Explain the Difference(1911)


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February 3, 2006, 09:09 PM
Shot my friends SA TRP the other day, felt recoil was noticeably lighter and followup shots were faster than my former Kimber Custom II. Why is that? Only change I made to the Kimber was a GI guide rod.

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Old Fuff
February 3, 2006, 09:17 PM
The FLGR adds weight toward the muzzle, and forward of the pistol's balance point. As such it dampens recoil a bit. Adding a weight under the dust cover will have a similar effects. So will going to a tapered barrel fitted to the slide at the muzzle, rather then a barrel bushing.

jungle
February 3, 2006, 09:33 PM
Not really enough in your post to say why, but there are many possible reasons.

Ammo is a big factor. Was it the same? Recoil spring weight can alter the perception of recoil, with heavier springs giving a more direct feeling of recoil and lighter springs reducing that effect. Overall weight of the pistol can effect recoil feel, but this applies to larger differences, I.E. Aluminum vs Steel frame.
Guiderods and heavy barrels can have a small effect, but being the insensitive clod I am, I cannot discern it.
Sometimes a tighter fit of slide to frame and slide to barrel can mitigate felt recoil, and this may be due to more friction in the operation. I notice a real difference in feel between tight and loose pistols when firing, but this may not be all recoil related.Subtle differences in fit of the beavertail shape and size to the hand can lower bore axis and provide a broader surface to absorb recoil, as can grip thickness and texture. Most of these factors are subjective and the only true test is to shoot the guns side by side within a short time frame.

1911Tuner
February 3, 2006, 09:40 PM
Simple...The Springfields with the ILS system utilize a 28-pound mainspring.
The effect is much like the small-radius firing pin stop with the standard 23# mainspring. Adding resistance to cocking the hammer really does make a difference in muzzle flip and recovery between shots.:cool:

Boats
February 3, 2006, 09:49 PM
Tuner's got it.

I took the ILS off my SA Champion in exchange for GI standard parts/mainspring and found it kicked a little harder, so I put it back on after loctiting the keyhole stuck in the unlocked position. It is by far my most shootable Commander sized rig.

jungle
February 3, 2006, 09:51 PM
Tuner, It seems that the combination of recoil and hammer spring are what give the feel. I tend to go fairly light on both and it works for me, with the heavier springs giving a sensation of more recoil.
The ILS is an obstacle to easy experimentation, but fixed with ease and a couple of parts.
A good test of what is right for your grip and load is to try a few double taps and watch the movement of the front sight. I think most people are surprised when the lighter setup yields less muzzle movement. Going higher than standard spec. isn't good for reliability, but a 16lb recoil and 19 lb main seem just right.

1911Tuner
February 3, 2006, 09:57 PM
Tuner, It seems that the combination of recoil and hammer spring are what give the feel. I tend to go fairly light on both and it works for me, with the heavier springs giving a senstion of more recoil.
The ILS is an obstacle to easy experimentation, but fixed with ease and a couple of parts.
A good test of what is right for you grip and load is to try a few double taps and watch the movement of the front sight. I think most people are surprised when the lighter setup yields less muzzle movement.

Heavier recoil spring does increase felt recoil. The heavier spring pushes the frame back as hard as it pushes the slide forward. Increasing the mainspring load has the opposite effect. That's why the firing pin stop with the .075 radius makes the guns feel so...right. Decreases mechanical advantage in cocking the hammer...Delays the slide movement at the outset for a tick,
and redirects some ot the slide's momentum to the mainspring. Slide velocity is lower...frame impact is reduced...felt recoil is reduced..and even allows the use of a slightly lighter recoil spring without sacrificing frame to slide impact buffering.

FWIW...The small-radius stop was the original dimension for that part.
Changed later at the Army's request to make the gun easier to hand-cycle with the hammer down.

jungle
February 3, 2006, 10:07 PM
Tuner, Do you feel a 28lb mainspring is a benefit for reliability? The original design seems to have gotten along just fine with the 16/23 recoil/main weights and radiused slide stop. It would seem that slide velocity is OK within a certain range and that if it is allowed to run too fast or slow reliability suffers. Lots of people are running 14/17 combos with stellar reliability in the full size slide.

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February 3, 2006, 10:47 PM
Uh........I think I'm more confused than ever. :scrutiny: :banghead: :D

Tuner, are you saying Kimber and Springfield use different springs?

jungle
February 3, 2006, 10:53 PM
If the TRP you shot had a stock ILS setup the answer is yes, if not who knows?

ziadel
February 3, 2006, 10:55 PM
crap, I was gonna have a trigger job done to my 1911, but I dont wanna give up that 28 pound spring...

how much will that interfere with a good carry trigger? let's say 4.5 pounds.

1911Tuner
February 3, 2006, 11:06 PM
Tuner, Do you feel a 28lb mainspring is a benefit for reliability? The original design seems to have gotten along just fine with the 16/23 recoil/main weights and radiused slide stop. It would seem that slide velocity is OK within a certain range and that if it is allowed to run too fast or slow reliability suffers. Lots of people are running 14/17 combos with stellar reliability in the full size slide.

Howdy Jungle,

The 16/23 combo along with the 7/32nd firing pin stop works well, and has since the firing pin stop was modified. The original .078 radius (nominal)
has an effect on the slide's rearward speed and impact that really has to be felt to be understood. The spring rates were the same for both designs.


The benefit is in reducing the slide's rearward speed and momentum...which reduces impact with the frame without the drawbacks of using a heavy recoil spring. Sharper felt recoil and muzzle rise...less critical as to magazine timing,
etc. Like I said...The slide's initial rearward movement is delayed slightly.
Remember the other thread on the effect of a weaker vs a stronger recoil spring concerning unlock timing? By reducing the slide's initial move, it gives the bullet a little longer to exit before unlock starts, though it doesn't change the point of unlock...and many report a slight increase in accuracy when using the small-radius stop.
************************

.. said:

Uh........I think I'm more confused than ever.

Tuner, are you saying Kimber and Springfield use different springs
*************************

Yes..but only the ILS-equipped Springfields. The mainspring is than the standard design mainspring in order to acommodate the longer mainspring cap in that system. Since it's shortened, it's necessarily heavier...not only to make up for being short, but to insure reliable ignition with the uber-heavy firing pin spring. The ILS manispring housing also doesn't use the small cap retaining pin in order to provide all the length that the spring can provide.

jungle
February 3, 2006, 11:08 PM
ziadel, You will find very few gunsmiths doing trigger jobs with 28lb mainsprings. It won't be healthy for the sear/hammer interface either.

Springfields light firing pin, heavy firing pin spring and ILS short heavy spring create more problems than they solve. Changing the ILS spring weight really needs to include another firing pin and spring to get back to original spec.

robmkivseries70
February 3, 2006, 11:11 PM
Good Day,
Hope this is on topic: Does the smaller radius on firing pin stops decrease the life of the hammer or hammer pin? Seems that the initial force applied to the hammer would be closer to the fulcrum in this arrangement and tend to drive the whole hammer assembly to the rear. Thanks!
Rob

1911Tuner
February 3, 2006, 11:19 PM
Good Day,
Hope this is on topic: Does the smaller radius on firing pin stops decrease the life of the hammer or hammer pin? Seems that the initial force applied to the hammer would be closer to the fulcrum in this arrangement and tend to drive the whole hammer assembly to the rear. Thanks!
Rob

Howdy Rob, and welcone abaord.

Although the lowered point relative to the fulcrum would tend to throw higher forces on the pin, it hasn't adversely affected any of my hard-use range guns
in over 50,000 rounds per gun since I switched over to'em. Of course, frame
and pin material would play a part in that too. Cast frames may not be as durable as machined barstock. Soft pins and/or MIM/cast hammers likewise.

Uesd to be that I'd search the gunshow parts bins for the WW1-era stops...but since EGW starded making a square-bottomed stop that allows me to cut my own radius...which I usually cut even smaller (1/16th) than the old standard...AND they're slightly oversized to allow fitting to keep the extractor square...I haven't had to search for'em. They're available in Series 80 and pre-Series 80 type. 15 bucks a copy.

I've seen guns halve the distance of ejection with just the addition of the stop.

robmkivseries70
February 3, 2006, 11:40 PM
Hi Tuner,
Thanks for the reply, I was off down the list and decided to check the thread. I just put an EGW over sized FP stop on my Loaded to stop the extractor from clocking. I did add some radius and now wonder about the slide velocity LOL. I think the recoil spring is 16#, don't know the main spring weight except it is stock, not ILS. Anyhow, thanks again for the help.
Rob

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February 3, 2006, 11:42 PM
Thanks Tuner.

1911Tuner
February 4, 2006, 12:07 AM
Hi Tuner,
Thanks for the reply, I was off down the list and decided to check the thread. I just put an EGW over sized FP stop on my Loaded to stop the extractor from clocking. I did add some radius and now wonder about the slide velocity LOL. I think the recoil spring is 16#, don't know the main spring weight except it is stock, not ILS. Anyhow, thanks again for the help.
Rob

If it's not an ILS system, the mainspring is probably 23#. The stock Springfield recoil springs used to run around 16, but lately they've been ckecked at 13.5-14 pounds even. The EGW stops should be radiused a little, or at least a slight bevel on the corner. Whichever you use, ti needs to be straight to prevent side-loading the hammer.

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April 29, 2006, 01:15 AM
Tuner, if I remove the ILS from my loaded what spring combo do you recommend and will it increase felt recoil?

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