Measuring Recoil Springs

First topic message reminder :

List members of the original Bullseye-List may have recalled Ed Masaki mentioning that the listed weight on the package tend to be lower than the actual measured weight.  Around 10 years ago, Ed was kind enough to measure a number of my extra old recoil springs sitting in my garage which had no labels.  He also checked several of my brand new Wolff recoil springs to verified the labelled weights.  The recoil spring tester was I believe the only one available which was the gold standard. After a search I don't see it online anymore (made by SDM?? but not sure).  I pulled out the box of Wolff springs to reviewed what I had recently posted about the actual spring weight.  Here's what we found:

Labelled:  11 lb.     actual weight:  12 lb.
              12 lb.                          13 lb.
              12 lb.                          13 lb.
              13 lb.                          13 lb.
              13 lb.                          14 lb.
              14 lb.                          14 lb.
              16.5 lb.                       18 lb.

I also have a 9 lb. and 10 lb. Wolff spring which were not measured, but the 9 lb. "felt" like 10 lbs.  The 10 lb. felt like another spring that was measured at 11 lbs.
Has anyone doubled checked their new springs to verify the weight, and have you found any differences to the label?  I bring up this topic because when testing loads in conjunction with the recoil springs, there may be a source of error in our findings.   Thanks for reading.

Wobbley wrote:This video shows the 1911 doesn't recoil so much from the bullet being fired, but more from the slide hitting the frame.  Notice the impact to the hand and the twisting of the wrist when the slide hits the frame.  The recoil spring has almost no effect.  This explains why a rib and/or an optic mounted on the slide tends to soften the recoil.   As the slide weight goes up the slide velocity goes down. 

https://youtu.be/jig-RvZr1OM

I think these slow motion videos are so cool. I used the YouTube option to slow it down even more. Very interesting, to me anyway.
Looks like the bullet always leaves the barrel before any unlock. Maybe some very small push back.
Looks like the most sever part of "recoil" is when the slide hits the frame and then the whole gun goes into recoil into you.
I find it just amazing that so much powder comes out of the barrel un-burned.

Is that why long slides 45 where made? Soak up more slide velocity?

Stan

I think the long slides were mainly for sight radius originally but then Bomar came with the extended front sight on the 5 inch guns. 

Of course the Clark long slides did come with a 1.5" test target.... shooting one is a joy IF you can hold it.

Yes the slide impacting the frame will cause a sharp jolt to the shooter, the energy is transferred to the shooter in a short time period. Increasing the spring weight will slow the slide and stop it before it impacts the slide primarily because it's not good to have the slide impacting the frame. However the energy is transferred from the spring to the frame and again eventually to the shooter but at a longer time period. The amount of energy transferred is still the same except over a longer time period. It is now felt like a push rather than a punch. The amount of weight needed to absorb the energy is far greater that the weight of a slide, it then requires the weight of the shooter! Like a fish scale held in the hand, the spring limits the movement but the entire weight of the fish and the scale is supported by the hand.

Since were sorta kinda talking recoil here is an interesting article on how to reduce recoil on a 1911 and how much reduction you can expect.

http://www.shootingtimes.com/gunsmithing/reducing-recoil-traditional-vs-bushing-compensators/

I'm wondering if a compensator actually has any effect on recoil at all. Recoil is rearward, the reason the gun rises is because it's the path of least resistance. Yes it probably reduces upward travel and the result just might be greater rearward force. Getting kinda above my pay grade but I'm thinking the gasses exiting have little to do with recoil though there must be some like an air hose whipping around like a drunk snake. Again beyond my pay grade is the statement that heavier powder will produce more gas, I don't think that's quite right. Weight has little to do with the amount of gas produced and will only be true with the weight difference of the same powder. It is also possible that a heavier by volume powder can produce less gas than a lighter one. It also does not take into consideration any inert components nor the amount of unburned power. Another issue that comes to mind is how was recoil measured? It seems that the amount of rise might have been used.
 A looong time ago when I was in college I might have been able better determine the accuracy of the article. Years of not using Vector Analysis and chemical formulation only has me guessing. Though that knowledge is rattling some where in my brain all I get is I don't think so when thinking about the issue.

Compensators or muzzle brakes require gas volume and muzzle pressure to function at all.  Both of these requirements are opposite to what Bullseye shooters are trying to do which is load for accuracy.  The best approach is to load lighter bullets and load as low as reliable function allows. 

Decades ago, there were "recoil buffers" sold that had a plunger sticking out of a recoil spring guide.  The plunger had a heavy spring behind it and you had to use a special thicker recoil spring plug.  This outfit is making something along a similar vein.  Perhaps Jon might comment.

http://www.sprinco.com/recoil.html

speaking of recoil springs, I have a new old stock spring for my P240 hammerli, If i was looking to have a new spring made in a higher weight. What measurements would i need off the spring and gun? 

Guessing

Length before compression
Length fully compressed
OD and ID of spring. 
Wire thickness
# of coils
current recoil spring weight (not sure how to figure this one out)

If you have the wire diameter, the OD, number of working coils, the free length before compression, and the type of ends, you have all the info you need.

http://springipedia.com/compression-end-types.asp

Search these folks catalog for a spring that matches closely to what you're looking for: http://www.asbg.com/ If you ask nicely, they may sample one for you.

Compensators and buffers. Comps require frame mounted optics which is not typical of majority of BE pistols. They can shoot just as accurate as non-comped gun. Buffers change the feel of recoil adding an extra felt impulse; normally only a seasoned/experienced shooter will feel it. High Masters won't use one because of the 'feel'. Comped 9mm requires a lightened slide to run reliably with standard 9mm velocities. Bianchi pistols are set up like this and are finicky beast. In my experience the comped 9mm will reduce recoil approx. 50% compared to same pistol and same ammo without the comp. Comped 9mm requires extremely light recoil spring; 5-6#. Ruby Fox shot exactly 2650 for the first time using a comped 45 pistol. 
Jon

I don't doubt that when adding a comp. there will be a change in felt recoil. But one has to understand that not only are gasses directed in another direction the compensator adds weight to the very end of the barrel. I've added weights to various guns and found that a small weight at the end of the gun adds quite a bit to the feel. Adding weight to the barrel of a 1911 is a bit out of my pay grade to determine what it will do to the functioning of the gun by adding weight to the barrel.  Also recoil begins as soon as the bullet exits the barrel yet a compensator extends past that point. If comp.s did preform as well as some say I would think that most shooters would have them, something like the way the red dot sight was just about an over night addition to just about everyone's gun and still are an addition in demand. I don't think there is a current top contender that's not shooting Red Dot but know of none that has a comp., but then again I don't know everyone. Same goes with the buffer, at one time every vendor at Perry had them, now I don't see any. From my experience they did nothing but limit the slide travel and caused problems.

I have comps on several on my pistols but the only BE pistol with one is my Victory with the VQ forward blow comp on their fluted SS barrel.  That comp only directs the gasses and sound forward and does make the gun muzzle heavy.  It is a nice looking comp so I leave it on the gun.  You know my motto (If I can't shoot good I can at least look good trying to.)  The comp in my M&P 9L 9mm does help but they require the proper load to work that need to be hot.  Probably why you don't see BE shooters using them.  Don

I can understand having a nice gun.
 Am I missing something? A comp. is attached to reduce recoil yet in your M&P 9L you have to use hot loads. But hot loads increase recoil.  Then what's the reason to add the Comp.??

I'll just take a guess here: Perhaps to reduce the amount of recoil of his hot loads?  

Don

Froneck wrote:I can understand having a nice gun.
 Am I missing something? A comp. is attached to reduce recoil yet in your M&P 9L you have to use hot loads. But hot loads increase recoil.  Then what's the reason to add the Comp.??

Maybe hot loads is not quite the right wording.  You need enough gas to make the comp work.  You have to meet a Power factor no powder puff loads.  Speed is the name of the game because the large size of the target and the very short distances shot with two hands accuracy is not the big thing.  This is why I switched to BE from IDPA I like to take the time to aim my shots.  In IDPA I was finishing a match with the least points down and was twice as slow as the next slowest person.  

And if this is a pick on Don post I am fine with that by the way I like recoil hand cannons are fun to shoot just not for a BE match.  Besides my comp looks cool.  Don