[gearbox]

I was instructed by the good folk at sigforum that I should try to solve my 870 woes here. I thank you all in advance for your charitous services.

Originally I had a 28" 870 Express Magnum with wood furniture chambered for 2 3/4" and 3" Mags. Semi-recently I replaced the stocks with factory synthetics. Also recently I purchased from Cabela's a factory 20" Improved Cylinder non-rifled barrel with rifle sights (Rem model #24622) for the intention of using the gun as a general home defense gun.
Before replacing any of these things, the gun had fired a good 600 or so Federal "Multi-Purpose" shotshells FLAWLESSLY.
When I received the first barrel I took the gun to an indoor range to test only for functionality. Good thing I did, because the action wouldn't cycle once the cartridge was fired. I had Cabela's replace the barrel at the cost of $30 (shipping) but received similar results.
What happens when shooting is this: the shell will chamber perfectly. Then, post shooting, the slide will only move as much as if the action is still locked. Upon checking the release, I notice that it is has dropped to normal after-trigger-pull position. Jerking back and forth (as safely as possible), the shell comes free very suddenly.
I thought that maybe it could be the chamber was headspaced incorrectly or it could be the specific box of ammo I was using. I went skeet shooting later with the 28" barrel and had no problems. I used the same and different ammo in the 2nd barrel and it appeared that the problem was mostly the ammo, but not wholely conclusive. It's my belief that the barrelmay not fully support the casing, because a part of the firing casings could be observed to be very slightly expanded/bulged. Moreso than a casing ejected after a healthy cycle.
A few days ago I bought some A-Zoom snap caps and noticed that even without firing, the bolt left an indentation in the aluminum, located approximately where the lower corners of the bolt contact it. I noticed this in the fired shells as well. Also, the slide must be pulled back very vigorously in order for the extractor to continue its grasp once the front end of the shell has cleared the barrel, but before the ejection port. This may be a problem only with the snap caps. It seems to simply drop back into the elevation lever if the slide is pulled back gingerly.

I've already taken the gun to the only reputable gunsmith in San Jose and he has unconsciously informed me of his ignorance. He said that the magazine tube dimples can't be pounded out or filed down when I had the follower replaced with one from Wilson Combat.

Is there a chance that I damaged the bolt when I removed it upon changing the fore stock?

Thanks again.
-Gabe

[RussB]

The bolt has a swinging locking lug that locks up into a cut-out in the barrel hood. Look for burrs/sharp edges in the hood of your new barrel. A little careful filing with a small swiss-pattern file may be all it needs to smooth it up.

Also, those Federal "Multi-Purpose" shells are notorious for sticking in the chamber. A bunch of Trap shooters in my area use them, some have had extraction issues with them in their particular guns...

[Dave McCracken]

First,try other ammo.

Second,check the bolt recess like Russ said.

A deep cleaning may also help.

[gearbox]

I've casually inspected the bolt recess. It appears to be unburred.
I've also taken the gun to the range and fired 10 each of Winchester and Remington light target loads. No problems.
Does this indicate that the batch of Federal I was shooting is at fault?
Can I expect reliability if this is the case?

[Old Fuff]

Gearbox:

I answered another post you made regarding polishing out "dimples" in a barrel by recomending Brownells (www.brownells.com). They also sell a gunsminthing manual that covers everything about the Remington 870. A copy of this book will explain, in ordinary English, everything you want to know. They also have a first-rate technical staff that will answer your questions - and the service is free.

[gearbox]

Thanks!

[Guyon]

Smells like a bad batch of ammo to me. You ought to write Federal and let them know how much grief these shells cost you.

After you've put 100 or so Win/Rem shells down barrel, give us a report.