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Posted: 10/22/2011 9:59:29 PM EDT
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I am curious if this feed ramp is something that should be fixed. How much out of alignment is considered too much, if any? I have noticed when cycling a round out the mag by hand, the bullet gets pretty scratched up. Any help is greatly appreciated.
Feed Ramp |
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http://www.ar15.com/forums/t_3_118/546870_What_are__extended__feed_ramps_.html
<edit> Original source: http://www.ar15barrels.com/gfx/feedramps.jpg </edit> |
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Quoted: I am curious if this feed ramp is something that should be fixed. How much out of alignment is considered too much, if any? I have noticed when cycling a round out the mag by hand, the bullet gets pretty scratched up. Any help is greatly appreciated. Feed Ramp  |
| I dont think he was asking what the difference in the ramps are. OP, your ramps in the pic look "ok", they arent the best fit but def not the worst. If you are skilled enough with a dremel or file then you can probably get them to match better and then polish them out. If it is working fine then I wouldnt worry too much about them. Shoot 1k rounds through it and if it has multiple problems then try to fix it, if not, dont worry and shoot the hell out of it. |
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The majority of the scratches are likely coming from the cut outs for the bolt lugs. If you notice the tops, they're very squared like all barrel extensions. When the bullet feeds, and you can see the brass marks in your pic, it glides over that area.. My LMT mk18's barrel extension was very harsh compared to others I own and would put more of a gouge in the bullets. They still fed, so it's no big deal.. I checked again about a month or two later and it wasn't nearly as bad. I put about 750 to 1,000 rounds through it and that seemed to smooth it out. I don't know if that's the only place the scratches come from or if has anything to do with the rifling as well since the scratches appear t have a twist, so I wouldn't worry about that at all.
As for the mating of the extension and feed ramps, they look acceptable. If you watch closely during the feeding of the round, most likely it won't even contact that area. The only thing to be concerned about is if there's a lip where the extension meets the feed ramps. If the extension protrudes farther back or the feed ramps are cut to low or deep and get under the extension, it leaves an area for the bullet to catch. If you look at the comparison pics, the one that is bad is what I'm talking about, though that's an extreme example since it is an upper with the M4 cuts and a rifle cut barrel extension. Yours looks fine to me. Here's a pic from one of my SR15's. These don't match up very well and you can see some fabric caught due to a small lip where they meet. Never had an issue in 4,000 rounds on that rifle. The SR15, as you may know, uses an e3 bolt and barrel extension which is why it's rounded and not sharp like standard locking lugs... Just figured I'd mention that for anyone that wonders why they look the way they do. 
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Looks OK to me. If is feeding ok I would not mess with it. It feeds great with GI mags, but I just bought several 20 and 30 rd P-mags, and sometimes the bolt gets hung up feeding the first round. I think it may just be that I forget to give a good tug downwards after I insert the mag.  I'm not positive though.
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| Load up a mag and fire a couple of rounds through it at the range. Extract the next round without shooting it and examine the bullet tip to see if it got shaved. I had a problem with my ramps doing the same and sometimes the tip would get hung up and fail to feed. In my case the extension had a lip that sat a bit higher than the lower and looked like the picture linked in the first post. I sent the upper back to the company I bought it from and they polished it. The upper hasn't come back yet, so I don't know yet how it's all worked out |
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Quoted:
Load up a mag and fire a couple of rounds through it at the range. Extract the next round without shooting it and examine the bullet tip to see if it got shaved. I had a problem with my ramps doing the same and sometimes the tip would get hung up and fail to feed. In my case the extension had a lip that sat a bit higher than the lower and looked like the picture linked in the first post. I sent the upper back to the company I bought it from and they polished it. The upper hasn't come back yet, so I don't know yet how it's all worked out Yeah, I took another look at it, and there is def a small lip where the ramp meets. I didn't even notice an issue until I started using the P-mags. Now it does it with the GI mags sometimes. Weird.  I don't wanna send it back, but the rifle is pretty new and I guess I'll be forced to. I have an e-mail in with the company, so we'll see how it goes. The last time I tried to contact them it took awhile. I've had only a couple minor QC issues, but it is still annoying. I've seen some issues with the wrong gas tubes and such from them here lately. That shit is crazy!
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| This is why you must pay for qaulity. PSA sells cheap uppers for a reason. When you take the time to match barrel feedramps and uppers that actually match up it cost money and time and time is money. Same for test firing time is money. The gastube deal is well amazing. Pay once cry once. What scares me is headspacing and torque values on some companies stuff. If they are missing things like a gas tube what else are they missing forgetting etc. Sometimes things that we don't see or know about. |
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This is why you must pay for qaulity. PSA sells cheap uppers for a reason. When you take the time to match barrel feedramps and uppers that actually match up it cost money and time and time is money. Same for test firing time is money. The gastube deal is well amazing. Pay once cry once. What scares me is headspacing and torque values on some companies stuff. If they are missing things like a gas tube what else are they missing forgetting etc. Sometimes things that we don't see or know about. Yeah, I hear ya. Live and learn I guess. 
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I'll be surprised if PSA gives you the time of day after the shit you've already pulled with them. http://www.ar15.com/forums/t_2_301/210013_Problems_w_PSA___.html |
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I'll be surprised if PSA gives you the time of day after the shit you've already pulled with them. http://www.ar15.com/forums/t_2_301/210013_Problems_w_PSA___.html
Well obviously it was for a reason. Their QC is sucking as of late. I believe I even said something to the effect, if something that small is happening there could def be bigger issues in QC. I guess I was right. I just hope everything gets made right with those gas tubes. My feed ramps are one of the early problems they had I guess. That is what I am reading anyways. |
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Quoted: Quoted: I'll be surprised if PSA gives you the time of day after the shit you've already pulled with them. http://www.ar15.com/forums/t_2_301/210013_Problems_w_PSA___.html Well obviously it was for a reason. Their QC is sucking as of late. I believe I even said something to the effect, if something that small is happening there could def be bigger issues in QC. I guess I was right. I just hope everything gets made right with those gas tubes. My feed ramps are one of the early problems they had I guess. That is what I am reading anyways. I thought the feed ramps looked like a problem, but the one picture you posted wasn't enough to be sure if there's a gap where the point of the bullet can stick. Good luck having that taken care of after your history with them. You would have been better off today if you had just tightened up the gas block and not did the charge back to "get their attention". Not taking sides either way, I see where both parties could have done better over the last problem. |
| Nothing lines up perfect but I have had great matching with BCM,Colt,Bushmaster barrels on BCM,YHM and CMT ramped M4 uppers.PSA in another thread already addressed the gas tube issue..my issue is that people will bitch here before contacting the company and p[osting the entire outcome beginning to end...like bitching here first will cure the problem..when theres a problem CONTACT THE COMPANY FIRST...then how ever it ends up post the whole story good or bad seems like around here its ok to post first and bitch about some companies but not others before said company is contacted.Shoot the damn rifle if it malfunctions or has accuracy problems related to the ramps then act..if its running like a sewing machine clan it,maintain it keep in good repair and have a nice day. |
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I'll be surprised if PSA gives you the time of day after the shit you've already pulled with them. http://www.ar15.com/forums/t_2_301/210013_Problems_w_PSA___.html
Well obviously it was for a reason. Their QC is sucking as of late. I believe I even said something to the effect, if something that small is happening there could def be bigger issues in QC. I guess I was right. I just hope everything gets made right with those gas tubes. My feed ramps are one of the early problems they had I guess. That is what I am reading anyways. I thought the feed ramps looked like a problem, but the one picture you posted wasn't enough to be sure if there's a gap where the point of the bullet can stick. Good luck having that taken care of after your history with them. You would have been better off today if you had just tightened up the gas block and not did the charge back to "get their attention". Not taking sides either way, I see where both parties could have done better over the last problem. Yeah, I don't disagree that it could've been handled differently. I got angry, prob more than I should've. I got rude given to me so I gave it back. It's always easier to look back on it and see what you could've done different. Hindsight is always 20/20 I guess. Oh well, can't change it now. I'll get it fixed somehow. I have a dremel, but using power tools that close to the barrel makes me nervous. I wonder how long it would take to blend by hand?
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| Ive matched extensions to ramps use a sharpie while its still assembled and mark off on the extension where material needs to come off to match.Use the right bit to match and go real slow you can check by setting the barrel back in the upper as you go but to do it right the barrel should come off from the upper.Then touch up with cold blue and your all set.Its also important to keep the same angle the extensions ramp already has. |
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