Feed ramp fix for blunt bullets.

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Friar_Tuck
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Feed ramp fix for blunt bullets.

Post by Friar_Tuck »

In my search for a cast bullet that shot well and cycled well in my 8.5” SBR in 300 Blackout, I have really enjoyed this mold.
http://noebulletmolds.com/NV/product_in ... v3gcc7jog6
That bullet, over 13 grains of Lil-Gun is a great shooter for me.
The only drawback is that chambering the first round was often a bit finicky.
It would often hang up on the ramps.
Then I noticed when taking an unfired round out of the chamber that they had 2 gouges in the bullet from the ramps as seen below on the left bullet.
Image
When I looked at the ramps it was obvious from the marks on the corners where the bullets were hanging.
Image
As much as the thought of going after my nice set up with a Dremel tool made me nervous, the thought of marred bullets and the first round hanging up often was worse.
I went in with a small round end sanding drum and beveled the corners a bit, leaving the bottoms and chamber end of the ramps as was.
Image
Image
I reassembled it and it feeds smooth as butter now!
Now that I know the profile is as I want it, I may take it down once more just to give it a good polishing.
As nervous as I was to tackle the job, it was very simple, and turned out great.
Thanks to all of you on here that share your knowledge, so we can tackle things we would have never thought of!
Jim
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rebel
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Re: Feed ramp fix for blunt bullets.

Post by rebel »

Nice job man. I feel your nervousness when the dremel fires up on a first time deal!
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tallburnedmidget
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Re: Feed ramp fix for blunt bullets.

Post by tallburnedmidget »

Glad it worked out! I ruined a barrel by accidentally lowering feed ramps on while trying to widen them. now Bullets fall short of going into the chamber and just jam on the metal below the hole :(
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bangbangping
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Re: Feed ramp fix for blunt bullets.

Post by bangbangping »

tallburnedmidget wrote:Glad it worked out! I ruined a barrel by accidentally lowering feed ramps on while trying to widen them. now Bullets fall short of going into the chamber and just jam on the metal below the hole :(
Dremel? That thing is evil. OP's looks like it worked fine, but I wouldn't touch a firearm with one. Files and or sandpaper when I need to remove metal.
DutchV
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Re: Feed ramp fix for blunt bullets.

Post by DutchV »

tallburnedmidget wrote:Glad it worked out! I ruined a barrel by accidentally lowering feed ramps on while trying to widen them. now Bullets fall short of going into the chamber and just jam on the metal below the hole :(
A high-temp epoxy might fix that. Like Devcon Steel maybe. Can't hurt, since you already think it's ruined.
Making the bad man go away since 1982.
tallburnedmidget
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Re: Feed ramp fix for blunt bullets.

Post by tallburnedmidget »

Ya Dremel. I angled the stone too much to where the ramp lost elevation while widening.

As for the the high temp epoxy I thought about something like that. You're right it can't hurt. My simple little idea was to put some PC paint there and then use pieces of electric tap to hold the powder in place while it bakes in the toaster oven. Then just file it down and pray lol. I've just had zero motivation to even attempt.

Maybe some day lol
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r.tenorio671
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Re: Feed ramp fix for blunt bullets.

Post by r.tenorio671 »

tallburnedmidget wrote:Ya Dremel. I angled the stone too much to where the ramp lost elevation while widening.

As for the the high temp epoxy I thought about something like that. You're right it can't hurt. My simple little idea was to put some PC paint there and then use pieces of electric tap to hold the powder in place while it bakes in the toaster oven. Then just file it down and pray lol. I've just had zero motivation to even attempt.

Maybe some day lol

...the dangers of our rush to "get it built and in the field", the struggle is real :cry: :lol:

....this is where jewelers files come in handy, along with patience and light hands :mrgreen: ...it's always better to remove the barrel too and clamp it into a vice at an angle that matches your natural "stroking". I've seen some results of others attempts made while the barrel was still installed....... the receiver and barrel extension both got hosed :shock:
Luis_R.
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Re: Feed ramp fix for blunt bullets.

Post by Luis_R. »

tallburnedmidget wrote:Ya Dremel. I angled the stone too much to where the ramp lost elevation while widening.

As for the the high temp epoxy I thought about something like that. You're right it can't hurt. My simple little idea was to put some PC paint there and then use pieces of electric tap to hold the powder in place while it bakes in the toaster oven. Then just file it down and pray lol. I've just had zero motivation to even attempt.

Maybe some day lol

This may sound a little difficult, but if you pull the pin on the barrel extension (this is probably the hardest part cause it's so small) you can remove the extension and then but a new one on. I haven't looked recently, but Brownell's used to carry them and they are not too expensive.



I may be wrong, but the AAC barrels that I have look like the ramps may be wider than standard M4 ramps.


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Luis R.
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tXr
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Re: Feed ramp fix for blunt bullets.

Post by tXr »

I have opened up at least 8 barrel extensions feed ramps to clear 30 cal bullets, You widen the feed slots and DO NOT TOUCH the depth. With the barrel already removed it takes less than 30 seconds and then about 5 minutes worth of polishing.

If you want to use epoxy to "fix" your goofed up extension JB weld will not last and hold-up, it is capable of a lot, but it just isn't strong enough. You would want a material like Belzona 1111. It is far cheaper to get a new extension......
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tallburnedmidget
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Re: Feed ramp fix for blunt bullets.

Post by tallburnedmidget »

Thanks for the input guys. I never bothered thinking about the extension. The barrel is a 7.5" barrel and I lost all interest in it once I found such low velocities from it. Maybe I'll fix it or sell it to someone who will fix it. I even had a Midwest Industries handguard shorted just for it too.

I'll look into replacing extensions but it is low low low on my project list and might be a couple of years before I get to it lol.
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