FTFeed – Sub 2000

[Bucky623]

I got a used Kel-Tec Sub 2000 a few months ago and it hasn’t fed a complete magazine without a FTF yet. It’s a 9mm that takes the S&W mags. I have the original Mec-Gar as well a S&W factory 20 rounder and some aftermarket mags but they all do the same thing.

The round nose bullets feed about 90% of the time which is a pain but OK for plinking but not nearly good enough for a defense carbine. The JHP’s feed 0.0% of the time. They all get hung up on the small feed ramp cut in the bottom of the chamber. This ramp is cut 0.043 deep. I think by putting a little more slope on the ramp it will help it feed better, however, I don’t want to get it too deep and risk having too much of an unsupported case wall. Would you guys with Sub 2k’s please check the depth of you your feed ramps and let me know how deep they’re cut?

I don’t want to send it back to the factory if a little grinding and polishing will take care of it.

[FONT=&quot]Bucky

[/FONT]

 

[ATF Consumer]

You might also post this over at KTOG Forum - Sub9 and Sub2000 Rifles

 

[Bucky623]

You might also post this over at KTOG Forum - Sub9 and Sub2000 Rifles

That’s a good idea. I’m a member at KTOG and will post there also but I wanted input from the ‘Team INGO’ as well.

Bucky

 

[esrice]

Is that a feedramp? It looks more like a scratch!

 

[FishersCPA]

This issue is not just a 9mm issue. My Sub2000 in .40 has the same problem. If you come up with a solution to the problem please let me know. It is too bad- I love the compactness of this weapon but can't rely on it due to the FTF issue.

 

[ATF Consumer]

I have a Glock 9mm version and the only time I have ever had this problem was with a Scherer 33 round mag.
After thinking about this for just a bit, I think it might simply be a mag issue. I'd suggest cleaning the inside of the mag and ensure there is nothing for the spring to get hung up on or caught, that may be restricting its movement. Lightly oil the spring and inside walls of your mags. It seems like your rounds are nose diving, which I have experienced on my 995 carbine, and that is either because the spring is getting resistance from the mag or the spring is too weak.

 

[ATF Consumer]

Looking a bit further, sounds like you may have an issue with your feed ramp.
Below are the images of mine, which at the feed end of the barrel are slightly different, the ramp on the actual barrel end appears to be about the same.
I'm talking about the little synthetic ramp that is right below your barrel. Here is the link to the PDF manual (http://kel-tec-cnc.com/images/downloads/sub2kmanual.pdf) which shows the ramp as item 121. If this is worn or broken, that will most certainly cause an issue as you have described. But from the pics you have posted, I can't tell for sure. When your round hits the feed ramp, it should angle it upward enough to line up with the barrel end. I'm thinking that if enough HJP rounds have been fired through this rifle, that could slowly dig away at that plastic feed ramp and cause your failures. I only shoot FMJ through mine.

Here are some high res pics of mine so you can compare...

 

[Bucky623]

...I'm talking about the little synthetic ramp that is right below your barrel...

Thanks for the pics ATF.

I don’t think the bullet even touches the plastic part of the feed ramp. I close the bolt till it stops with the bullet nose pushed up against the notch cut just below the chamber. Then I open and lock the bolt in the open position then fold the barrel up all the while watching the bullet to see if it moves. It doesn’t. Then I reach in the auction with a pen and I can push the bullet nose down just a little bit before it touches the plastic part of the ramp so it looks like the ramp is too low. It didn’t appear to be worn down but it’s hard to get a good look at it without taking the side off.

Bucky

 

[ATF Consumer]

I see what you are saying. I don't think they designed this to use HJP ammo, at least that appears to be the case.
Looks like you could Dremel out the barrel end at more of a 45 degree angle so the tip of the HJP would not catch on it or the first thing I'd try would be to build up the plastic feed ramp so that it forces the HJP round upward a bit more.
Not sure how much that little part costs, but I'd think it would be cheaper than replacing the barrel if you happen to mess it up.
For no more of a part than that is, you could probably pop that out and replicate it with a piece of wood or a small chunk of plastic and make the replaced part with a taller ramp. I'd think it would be worth trying anyway. You could also glue a small shim of material to the existing feed ramp to make it work. Hope this helps.

 

[chubbs]

i had the glock 9 version. Never had an issue. I had a couple stove pipes. But that was it, maybe 1 ever 150 to 200 rounds

 

[Bucky623]

... the first thing I'd try would be to build up the plastic feed ramp so that it forces the HJP round upward a bit more....

You could also glue a small shim of material to the existing feed ramp to make it work...

I have considered adding to the plastic ramp to make it taller using JB Weld or a thermal welder but that piece is probably too small to weld to, it would most likely just melt into one big drip on the floor.

Bucky

 

[ATF Consumer]

I have considered adding to the plastic ramp to make it taller using JB Weld or a thermal welder but that piece is probably too small to weld to, it would most likely just melt into one big drip on the floor.

Bucky

Probably right about that...you could probably super-glue a plastic shim on it and it should pop off without too much trouble if it doesn't work.

 

[Bucky623]

Looking at the way your metal ramp is ground, it looks more complete, is in, it goes all the way to the chamber. My ramp looks like it stops just short of the chamber and it also looks like it was ground with a spherical grinder (as if it were dipped out with an ice cream scoop) while yours was ground with a more cylindrical tool.

You can see in the close up picture of my ramp that the outer edges of the ramp don’t reach the chamber. The bottom part of the ramp, closest to the chamber, is almost perpendicular to the bore. That is where the bullet gets hung up.

Below are the types of ammo I have tried. Looking at the tip of the round nose on the left you can see where the portion of the ramp next to the chamber has shaved off a bit of the lead bullet as it was being chambered.

[FONT=&quot]Bucky

[/FONT]

 

[Bucky623]

Can you measure how far your ramp goes into the chamber? If yours is cut deeper than mine, then it’s probably safe to take mine a little deeper.

Bucky

 

[ATF Consumer]

Ok, The length of the ramp measures 3mm inward and the width at the inside of the barrel measures 7.5mm across.

 

[dross]

I looked at mine, it doesn't even have that little ramp on it. Perfectly round, and I've never had a problem with feeding, though it fails to extract Federal ammo.

 

[Bucky623]

Ok, The length of the ramp measures 3mm inward and the width at the inside of the barrel measures 7.5mm across.

I have 4.5mm inward and 7mm across.
How deep is your ramp cut, measured from the face of the breach toward the muzzle. Mine is only 1.1mm deep.

It looks like my ramp may have been made be just a bit too far from the bore.

[FONT=&quot]Bucky

[/FONT]

 

[ATF Consumer]

1.65mm

I noticed that yours starts on the outer ring and mine starts at the edge of the inner ring. I wonder if that is the difference between the S&W & Glock or is this a quality control issue?

And mine of course has the metal stop tab to keep the round from pushing above the barrel, while yours does not

 

[Bucky623]

1.65mm

0.55mm difference isn’t a lot but it might be enough to get rid of that edge that the bullet catches on and still be safe.

And mine of course has the metal stop tab to keep the round from pushing above the barrel, while yours does not

That might be something added to the later models. The build date for mine is Oct. 2002.

Bucky

 

[Bucky623]

I raised the plastic feed ramp (number 121 in the Kel-Tec exploded view that ‘ATF Consumer’ gave in post No.7) 0.060” and now my little carbine has a new life. In raising the ramp a little bit, and in turn raising the bullet nose, the Sub 2000 now feeds HP and RN ammo just fine.

I initially considered adding to the top of the ramp with a glued-on piece or building up the ramp with JB Weld but with this type of plastic I don’t think whatever I added would hold up with bullets repeatedly slamming against it.

After a lot of measuring and head scratching I decided the best way to get the feed ramp higher would be to widen the lower portion of the crescent shaped groove in the front of the plastic feed ramp and just move the entire ramp up.

I enlarged the groove in the ramp using a Dremel Tool and modified the receiver nut just below the ramp to hold it into place by rapping the nut with electoral tape till the O.D. of the tape was about 3/8”.

The electoral tape is temporary, as it would most likely start to mush and move around when it gets warm. I will try to find some hard plastic tubing to slip over the nut in place of the electoral tape. I also plan to fill the remaining gap in the front of the plastic feed ramp with JB Weld to keep it from moving around, though it seems solid without it.

I would recommend doing this in small steps.
A) Grind a little off the ramp grove.
B) Add a little tape.
C) Test the action.
Repeat if necessary.

The most difficult part of the fix was the planning stage. The actual work I did on the carbine wasn’t too tough.

1) Disassemble.
2) Open up the ramp grove with a Dremel Tool.
3) Build up the receiver nut. (first w/tape, then plastic tubing or the like)
4) Fill in gap with JB Weld.
5) Reassemble.

Note: Here is a link to some very good disassembly and reassembly instructions in PDF format.
http://www.1bad69.com/keltec/DisassemblySUB2000.pdf

Bucky



Before modification.

After modification.

Feed ramp with Dremel Tool after modification.
Note: The material was removed from the bottom of the grove. The plastic burrs hanging from the top are from where I bumped against the factory edge while starting the cut on the bottom of the grove.

Two receiver Nuts.

Thank you to all that contributed and a special thanks to ATF Consumer.