Wynn's Mag-Na-Ported P40 BLOG updated

[wyntrout]

One parting thought, too. I just sent CTD a note asking them about their 180-grain Remington Ultimate Home Defense for .40 S&W. It has the same ballistics as the ONLY listing at Remington... under shotgun ammo??? But for .40 S&W they only list one at the factory... 165-gr. After shooting off an inquiry to CTD, I checked at least two other major sites and they list 180-grains as well, but the ballistics don't jibe with the heavier 180-gr bullet???

Wynn

[wyntrout]

I'd say a couple of those fold up TV trays would be a good cure for you gun working station. Priorities don't ya know.

I do that sometimes, but that's even more clutter... you just wouldn't believe my "storage system"... more like those reality TV shows... Hoarders, and such!

Gotta get busy!

Wynn

[wyntrout]

I got a quick answer back from CTD that I was right about the .40 S&W Remington Ultra Home Defense being 165-gr, and I told him that two other other major sites were listing it the same as he did... weird... assuming??

Dang! Time's running out... gotta get busy!

Wynn

[wyntrout]

Wifey was over an hour late so I got most stuff squared away and some chores done.

Today, I got the DLT (Dremel-Like-Tool) out and put a new polish wheel full of polishing compound on it and polished the heck out of my P40's chamber and feed ramp. I thought I might be able to get to the range and see if that took care of the Failures To Feed. I decided I should test the chamber and see if cartridges stick when I slid them in while pressing them up or down against the chamber rim going in. Crap! They still caught!


Even a stove-pipe!





Well, I though I would try chambering live rounds while trying to do it as briskly and with as much force as I could. I put a glove on my left hand and held the loaded pistol in my right hand... AND, while pointing at the floor in an area I plan to refloor, anyhow, I used my gloved left hand to snatch the slide to the read as hard as I could, while pushing the pistol forward with as much force as I could with my right hand. The slide was ripped from my left hand at the limit of rearward travel and must have approximated actual firing... or as close as possible doing something like that.
Anyhow, I had two or three jammed rounds, cocked upwards in the chamber.
I could pull back (~1/32" or 1/64"... still in contact)and barely reduce the pressure of the slide on the round and it seemed like there was a slight click and the trapped round shifted a minute bit to the left and then would easily chamber if I let the slide go. I repeated this with each FTF.

Okay. I decided to take Sharpie pens and mark the case mouths so I could see what was going on.





Here's the link to the Photobucket Album "P40 FTFeed Tests" where I uploaded the pictures:

http://s1134.photobucket.com/albums/...TFeed%20Tests/

Anyhow, I took lots of pictures and posted most to PB.

I can't see any "hangs" or rough areas around the mouth of the chamber, but the cases sure catch there, and there are marks on the top and the bottom of most cases, especially the ones that got stuck.

I took pictures after the feed tests to show marks in the chamber. What do I have to do... use fine sandpaper or a sanding roller in the DLT or just sandpaper on a dowel, or what??

Any suggestions??

Wynn

[wyntrout]

Here are more pictures of the second magazine with 7 marked rounds. The first 4 went fine, as did #7, but the 5th and 6th rounds caught on the throat of the chamber or just inside:





The closeups got confusing so I put numbers in front of the rounds. These are showing the bottom as inserted in the chamber:



FTFeed rounds #5 and #6 from the front or top as inserted in the chamber:



#5 and #6 from the rear or bottom as they were in the chamber:

[wyntrout]

On the bottom side at the case mouth, slightly left of center, of #5 is the largest nick, but there are some faint marks on the top sides with the red lines.

I also took pictures from nose on of the FTFeed rounds and there are some marks on the nose(s), too.





Some pix of the chamber showing some of the marks made during the chambering test:







Any ideas?

Wynn

[TucsonMTB]

I had similar issues with the first of my PM40 pistols. As part of a kit of bits that I bought for my Dremel, there are some felt cylinders (fat discs?) that attach to the mandrel that has coarse screw threads on the engagement end.

I mounted one of those and then spun it up in the Dremel to sand it down so that it would just barely enter the chamber. Then I applied a little red rouge from the same kit and polished the hdqq out of the chamber, especially to top side.

Polishing the top of chamber, where the bullet nose hits, is an old 1911 reliability trick, which is where I got the idea. It helped a lot. I did that several times before my PM40 had enough clearance to feed reliably.

Because the felt is roughly a small cylinder, I don't believe I changed the shape of the chamber or removed much material, but it sure is shiny and it seems to work now.

YMMV. I would wait to see what Greg has to say about this, presuming he sees the post.

Best of luck. I will be watching your progress and marveling at how scientific you are. Me, I just polished away without much concern figuring Kahr would bail me out if necessary. Mine was purchased new and they had already worked on it, without much result, so I figured they might be game to help again if necessary.

Brave? No. Foolish? Probably, but my first semi-autos were Kel-Tecs so polishing is almost a reflex.

[wyntrout]

This is a ported barrel so I need to be careful. I did use a buffer wheel/disc that just screwed onto the bit you described. The wheel is larger than the chamber, but I worked at it and got it inside... with greatly reduced speed and lots of heat from friction, and with lots of polishing compound. I did try that several times and concentrated on the top and the bottom of the chamber mouth... just inside and further, thinking that I was surely overdoing it, then it did the FTF's in my testing.

I can't see or feel anything, but the cartridges sure hang up... top and/or bottom.

Wynn

[TucsonMTB]

By the way . . . I do see a couple of tooling marks in your chamber photos. I think I would polish until they disappear . . . but, it is your gun not mine . . . so don't let this old fool cause you to rush in. Poke Greg before you do anything drastic.

[wyntrout]

I was hoping to go test fire it today, but I'm sure the FTF's would have occurred during firing as well. WAH!

Wynn

[wyntrout]

I think that some of those marks are from the case mouths... just inside the chamber... those faint parallel lines.

Wynn

[TucsonMTB]

I think that some of those marks are from the case mouths... just inside the chamber... those faint parallel lines.

Wynn

Could be. I would still make them go away by polishing, if possible. Try some jeweler's rouge on a Q-tip with lots of pressure but an motion parallel to the path of the bullet.

Just a suggestion. It's easier to suggest than to do . . .

[wyntrout]

I was just going to wait until someone gave me some good ideas... maybe involving sanding media! I was pretty bummed out after all of the buffing and polishing inside the chamber!

Wynn

[TucsonMTB]

If it helps . . . I have 600, 1000, 1500 and 2000 grit wet-or-dry production papers. Any will produce a mirror-like surface as they loose their grit. Even 400 will make a very smooth surface as it wears during use.

320 is probably too coarse, in my estimation.

All of the wet-or-dry stuff holds up well during use which is important. You don't want bits of abrasive floating around if you can avoid it.

Generally, your motion should be parallel to the bullet path . . . but I am sure I am preaching to the choir on that issue.

[wyntrout]

I have Chinese stuff going upto at least 1200... Harbor Freight Tools... OR China Tools, Inc. And 3M from 100 to 400.

I have some real torture tool implements in my DLT Kit. I have gotten trouble with some of the diamond bits... real moments with the feed ramp on my P380. I thought it was toast but I managed to straighten that out using sandpaper and a dowel.. or round file... LOTS of filing and polishing.

Wynn