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Discussion Starter · #1 ·
I converted my 77/22 to 17 a couple of years ago. It was a zytel stock, so I shot it single-shot for a couple of years and just got around to buying a laminated stock and the correct fixtures so I could use a clip. My clip came in today and I have problems. The gun refuses to chamber rounds. The extractors are "riding down" on the rim, putting too much downward pressure on the rim of the cartridge so that it binds going into the chamber.

Could this be an alignment problem with the magazine?

Tomorrow I will take the barrel and action out of the stock and put the magazine in the action and see if it will feed. It has been a long day and I need to get some sleep, now.

If anyone has any ideas, I would appreciate hearing from them.

LB
 

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Discussion Starter · #3 ·
It seems to be about halfway of the chamber length. There is still about 3/8" of the cartridge showing, maybe more.

Thanks for the reply. See my other (more recent) post on this, also.
 

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You said a 77/22, I assume it started off as a .22lr ? And you converted it to a .17HMR?

If so the problem may be in the bolt face. The rim thickness in the magnum case is a little larger then the long rifle and its probably hanging up trying to slide under the extractors coming out of the magazine. If so, a little tune up on the extractor hook should open it up enough the mag cases can slide in there.
 

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Discussion Starter · #5 ·
Thanks, ShootNut,
I was just thinking last night that I had read somewhere that the rim was thicker on the Hummers. I'm pretty sure you hit the nail on the head on this one. I had noticed that you could finally push the cartridge up into the face of the bolt with your fingers if you use enough pressure. Looks like I will need to put the ol' Dremel tool to work on those extractors.
 

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I have converted the 77/rim-fire in all flavors. Starting with the 22LR I have found is usually the most trouble free.
I know you have been studying and observing what is going on. If you feel it is the extractors are the problem (which is possible) I would not use a dremel. I would get some jeweler type files, that is small. and work with them on a trial and error basis.

It seems that the extractors worked when you were using it single shot. So you might just have to slightly file the outboard areas just behind the extractor (for lack of a better word) hook. Just enough so no additional pressure need be applied to the round to seat it flat on the bolt face as it moves forward towards the chamber.

Good luck and keep us advised.
 

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mbowerma is right, it shouldnt take much to solve the issue. Just a very slight angle to the bottom side of the hook of the extractor should let the thicker rim slide under it as it comes up. Shooting it single shot, the extractors will open around the rim into the notches of the breech and should stay opened around the rim as the case is extracted. But feeding out of the magazine the rim is coming up at a slight angle and trying to force the extractors apart from the bottom, so being a little tight could make a difference.
 

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I just tried a little experiment with 3 of my 77/22s. I have a Magnum and a LR and a 17M2. With the magnum, as I close the bolt, and the round is released from the magazine, the rim slides under the extractors and is fed into the chamber. Actually a better description is that as the round clears the magazine feed lips, it literally jumps into the extractors. I guess this is how it is supposed to work as opposed to the extractors "snapping" over the rim. I also tried this with 17HMR ammo with the same result. I then took the bolt from my LR and put it into the Magnum and there was a slight difference in the round sliding under the extractors ( it didn't leap) - and a very little more force was needed to feed the round, and the round was marked from contacting the bottom edge of the chamber. It is almost like the extractor tension was greater with the LR bolt as they contaced the rim. I also tried this with the 17M2 bolt in the Magnum and the results were very similar.
If this were mine, I'd do as others suggested and take a little off one or the other or both of the extractors at the bottom towards the bolt to give a little extra clearance to the Magnum/HMR rim. Even though I've read here there is little or no difference in the 77/22 LR and Magnum actions, there is enough difference when I put my LR/17M2 bolts into the Magnum that I can feel it when I close the bolt. Keep in mind that these are only my three individual rifles, and may have different results with other rifles.
 

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Discussion Starter · #9 ·
Thanks, guys.

I took out the bolt and popped a .22LR cartridge right into the extractors.
When I tried a Hummer, it took a LOT more pressure to pop it in.

I probably won't get back to you on this for several days, but I will let you know how it turns out. Someone else might run into the same trouble someday and maybe they can use this thread to help solve their problem.
 

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Discussion Starter · #10 ·
Fixed!

Well, that didn't take long. Didn't even have to remove the extractors. I had a cutoff wheel on my Dremel that was worn down to about 1/2" diameter. I put on a magnifying glass and put the cutoff wheel behind the hook on each of the extractors for just a second and put a little forward pressure on the tool, barely grinding the hook. When I finished the second extractor I decided to see if I could feel any difference. Inserted a .17 and it snapped right in. It was a bit tighter than the .22 I had been trying, but I decided to put the bolt in and try a shell in a magazine. It snapped right in and chambered. I loaded up a full magazine and it chambered each round flawlessly!

Problem solved! Thanks, everyone, for the input.

Longbeard
 
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