Square Bottom FP Stop

[Intel6]

I have been having some extraction issues in an STI Eagle bushing .40 and followed a recent thread about the same thing. Not looking to rehash but I have put in an AFTEC, tried different springs etc... In my case it seems to become a problem when i put in my major loads because it will eat lighter loads all day. It seems that the extractor is jumping off the rim and it does the same thing with both the regular and the AFTEC extractor. The next thing I plan on trying is a square bottom FP stop to slow down the initial barrel unlocking and possibly keep the extractor on the rim. I am working the cheaper things before looking into the more expensive options.

So, my question is, do you leave the bottom untouched? I was figuring I would break the sharp edge but other than that should I leave it alone?

Anything else I need to know about one of these?

Thanks for any help,

Neal in AZ

[Joe4d]

If problem happens with certain ammo I would be more inclined to believe it is ammo/ barrel related. Overpressure ammo causing it to stick, a dirty chamber, moly or lead build up on the very beginning of the rifling, Brass been loaded too many times without trimming, The square FP stop does offer a little more resistance to unlocking but at 165-170 pf 40 it shouldnt make much of a difference. I would check the recoil spring with a known weight.

[mike cyrwus]

I start with a very small 1/16" radius on the bottom and then tune it more if necessary after test firing.

[OpnBlstr]

Just dropping in an AFTEC isn't a guaranteed cure-all. The extractor tunnel could be undersize or offset as well. I have seen this on quite a few slides of a well known major manufacturer lately (the past 18 months).

The extractor may just need more arc of movement inwards. Reshaping either the standard or AFTEC will likely solve your problem. It doesn't take much - go slowly. This will require reshaping the hook as well for proper engagement with the rim. Get the rim to go all the way into the corner of the hook, not be held 'way out there' on the hook which can cause extractor failures as well.

Another thing to look for is a rough chamber. It doesn't take much roughness to make the brass stick tightly.

Is this a new gun to you? Did the gun run for a while then start having troubles? If it is a new gun (or new to you), try having your gunsmith run a finish reamer on the barrel. It can reveal a lot of otherwise confounding problems caused by slightly short chamber, short leade, crappy leade, etc.