What happens when the first round fails to feed? Does it look like the round is hanging up on the chamber, or isn't it stripping from the mag? How many rounds are you loading, and does it have the same problem if you only load a few rounds in a mag?

When a round slides in the chamber easily by hand, but won't go in without a good beating from the bolt, it is symptomatic of the nose of the round being deformed during feeding. Typically it feeds but the top of the projectile rubs the top of the chamber and causes a jam as the lower portion of the projectile pivots across the transition between feed ramp and chamber. Polishing the feed ramp, top inside of the chamber and smoothing out the lower mouth of the chamber/feed ramp extension should help.

I am a little puzzled why rounds would hang up still inside the mag feed lips. Sounds like the bolt isn't moving forward fast enough, which could also exacerbate the problems with round deformation. (For some reason, the slower a round feeds into the chamber, the easier it hang up and gets bent). Could your bolt be dragging on the hammer or something else in the lower?



If rounds fall off of the bolt face fairly easily, you might want to consider replacing the extractor hook with one of the newer ones. I modified mine, but the process is a little involved, so get Tom to send you one and save yourself some time later.

Boatbod,

Updated report: As suspected, the fire control system was part of the problem with this particular ST22. I replaced the original FCS with a Rock River two-stage and shoot 100 rounds of Federal Value Pack 22 (red box) with only three malfunctions. Later, I received a modified extractor from Spikes Tactical and installed it. Although the extractor doesn't hold the rim of the case against the bolt face, it performed very well with zero malfunctions in 50 rounds. I realize that this is not enough rounds to inspire confidence, but that was all I had time for after a carbine match.

Gary

I'd be really surprised if a double feed caused the ding in the chamber because brass just isn't hard enough to indent steel. Not saying there isn't a ding, merely that a jam was not the principle cause.

Is the damage located at the 12 o'clock position? If so, it would suggest dry firing as the culprit, which in turn would suggest the firing pin is able to protrude further than it normally should.

Depending on the severity of the damage, it may be possible to eliminate the burr using a chamber ironing tool. If its any more severe than a slight nick, I would recommend sending the complete upper back to Tom for a thorough inspection.

Quite possibly the round jammed and got bent because it hung up on the burr at the top of the chamber. (The top is where the nose of the bullet contacts first, before it pivots over the feed lip).

First thing I would do is check the firing pin (FP) for damage - from what you've said, it's quite possible it may be broken. If you have a set of punches, you can drive out the FP retainer roll pin and take it out for inspection. It should be one piece, but they have been known to snap in half.

You can check maximum FP protrusion quite easily by pushing on the back of the pin with a small punch or screwdriver and checking how far the wedge sticks out of the bolt face. It should not extend beyond the flat surface that mates with the breech or barrel collar.

Looks to me like the end of your firing pin is missing, and probably caused the breech damage when it broke free.

It should look like this:

You're welcome!
Tom will get you squared away.

I just started to work on mine again nearly a year later. I truly just had enough after buying a new chamber adapter last year and it still didn't work for shit.

Now it will feed with Federal - but it won't extract. I get a ton of stove pipe type jams and the ones where it extracts 12 o' clock into the charging handle and becomes jammed between the bolt and the charging handle. These are tiresome when they happen 6-8 times per mag.

I installed the uncut spring that came with my kit ( 1 long one precut) and it does the same thing. So I reinstalled my precut spring and trimmed a few coils off one by one. (Maybe 4-6 total) No dice. It still extracts into the charging handle.

This is why I put this thing up for months at a time. It makes me want to suffocate kittens and kick babies every time I attempt to use it.
Should I just keep trimming - or - is there something else I should be looking for?

This adapter feeds it just does not extract well. Or specifically in the correct direction. It will typically extract rounds manually with the charging handle. (the last one didn't)
But will not run with any consistency due to extraction problems.

Here are some pictures in case anyone spots anything.

Try one less round in the mag?

Sounds like an extractor problem.

With the bolt removed from the rails, will the extractor hook hold an empty case snugly against the bolt face, or does it drop off/slip down at the slightest bump? If it's too loose, casings can slide down the bolt face and hit the mag lips, causing charging handle stovepipes.

Would you mind explaining what you mean exactly? Or at least see if I'm understanding correctly. You're saying a fired round is sliding down the bolt face due to a loose extractor fit and then when it hits the ejector it's kicking it up into the charging handle?

The round gets caught in the groove of the charging handle between the "nose" of the CH and the conversion bolt group spring guide portion. It then smashes the casing flat and is a whore to get out.

This is caused by it hitting the magazine while it's being ejected?

It seems pretty random and does it with all the mags I have too. But it's frequent enough that it drops the enjoyment factor to 0. And when it isn't doing the CH jam it stovepipes in the bolt (more common) CH jams are about 1/5. With the majority being stovepipe type jams. But when you are getting 5-6 per mag that means you're digging one out of the CH per mag. Which is infuriating by the third magazine. It feeds fine when it does not have an extraction problem. And fast or slow shooting seems to make no difference either.

I'm using Federal copper plated bulk packs and Auto match at this point to eliminate ammo as the problem. It does the same shit with all of it.


EDIT: Ok I took the thing apart to see how well the extractor holds the round. Answer - it doesn't hold it very well. Any slight movement and it will drop the round.

Here's pics to show the "hold" it has when holding a round. It's hard to show but only one small part of the claw is touching the case at all. And it's pretty wobbly.





Is this the problem? This was one of the original kits and I thought I saw someone mention an improved extractor somewhere so this surely isn't it.
I could probably increase spring tension here and or reshape the claw so there is more contact area closer to the rim to "buckle it down" instead of just sitting against the side of the case.
It looks like it's on the rim of the case but it really isn't.

So this is probably the issue then?

Is there a new type of improved extractor? I saw you mention something about that above.

Or should I just try to reshape it myself and put a stronger spring in there?


I could send this back to Spike's I think. When I mentioned my continued issues with the conversion Badazzar said send it back and let them deal with it.
I think I may just do that unless it's a simple fix.

Still having issues after polishing the chamber, it'll run say three magazines after being cleaned, then it'll start jamming up when you load the first round from a new mag, it'll get stuck half-way in. I wonder if I need a stronger recoil spring?