.17 American Rimfire Feed Problems

[Large Bob]

I have a .17HMR American Rimfire rifle. It is wonderfully accurate varminter (my primary use for it), but it does not feed smoothly alot of the time. The bullet rim seems to first hang up on 2 tiny half-moon notches about a 1/4" in front of the rear of the magazine feed lips, and then the bullet shoulder hits the chamber mouth, shutting down the whole feeding operation, causing me to have move the bolt backwards to free the bullet up so it will feed. I can force the bullet into the chamber by pounding on the bolt handle with my hand, not exactly a great solution. This happens with all the ammunition brands I have tried, which is most of them, and with all 6 of my magazines. Anyone else having this problem?

 

[contender]

Welcome to the Forum!

I have the 77/17 & not the American. Never had any feeding issues with mine. MAYBE a polite call to Ruger customer service is in order?

 

[JAYDAWG]

I have the American in 22mag.
Shoots like a dream.
Suppressed on the crows makes me giggle!!
Agree with contender, give the good folks at Ruger a call.
Be patient, they are a bit short staffed.

JAYDAWG

 

[Mobuck]

No feeding problems with either 77/17 or RAR17.
How many shots through this rifle? Using factory OEM magazines?

 

[Iroc]

Since it's happening with every magazine and brand of cartridge my thought is it has to be where the bullet shoulder hits the chamber mouth and is hanging up, I'd try polishing that area and/or putting a little relief on that edge, it might be a little ruff or have a small burr on it.

 

[Large Bob]

I've been living with this issue since I bought the rifle 10 years ago. All OEM mags, new and old, thousands of rounds at ground squirrels. I hesitate to modify anything on the rifle because the good folks at Ruger tend not to like that on any firearm they service (if I have to send it in), and I have made some trigger improvements they would rip out and return to factory parts. However, I will give them a call to see what they suggest as far as the feed issue. By the way, I worked in a gun shop for 9 years before I retired and had frequent conversations with customer service there, and they are the best. Also, chamber mouth is smooth, maybe a light chamfer on the bottom edge is in order if Ruger can't help.

 

[Mobuck]

I'd be really careful if doing any 'chamber chamfering'. Doesn't take much of that sort of thing to cause blow outs with the HMR.
I'm sitting here looking at a Ruger HMR magazine loaded with Hornady tipped ammo. As I push the rounds forward, I see that they 'pop out' as the rim reaches the cutouts in the feed lips. When inserted in the action, the bolt pushes the cartridge forward to this point and the cartridges 'pops' up in front of the bolt face but has already started to enter the chamber. If the cartridge is not exiting the magazine feed lips by this time, it will snag the rear of the chamber.
Is this what's happening?

 

[Mobuck]

I took a look at my American 17HMR and while it's not as smooth feeding as the 77/17, it's not having the issues described. Just a touch of drag as the round passes out of the magazine's feed lips.
I'd give a look at the extractors as at least part of the problem. The spot the OP described is also the area in which the cartridge rises up to the bolt face and could be getting interference from the extractors.
Addendum: After thinking about this over night, I'm fairly certain the extractor(s) interference is your primary problem. I can't offer a solution by long distance but maybe this helps.

 

[Large Bob]

Thanks, I will investigate the extractor further. The bullet nose enters the chamber, but it is at an angle with the chamber (the rear of the cartridge low}, and the shoulder catches on the lower edge of the chamber mouth. Are you thinking the extractor is too tight and the rim can't quite fit between the bolt face and extractor hook?

 

[Mobuck]

"Are you thinking the extractor is too tight and the rim can't quite fit between the bolt face and extractor hook?"
That is my initial assessment of the problem. The misfeed is the result of the base of the cartridge not rising to the level of the bolt face when it should. Any sort of burr or roughness would cause drag as the case rim is moving against the bolt face and engaging the extractor hooks. This could also be caused by the firing pin not retracting as it should.
I hope this helps but if you discover a different cause, let me/us know.

 

[Large Bob]

You guessed right, it was the extractor. Room enough between the extractor hook and the bolt face, but the point of the extractor hook was very sharp and dragging against the brass in front of the rim. I polished the hook down with a diamond hone so it was not so sharp and rounded the leading edge a smidge where it first makes contact with the brass, and on the bench the rifle now cycles smoothly. Another contributing factor was the magazine springs on several of the magazines. They were barely strong enough to push up the last few cartridges, which helps push the cartridge into proper alignment. Stripped those down and cleaned them and tightened the springs so they function properly. I will be testing the fix in the field the next several days - got both a marmot and ground squirrel planned.
Thanks for your suggestions

 

[Mauser9]

Glad to hear you figured it out. Had my R/A model 8323 magnum for almost 10 years. Noticed the first/last rounds seemed sticky to feed at first. Called Ruger and they sent a new magazine. Agree with your assessment on the mag. springs. They seem rather weak but the second mag. did help the problem considerably. Seemed to me spring pressure was not strong enough for reliable feed. Overall glad I purchased my R/A. Great for wood's varmints and accurate.

 

[Iroc]

That's nice you got it fixed Large Bob, chalk one up for Mobuck and his analytical mind.