Rimfire chamber and feed ramp polishing?

[Bruce in WV]

I read in an pre-2000's home gunsmithing handbook that polishing a rimfire chamber with very high count compound (800-1200+) and the feed ramp (600+), should be standard practice for semi-auto rimfire rifles and pistols to aid smooth feeding from a magazine, and easy extraction.

Is this still recommended?

 

[boltfluter]

Unless you're having a problem, I would say just shoot it.

 

[Bruce in WV]

I was having failure to feed, failure to fire and failure to eject issues with an older MKIV and 10 older magazines.
I replaced all my magazine springs with the Volq green spring kits and "tuned" the mags. The followers all look OK; there are no cracks in any mag 'spine'.
I also replaced the firing pin and extractor with the Volq parts/spring kits. This solved the FTFeed/Fire issues, but I still have occasional FTE events in this group of magazines, not limited to a specific mag. I don't think a FTE would be mag-related.
The chamber looks OK to the naked eye with a OTC bore light, (just being a little OCD) polishing the chamber seems the only 'fix' I'm aware of remaining to be done. Polishing the feed ramp would just be an additional, small, nice-to-do task while I have the gear on the bench.

 

[marazzi59]

How does the case and loaded round that wasn't fire but ejected look? Any marks, burrs anything?

 

[Idaho-Lefty]

I read in an pre-2000's home gunsmithing handbook that polishing a rimfire chamber with very high count compound (800-1200+) and the feed ramp (600+), should be standard practice for semi-auto rimfire rifles and pistols to aid smooth feeding from a magazine, and easy extraction.

Is this still recommended?

I polished my Green Mountain SS, 10-22 Barrel's, BENTZ Match, Chambers, "Throat area" with, JB's slathered on a Patch over, a Bronze Brush,.. 8-10 strokes to, LIGHTLY polish the "Sharp edges" that WERE, "Holding" the Live Rounds From,.. Extraction.
Did, the Bore ( to Muzzle ) the SAME Way But, with, a ONE way, "Stroke" ( Remove Brush, pull Rod, back Thru ! ).
Saves Ammo on "Break-in" of, Barrel ( Green Mth said to, clean / Shoot, for 200 Rounds,.. YIKES ! )
Shot 10 rds, Cleaned, shot 10 Cleaned, AGAIN,.. DONE !
And I polished the Ramp area with, 600 grit Wet / Dry on, a slotted Rod.
Also changed to, a Beefier F-Pin and Volqt, Extractor,..
Runs,.. PERFECT ! Shoots Mid-Priced, SK- Std Plus, Wolf Match extra, etc. into, the 3's and 4's at, 50 yds.
I Highly Recommend THIS,.. "Work" !
I have done Many of these 10-22's over, the Years ( 20+ years of, Experience as, a Former Gun Smith ).
PS; Buy or "Tune Up" your Trigger pull for, GREAT Accuracy ! ( Used, a Volqt Kit on Mine to, achieve a 2.25 Pound trigger Pull )

 

[Bruce in WV]

"How does the case and loaded round that wasn't fire but ejected look? Any marks, burrs anything?"

Cases look like new. Since they had not been fired and expanded against the chamber walls, that may mean that any roughness effecting extraction was too fine to leave a mark without firing. Since my FTE is limited to fired cases, that helps to analyze the possible problems.

 

[Bruce in WV]

Solved it, I think: mismatched Volq "Gold" spring with SV ammo. The Volq reference shows that to be a heavier spring than OEM. Put the Ruger OEM recoil spring back in and going to the range tomorrow to check it out.

ETA: Success! No extraction problems with any magazine using the Ruger OEM recoil spring and CCI SV ammo.