Any reason not to deburr stripper rail?

[Buck13]

I recently posted about jamming in my wife's .380 Sig P290RS. After cleaning off the slide, frame and barrel with starting ether (whoooo, even done outdoors, that was fun; I was a little groggy later from the ether, or maybe that was the toluene) and cycling it dry a bunch of times, and polishing the feed lips of the magazines with 600 grit paper, I re-greased what I could reach, including a light application on the mag follower, and put a little CLP on what I couldn't reach, like the firing pin.

Loaded the mag with five rounds a couple of times and let the slide fall with the slide release on each round. All chambered well like that.

However, an interesting observation: After ejecting a round and locking the slide open, I noticed a mark on the top of the next round in the magazine, about 1/4 of the way down from the case mouth. I think as the round above clears the feed lips and moves up, the next round is hitting the lower-front corner of the ridge on stripper rail hard enough to make a tiny gouge/dent.

The way it was jamming at the range (about 3/4 closed, and had to drop the mag to get the slide to continue forward) I think this is the key problem. If the next round pops up early enough the contact the corner of the rail, it's digging into the brass of the case. So, I'm tempted to fairly aggressively deburr the corner of the rail with some 600 grit paper, or maybe even 400 then 600, so it can glide across the case with less digging-in. Am I gonna regret doing that for some reason?

 

[Bazoo]

I haven’t any experience with that model of gun. But if it were mine, I’d do it lightly. That area shouldn’t be sharp as a scraper. Just not rounded either.

 

[Buck13]

I haven’t any experience with that model of gun. But if it were mine, I’d do it lightly. That area shouldn’t be sharp as a scraper. Just not rounded either.

My thinking was that I would put a radius on it (in profile) that would be small enough that you'd need a hand lens to see it. Hopefully still flat in cross section. Probably I'll glue a skinny little rectangle of 600 grit onto the side of an unsharpened wooden pencil to use as a tool.

 

[Bazoo]

That’s pretty darn close to how I’d do it. A popcycle stick and some 600 grit.

 

[Buck13]

That’s pretty darn close to how I’d do it. A popcycle stick and some 600 grit.

The rail already had a tiny bevel on the corner. It didn't feel terribly burry to my finger. I loaded up a mag and deliberately rode the slide down on a few rounds to induce the jam. They all had a small dent and a slight gouge in the brass. I smoothed the corners of the bevel lightly, maybe a dozen or so strokes of 600 grit, and repeated the mis-handling of the slide while loading. They still hung up, now with a dent but less obvious gouging of the brass. I doubt the guys who designed and made the slide would notice the difference. I'm gonna stop there and see what the next range trip reveals.

 

[gc70]

My wife's S&W 380EZ has a 45-degree bevel on the bottom front of the rail.

 

[gc70]

Here is something a little more specific from page 83 of The U.S. M1911/M1911A1 Pistols & Commercial M1911 type Pistols - A Shop Manual (Volume 2) by Jerry Kuhnhausen:

4. Breech Face - The cartridge seat and breech face area below the seat must be sufficiently smooth to allow unimpeded cartridge feeding and cartridge rim engagement by the extractor. The 45-degree edge break at the coincidence of the bottom of the breech face and the central slide rail must not exceed the ordnance specification of .001"+.006".

 

[halfmoonclip]

Brownells markets an assortment of fine stones to work on such things; emery cloth attached to a coffee stirrer works too.
Proceed with caution...have you talked to SIG customer service? Maybe don't do anything that you can't later deny.
Moon

 

[Rule3]

I
The way it was jamming at the range (about 3/4 closed, and had to drop the mag to get the slide to continue forward) I think this is the key problem. If the next round pops up early enough the contact the corner of the rail, it's digging into the brass of the case. So, I'm tempted to fairly aggressively deburr the corner of the rail with some 600 grit paper, or maybe even 400 then 600, so it can glide across the case with less digging-in. Am I gonna regret doing that for some reason?

So you are guessing gunsmithing and just gonna start aggressively deburring?
Heck get the Dremel out!

 

[film495]

uhhh, if it jams when 3/4 closed, are two rounds stripping and causing the jam, or does the one on the top miss the chamber? only so many reasons it can do that. first thought is always magazines, well - for each of these two examples it is most usually something with the magazine. or does it catch the fired round in the ejection port and stovepipe, that's a whole other thing that can happen.

 

[Buck13]

So you are guessing gunsmithing and just gonna start aggressively deburring?
Heck get the Dremel out!

Dremel? Do you take me for a KelTec owner?

 

[Rule3]

Dremel? Do you take me for a KelTec owner?

No but the rails was not meant to be messed with
I have the same gun in 9mm. It works great and did not need to mess with it,

I do not know how old your gun is but sound like a call to SIG, maybe they will fix it under warranty??