5.56 AK feeding issues

[mojo]

Ok, a while back a few of us were talking about feeding issues in AKs that are chambered in 5.56. Well, I finally found the thread that I read where the issues was discussed. I know that Al said that he hasn't had any issue with his and I can't remember if LisaA did or didn't.

Here is the thread that I couldn't find before.

http://www.theakforum.net/phpBB2/viewtopic.php?t=30242

for those that don't have an account here is the main point of it.

I used to own a Norinco 84S and it was the only AK I have ever owned that was problematic. Didn't feed reliabily and I was using Norinco mags. That was years ago and I wasn't as involved in gunsmithing and building AK's as I am today so I sold the gun. Looking back I think I realize now what the problem was and just thought I would pass the experience along. Several things prompted my thoughts to jell and being old enough to be the grandpa of some of you guys I have a list of mistakes-made and lessons-learned longer than most. Just thought I would pass this along.

Since Arsenal-Las Vegas came out with their 5.56 AK's I keep hearing about feed problems and several guys have posted their experiences and pics in the Bulgarian forum. I borrowed some of their photos and hope they don't mind.

Secondly, with the influx of kits from various countries and my recent hobby of AK building I noticed differences in the chambers that caught my attention and quickly gave me deja vu back to the 84S problem days.

I noticed some of the chambers of the AK barrels are just machined off flush or have a slight angle cut all the way around the chamber. I think the Chinese barrels are just machined flush but I don't currently have one so am going from memory. I also noticed some of the Euro AK barrrels have an angle cut done with a round cutter on the bottom edge of the chamber. The Polish AKM rifles (best AK quality bar none) have the cut and some Romanians do and some don't. The purpose of the extra cut is obvious, it is there to provide a feed ramp for the bullet tip and that is a basic gunsmithing 101 be it a .22 pistol or an AK rifle.

Picture of a 7.62 Polish chamber with the feed ramp cut. Before I pressed this barrel in I smoothed and polished the ramp. From the factory the edges were a bit sharp and not blended as well as it was just a production machine cut:


Next up is a picture of an Arsenal-USA 5.56 chamber without the cut. Notice the bottom edge is 90 degrees and fairly sharp. You can see where the bullets have rubbed the paint off the end of the barrel. No feed ramp:


This is a picture of an Arsenal-USA 5.56 chamber after they started getting a ton of complaints and rifles returned due to feeding problems. To repair this rifle they machined a feed ramp into the chamber. Note the rub marks where the bullet tips are hitting the ramp. Without the ramp the bullet tips would be jamming head-on into the flat surface. Unfortunately they left the edges of the cut fairly sharp which results in brass being scraped off the cartridge. Note all the brass flakes. The problem of brass flakes building up was a problem with my 84S. Obviously the 5.56 surplus we shoot is brass cased so this is something that doesn't happen in the steel-cased 7.62 ammo.


This is a picture of a current production Arsenal-USA 5.56 and it has the feed ramp incorporated. A little paint in the chamber.


This is what it should look like; ramp cut, blended, and polished.


The 5.56 cartridge is smaller diameter and also longer than the 7.62 for which the AK was originally designed and dimensioned. That can complicate feeding problems and the flat, sharp-edged chamber suddenly becomes a problem it didn't always present in the 7.62. The bullet tip on the 7.62 has a larger radius due to it's larger diameter and will find it's way into the chamber better. Being shorter than a 5.56 the nose also is tipped up by the feed ramp in the trunnion earlier on it's way to the chamber.

The feed ramp cut is an issue the Poles and Romanians, probably others also, saw or they wouldn't have started incorporating it into their process. As I said, it can make any firearm more reliable and I think on a Norinco 84S it will do a ton of good.

I have done this mod with the barrel in the rifle by using a round-tipped Dremel stone. Then using a bullet-shaped Cratex polishing tip in the Dremel. It is a job that requires a steady hand however as one slip of the Dremel and you can do damage to your chamber. I would recommend it to any AK, especially a 5.56.

If you don't feel comfortable doing it I would take it to a good gunsmith and tell him what you want. If he has been around awhile and is a REAL gunsmith he will understand and be able to do the job. You need a mag loaded with two rounds, after removing the bolt carrier insert the loaded mag, push the cartridge forward and note where the bullet tip hits the barrel. Being a double-stack mag the left cartridge hits in a different spot than the right cartridge. Refer to the photo above where the spots are rubbed on the ramp.

Had I done this fifteen years ago I probably would still be shooting the Norinco 84S.

BTW ... the pics were taken off of photobucket, so I removed the links to them.

[TonyF]

I have a late issue Arsenal SLR-106 and it runs like a sewing machine with Gen 2 magazines.

They did "fix" the feed ramp" problem and IIRC, the Gen 2 mags have enhancements as well.

[mojo]

Originally Posted by TonyF

I have a late issue Arsenal SLR-106 and it runs like a sewing machine with Gen 2 magazines.

They did "fix" the feed ramp" problem and IIRC, the Gen 2 mags have enhancements as well.

yep ... all newer production guns have the fixed feed ramps. Didn't know about the Gen 2 mags as I don't really keep up with 5.56 AK stuff.

[MartinBrody]

Arfcom has a sticky about this in the AK47 section in the Bulgarian section.

http://www.ar15.com/forums/topic.html?b=4&f=76&t=106540

I think this is the same thing the AK forum is talking about, but arfcom has the pics.

My later model SLR106F runs great as well.

[Willie D]

I'm curious as to why this isn't an issue with 5.45.

[TonyF]

Originally Posted by Willie D

I'm curious as to why this isn't an issue with 5.45.

Part of the reason is the 5.45 case has much more taper to it than the 5.56 NATO.

[mythaeus]

Thanks for posting that info! I had feeding issues with LisaA's 84S-1, but not with mine. It was jamming every 2 rounds or so, but hers had some replacement parts (can't recall what) and mine is all original. We didn't have time to test with different ammo, but I believe we tried with both Wolf and Remington .223, both 55gr. I'll take mine out again since I haven't shot it much to really thoroughly test it.

Al
PS: You would go nuts if you knew how little LisaA paid for her 84S-1. Whatever you end up guessing, divide that in 1/2 and 1/2 again