Last round ftf

[Fortyforfun]

This is my first post on this or any forum. I have a limited gun I recently built myself using STI slide and frame and a Kart easy-fit barrel. This is my first ground up build although I have been shooting and tinkering with single stack 1911's and Para doublestacks (.45) for quite some time. It always seems that I've had to work on most of my 1911's to make them run. I usually shoot in Limited Ten with my duty gun (Springfield TRP .45) but I wanted a .40 to play in Limited.

It is STI long wide frame and unique slide with Kart easy-fit bushing barrel in .40. I'm using STI tubes with Gramms guts in three of my mags and DP followers with IMSI springs in two others. Tubes appear to be in spec. I have my slide stop and followers set up to not lock back the slide.

The problem I am having is intermittant failures to feed usually on the last or next to last round in the mag. Ammo has been all factory length (Win. white box 180 and 165, Speer Gold Dot 180's, and S&B 180's). The failure occurs with all the mags. The round usually ends up with the bullet nose on on the top of the chamber with the cartrige laying vertically on the feed ramp. Most recently I had a stovepipe with a loaded round (last round in mag). Obviously the problem occurs as the pressure from the mag spring decreases (the springs are new). It appears that the rounds anre making contact with the bottom of the feed ramp before the malfuntion occurs as there is an impression on the nose of the bullet. Also if I do a press check with one or two rounds remaining I can see the round beneath being pushed into the bottom of the ramp. I ran the gun a few times with the bottom of the ramp protruding into the magwell so much so that I had to remove material from the front of the mag tube to prevent contact with the ramp. I recently removed material from the bottom of the ramp to make it even with the mag well when the barrel is linked down; however the problem remains.

Any help at all would be greatly appreciated.

[CDRODA396]

I had the same problem, last or second to last round, magazine immaterial. Tried an order of 300 rounds of loaded long ammo from Atlanta Arms and Ammo (I'm still saving for my reloading set up!) and the problem went away completely. I'd get a hold of a couple hundred long loads and see if they run in it.

[HSMITH]

Try a good tuned magazine. The top round in the tube being up near the ramp is normal. What it is not doing is popping up high enough or staying high enough during feed. Location, angle and size of the feed lips have a lot to do with this.

[Fortyforfun]

Try a good tuned magazine. The top round in the tube being up near the ramp is normal. What it is not doing is popping up high enough or staying high enough during feed. Location, angle and size of the feed lips have a lot to do with this.

I spoke with Beven Grams about this a couple of months ago, he seemed to think it may be slow mag or the gun is shortstroking. It does not appear that the gun is shortstroking, and I find it odd that all of my mags would have the problem with different combinations of spring and follower. It seems as if the round is being pushed up and out of the tube by the bottom the ramp as the barrel unlocks. There is usually a hard impression in the nose of the bullet and the round will jam nose up against the top of the chamber or be caught between the hood and breachface like a stovepipe.

[Flexmoney]

One thing that a column of bullets in the magazine seems to do is provide a base/support...for the bullet that is being feed.

How is your extractor? I think Brazos has his extractor tuning article up on his website.

As mentioned, long loaded ammo my work better. The 40 at factory spec is a shorter round than was designed to be run in a 1911/2011 based gun.

I ran the gun a few times with the bottom of the ramp protruding into the magwell so much so that I had to remove material from the front of the mag tube to prevent contact with the ramp. I recently removed material from the bottom of the ramp to make it even with the mag well when the barrel is linked down; however the problem remains.

Is the ramp extended back further than the frame, at any time ?

[Fortyforfun]

One thing that a column of bullets in the magazine seems to do is provide a base/support...for the bullet that is being feed.

How is your extractor? I think Brazos has his extractor tuning article up on his website.

As mentioned, long loaded ammo my work better. The 40 at factory spec is a shorter round than was designed to be run in a 1911/2011 based gun.

I ran the gun a few times with the bottom of the ramp protruding into the magwell so much so that I had to remove material from the front of the mag tube to prevent contact with the ramp. I recently removed material from the bottom of the ramp to make it even with the mag well when the barrel is linked down; however the problem remains.

Is the ramp extended back further than the frame, at any time ?

The extractor is not coming into play, it seems to be a bolt over base type failure with the slide moving over the top of the round. It is possible that the case head may be coming into contact with the breach face at the very bottom, but the round is not making it up to the extractor.

Initially the ramp was extended approx. 3/16 or so back further than the frame. As I stated , I had to cut down the front of the mags. The first time I tested the gun, I only cut one mag. By mistake I grabbed one of the uncut mags and it was forcefully ejected from the gun as the bottom of the ramp contacted the mag as the barrel unlocked. The modified tube ran just fine with 100 rnds of Win wht. box 165 gr. first time out. My most recent mod. was to remove material from the bottom of the ramp to be nearly flush with the frame with the barrel linked down. This of course reduced the surface area of the ramp for the bullet to contact should it nosedive; however I don't appear to be having that problem.

I read a post by Benny Hill in which he stated that if the gun was right it would run on factory length ammo.

[HSMITH]

Try a good tuned magazine.