets the flat face of the hammer at a single point across the face while it's cocking the hammer.

You're right. I slowly hand cycled my gun and the entire flat face of the fps pushes the hammer back. For some reason, I was thinking that the fps radius is what first made contact with the hammer.

[sublimaze]

[QUOTE=Hawkmoon]The difference in the small-radius firing pin stop lies not in the contact area, but in lowering the point of contact closer to the rotational axis of the hammer. That means a reduced moment arm (less leverage) in terms of the slide pushing on the hammer. The amount of effort needed to move the hammer is a constant (for whatever spring is used), so if you reduce the moment arm length you increase the amount of force that has to be exerted by the slide.

As I realized in niemi24s' post if the entire flat face of the fps is what initially pushes the hammer back, then your not really lowering the point of contact closer the the rotational axis of the hammer. It would seem as if the .078 radius wouldn't touch the hammer until it's at least past half-cock therefore you're not really reducing the moment arm. This is assuming that the face of the fps and hammer are parallel and incontact with each other.

[1911Tuner]

then your not really lowering the point of contact closer the the rotational axis of the hammer.

Sure does. Picture a 6-foot post in the ground. If you apply force against it near the top, you can push it over easier than if you applied the force close to the bottom. If you push against it with a flat tool, 2 feet tall...as soon as the post starts to break over, the higher point of contact is lost, leaving the bottom corner of the tool still bearing on the post.

While fixing this picture in your mind, remember that the hammer rotates around a pin.
The farther from the pin, the more the amount of movement, and...inversely...the closer to the pin, the less movement you see. As the slide starts to move the hammer, the upper contact is broken first as the hammer angles away from it...while the lower part of the firing pin stop is still in contact. The smaller the radius, the farther dow on the hammer the flat part touches it.

The effect of the stop doesn't last long because as the hammer's speed and momentum increase, it begins to lose contact with the stop...as it does with the larger radiused stop. But, while it IS in contact, and the smaller radius does have it's effect...it's effect is multiplied by the reduced mechanical advantage in rotating the hammer against the mainspring's resistance.

[Hawkmoon]

The difference in the small-radius firing pin stop lies not in the contact area, but in lowering the point of contact closer to the rotational axis of the hammer. That means a reduced moment arm (less leverage) in terms of the slide pushing on the hammer. The amount of effort needed to move the hammer is a constant (for whatever spring is used), so if you reduce the moment arm length you increase the amount of force that has to be exerted by the slide.

As I realized in niemi24s' post if the entire flat face of the fps is what initially pushes the hammer back, then your not really lowering the point of contact closer the the rotational axis of the hammer. It would seem as if the .078 radius wouldn't touch the hammer until it's at least past half-cock therefore you're not really reducing the moment arm. This is assuming that the face of the fps and hammer are parallel and incontact with each other.
But the entire face of the stop does NOT push the hammer back. That would be possible only if the hammer slid back horizontally. It doesn't -- it rotates. The hammer is pushed back by the point of contact where the firing pin stop impacts the hammer face, and the small-radius stop does lower that point slightly.

Fire up the STI animation and pay close attention to the slide and hammer interface. What you are describing is physically impossible.

[1911Tuner]

I beat ya to it, Hawk! :D

[sublimaze]

Sure does. Picture a 6-foot post in the ground. If you apply force against it near the top, you can push it over easier than if you applied the force close to the bottom. If you push against it with a flat tool, 2 feet tall...as soon as the post starts to break over, the higher point of contact is lost, leaving the bottom corner of the tool still bearing on the post.

While fixing this picture in your mind, remember that the hammer rotates around a pin.
The farther from the pin, the more the amount of movement, and...inversely...the closer to the pin, the less movement you see. As the slide starts to move the hammer, the upper contact is broken first as the hammer angles away from it...while the lower part of the firing pin stop is still in contact. The smaller the radius, the farther dow on the hammer the flat part touches it.

The effect of the stop doesn't last long because as the hammer's speed and momentum increase, it begins to lose contact with the stop...as it does with the larger radiused stop. But, while it IS in contact, and the smaller radius does have it's effect...it's effect is multiplied by the reduced mechanical advantage in rotating the hammer against the mainspring's resistance.
Got it! :D Thanks

Getting back to one of my original questions, are there any benefits to just swapping out my original factory springs to 16/23?

[1911Tuner]

are there any benefits to just swapping out my original factory springs to 16/23?

Yes. It's part of the system. The 23 pound mainspring provides the full benefit of switching to the small radius on the stop, and staying with the 16 pound recoil spring...or even 14 pounds...keeps felt recoil lower than if you use a heavier spring.

[John]

I would expect that by changing the 17/19 to 16/23 you will have some increase in your trigger pull weight, but as far as a Nighthawk is concerned, that's a good thing for me. These pistols are typically shipped with trigger pulls around 3.5 - 3.8 lbs. For a carry gun I prefer the pull to be between 4.0 and 4.5 lbs preferably towards the upper end of that range. The difference in the main spring will probably move you in that range. Try it, you will love it.

[1911Tuner]

The difference in the main spring will probably move you in that range.

It may not change it even that much. I just swapped out the mainspring housing in a Springfield that had a nice trigger, and it seems to have crisped it up a bit...and I can't detect any change in the force required to drop the hammer.

[Candiru]

It may not change it even that much. I just swapped out the mainspring housing in a Springfield that had a nice trigger, and it seems to have crisped it up a bit...and I can't detect any change in the force required to drop the hammer.

Was it the factory MSH? Because I thought the Springfield ILS used a fairly heavy mainspring; i.e. more than 23 pounds.

[1911Tuner]

Was it the factory MSH? Because I thought the Springfield ILS used a fairly heavy mainspring; i.e. more than 23 pounds.

Nope. This is an older, pre-ILS Springfield Mil-Spec that had essentially been upgraded by another smith to "Loaded Model" status. Nicely done, too I might add. A few minor details overlooked...but overall a nice pistol.

The mainspring appeared to be the original, and the wire diameter matched that of the Wolff 23-pound spring...which is likely because it was a Wolff spring as installed by Springfield.

[berkeleygiraffe]

so if i'm reading this right, the advantage of the "system" is a heavier trigger pull? Doesn't sound like much of an advantage to me...

[Greyswindir]

Nope,

Reduces the felt recoil of the pistol...if you swap out a 19lbs. for a 23lbs. you're only talking about 1/4 lbs difference in pull feel, depending on the quality of your hammer and sear job. So the advantage is a reduction in felt recoil...supposedly...it all depends on the person perceiving the recoil in the first place. The actual force driving the system doesn't change.

-greyswindir.

[1911Tuner]

so if i'm reading this right, the advantage of the "system" is a heavier trigger pull?

Nope. Not all that much. I could switch'em back and forth for a blind test, and you'd be hard pressed to detect the difference, and in some pistols...may even make the trigger better, though It'd be tough for me to try to explain it...mainly 'cause all I've got is theory right now. (See this thread, post #13.)

[Greyswindir]

No Tuner...that's not theory, a bit of extra pressure should crisp things up a bit, and take away any "mushy" feel to a trigger, especially if there was a bit of creep to begin with. If it's your direct experience then there is no theory, unless you're talking about something I haven't thought of...I did read #13. Where's the theory you were talking about?

TG.

[1911Tuner]

I did read #13. Where's the theory you were talking about?

Meant that 13 described a recent experience with installin' a new spring and the trigger gettin' better...Theory as to exactly why that happens. Pretty sure you're correct, but haven't really put it to the test yet...so theory it remains until proven.
Also...It doesn't happen every time...so it's not a consistent way to improve a trigger.

[John]

so if i'm reading this right, the advantage of the "system" is a heavier trigger pull? Doesn't sound like much of an advantage to me...

That's what you understood??!?!?!?!? :(

I suggest you re-read everything again. Especially this:

http://forum.m1911.org/showthread.php?t=13060

[Greyswindir]

Wonder why the feel is inconsistent? That's odd?

[John]

I guess what Tuner meant is that the results are not the same when the spring is changed in other pistols. In other words, changing the spring, in one pistol made the trigger better, in another it didn't.

[Greyswindir]

I got that part John...inconsistent... ;)

What I meant was, I didn't expect such a vast difference over just a few pistols. The inconsistency probably lies in either the way hammer hooks have been cut or the way the sear was/is stoned.

-greyswindir.

[CZJedi]

For "the system" to work, does it make any difference if the firing pin spring is extra power or not?

[Greyswindir]

Nope, no difference at all.

[CZJedi]

How much difference would a 22# mainspring cause? The reason I ask, is that I really like ISMI springs, and 22# is all they go up to. If I did that, should I change the recoil spring by a pound either way (15# or 17#)?

[1911Tuner]

How much difference would a 22# mainspring cause? The reason I ask, is that I really like ISMI springs, and 22# is all they go up to. If I did that, should I change the recoil spring by a pound either way (15# or 17#)?

Not enough for it to be a concern. You won't realize the full potential effect, but...since ISMI springs tend to outlast Wolff springs...it will balance out over the long haul unless you replace the mainsprings more often then they really need to be. (Like I do.)

I'm soon planning to go up to a 25-pound mainspring and dropping to a 14-pound recoil spring for all my regular beaters in order to lessen the strain on my tired old hands.

No need in upping the recoil spring, either. Stiffer recoil springs make recoil sharper rather than softer. I'm soon planning to go up to a 25-pound mainspring and dropping to a 14-pound recoil spring in order to lessen the strain on my tired old hands.

[CZJedi]

One last (possibly dumb) question... would the use of a titanium mainspring cap and hammer strut have any effect on this system (good or bad)?

[John]

They won't have any major effect on the system, but they sure will empty your pocket much faster.

[Greyswindir]

Hahaha!

John,

Do you really feel that the titanium MSH parts are a complete waste of money? I guess they are good for the guys who shoot in competitions, where a slight decrease in lock time would be the edge they are looking for. Like Tuner mentioned, for these guys, a tenth of a second or an extra thousandth of an inch could mean the difference between winning and losing. For us average shooters, we probably don't need the titanium parts.

Me personally, I'm a beginning bullseye shooter and would like to eventually get a titanium cap for my MSH. Might help a slight bit...maybe.

[1911Tuner]

Simple physics will prove that any reduction in mass will speed up the rate of acceleration...assuming that the magnitude of force is equal. That's why a 350 Chevy engine in a Vega makes for a quicker 1/4-mile car than the same engine in an Impala, assuming equal traction and gear reductions in the drive line.

How much practcal difference that a titanium cap will make is at best a point for discussion and debate.

Longevity is the issue with titanium parts. It doesn't seem to hold up as well as steel under hard or prolonged use. Of course...titanium varies in quality like any other alloy...so the long-term durability will also vary.

[Greyswindir]

That's interesting Tuner,

I always thought titanium was stronger than steel? Lighter also. I once did a hammer test on a titanium C-shaped fastener. I whacked it pretty good, numerous times and could only, after trying hard, bend the part only slightly. The titanium part was slightly less than 1/4" thick. Steel, of the same thickness, would have bent to such a degree that both ends would have eventually touched each other, after a few hit from the hammer.

Now, I don't know if the hammer test proves anything on the longevity of titanium gun parts but I think the results were interesting. So Tuner, I wonder why the titanium doesn't hold up as long as steel parts? There must be a logical reason. Is titanium stronger than steel? I know there is a difference between stronger or harder. A harder part isn't necessarily a good thing, since the harder a material is the more brittle it it usually becomes.

Stronger would be what we're after in 1911 parts, we want the parts to have some elasticity or...flex, in order to last longer, but not to such a degree that the "flex" effects the tolerances and mechanical fit of the part.

What say you Tuner?

[Hawkmoon]

I always thought titanium was stronger than steel? Lighter also.
You have fallen victim to advertising double-speak.

The world is full of marvel materials that are all stronger than steel. If you look into them, the fine print says "pound for pound, stronger than steel." That means a pound of Glyptonium is stronger than a pound of steel. But ... Glyptonium weighs one-eighth as much as steel, so to equal the strength of a steel part, the same part in Glyptonium has to contain six or seven times more material. For parts with fixed dimensional criteria, you just can't fit six or seven times as much material into the part, so you end up with a part made from this magic "stronger than steel" material that is actually only one-sixth or one-seventh the strength of the steel part.

The difference between steel and titanium isn't 8x ... but the same principal applies.

[John]

Believe me, I've been there and my wallet was made much lighter. Back then, the titanium hammer, hammer strut, main spring cap and firing pin were considered to be the best for improving lock-up times, and they cost more than 400$.

Unless you can now see 5 consecutive shots going in a cloverleaf, all holes touching together at 25 meters, your improvement by these parts will not be anything to write home about. If you can do the above, maybe these parts will allow you to shrink the cloverleaf by ... oh, maybe 1/4".

[Greyswindir]

Wow guys!

Ain't that clever marketing! and very deceptive! Just like they say a spiders web is the strongest substance around, same principle as you mentioned Hawkmoon. I feel stupid not thinking of it those terms. I guess that is why they are rich and I'm not!

I didn't know they sold Titanium hammers John? Shew! How much did the hammer set you back and did it last or did the part get messed up pretty quickly? $400.00 bucks for the whole shabang is a lot of money. Nah John, I still have a lot of practicing to do before I can get consistent groups that tight! I don't think I'll ever need to get that extra quarter inch out of my pistol. I like to shoot bullseye, but I do it for myself. I'm not big into the competition end of it. I might enter a match at some point, just for kicks, but I'm really testing myself, just to see how good I can become.

I have a titanium hammer strut, that's all. I guess I'll stop right there.

Thanks guys.

[1911Tuner]

Titanium doesn't do well as with impact stresses. I've seen titanium firing pins brad and mushroom.

[Greyswindir]

Hey Tuner,

Well, I'm glad I bought a spare firing pin for my Springfield from Ed Brown. Those S.A. firing pins are proprietary! I'm glad a few parts makers decided to make some out of good old steel! If mine does start to mushroom at some point in the future, at least I'll be prepared. After doing a bunch of mods and building another pistol I have plenty of spare part now!

[1911Tuner]

If you sawp the factory firing pin for the Brown...and your Springfield has the ILS system...you'll need to change out the rest of the group for the standard design parts.. Mainspring...Mainspring cap...Firing pin and spring. You'll also want the little-bitty mainspring cap retaining pin. Optional, but useful.

[Greyswindir]

I appreciate the warning/advice Tuner.

I swapped everything out ages ago, I never liked the idea of non-original designs in my pistols. John Browning did a wonderful job at designing the 1911. A century later the design is still viable, if not superior to the contemporary pistol designs. And that is not all opinion...the pistol has been battle tested and works very reliably if built properly, as you well know!

My Kimber still has the Swartz FPB installed but I modified it slightly so it works more smoothly. I'm eventually going to remove it, but I need a sight pusher to get the block out, which resides under the rear sight! I thought about lock-tighting the block in the "up" position but have thus far "wimped" out on doing that. If I did do it I would probably use blue loctite. I think the best way would be to remove the rear sight and just take out the blocking mechanism.

[John]

I didn't know they sold Titanium hammers John? Shew! How much did the hammer set you back and did it last or did the part get messed up pretty quickly?

I do not remember what the price was for the hammer only, but the whole set was about $400, that I do remember. The hammer lasted quite a long time, if you discount two grooves that appeared at its top end, from the thin walls of the disconnector recess (that was a Series 80 Colt, I used it in), but it didn't break or anything. Some filing would make the grooves dissappear I guess, but I have sold that pistol, so I do not remember if I ever bothered fixing them.

[Greyswindir]

Thanks.

I've yet to own a Colt 1911. Do you feel that Colts offer anything different or superior that another 1911 doesn't? You know how other people tend to think everything else is just a copy and feel the Colt is the cream of the crop. I have handled them before and I'm really impressed with the new WWII replica they have out. It's a really beautiful pistol!

[berkbw]

Some guys get to be "old timers" in less than 2 mo. Titanium is strong, light, and SOFT!

It niether makes a good hammer tool, nor something good upon which TO hammer.. 'cept it's soft. eh?

[Greyswindir]

Hmmm...

Wonder why our Military uses it in the A-10 Warthog...you know, the titanium "bathtub" that protects the pilot from harm. Those planes can take a serious amount of damage, some have flown home on a wing and a prayer, literally! Like Hawkmoon said, the thickness you need for a part is a lot different then the thickness you would use on a plane cockpit for protection, so I guess it is relative.

Some guys get to be "old timers" in less than 2 mo

:confused: