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Posted: 11/30/2015 3:39:18 PM EDT
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I am having some trouble with my frankenine when it comes to feeding. Below are the parts:
BCP LE9 dedicated lower Spikes AR upper receiver MAS Defense ramped bolt (AR trigger) Gorilla Machining 7.5" barrel ASC magazines $1.75 in quarters and an H2 buffer with a rifle spring I consistently get a round at a 45 degree angle with the ass on the feedramp and the bullet in the chamber. I can load one round, fire it, and the next one hangs up. I can hand rack one after the next and have no issues. No matter what ammo, it seems consistent that when it is fed from the right side position in the magazine this occurs. I have 2 ASC mags and it happens with both. I know it may be the magazine, so while I wait on a Metalform to arrive, could it possibly be something else? Perhaps the barrel needs some chamfering? Thanks for the help! |
| If you can take some pictures of the area where the rounds feed from the magazine into the chamber, you might get some feedback. This sounds an awful a lot like what others have encountered based on the angles either from their feed lips into the chamber or the angle of the chamber itself. Rudy from Macon Armory has a fix that he applies to the barrel chamber area that has worked for others. You might want to contact him. |
| Does your Gorilla Machining barrel have a rough face? Mine had a series of concentric circle machining marks. I polished the face around the feed area and it improved my feeding issues. Mine uses glock mags so I also had to adjust the ejector to allow the mags to ride a bit higher. |
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How many rounds through the gun? In the first picture it looks like the round is not coming out of the magazine well (Like it's binding on feed lips) By chance does the bolt feel like it's dragging when you hand cycle it? About 100 fired and another 50ish in the trash due to ruined brass from being slammed into the chamber at 45 degrees. Feels fine when hand cycled, maybe a little drag on the hammer. |
| I had horrible problems with a 9mm barrel that was ramped like that one. It can be fixed. I ended up selling it and going to an QC10 barrel which has a continuous curved ramp, not a hard angle ramp and it now treats rounds with kid gloves and they come out just like they go in, unscarred and without gouges in them. |
| This topic https://www.ar15.com/archive/topic.html?b=3&f=15&t=674866 has some good info about feeding issues, barrel feed ramp shape, etc. |
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Rudy is there anything I can do on my own to remedy this problem? I am a hands on guy and have access to some metalworking equipment. Is it just a matter of cutting a wider feed ramp? I set them up in a lathe and indicate on the chamber mouth for max concentricity. I have a small carbide form cutter I run in with the tailstock and the polish with a cratex point. Rudy |
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Quoted: 'Out of Spec' in what way? I have a 7.5" Gorilla Machining barrel on a pistol that works really well, but if it's out of spec in a way that makes it dangerous then I'd like to know. |
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So in general should I avoid the Gorilla barrel on a future build? They are one of the few that have a 7.5" which is perfect for my planned build. Runner also has a 7.5" barrel but I'm betting its the same barrel, profile and marking on barrel look identical. if you don't know you should check out this thread. i have never heard of them until about a week ago someone posted asking about their barrels. this is what i found with a simple google search. maybe they are a better company now. https://www.ar15.com/archive/topic.html?b=3&f=118&t=675970 |
when a barrel blank is made....ESPECIALLY pistol caliber, the bore tends to wander a bit over the length of a 16 or 17 inch blank....probably what happened is it was a cut from a longer blank, and just slipped by .........Barrel making is a tricky science....I have spent years developing our procedure to mass produce barrel and maintain concentricity......I'm sure they'll get the hang of it......with the tooling and process we have now we are holding .0015 TIR in barrels...... we have developed a process where all machining operations are indexed off the bore of the barrel......from crowning to profiling to chambering......it is a little more difficult....but worth it.
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if you don't know you should check out this thread. i have never heard of them until about a week ago someone posted asking about their barrels. this is what i found with a simple google search. maybe they are a better company now. https://www.ar15.com/archive/topic.html?b=3&f=118&t=675970 Quoted:
Quoted:
So in general should I avoid the Gorilla barrel on a future build? They are one of the few that have a 7.5" which is perfect for my planned build. Runner also has a 7.5" barrel but I'm betting its the same barrel, profile and marking on barrel look identical. if you don't know you should check out this thread. i have never heard of them until about a week ago someone posted asking about their barrels. this is what i found with a simple google search. maybe they are a better company now. https://www.ar15.com/archive/topic.html?b=3&f=118&t=675970 Thanks for the heads upl |
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when a barrel blank is made....ESPECIALLY pistol caliber, the bore tends to wander a bit over the length of a 16 or 17 inch blank....probably what happened is it was a cut from a longer blank, and just slipped by .........Barrel making is a tricky science....I have spent years developing our procedure to mass produce barrel and maintain concentricity......I'm sure they'll get the hang of it......with the tooling and process we have now we are holding .0015 TIR in barrels...... we have developed a process where all machining operations are indexed off the bore of the barrel......from crowning to profiling to chambering......it is a little more difficult....but worth it.Thanks Rudy. I sent you an email from your website. |
| Seems to be an issue with the link to me from website, if you can send direct It would be best. [email protected] |
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Quoted: So in general should I avoid the Gorilla barrel on a future build? They are one of the few that have a 7.5" which is perfect for my planned build. Runner also has a 7.5" barrel but I'm betting its the same barrel, profile and marking on barrel look identical. |
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A follow up to this with regards to Gorilla Machining, they have provided me with a full refund and a sincere apology. They are also sending me a complimentary barrel because of my troubles. My assumption is they got the original barrel back and noticed how out of whack it was..... |
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A follow up to this with regards to Gorilla Machining, they have provided me with a full refund and a sincere apology. They are also sending me a complimentary barrel because of my troubles. My assumption is they got the original barrel back and noticed how out of whack it was..... they maybe the best company out there, however with just my limited "googling" i saw all i needed to see. usually a company changing their "brand" indicates bad things. good on them for going above and beyond in this case (maybe they took their lumps and are serious this time around). at the end of the day no matter how good a machinist, or machine shop is, sometimes "shit just happens". |
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Seems to be an issue with the link to me from website, if you can send direct It would be best. [email protected] Okay, just saw this. I will. |
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