To the guy who says this is pointless I respectfully disagree. I have a Colt A2 upper with no ramps going into an M4 barrel by Ballistic Advantage. With certain mags I’m getting 1-2 rounds out of 30 that are getting hung up in the lip. With cheap ammo it even pushes the bullet into the casing. As soon as Dremmel part 952 arrives I’m doing this.
@martykean1967 less malfunctions. less failure to feed. some barrel have m4 ramps and some have rifle ramps. i just cut my upper to match the ramps, that all. Green Stainless Steel Polishing Compound works great. there are a lot of compounds out there. 1/8 twist. fed 223. i use mostly handloads now. thanks more video to come.
Personally, I would have plugged the barrel chamber with a rag of some sort to prevent shavings from entering the barrel. Great video otherwise. Thanks for sharing mate!
I really think it’s not a big deal I have heard that Colt used to send them out without anodizing them amongst a few other companies. For the most part unless you’re firing full Auto with weak mag springs it really shouldn’t matter. I put a little film of paint on the part that I buffed and removed the anodized from just about a millimeter of aluminum that was bare. Shot 50 grain 62 grain all the way up to 79 grain hollow points 30 rounds each there wasn’t even a sign that A bullet ever touched and I’ve tested in a lot of other different ways but that was the one that made me realize there can not be any wear. And I was squeezing the trigger as fast as I could. The only way a bullet would touch the aluminum would be if you had a weak max spring the military is notorious for using really old magazines to this day all I use is P mags and they put the bullet at least a millimeter above the steal feed ramp. If they spring became weak they may touch them but the followers in P mags won’t tilt like all G.I. mags. Probably just doesn’t need to be done but mine were so shallow and I had a M4 barrel feed ramp. I’ve actually seen a few upper receivers the military use with those still core bullets that have a metal tip actually poke holes below the ramp. And that was because Gi mags didn’t have anti-tilt followers like pmags. And all modern well at least P mags which are use lift the bullet much higher than they used to us making them for a feed ramps almost useless but mine were jacked up so I had to just in case I ever did need them. Look like a 10 year old kid dremeled it they were very shallow and had a wobble in them so I just fix them work great before works great now.
The upper is made out of aluminum with magnesium added to it. That’s how you get the 7075 forged or billit aluminum. He wasn’t grinding fast and removing a bunch of material, slow and easy. The only thing I would do different is put the buffer wheel and some compound on it with that dremel and polish it smooth like a mirror.
I got a little nervous when the dremel came out but those turned out nice. The bullet should never even touch the ramps if everything else is working correctly but it might help in certain situations.
You should have Just Got a upper Instead of doing that The analyzing Is the feed ramps strength If a bullet rides On those cuts you made It could cause problems Possibly jams in the future and Failure feed I would get a new upper a cheap one from anderson or something I would take the Barrel Off the gun And polish And cut the feed ramps on the barrel only To the new upper But never Cut on the aluminum Inside the upper and never polish it
I bought a complete upper in 7.62x39 and I guess they weren't completely finished machining the ramps before they shipped it out. It works fine with FMJ ammo, but HP hangs every other shot. Rather than spend the $20 for return shipping, wanted to see someone else do it well first. Also, good idea on the cone shaped bit. That plus the chainsaw sharpener as others mentioned can make for some smooth ramps.
I picked up a tid bi from an AR forum that may help. On this forum chainsaw sharpening dremel grinding bits were recommended (7/32 dia) as this size fits perfectly into the existing feed ramp radius. All that is left is slightly increasing the angle of the ramp with the grinding bit to extend the length of the ramp to include the receiver. After the ramp is cut to the desired length and depth a polishing bit is shaped and used to bring about a professional looking polish.
If the magazine is positioning the cartridge properly; the nose of the bullet should be about 1/3 of the way up the ramp in the barrel extension. You can insert a charged magazine and push the cartridge forward to see this. You won't hurt the receiver by extending the ramps; but if your cartridges are diving down and contacting that area, you likely have other issues.
Interesting point. What might be the cause of the rounds "diving" like that? I'm asking because I have an issue with a new build where once in a while rounds appear to be hanging up on the transition from the receiver ramps to the barrel extension ramps. I can feel a small rise there. The gun jams and the bullet is pushed a few mm back into he case. Should I focus on the transition not being 100% smooth or try to figure out why the rounds are diving? Happened with different mags. Thanks
@@jakereeves7385 I did what most people probably shouldn't but I've built a few AR's now and this one isn't super critical to me. I bought a set of small files and slowly worked on the very end of the barrel extension ramps until the transition between them and the receiver ramps was perfectly smooth. When I was satisfied, I racked a whole mag through to test and had no hang-ups. I've since had the gun out shooting and the issue never reoccurred even after several magazines. I wouldn't recommend doing this unless you're really comfortable with it - there is a chance you could damage your receiver and/or your barrel extension.
Anyone who is worried about the bullets woodpeckering the aluminum should also ask how could a gun even woodpecker any aluminum if it doesn't shoot reliable. You don't do this if your gun shoots everything reliably, but this is your only option if your gun doesn't like certain magazines or certain ammunition. I have a RRA upper I did this to in 2012 becuse it would not feed subsonic loads reliably or reliably feed 20 round pmags. Imo a gun isn't worth owning if it can't run everything reliably that the gun was meant to shoot. After doing this my gun feeds and shoots everything under the sun with any type of magazine to this day. I have shot a few thousand rounds through it and other than being a little scuffed up is still blended good with the barrel feed ramps with no overhang.
I'm not sure if it will necessarily hurt anything, but doing this really isn't necessary--the only problem you can really have is with a M4 feed ramp receiver and a rifle feed ramp barrel extension. Other than that, you're good to go. That being said, though, you did a good job aside from the fact that you can't really anondize them yourself.
what kind of dremel bit are you using for the aluminum feed ramps? I have an upper that has the feed ramps not cut enough towards the extension so I need to dremel it out a bit, but I dont want to ruin the barrel extension. also of I polish my feed ramps what bits do I use? I'm kind of new to this dremelness on the AR, however smith all my ARs.
I think he made the problem worse, and that's why he hasn't responded. He had to do further work, most likely, due to the barrel's extensions being higher than the improvised m4 cuts.
Your pretty skilled with that dremel tool but I don't understand why those ramps weren't already manufactured into that barrel. I'm missing something! If you have a few minutes could you send me a message or reply to this post and explain? Also, what polish do you recommend? What Twist is in that barrel, and whats your favorite CHEAP ammo? I suppose all this could be a good idea for a new vid huh? Thanks!
Better to just round off edge of lower not make a ramp.... or alignment situation will appear if you ever change barrel ....... I'm just saying WHO WILL GUARD THE GUARDS
So just accept your gun will always run for shit and jam, fail to feed and be totally unreliable??? People may have the money to piss away and throw out the old receiver, but why when there is a feasible option and your left with no other choice to utilize the components you already have.
This modification was done to smooth out the passage of the bullet being loaded into the chamber; this should make the rifle less likely to jam. Pause the screen at 2:57 and you'll see the comparison - the feed ram on the left side is not a clean, continuous passage. The modified ramp on the right side is smooth and continuous and hopefully allows the rifle to feed rounds into the chamber more reliably. I hope this answers your question, even though it's been 8 months lol.
Yeah and then throw out the old reciever??? That's like changing 50000 mile tires out at mile 100. It's a gamble worth taking if the end result is just to toss it. If you F it up you were gonna toss it anyway, if you get 1000 rounds of reliable use atleast you got some use out of it and learned something along the way. Than it's that much less wear and tear on the new receiver.
@@joediesel187 have you noticed any wear on the bare aluminum after firing over time? I know this video is old I left the feed on the receiver end? I had an m4 feed ramp that was just shallow and with some mother’s mad abrasion and some wool tip buffers I left them a little high just in case.
He’s right. Yes, they worked in this instance because he had very little work to do. The stones will eventually clog up and stop removing material. It doesn’t take long either. The correct too, to use if grinding aluminum on a regular basis is a HSS burr. Alternatively you can load the stone with beeswax to keep it from clogging with aluminum particles.
Since this is top comment, I just wanted to let everybody else know that no this is not necessarily true. Bullets will and do slam into the receiver below the rifle cut ramp. Its just typically not an issue. If you want to see for yourself just half ass chamber a round and look. Its not usually an issue because of how the bullet is tipping at that point, but its technically not ideal and can cause failures to feed and start damaging the upper receiver if its bad enough. The most common issue is feeding soft points terribly and/or mangling the hell out of the tips. Supposedly the lead build up from this can lead to all out stoppages later but thats one thing I havent seen yet. Another thing to alleviate this is pmags are extremely common now and do an excellent (ie, much better) job of tipping the bullet than the standard USGI design mags. Not to scare anybody because the majority of rifle cut ramps work as intended, bullet slamming or not. The m4 feed ramps are just a better design though. If you aren't having problems dont bother, and im not at all suggesting taking a dremel to the receiver either.
As JTR pointed out, your statement often does not apply to SPRN bullets. He even referenced Bushmaster's take on the feedramp solution to SPRN. I have 2, 7.62x39 AR47s from the same mfr. One feeds SPRN fine after removing the center divider. The other upper may need to have the M4 feed ramps blended 3/32 lower into the upper receiver (while keeping the same ramp/extension angle) when using the same C- Products-Defense magazines. I'm going to swap carriers, then the bolts, then test an ASC mag, followed by a few other things before blending the ramp further into the upper as a last resort. My 7.62x39 rifle's purpose of use is 90% for hunting and 10% for personal defense. SPRN is excellent at both due to rapid expansion and is also a decent intermediate range cartridge when the bullet isn't mangled by the feed ramp. If all you intend to shoot is FMJ for plinking (not distance), you likely won't need to touch anything. If you want to shoot SPRN, put on you're thinking hat as you will have problems to solve. As pointed out in the video.
I just bought a Colt A2 upper that doesn't have M4 feed ramps. But I'm going to swap all the parts over from a Sig M400 upper that does have feed ramps. Should I move the barrel and if it works, then not worry about it? And if there are feed issues, then cut ramps?
