Recoil Spring Study

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...and described its function, which didn't include deceleration of the slide or any mention of buffering or softening the blow.
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That's a narrow read of the document.

In the patent, he discusses a method for stopping the barrel so that the stress transmitted "to the frame ... due to the sudden arrest of the movements of the barrel" doesn't cause "injury...to either the barrel or the frame".

Clearly he understands that the barrel is moving fast enough and has enough mass that it could potentially damage the frame. He specifically points out that the patented design arrests the barrel movement in such a way as to prevent damage. However, the slide has considerably more mass than the barrel and, neglecting the spring, is travelling at roughly the same velocity at slide/frame impact as the barrel was at its earlier impact with the frame. Yet there is no mention of any steps taken to ameliorate the slide/frame impact.

Why isn't he concerned about injury to the slide or frame as a result of arresting the slide energy? Clearly if the barrel/frame impact is a concern, slide/frame impact must be an even greater concern due to the additional mass (and therefore greater momentum and energy involved).

There are 2 clues in the document as to why this is so. One is when Browning says that the slide "energy is stored in a spring", and "utilized to effect the return or closing movement of the" slide. The second is when Browning points out that the slide should be "as heavy as practicable...so that it may...store a maximum amount of energy...to complete the opening of the breech and the compression of the reaction spring". In short, he's not concerned about there being a violent slide/frame impact because he's actually concerned that there might not be enough slide momentum/energy to completely compress the recoil spring if the slide isn't "as heavy as practicable". In other words, he's concerned that the recoil spring might absorb too much of the slide's energy and there might not be enough slide energy/momentum to completely compress the spring.

Not exactly supportive of the theory that compressing the recoil spring doesn't absorb much energy.
 
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I found this on YouTube. It's a slow-mo video of a S&W 4006 at 1 million FPS showing the bullet being fired and leaving the barrel. You will notice that the locked barrel & slide move back together about 2/10ths of an inch as the powder ignites and the bullet leaves the barrel.

http://www.youtube.com/watch?v=otpFNL3yem4&feature=related

note the debris leaving the barrel before the bullet does.

10mm, when you care enough to send the very best.
 
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Not exactly supportive of the theory that compressing the recoil spring doesn't absorb much energy.
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That wasn't my point, either. What energy the slide absorbs is what it is. My point was that the slide doesn't hit the frame that hard...with or without a spring...and that the prevailing notion that adding an extra 2 pounds of spring is somehow going to make a measurable difference in the service life of the frame...is ludicrous. It's just not based in fact. It plays on our fears. Unfounded fears.

There's a Youtube video out there somewhere that shows a guy firing a Glock with his thumb pressed against the back of the slide. Hard to tell, but it doesn't look like the slide moves at all...though I'm sure that it has to move a little...and probably about 1/10th inch.

Given that...how hard could the slide hit the frame after compressing even a 5-pound spring? Really.
 
1911tuner,

just reread your op. my take on why the colt engineers use a heavier spring with a lighter slide: momentum. has to be the same to shuck a round out of the mag and into the chamber. with a lighter slide, you need more energy in the spring to have the same amount of force, applied to that round coming out of the magazine, as the heavier slide. so, the lighter the slide, the heavier spring required to maintain equal force to load the next round.

murf
 
There's a Youtube video out there somewhere that shows a guy firing a Glock with his thumb pressed against the back of the slide. Hard to tell, but it doesn't look like the slide moves at all...though I'm sure that it has to move a little...and probably about 1/10th inch.

Given that...how hard could the slide hit the frame after compressing even a 5-pound spring? Really.
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Try shooting a 12ga with the stock firmly against your shoulder the first time and then, the second time, with the stock held so that it's a few inches in front of your shoulder before the moment of firing. You'll note a significant difference in the force applied to your shoulder.

Similarly, if the thumb is held a few inches back from the slide and the gun is then fired, injury would be likely. The force applied by the impact of the moving slide is not comparable to the force required to hold the slide closed.
 
just watched that video with the guy shooting the glock with his thumb on the slide. smoke and mirrors! i can see the primer flash coming out the end of the barrel. no powder or bullet. takes a real "HE" man to hold back that load.

also, there are two springs arresting the rearward motion of the barrel and slide from the get-go. the hammer or main spring absorbs most of the slides energy since the barrel comes out of the locking lugs about half way through the cocking process and no longer contributes to the mass of the slide. probably why the barrel stop pin gets most of the beating as the barrel slams into it unabated. another consideration would be the drag of the barrel being pulled down out of the locking lugs by the link.

i'm sure all these actions play a part in the manufacturers choice of hammer and recoil spring design and weight.

(i'm enjoying this little debate)

murf
 
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have rethought my post #81. i'm wrong in my thinking. the weight of the slide has nothing to do with the force required to bring the slide back into battery. it doesn't matter how heavy the slide is. it could weigh 20 pounds and the recoil spring will bring it back into battery (will just take a little longer to do).

so, i'm changing my thinking on why colt put a heavier recoil spring in the commanders. it's to compensate for the increased rearward speed of the lighter slide and barrel when recoiling. couldn't have anything to do with returning the slide to battery, since the old spring rate does just fine as is.

flawed logic?

murf
 
(quote) i can see the primer flash coming out the end of the barrel. no powder or bullet.

I've never seen any primer that was that loud or would kick that much. Watch it again with your sound on.

10mm, when you care enough to send the very best.
 
his last two shots were aimed at the ceiling. again, smoke and mirrors.

murf
 
I just ran across this thread and wondered about the bottom line for a Commander spring. Where are you going to get a 14 or 16# recoil spring for it to even try it? Most all places sell the 18# or more for the Commander. do you buy a GI 16# and just cut a few coils off it?
 
I know you can get there by cutting coils off of a govt model spring but I don't know how many to cut off. Maybe someone who does will post it. 1911tuner knows - maybe he'll see this. :)
 
I want to say a total of 24 coils but I'll let tuner answer that. I just found out Wolff sells springs for the Commander from about 11 pounds to 16 pounds(under power).
 
As long as the Commander has a standard rod and plug recoil system, the 32-coil GM spring can be trimmed to work. For a 16-pound Wolff spring, I cut to 24.5 coils and test for stacking. A 14-pounder can use 25 coils...but check carefully for coil bind and stack. Pistols with bushingless, reverse plug systems aren't candidates for trimming the spring.

This doesn't work for Officer's Models, nor pistols that aren't true Commander clones, like the Springfield Champion and its 4-inch slide.
 
Would the 16# Wolff for the Commander work ok rather than trim the GM to 24.5 coils?. My XSE Commander has the full length guide rod. There should be no coil bind with that setup. Wolff does sell 14 and 16# springs in their "under power" packs.
 
1911Tuner quote: "........but check carefully for coil bind and stack. Pistols with bushingless, reverse plug systems aren't candidates for trimming the spring."

Your mentioning the possibility of the recoil spring binding/stacking when installing a trimmed Govt model spring would appear to offer the only good reason other than cosmetic (and that may not be a "good" reason) for installing a FLGR. With a FLGR in place the recoil spring couldn't bind up, right?
 
Coil bind...stacking...is caused by the spring compressing to the point that the coils form a solid cylinder before the slide hits the impact abutment. It can be pretty destructive, and the bushing will fail at the very least. It has nothing to do with the guide rod.

A quick check can be done by briskly racking the slide and listening to what the pistol is saying. If you hear a sharp metallic "clack" it's probably okay. If you hear a dull, crunchy "thud" it's not. Trim a half coil and retest.

The definitive test is to put a strip of tape on the frame spring tunnel and scribe a witness mark with the front of the bushing with the spring plug removed and the spring free. Then, reinstall the plug and pull the slide full rearward again. If the mark lines up with the bushing, you're golden. If the front edge of the bushing is forward of the mark...you have coil bind. Trim a half coil and retest.

I've never had a Commander go into coil bind with a 16-pound GM spring trimmed to 24.5 coils...but that doesn't mean that it can't happen. I have seen one coil bind with a Wilson 20-pound spring that was specific to the Commander, and it cracked the slide in the bushing lug raceway. A good practice is to check any Commander-specific spring that you replace.
 
Thanks for the explanation, Tuner. Obviously I didn't understand what "spring bind" meant - now I do.....and, I guess there's still no really good reason for a FLGR other than cosmetic. :) I guess the good news is that they don't do any harm either.
 
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Part of the continuing attraction of full length guide rods in the 1911 pattern is that, when hand cydling, pistols so equiped just, flat SOUND good.

Perception counts.

salty
 
Thanks Salty Dog. I'm gonna have to get one of each out and listen to the "sound" - I have a better than average ear (if I DO say so) when it comes to sound quality, rhythms and differences in comparison. I just never paid any attention to the fact that there is a difference in sound between the 2 types of guide rods.
 
My 16# Wolff spring for the Commander came yesterday and I'm going to try it out next week. Wolff calls it a "Reduced Power" spring but it's about an inch and a half longer than the one I pulled out of the Commander. However after being in there a while it was nearly the same length as the original. Both have 12 coils. The spring that was in the pistol was stiff, I had a hard time pulling the slide back, truthfully. I'm hoping this spring will work as well reliability wise and yet it's a bit easier to retract the slide slingshot method.
 
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