Do it yourself feed ramp

[SJMPCC022]

Time to bear my soul, for intel gathering and a learning opportunity.

 

A few weeks back I decided to grind a feed ramp into my Kaw Valley barrel. It didn't have one and I have seen pics of this being done before, including one from Max on this forum.

 

Granted the gun has never not chambered a round, not once, but I figured if the 360* chamfer around the chamber hole worked, a feed ramp would make it better !

 

This kind of stems from the TF +10 base pad not working worth a f**k, so I thought this may help, not to mention it makes sense. After all,  John Moses Browning made it work 115yrs ago, right ?

 

So I ground the feed ramp in and shot the gun this last Friday and Saturday, all good. Not to mention I've also shot it in the last week or so doing chrono testing working up a few different loads.

 

Fast forward to first stage today, the gun won't feed hardly at all ! 68 seconds in and about 10 rounds dumped out of the gun I quit. Four targets not engaged and the last one I did shoot at had one hole in it equals a ZERO for that stage!  Time to think on your feet!

 

I volunteered to go first on the next stage to see if this was really going to be my day.  On " make ready" the round wouldn't even chamber. I walked off the line, before the buzzer went off and headed for home, to take drastic measures to fix this gun that I probably messed up in the first place.

 

One match earlier in the year I had the roll pin that holds the charge handle latch walk it's way down and hang up on the upper, preventing the bolt from going to battery. The whole ride home I was thinking maybe this was the problem?

 

Got home and took the charge handle out, nope all good. The first charge handle was a cheapy, this one is a Strike Industries at about 40$. So, on to plan B. Since the only thing that changed since the last match was my home made feed ramp, it had to go away. I pulled the barrel off and tried to pull the orientation pin out. Not happening, press fit in the hole. ( FYI, that is  manufacturing no no 101. NEVER press fit into a blind hole! )

 

Get out the trusty file and file the pin down. Luckily it was soft and filed quite easily, if it would have been a dowell pin, I was done for the day. With the pin filed down, I clocked the barrel 90* and put it back together. The reason for this being I didn't want the feed ramp on top, I thought it would be out of the way better on the side?

 

Gun put back together, load a mag with 5 rounds and cycle them out on the floor, all good!

 

I head back to the range and my squad was just walking down from the stage I had left from. It was still empty so the RO ran me quick and  we continued on with our day. ( I forgot to mention I live about 4 minutes from this club, lucky for me !)

 

My gun ran flawless the rest of the day! Because of the bad stage my overall wasn't very good, but the rest of the stages were pretty decent, especially considering my muzzle brake was also clocked 90* to the side. Read that as the little holes on top being at 9 o'clock ! Being what it was I was pretty happy.

 

So the million dollar question...............................I shared this to try to figure out what happened. In my short time here so far there are a lot of knowledgeable people willing to put well informed ideas out there, I'm all ears.

 

Also, if you want to call me a dumbass for grinding a ramp in my barrel, feel free. I may deserve it but it also may be the ramp isn't big enough ! Depending on what I get for feedback, that may be on the agenda for tomorrow after work ?

 

 

[chevrofreak]

Have you got a picture of the ramp you cut?

 

If you really want a ramp you could just replace the barrel with a Shooting Innovations ramped barrel.  It has an actual ramp, not one cut into the chamber.   I replaced the barrel in my 9mm AR PDW with one so I could feed fat mouth 147gr HST without issues.   It would require a bit of modification to your BCG. 

[mveto]

When I wanted I ramp, I decided to use the Taccom ramp and just fit it into my upper receiver, I have had 100% functionality with that ramp. Close to 2k rounds through it.

[mstamper]

I suspect that your feed ramp, being cut by hand, was not lined up 100% with the mags and that is what caused your feed issues. 

IT maybe was not functioning properly with the BCG as well.

[Flatland Shooter]

Take a look at the pictures of the ramp found on the Stoner 9mm barrel at MidwayUSA.  I think this may be similar to what Max L. did.

 

How does yours compare?

 

https://www.midwayusa.com/product/1018781574/ar-stoner-barrel-ar-15-9mm-luger-lightweight-contour-1-2-28-thread-1-in-10-twist-chrome-moly-melonite

 

 

 

 

Edited September 10, 2018 by Flatland Shooter

[gerritm]

7 hours ago, mveto said:

When I wanted I ramp, I decided to use the Taccom ramp and just fit it into my upper receiver, I have had 100% functionality with that ramp. Close to 2k rounds through it.

This, put one in both PCC's we run and 100% going at about 5K rounds. Best $40 I have spent.

 

gerritm

[CalTeacher]

What bullet are you using?

[stick]

1 hour ago, gerritm said:

This, put one in both PCC's we run and 100% going at about 5K rounds. Best $40 I have spent.

 

gerritm

I also installed the Taccom feed ramp in one of my PCC's.  The other one has a ramped Barrel

[SJMPCC022]

12 hours ago, chevrofreak said:

Have you got a picture of the ramp you cut?

 

If you really want a ramp you could just replace the barrel with a Shooting Innovations ramped barrel.  It has an actual ramp, not one cut into the chamber.   I replaced the barrel in my 9mm AR PDW with one so I could feed fat mouth 147gr HST without issues.   It would require a bit of modification to your BCG. 

When I take it apart again tonite I will post a pic.

[SJMPCC022]

3 hours ago, CalTeacher said:

What bullet are you using?

115gr RN, Xtreme.....1.120 OAL, this never changed

 

11 hours ago, Flatland Shooter said:

Take a look at the pictures of the ramp found on the Stoner 9mm barrel at MidwayUSA.  I think this may be similar to what Max L. did.

 

How does yours compare?

 

https://www.midwayusa.com/product/1018781574/ar-stoner-barrel-ar-15-9mm-luger-lightweight-contour-1-2-28-thread-1-in-10-twist-chrome-moly-melonite

 

 

 

 

Mine is similar in size, but it was probably an alignment issue. With the pin being gone, I can line it up no probbo !

[CalTeacher]

There’s no reason a ramped Barrel is needed with round nosed bullets.  

[Startingover]

17 hours ago, SJMPCC022 said:

 

 

Granted the gun has never not chambered a round, not once

 

 

This part right here,  seems like the most important part of the whole post.

 

It makes me laugh, because I am the same way, can't leave well enough alone, I gotta mess with.

 

So I feel your pain right now

[SJMPCC022]

4 hours ago, Startingover said:

This part right here,  seems like the most important part of the whole post.

 

It makes me laugh, because I am the same way, can't leave well enough alone, I gotta mess with.

 

So I feel your pain right now

Sometimes I live by the motto, " let's see what we can f**k with next"! It usually works, this one bit me.

 

I tried to upload the " before" picture but it won't go. This is how it looked after I tweaked it tonight, I thought it was maybe a little small with the first try. Since I took it apart yesterday during a match I didn't really look close to see how it was lined up. After removing the pin I had it lined up nice this time, figured this sucker is going to fly ! NOPE, tried jacking rounds through it in the basement and had a few that wouldn't feed. Three different mags, it was hit and miss.

 

Experiment over, I indexed my new feed ramp 90*, so now there is extra clearance for the brass to fly out of the ejection port. Tried running rounds through it again and EVERY one went. Will shoot it a little tomorrow to verify, but I think it will be fine. Another match Sunday, I sure hope so !

 

Oh well, nothing ventured, nothing gained!

 

Edited September 11, 2018 by SJMPCC022
add content

[Startingover]

Nice recovery 

"Its an ejection relief cut"

[chevrofreak]

What did the jams look like?

[Acer2428]

To me it looks like the ramp dog-legs from right to left. Rounds are likely hitting the ramp 2/3 of the way up and getting pinched. You want it to taper down towards the chamber, but it almost looks like you've got it the other way around. I'd open up the bottom of the ramp and I think you'll like it. I also dremel'd my 5.5" BA barrel as an experiment and it seems to work just fine, but I was working with colt mags which required an even wider taper.

[SJMPCC022]

15 hours ago, Startingover said:

Nice recovery 

"Its an ejection relief cut"

Thanks

 

14 hours ago, chevrofreak said:

What did the jams look like?

The round would go about a quarter of the way into the chamber, then stop.

[SJMPCC022]

3 hours ago, Acer2428 said:

To me it looks like the ramp dog-legs from right to left. Rounds are likely hitting the ramp 2/3 of the way up and getting pinched. You want it to taper down towards the chamber, but it almost looks like you've got it the other way around. I'd open up the bottom of the ramp and I think you'll like it. I also dremel'd my 5.5" BA barrel as an experiment and it seems to work just fine, but I was working with colt mags which required an even wider taper.

Thanks for the info, that is why I posted this!

[chevrofreak]

2 minutes ago, SJMPCC022 said:

Thanks

 

The round would go about a quarter of the way into the chamber, then stop.

That sounds to me like there is a sharp edge digging into the case. It does appear that there might be a couple of sharp points at the top of your ramp where it transitions into the chamber.  I would widen the bottom of the ramp, and try to blend the edge of the ramp with the existing cone so there are no high spots that the round can catch on.  

[SJMPCC022]

11 minutes ago, chevrofreak said:

That sounds to me like there is a sharp edge digging into the case. It does appear that there might be a couple of sharp points at the top of your ramp where it transitions into the chamber.  I would widen the bottom of the ramp, and try to blend the edge of the ramp with the existing cone so there are no high spots that the round can catch on.  

There were small pieces of brass in there, but even with my best cheaters I couldn't tell where it was rubbing. This may be a winter project, we are done after October. Thank you again for the good info.

[Acer2428]

1 hour ago, chevrofreak said:

That sounds to me like there is a sharp edge digging into the case. It does appear that there might be a couple of sharp points at the top of your ramp where it transitions into the chamber.  I would widen the bottom of the ramp, and try to blend the edge of the ramp with the existing cone so there are no high spots that the round can catch on.  

 

A LIGHT chamfer on both the top and bottom of ramp. One or two passes with some emory cloth/super fine grit sandpaper should do the trick. You'll break most of the edge when you widen that ramp at the bottom anyways. Think of it as a funnel. Widening it at the bottom gives you more L/R, but if you have a sharp edge on the bottom, it'll catch there too. 

 

Don't wait. Break out that dremel, some sandpaper, and the polishing wheel and get it done. Pretty easy fix IMO. You've already done the hard/stupid part

[SJMPCC022]

7 hours ago, Acer2428 said:

You've already done the hard/stupid part

I accept and deserve every bit of that one !

 

I shot the gun tonight  with my new feed ramp/ejection port clearance pointed at the ejection port. It ran 100%, just like it did before I earned the stupid part of your post!

 

I have a match this Sunday and next, I think after that one I will play with this some more. One after that is second Sunday of October, gives me a bit of time. This thing should just swallow up 9mm rounds, and I think it will. Just needs a bit more attention on my part. The other option is to do what I should have done in the first place..................... take the damn barrel to work and set it up in a vice at the correct angle, pick up center on the barrel and work the ramp in with a .375 endmill !

 

I have one more swing at this  with some paper and finesse', besides it's way more bad ass to do this by hand as opposed to using the mechanical advantage .

 

Thanks for the support and motivation !  

[CalTeacher]

This is way too much effort for zero gain.

[SJMPCC022]

21 minutes ago, CalTeacher said:

This is way too much effort for zero gain.

The zero gain part is yet to be determined......................................

 

Every bit of effort up to this point, including reading all the posts here are intel into the PCC building bank ! As an example, and I assume your comment is placed here because you have been following my journey ?

 

In my original post I told how I left the match and went home to try to fix my gun. The only reason I left the range is because I knew EXACTLY what I was going to do when I got home, otherwise I would have stayed and ran the other guys on my squad.  I stated I took my barrel out and wacked the orientation pin off so I could index the barrel to a point where my feed ramp would not feed.

 

The only reason I thought of that was an earlier post on here where someone showed the Taccom 5" barrels with the carbon fiber tube and the muzzle brake , sold with out an orientation pin to allow the end user to index the barrel for the muzzle brake. 

 

It may or may not make much, or any difference on this gun ?

 

But the next, and the next ??????????????????????????????????

Edited September 12, 2018 by SJMPCC022
good reason

[CalTeacher]

Well if you want to call it a learning experience then that’s cool I guess.