9mm 2011 Ejection

[leewhiskey]

If it matters, here are the basic specs. STI 2011 9mm 5", Bull barrel, Ed brown internals, 11 lb recoil spring, 19 lb main spring. Gun has had several thousand rounds through it and has been 100% reliable with anything I feed it. The problem is the empty brass barely comes out of the gun, it'll land within a foot or so of where I am standing. Racking the slide by hand will send a loaded round a good distance, but a piece of brass by hand does the same as when fired. I tested it with an 8 lb recoil spring, thinking a faster slide would help, but it was no different. My ejector is not broken, my extractor tension is good, ammo is about 132 PF, and everything seems to line up properly when I check cycling by hand. As soon as I get time I was thinking of trying a lighter mainspring. I am usually not one to mess with something that works, but I guess I never noticed it until now, and it's bugging me. Any ideas or suggestions are appreciated.

[yoshidaex]

When was the last time you chrono'd your loads thru the gun?

[donnyglock]

You can try a 17 or even 15lb mainspring. If you go that light make sure you have an extended firing pin. Sometimes a shorter ejector will work as well.

[al503]

Yup. I'd try a 17 lb mainspring.

Another part that affects the slide speed is the bevel on the slide stop. The higher the contact point, the easier the slide unlocks.

[leewhiskey]

Yup. I'd try a 17 lb mainspring.

Another part that affects the slide speed is the bevel on the slide stop. The higher the contact point, the easier the slide unlocks.

I assume you mean firing pin stop, that is rounded quite a bit. The loads have been through the chrono recent enough to know they are that power factor. I am going to try the lighter mainspring today if I get a chance.

I am still wondering if anyone has any idea why it would eject a loaded round several feet when I rack the slide by hand, but doing the same with just a piece of brass puts it at my feet.

[BrianATL]

Yup. I'd try a 17 lb mainspring.

Another part that affects the slide speed is the bevel on the slide stop. The higher the contact point, the easier the slide unlocks.

I assume you mean firing pin stop, that is rounded quite a bit. The loads have been through the chrono recent enough to know they are that power factor. I am going to try the lighter mainspring today if I get a chance.

I am still wondering if anyone has any idea why it would eject a loaded round several feet when I rack the slide by hand, but doing the same with just a piece of brass puts it at my feet.

That sounds like an extractor problem where the extractor is losing control of the empty case before the case hits the ejector. Are you using an extended ejector? A loaded round doesn't have to travel as far back to meet the ejector unsupported as the loaded round is much longer. You might want to try increasing your extractor tension.

Edited April 28, 2012 by BrianATL

[CraigS.]

It might help if you can show pics of the ejector (the length and any angles of the tip)

How tightly is the brass held by the extractor?

[al503]

Yup. I'd try a 17 lb mainspring.

Another part that affects the slide speed is the bevel on the slide stop. The higher the contact point, the easier the slide unlocks.

I assume you mean firing pin stop, that is rounded quite a bit.

Sorry. I did mean the firing pin stop.

[Tom Freeman]

A 17 lb mainspring and 8-9 lb recoil spring works for me with both a bushing and bull barrel.

[Dan Sierpina]

A 17 lb mainspring and 8-9 lb recoil spring works for me with both a bushing and bull barrel.

Mr Freeman has the good set up! Drop the 19 lb mainspring first.

[leewhiskey]

Turns out lighter mainsprings did not help. What I found was the extractor was contacting the inside of the hole and filing off a little behind the hook allowed it to move inward more to get more contact with the brass. Still not throwing it as far as other guns, but its better than it was.

[superdude]

what load are you running? you can get a stronger recoil impulse by using a gunpowder that requires a larger charge weight for the same velocity.

[leewhiskey]

what load are you running? you can get a stronger recoil impulse by using a gunpowder that requires a larger charge weight for the same velocity.

124 gr precisions over roughly 4.3 of 231. Don't remember the exact charge weight or OAL, would have to look at my notes. I put them through the chrono again yesterday, 1050 to 1100fps.

[yoshidaex]

Has the casings always landed 1 foot from you or is this something that recently happened?

[superdude]

what load are you running? you can get a stronger recoil impulse by using a gunpowder that requires a larger charge weight for the same velocity.

124 gr precisions over roughly 4.3 of 231. Don't remember the exact charge weight or OAL, would have to look at my notes. I put them through the chrono again yesterday, 1050 to 1100fps.

231 is a moderately fast gunpowder and tends not to produce a very large recoil impulse. though it's not bad either. gunpowder-wise you have a couple of options to see if that might help you. one is to up the 231 load a little bit, by at least 0.2 grains for an appreciable difference.

if you have other gunpowders, you could try them to see if they might help. something that requires around 5.0 grains or more for the same velocity. check a loading manual for suggestions compared to 231 and whatever you have on hand. a greater charge weight for the same velocity will produce more gas and will increase the recoil impulse.