9mm STI recoil spring question

ChromeArty

ChromeArty

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So I've been putting up with this for a while now, but I'd like to figure it out!

My 9mm 1911 likes to catch the spent casing in the ejection port. Not a stovepipe, but laterally. It's like the slide is returning so quickly, the casing has no time to clear the port.

My question is, do I go heavier or lighter on the recoil spring... My guess is lighter. Problem is, I bought this gun used ages ago, and have no idea what weight the spring is...

Any ideas out there?

Thanks!

Trev

And if the answer is, buy a kit with a bunch of different weight springs and fly at er... What kit do you suggest?
 
juancarlos said:
According to the STI website a 5" 9mm comes with a 10lb spring. http://stiguns.com/resources/faqs/

You could try an 8lb or 9lb and see if that helps. I have had the same issue once in my 9mm Sentry and it turned out the ammo just didn't have enough powder to push the slide back far enough to eject the spent casing.
Click to expand...

Huh... It could be that simple... I tend to go on the lighter side with my handloads to avoid lead fouling...

Thank you JC
 
ChromeArty said:
Huh... It could be that simple... I tend to go on the lighter side with my handloads to avoid lead fouling...

Thank you JC
Click to expand...

There's your issue. If you're loading on the lighter side then fit the lighter recoil spring.

I'd tend to go with the 9lb spring and then power up the loads slightly if you still have the same issue occasionally. My concern is that the recoil spring needs to run the slide back into battery and have enough force to strip and chamber the next round at the same time. If the spring is too light the return might become rather slow and even sticky. The slightest fouling or other sources of friction could result in the slide stopping while still slightly out of battery. So if you want to shoot lighter lead reloads I'd suggest the 9lb spring and then load the rounds to suit so they are just strong enough to get full travel out of the slide so you avoid the hanging up and get as snappy a return of the slide as you can. They will still be lighter than factory loads but should make the gun work in an overall happier manner and be a bit more tolerant of less than pristine cleanliness and oiling.
 
I use a 9lb Wollf spring in my 9mil Spartan.My loads are fairly light(124gr at 1050fps)and the gun works perfectly and I haven't had a extraction issue for many thousands of rounds.

If despite using a lighter spring you are still getting these jams,then think of an extractor issue.The extractor that came with my gun lost its tension after a few hundred rounds and wouldn't keep it with tuning so I switched to an Aftec extractor and havent looked back,not a single malfunction after that.A good test for adequate extractor tension is to see whether the case will extract on firing without a magazine in the gun,do this a few times and if tension isn't adequate,you will get stovepipes or else the case will extract through the mag well.Also,if you have a shockbuff,get rid of it,they are really not needed in a 9mm 1911 and just cause issues.
 
Wolff Springs makes a line of reduced power 1911 springs specifically for light loads. You can purchase them from Brownell's. There may also be a sponsor that carries them.
 
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I never have had much luck with 9mm 1911 ejection. My Spartan barely dribbles the case out, even with the 9lbs variable recoil spring; it's extremely reliable but case extraction is juuuuust enough. Multiple springs/extractor tuning haven't yielded any improvements.

The same ammo out of the M9A3 will land a good 3ft away and out of the Shadow it's probably landing in the next province. Try increase the powder charge and see how it fares.
 
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