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I understand that 16 lb recoil spring is standard for 5" government model .45 pistols.
I shoot full power loads and sometimes a little heavier reloads. I would like to use a little heavier spring.

What is recommended for a heavier spring weight and still insuring reliable functioning ?

Thanks
JMV375
 

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Rob is, of course, correct.

Another thing you can do to slow the rearward velocity of the slide is to fit an oversized, flat bottom firing pin stop. In fact, using this inexpensive part in combination with a heavier mainspring may allow you to use a lighter than 16lb recoil spring even with your heavier loads.

Slowing down the forward velocity of the slide will increase reliability by allowing more time for the magazine spring to push the cartridge column up against the feed lips. It will also increase "shootability" by reducing muzzle dip as the lower barrel lugs slam into the slide stop as the barrel returns to battery.

Using a heavier recoil spring is an absolute last resort if nothing else works.
 

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I posed a similar question here.
Looks vaguely familiar :)

Some folks will use the distance the empty brass flys as the indicator as to what weight recoil spring to use. Others depend on how the front sight tracks as the indicator. I imagine the bullseye guys like the first way while the speed demon shooters like the second way.

Everyone has their own preference and mine is to always fit a flat bottom firing pin stop, a 23lb mainspring, and a 16lb recoil spring first followed by the pistol's first test firing. I don't use a heavier than 16lb recoil spring in 5" .45s. If the slide is moving too fast to the rear, I'll follow Rob's advice by dropping in a 25lb mainspring which very often allows me to use a lighter recoil spring. If the slide's rearward speed isn't excessive, I'll swap in a lighter recoil spring and re-test. There's no measurable science in this and the final outcome isn't predictable. It's just a series of experiments until I'm satisfied with the way the pistol functions and feels.

Here's the video everyone has probably seen about the effect of recoil springs on slide speed:

 

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yes, it took me a while to acutally wrap my head around this concept. I always understood what the springs did to a certain extent....but....I finally got it.
 

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But..., but..., what about the trigger weight with those heavy mainsprings?
Rob would have a better answer than me but from my experience going from a standard 23lb mainspring to a 25lb mainspring changes the trigger pull weight by single digit ounces.

Personally, trigger pull weight doesn't seem to affect my shooting as much as gritty, mushy feeling pulls. I have a lot more trouble with really light triggers than with 3lb to 4lb triggers.
 

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Are you really curious though?
Well, I know a great 3.0-3.5lbs trigger can be achieved with a 23lbs mainspring because that is what I believe is installed on the ACW gun I have. Or at least on the Baer you customized for me since I installed that mainspring myself when I bought that gun used :).

What I am curious about is:

1) Why many (according to internet posts) choose to drop their mainsprings to 21, 19, or even 17 pounds for their .45 guns?

2) Is the lighter weight mainspring needed to get the trigger below 3 pounds?

3) Why 23lbs mainspring works for both .45 and 9mm with different weight recoil springs .

As always, appreciate the education.
 

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Fellows. Some what O.T. I have a RIA Mid-Size 1911. It features a bull barrel (no barrel bushing).

Would any of the input to this thread apply to my 1911? If so, what weight springs (any of them) be recommended? What about the FPS?
 

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Fellows. Some what O.T. I have a RIA Mid-Size 1911. It features a bull barrel (no barrel bushing).

Would any of the input to this thread apply to my 1911? If so, what weight springs (any of them) be recommended? What about the FPS?
Assuming it’s a .45, standard recoil spring is 18lbs. So as the slides get shorter, the rating needs to go up. No changes in mainspring weight as far as I know.
 

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Does a lighter or stronger main spring reduce felt recoil?
An interesting question. The answer is yes and no. Physics class was a very long time ago for me and I don't have a mechanical engineering degree so I humbly accept any corrections to what I've written below.

Explanation of the NO answer

As with all springs, the recoil spring pushes in both directions at the same time. As it is compressed by the slide moving backwards, it is pushing forward against the spring plug and it is pushing backwards against the shooter's hand. This backward force is felt by the shooter and interpreted as felt recoil. Therefore, the stronger the recoil spring, the more force is felt by the shooter.

Explanation of the YES answer

The impact of slide against the frame abutment results in a sudden stop which causes the muzzle to flip upwards and is felt by the shooter. The less impact that occurs, the less force will be felt and the less muzzle flip there will be. Theoretically, a recoil spring could be manufactured with precisely enough strength to barely allow the slide to just kiss the frame abutment thus reducing the impact and muzzle flip to the lowest possible amount. However, there are so many other factors involved that this is a practical impossibility.

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If muzzle flip is the objection, there are compensators that will eliminate it.

If felt recoil is the objection, lighter bullets will reduce it as will the use of stronger mainsprings and flat bottom firing pin stops that will allow for the use of lighter recoil springs. These things will reduce the felt recoil but cannot eliminate it.

There are no perfect answers which is why we all continue to experiment to arrive at a solution that is best for us based upon a multitude of factors that are unique to our individual situations.

------ edited to actually address the question -----

I went off on a rant about recoil springs and didn't directly address the question.

Without changing anything other than the mainspring, a lighter mainspring will allow the slide to move faster to the rear while a heavier mainspring will slow the rearward velocity of the slide. The faster the slide moves, the greater the impact between the slide and the frame. The greater the impact, the more felt recoil and muzzle flip.
 

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Crabby Old Gunsmith
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1.) It's an urban legend. Believe it or not, the speed in which the hammer hits the firing pin will trick you into thinking you've changed your trigger pull characteristics. Does a lighter mainspring give you a lighter trigger? Yes, but only a minimal amount. Your pull weight comes more from sear/hammer hook engagement and sear spring pressure. Your "lighter" trigger by way of lighter mainspring comes at the cost of compromised timing and increased possibility of the slide battering your frame.

2.) No, it's not necessary for under 3# triggers. A sub 2# trigger can be done with a 23# mainspring. Going below that to a trigger pull measured in ounces requires a lighter mainspring, and reloads made for that setup. This is for guys splitting every hair there is to split such as Rob Leatham.

3.) 23# mainsprings don't really work for 9mm very well. For factory ammunition, 9mm cycles quite well with a 19# mainspring. This allows you to run an adequate recoil spring in 9mm too.

You have to remember that probably 80% of the initial firing force is taken by re-cocking the hammer (the mainspring). The recoil spring is at full extension when the gun is fired, which means it's at the point of exerting the least amount of resistance that it can.

Bull barrels can add to all of this complexity due to their mass. The barrel and slide cycle as a unit until linkdown, so moving that heavier unit is more difficult. It works nicely in .45 but when you start getting into the bull barrel 9mm category, stepping your mainspring down to maybe 17# will lead to much more lively ejection than 19#.

Well, I know a great 3.0-3.5lbs trigger can be achieved with a 23lbs mainspring because that is what I believe is installed on the ACW gun I have. Or at least on the Baer you customized for me since I installed that mainspring myself when I bought that gun used :).

What I am curious about is:

1) Why many (according to internet posts) choose to drop their mainsprings to 21, 19, or even 17 pounds for their .45 guns?

2) Is the lighter weight mainspring needed to get the trigger below 3 pounds?

3) Why 23lbs mainspring works for both .45 and 9mm with different weight recoil springs .

As always, appreciate the education.
 

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I am actually enjoying this very informative thread, It is much better than cleaning out my garage for the third time in the past 6 days. Thanks guys for the very, very good information.
 

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Information tagged :)
 

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Crabby Old Gunsmith
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I personally feel that a lot of 1911 manufacturers really make a mistake when they step down mainspring weight in the name of easier "drop in" trigger tuning. It makes the slide unlock much faster and can lead to both feeding and ejection issues. Barrel timing is talked about frequently. Giving the mechanism more time to perform it's job leads to a better job being done.

In the end, muzzle energy dictates all. Bullseye ammo will allow you to step down mainspring and recoil spring weights. +P ammo will do the opposite. If a 5" 45 were to get a steady diet of +P ammo, I would do a flat bottom firing pin stop and 25# mainspring as a baseline.
 
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