Recoil spring question: 200 gr LSWC over 3.5 gr bullseye

Asking the brain vault, I loaded up the above 45 acp rounds (Brazos bullets h&G style 1.43 COAL) and shot them in my Colt GCNM series 70 with a Wolf 16lb recoil spring and the original mainspring (presumably 23lb??? I don’t know the spec for sure). 

Correction! 1.243”

Functioned fine but the cases were going maybe 1-3 feet max (several landed in my shoulder like a pirate’s parrot). I was surprised because I brought a 14 and 12lb spring just in case. 

Should I try a lighter recoil spring? My wondering mind thinks maybe I should to reduce battering. 

Thanks in advance for any insights. 
Rod

Factory is 16 pound (near as dammit).  My Wadgun with dot sight on it  functions with 12 pounds and 4.0 (+/-) BE with the same bullets.  

But this wadgun is very likely tighter than a Colt GCNM….i shot 3.5 for some years in my GC series 70.   I should put a dot on it at some point and see just how well it really does.  So lockup affects the minimum functioning load and spring weight.  If your gun functions 100% with no alibis I’d leave it alone for now.

Wobbley wrote:Factory is 16 pound (near as dammit).  My Wadgun with dot sight on it  functions with 12 pounds and 4.0 (+/-) BE with the same bullets.  

But this wadgun is very likely tighter than a Colt GCNM….i shot 3.5 for some years in my GC series 70.   I should put a dot on it at some point and see just how well it really does.  So lockup affects the minimum functioning load and spring weight.  If your gun functions 100% with no alibis I’d leave it alone for now.

Thanks Wobbley.  Your gun is undoubtedly tighter than mine.  Mine had got a fair amount of movement between slide and frame.  Not quite following the part, can you explain a bit more? “ So lockup affects the minimum functioning load and spring weight.”

The tighter the lockup, the lighter the spring as the lockup requires more “oomph” from the cartridge to “unlock” and cycle.  A loosey-goosey old army beater may function just fine with 3.2 Bullseye and a 16 or even 18 pound spring.

Ahh, I get it.  So a tight lockup and a tight slide to frame fit add inertia / friction to the spring weight.  Adding an optic does the same. No optic, loose lockup and loose s/f fit... you can have a higher spring weight and still function with a “light” load. 

I am learning more than I thought there was to learn.  Thank you!

All it has to do is function...

bruce martindale wrote:All it has to do is function...

Mission accomplished. Now all I need is for the other half of the system to function... sooo, it’s back to staring intently at a little black rectangle in font of a white wall.

RodJ wrote:Asking the brain vault, I loaded up the above 45 acp rounds (Brazos bullets h&G style 1.43 COAL) and shot them in my Colt GCNM series 70 with a Wolf 16lb recoil spring and the original mainspring (presumably 23lb??? I don’t know the spec for sure). 

Correction! 1.243”

Functioned fine but the cases were going maybe 1-3 feet max (several landed in my shoulder like a pirate’s parrot). I was surprised because I brought a 14 and 12lb spring just in case. 

Should I try a lighter recoil spring? My wondering mind thinks maybe I should to reduce battering. 

Thanks in advance for any insights. 
Rod

I will preface my statements with the fact that I am extremely new to BE shooting. 

My understanding is that on a 1911 one wants to shoot with the heaviest (most stiff) recoil spring possible that will still allow the gun to cycle and lock back after last shot. I was told that using the heaviest possible recoil spring helps to smoothen out the recoil whereas using lighter springs may make the recoil feel more “snappy”. I found this to be true in my 9mm 1911. 

I was told to buy a set of recoil springs and conduct a function fire test of about 5 rds. shoot one rd out of the magazine at a time to ensure the slide locks back. If the slide locks back then try the next higher spring and repeat the function fire test. Keep increasing spring weight until the gun no-longer locks to the rear and this tells you what your max spring weight is for that gun and that load. 

I thought this was common practice. Curious to hear what others have to say. 

-Trevor

Thanks, Trevor, that makes a lot of sense for precision shooting. My brain wondered about how hard the slide slams closed with a heavier spring. Then again, when it does go forward, the next cartridge helps slow it down.

If it isn’t obvious, I’m very very new myself. Not to shooting but to competition and thinking about pistol set up and equipment.  And technique... but I’m learning.

Much appreciated!