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Old 08-17-2012, 06:48 AM   #1
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Feed ramp issue?

I have a RIA FS A1 that is having feeding "concerns". I have about 500 rounds through it but it runs very hard when feeding a new round into the chamber.

I checked the extractor tension and it's good (holds case loose but won't release on its own)
lightly polished the feed ramp with scotch bright and 600 grit just to "clean"

I found that if I try to release slide and by hand, slowly try to feed round the bullet gets hung up on the feed ramp and won't chamber.

If I release slide and let the spring chamber the round there is a big clunck noise but will load.

I have ejected the round and sometimes find the bullet has been pushed in slightly (with both factory FMJ and reloaded FMJ using Lee factory crimp) and I am afraid of pressure issues.

gun will not shoot anything but FMJ.

I'm thinking that a gunsmith might need to work on the ramp but would like to make sure that there isn't another issue gong on?

Any help would be appreciated.
 
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Old 08-17-2012, 08:07 AM   #2
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Check the breech face, make certain it's clean and smooth. Pay particular attention to the firing pin hole. Often there's a burr around the hole. Also check the feed blocks below the breech face, make sure they are clean and burr-free. Keep in mind that the feed ramp is only 1/3 the feed equation; the other two thirds are the extractor and the breech.

Regards,

Walt
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Old 08-17-2012, 09:44 AM   #3
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Is it a new gun? Have you tried different mags with it?
 
Old 08-19-2012, 03:50 AM   #4
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Quote:
I have ejected the round and sometimes find the bullet has been pushed in slightly (with both factory FMJ and reloaded FMJ using Lee factory crimp) and I am afraid of pressure issues.
That tells us that the bullet nose is impacting the barrel ramp instead of gliding over the top corner...and the result of that is the fairly common 3-Point Jam.

Essentially, the barrel is being pushed forward by the bullet, and when it moves forward, it moves up, working to engage the barrel upper lugs with their mating lug recesses in the slide. If that happens too early, the lug corners crash...barrel front to slide rear...and it all comes to a halt.

If your jammed rounds have a little smiley face mark about 1/8th inch below the case mouth...there's your sign.

If the frame ramp angle is out of spec, this usually happens, and you can polish it until you can see your face in it, and it won't help. If, during the polishing, you round off the top corner of the frame ramp...even a little...it makes it worse.

If the barrel ramp angle is out of spec...too steep or too far rearward, it can also happen. Check to see that there's a small gap between the lower edge of the barrel ramp and the top corner of the frame ramp. A little is all it takes...about a 32nd inch...but it does have to be there. If the barrel ramp is flush with the frame ramp's top corner...or in some cases overhangs into the mag well...that's where the bug likely nests.

With pistols that are right on the edge of doing a 3-Point, bad extractor function can push it over that edge...and it's not just about tension. Most often, it's excessive extractor deflection that causes the problem.

Flip the slide upside down and look carefully at the extractor, and how much of the tensioning wall is extending beyond the small guide block that it passes through. More than a 64th...about .015 inch...is right on the peg. I like to see .010-.012 inch. With that, the pistol will tolerate quite a bit of tension without causing problems, and ejection will be more consistent. Less than that much, and you get failures to extract, and ejection issues.

Remove the extractor and use a dial caliper to measure the distance between the two guide blocks. .484 inch is about right. Be careful not to let the point of the caliper jaw get into the extractor channel, or you'll get a false read.

Sometimes...even with the correct deflection...the bottom corner of the tensioning wall is too sharp to let the rim open the extractor. With these, a light bevel on the bottom to create a more gradual camming open of the extractor usually goes a long way to smoothing up the rim pickup. Just don't get carried away. If the bevel extends too far upward, you can get all sorts of failure to eject problems.

About 2 weeks ago, I got a PM on a gun board about a Springfield Standard Mil-Spec that was giving intermittent failures to go to battery. The guy was local, so he made the trip to Castle Dogtown for a peek. The extractor deflection was a little more than I like to see. Because I didn't have a new one on hand...and because I can't add material to the front pad to move it out of the way...I used the edge of a safe-side rail file to cut the tensioning wall .003-.004 inch deeper, and knocked a like amount off the claw, and cut a light radius on the bottom edge of the claw itself. He reports that his problems have gone the way of the dinosaur.
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Last edited by JohnnyT; 08-19-2012 at 04:01 AM.
 
Old 08-19-2012, 08:13 PM   #5
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Out of the 7 Rock Islands that I have only one had the same issues that you speak of. I contacted Rock Island in Nevada and spoke with Arnel, (master Gun smith) for Armscor. He suggested I send it back which I did and at no charge to me. He changed springs, polished the feed ramp and barrel throat. He also opened up the mag well. upon return he sent me two extra mags, for poker chips, a real nice towel and a complete list of what he had done. In his hand written note he said that it would feed HP's and any other types of ammo. Also stating it would feed wad cutters. Ya right.. Well I had no 45 wad cutters but I did have a friend that had some loaded and of to the range I went with about all kinds of different ammo. I'm here to tell you it never missed a beat. Worked 100% with all ammo, even 20 wad cutters. Arnel. the Master of the Rock Island. No charge, 18 day turn around! Thanks Arnel, and Armscor you have a great Gun smith. What great service. My daily carry now. over 600 rounds now with any problems. I am so happy. My officer model is there now having 30lpi on the front strap and 3 1/2lb trigger pull with new Ed Brown custom trigger
 
Old 08-20-2012, 04:17 AM   #6
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Quote:
In his hand written note he said that it would feed HP's and any other types of ammo. Also stating it would feed wad cutters. Ya right..
I've got several unaltered USGI pistols...A1 and pre-A1...that can't tell the difference between hardball and Hensley & Gibbs #68 SWCs. A modern production pistol should feed'em just fine if the ramp geometry is to spec and the magazines are good.
 
Old 08-23-2012, 05:45 AM   #7
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Thanks for the great info! I need to look more closely at the casings also but so far no smileys. I also have a match and officer model that do the same SLIGHTLY but not anywheres as bad with the same mags. I would think that it is more of a gun specific issue.

I polished the feed ramp using a 1/2" dowl, starting with 220 and finishing with 600 grit emery. Then put a LIGHT coat on grease. Didn't change the contour, only cleaned it up. It helps some but didn't fix issue.

With gun apart the extractor holds a shell good. Breech face is smooth and clean.

I started looking at the mag that I have and found that if the mag is full (8 rds), when I push out the top round out with my finger it will NOSE DIVE(even if I pull up on the front of the bullet at the same time it still forces nose dive) and the rim gets caught on the 2nd round. If I remove the top round and do the same again. It gets easier (less binding) as I remove rounds. The spring is too stiff? Is there a fix? Only with my ACT-MAGS. (that's all I have). I don't think this is the real issue but just another issue that needs to be fixed.

What ever this is, it has to be tweaking my extractor HARD every time I load the first round in a full mag. The mag is forcing a nose dive which causes the bullet to smash into the ramp and push the bullet into the casing 1/16"-1/8".

Thing is that the guns are otherwise great and a joy to shoot. I am guessing it is time to call Arnell at RIA in NV and talk with him next.
 
Old 08-23-2012, 07:14 AM   #8
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Quote:
Originally Posted by 1911Forum View Post
ALL 1911 magazines have nosedive in the exact way you described. ALL of them. All manufacturers, all types of follower designs, all calibers. ALL of them. The more rounds that are loaded in the magazine, the larger the gap between the top round and the underlying round. This nosedive gap allows the nosedive. This in normal for single column magazines.

While you might be seeing a difference in magazines when you do this hand, they ALL act the same in the gun when fired. see the video below.

Nosedive Video

Also, bullet setback is common. It is greater the more the round nosedives. see this link bullet pushed into cartridge - 1911Forum and my posts # 8, 13 and 15.

Your extractor is not involved in nosedive. See post #13 in the above forum link. .
I found this discussion on the 1911 forum about this issue. A different perspective?
 
Old 08-23-2012, 07:21 AM   #9
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Quote:
Originally Posted by JohnnyT View Post
That tells us that the bullet nose is impacting the barrel ramp instead of gliding over the top corner...and the result of that is the fairly common 3-Point Jam.

Essentially, the barrel is being pushed forward by the bullet, and when it moves forward, it moves up, working to engage the barrel upper lugs with their mating lug recesses in the slide. If that happens too early, the lug corners crash...barrel front to slide rear...and it all comes to a halt.

If your jammed rounds have a little smiley face mark about 1/8th inch below the case mouth...there's your sign.

If the frame ramp angle is out of spec, this usually happens, and you can polish it until you can see your face in it, and it won't help. If, during the polishing, you round off the top corner of the frame ramp...even a little...it makes it worse.

If the barrel ramp angle is out of spec...too steep or too far rearward, it can also happen. Check to see that there's a small gap between the lower edge of the barrel ramp and the top corner of the frame ramp. A little is all it takes...about a 32nd inch...but it does have to be there. If the barrel ramp is flush with the frame ramp's top corner...or in some cases overhangs into the mag well...that's where the bug likely nests.

With pistols that are right on the edge of doing a 3-Point, bad extractor function can push it over that edge...and it's not just about tension. Most often, it's excessive extractor deflection that causes the problem.

Flip the slide upside down and look carefully at the extractor, and how much of the tensioning wall is extending beyond the small guide block that it passes through. More than a 64th...about .015 inch...is right on the peg. I like to see .010-.012 inch. With that, the pistol will tolerate quite a bit of tension without causing problems, and ejection will be more consistent. Less than that much, and you get failures to extract, and ejection issues.

Remove the extractor and use a dial caliper to measure the distance between the two guide blocks. .484 inch is about right. Be careful not to let the point of the caliper jaw get into the extractor channel, or you'll get a false read.

Sometimes...even with the correct deflection...the bottom corner of the tensioning wall is too sharp to let the rim open the extractor. With these, a light bevel on the bottom to create a more gradual camming open of the extractor usually goes a long way to smoothing up the rim pickup. Just don't get carried away. If the bevel extends too far upward, you can get all sorts of failure to eject problems.

About 2 weeks ago, I got a PM on a gun board about a Springfield Standard Mil-Spec that was giving intermittent failures to go to battery. The guy was local, so he made the trip to Castle Dogtown for a peek. The extractor deflection was a little more than I like to see. Because I didn't have a new one on hand...and because I can't add material to the front pad to move it out of the way...I used the edge of a safe-side rail file to cut the tensioning wall .003-.004 inch deeper, and knocked a like amount off the claw, and cut a light radius on the bottom edge of the claw itself. He reports that his problems have gone the way of the dinosaur.
This makes even more sense now...thanks!
 
Old 08-23-2012, 06:56 PM   #10
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Check it without the extractor. If the problem goes away...it's the extractor. If it doesn't...keep lookin'.
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