I'm sorry to hear you're having trouble with your 9mm barrel. I've had one for a long time and just got around to trying it out this past weekend. I've got to say, I was surprised it worked so well. I had no issues whatsoever with feeding, extracting, or accuracy.
Regarding the bullet to barrel fit, I DEFINITELY would not go messing with the chamber. I agree with skucera. Check the ammo first and foremost. If you can easily pull the cartridge from the chamber with your fingers, but it won't fall out under it's own weight, I'd first check to see if the bullet is just hanging up in the rifling. This can happen if the OAL on the ammo is too long and/or the ogive of the bullet is too fat for your barrel. The best way I was told to check this is to color the projectile part of the loaded cartridge with a Sharpie, remove the barrel from the gun, drop the bullet in gently, and turn the barrel upside down or remove bullet by hand, if necessary. Look at the bullet...if the Sharpie ink is scratched off, that's your problem. PM Wobbly over in the reloading forum, he can explain it better. He's who I learned this from.
Unless the cartridges are sticking tightly in the chamber (i.e. it's hard to pull them out with just your fingers) I doubt that's causing your feeding/cycling issues, though. If the jams/stove-pipes are loaded ammo, the issue may be that your mags just need to be tuned a bit. Try pushing the follower down into the mag and ever so slightly squeeze the feed lips together. Test fire and repeat until the double-feeds/stove-pipes stop. If the jams/stove-pipes are spent cases, I'd try replacing the extractor spring first before I took it to a smith and paid big money.
Good luck
