Adding Weight to 1911 slide

[big50_1]

Just joined THR. Have been reading this forum for some time and have been very impressed with the level of knowledge. I have been shooting for fun for over 4 decades and have owned (or own) 1911s in .45 and 9mm, S&W 39-2 (several), BHP, CZ 75B SA, Glock 17, CA 83, Browning BDM, S&W 28-2, S&W 29-3, S&W 49, Ruger Blackhawks, Vaqueros and Single Sixes, Security Sixes (several), P94, Mk II, and 22/45, Ballester Molina (this was delivered to my college room via mail and left on my bed pre-1968 gun laws), Beretta 92FS, and Beretta mdl. 70 plus all kind of rifles. Started my firearm training in the military so I'm not a stranger to firearms. I like 9mm for the cheap (er) ammo but understand the "authority" of a well-placed .45 ACP round and also understand that the likes and dislikes of a particular gun is very subjective. Blue steel and wood are my preference but plastic receivered guns have their place. I've had a Glock 17 since 1995 and every once in a while, I think about getting rid of it but darn it all, it always fires, looks as good as the day I bought it, and when the SHTF all you got to do is squeeze the trigger. --
Anyway, here goes:

I've been following the threads re using different recoil spring weights in the 1911 and have been experimenting on a SA 1911 9mm. A 14 # recoil spring is nominal for the 9mm, so I've gone to 16# (EP), 12# (RP), and 10# (RP). With the 16# EP, the 1911 recoil is more of a big push (I think the spring pushes the frame and the gun is in recoil when the slide hits the frame). The RP springs give less and less push until with the 10# the effect is like the gun "popping" in the hand as opposed to recoiling. Does that make sense? Little up and down movement but more of a back and forth movement. O.K. so far? I understand that top competitors routinely underspring their race guns to get just that effect to minimize the sights coming off target during competition. -- I also understand that by the time the 1911 slide moves about .1 inch, the bullet is out the barrel and imparted momentum completes the guns operation. I added a heavier Cominolli tungsten recoil plug and have the distinct feeling that the slide slowed a little. I sense a slight hesitation between firing and frame impingement. Also, it seems that my groups get slightly smaller when I use the heavier recoil plug. What do you all think? -- Lee

 

[HSMITH]

Welcome to THR!!!

We could have 5 guys that shoot a LOT answer this and have 5 different answers that are all correct. Personal preference plays a big part.

Personally I get about the same feeling from the spring changes that you do. I like the lighter springs, and in competition the timer tells me that the light springs are more efficient for me.

Adding weight to the slide will change the timing of things just a little, and the slide feels a little slower to me. I find in competition that it adds time, getting that extra mass back on target requires more time for me. The feeling I get is that I am working harder to do the same things with the extra weight vs. shooting a lighter setup.

Group size shouldn't change, but it very well could have.

Mainspring weight and firing pin stop radius also make some pretty noticable changes in the feel of the gun. I am working with these two now 'finish' tuning my race gun, I have a great load and gun but if there is a little polish here and there to make it a little better I am always looking for it.

 

[Double Naught Spy]

I think you would get still better results with a Wilson Combat tungsten FLGR and it won't change the timing. The heavier guide rod plug should NOT have affected the timing either, although it may have affected felt recoil, hence giving you the perception that the timing is different.

 

[1911Tuner]

Slide Weight

Anything that adds mass to a moving part delays the onset of movement and slows the acceleration of that part. Simple physics. That's part of how the 1911 works. When the slide is slammed rearward, the locking lugs engage, and it draws the barrel rearward with it for a short distance, thus delaying the breech opening by way of that added mass until the bullet exits. The breech doesn't "unlock"...and can't without damage...until after the bullet is gone.

There's a misconception about timing here...or rather between the terms "Timing" and "Time" Timing is a fixed mechanical event that occurs where it occurs, regardless of the slide's rate of acceleration. Time is how long it takes for the event to occur from start to finish.

Pull the slide to the rear and watch the barrel drop. That will take place
at the same point, whether the slide is cycled by hand or under a full head of steam. Timing vs Time.

So...Adding or subtracting weight (mass) to the slide will alter the elapsed time of its cycle, but not the timing of barrel linkdown and drop.
More simply stated...A heavy vs light bullet with the same powder charge doesn't change the bullet's timing...It only changes the time that it takes the bullet to get to the muzzle.

This may not be clear as water...The steroids are still cankin' my head up.

 

[big50_1]

Thanks much to all for the info. All makes sense to me. The 'Time' vs 'Timing' point was informative and clear. I've gone to a SA 9mm 1911 with a Cominolli frame-saver guide rod (has shock buffs on both side of guide rod flange/head) so I can shoot 'quantity'. BUT I love this .45 parts gun I had a 'smith do in 1982 (kinda' has that '80s look). Colt split-bushing barrel, Rem. Rand slide and Crown City Arms frame, Cominolli frame-saver FLRG and Cominolli tungsten recoil plug. I use mostly CCI blaser aluminum cased ammo and it's an easy shooting gun.

 

[big50_1]

I like the way the picture came out. The slide flats are highly polished and I was careful not to get flash reflected into the camera.