FTF-Mag Problems?

[ticknc 5]

So I did some mods to the springs and gas system to correct my Failures to Eject. Now I am getting a Failure to Feed when I am using the Golden Bear Buck-shot Brass Plated Steel Case, 410, 2 3/4", #4 Buck - 5 Pellets. From the replies on the FTE string, I am thinking it may be the Mag.

 

Check the receiver at the front and rear of the mag 'hole'. A slight bend at either place will cause FTE,or FTFeed. The steel hulls have a thicker rim and also slightly larger diameter. A mis aligned mag will screw up with them before it will with American sized rounds.

 

I will take a closer look at this. From all initial appearances it looks ok.

 

It was probably mentioned already back there somewhere but, does it do any better with the factory 4 rd mag? Mine will cycle the steel hulls better with the four rdrs.

 

I have not tried it with the factory mags. This may help me eliminate if it is the mag causing the problem.

 

My Mags:

 

2 - 4 rd factory mags

1 -10 rd factory mag

3 -15 rd Surefire mags

 

I had to take apart the Surefire mags and clean them. The spring had a protective coating that was making the follower stick. I could not load them all the way full and they definitely would not feed (see this link).

 

The differences I can see in the mags:

 

*Factory mag has more of the back side of the shell exposed, because it has a metal retainer. The Surefire mag is all plastic and does not expose as much of the shell.

 

*With the mags partially loaded, the front edge of the shell is about 1/8" higher in the Surefire mag. This makes it catch the front side of the guide when I insert the mag with the bolt held open (does this with the plastic shells too). I have been sticking my finger through the bolt cover to help guide it while I insert the mag.

 

I have noticed, as I watch the action when the round is chambered, the mag pushes the shell off-center to the left. Is there something I can do to the mag that would correct any of these problems?

 

The sharper edges on the Brass Plated shells tend to catch on the edge of the entry to the barrel. Is there a mod to the guide that would help it go in more smoothly?

Edited January 13, 2010 by TickNC

[gpqueen 545]

Golden bear shells are a bigger diameter and will jam the mags. Silver bears work fine.

[ticknc 5]

I have not field tested with the factory mags yet, but I have been doing some measuring etc.

 

The shell casing on the Golden Bear Brass Plated are actually about .004" smaller than the Winchester plastic casings. The only real reasons I can see for the failure to feed is either the inflexibility of the casing or the sharper front edge (the plastic ones are crimped).

 

The mag still pushes the shell off-center to the left with the factory mags as well. When I compare the differences between the Surefire and factory mags, the factory mags seem to be worse for pushing it off-center. It's like the receiver is supposed to have a guide for the back of the shell to hold it straight while the shell is chambered, or there needs to be a smoother (thicker?) guide on the front to keep the front edge of the casing from catching.

[ThirtyAughtSix 101]

I know this may seem stupid or something that could never happen but it happened to me... When you put the mags in, is there a positive CLICK... When I first got my .410, I wasn't loading the mags properly, hey would stay in but it didn't click and I'd get feeding problems all the time. Then I figured out if you load the mag straight up, pushing the shells into the mag, it will click really loud and be locked in real tight. Just a thought, happened to me...

 

ETA: It can take a while to get the mag inserting procedure just right, its a little funny on the .410 and I wouldn't recommend inserting them like normal AK style mags at an angle like everybody else does.

Edited February 13, 2010 by ThirtyAughtSix

[ticknc 5]

I know this may seem stupid or something that could never happen but it happened to me... When you put the mags in, is there a positive CLICK... When I first got my .410, I wasn't loading the mags properly, hey would stay in but it didn't click and I'd get feeding problems all the time. Then I figured out if you load the mag straight up, pushing the shells into the mag, it will click really loud and be locked in real tight. Just a thought, happened to me...

 

ETA: It can take a while to get the mag inserting procedure just right, its a little funny on the .410 and I wouldn't recommend inserting them like normal AK style mags at an angle like everybody else does.

 

Are you talking about loading the Mag "straight up" with Shells or loading the Mag into the Gun "straight up"?

 

When I load the Mags into the Gun, I tend to have to hook the Mag in on the front and then roll the Mag back to hook on the release. Unless I have the Bolt closed, this rolling action causes the front edge of the Shell to catch on the Guide. So with the Bolt open I have to stick my finger through and give the front side of the Shell some help, especially the Steel Cased shells.

[ThirtyAughtSix 101]

I know this may seem stupid or something that could never happen but it happened to me... When you put the mags in, is there a positive CLICK... When I first got my .410, I wasn't loading the mags properly, hey would stay in but it didn't click and I'd get feeding problems all the time. Then I figured out if you load the mag straight up, pushing the shells into the mag, it will click really loud and be locked in real tight. Just a thought, happened to me...

 

ETA: It can take a while to get the mag inserting procedure just right, its a little funny on the .410 and I wouldn't recommend inserting them like normal AK style mags at an angle like everybody else does.

 

Are you talking about loading the Mag "straight up" with Shells or loading the Mag into the Gun "straight up"?

 

When I load the Mags into the Gun, I tend to have to hook the Mag in on the front and then roll the Mag back to hook on the release. Unless I have the Bolt closed, this rolling action causes the front edge of the Shell to catch on the Guide. So with the Bolt open I have to stick my finger through and give the front side of the Shell some help, especially the Steel Cased shells.

 

Wish I had a video to show you... I don't use the hook to get it in. With the mag loaded, bolt closed, you push the mag up, the bolt pushes the shells down a little then you just kind of put a little pressure towards the front (where the catch is) and it should click. It takes a while to get used to it, I still have some trouble with it. But, when I load them this way with the bolt closed it seems to line the shells up just right and I never have a failure to feed. I'll see if I can get somebody to record me inserting the mag and post the video... will have to wait till after midnight. It's a really awkward procedure with the bolt closed but I swear it makes feeding a non issue.

[G O B 3,516]

As it says on the factory mag instructions "file for most perfect fit". There is a molding rib on the front of the mag,and this can force the mag too far back. There is also a molding rib at the rear, and this can cause the mag to sit too low, or be too tight. Look carefully at HOW the mag seats when inserted. Factory mags with the steel feed lips are the best for reliability, but with any mag some fitting may be required, but make sure that gloppy factory paint on the receiver is not the problem FIRST! And when filing , use a fine file and go SLOW! Material is easy to remove, but nearly IMPOSSIBLE to put back!

[ticknc 5]

As it says on the factory mag instructions "file for most perfect fit". There is a molding rib on the front of the mag,and this can force the mag too far back. There is also a molding rib at the rear, and this can cause the mag to sit too low, or be too tight. Look carefully at HOW the mag seats when inserted. Factory mags with the steel feed lips are the best for reliability, but with any mag some fitting may be required, but make sure that gloppy factory paint on the receiver is not the problem FIRST! And when filing , use a fine file and go SLOW! Material is easy to remove, but nearly IMPOSSIBLE to put back!

 

Ok, so I looked pretty closely at how my unloaded Mags fit into the Receiver. I found no signs of "gloppy factory paint on the receiver". I'm still unsure what "ThirtyAughtSix" is trying to describe. I still have to rock the Mag from the front of the receiver towards the back to get it to go in, it won't go straight in.

 

The Factory Mags look like the are fitting well into the Receiver. When they are mounted there is about a 1/16" parallel gap between the top of the Mag and the plate on the inside of the Receiver. Front to back there is a small amount of play. Side to side there is a small amount of play. The Follower looks like it is parallel with the Barrel.

 

The Surefire Mags fit well also. When they are mounted there is the same 1/16" gap between the top of the Mag and the plate on the inside of the Receiver except it's not exactly parallel (slightly higher in the back). Front to back there is a small amount of play. Side to side is very tight. The Follower looks like it is riding a little high and not parallel with the Barrel.

 

Maybe adjustments to the Surefire Mag Follower or file some more off of the back catch-release to get it more parallel? If I go for more parallel, the front of the Follower will sit even higher.

[ticknc 5]

Field tested Factory Mags today:

 

Test firing Golden Bear Buck-shot Brass Plated Steel Case, 410, 2 3/4", #4 Buck - 5 Pellets.

5 rounds (1+4) in a Factory 4 round Mag.

 

Gunfixers setting #-1.

Failure to eject, first round.

 

Gunfixers setting #+1

Failure to eject, second round.

 

Gunfixers setting #2

Shot flawlessly, including reloading 2 different Mags.

 

Test firing Golden Bear Buck-shot Brass Plated Steel Case, 410, 2 3/4", #4 Buck - 5 Pellets.

10 rounds in a Factory 10 round Mag.

 

Gunfixers setting #2

Failure to eject, intermittent.

 

Results: The factory Mags seemed to work better with the Steel Cased shells. There are still some reliability issues to work out. I am going to try cleaning the factory 10 round Mag to see if that helps. I may also try a mod to the Surefire Follower to see if I can get the front angle down a little. I still may be having trouble with the Gas System or the Ejector Ramp. Planning on having Cobra give it the once over when he's feeling better.

[ticknc 5]

Had my once over from Cobra and went out shooting today. I wanted to make some noise on Independence Day .

 

I had a few Failure To Feed's with my Surefire Mags. I am convinced that, based on the picture below, the Surefire Mags do not allow the shell to be picked up. There is not enough of the back of the shell exposed.

 

 

I put 2 rounds in each Mag. If I put only 1 round in the Surefire Mag the follower causes the back of the shell to sit even lower. Maybe I can get someone to mod the Surefire Mag with the metal retainer on the back like the Factory Mag.

[Cobra 76 two 2,677]

Did you try swapping the recoil spring back to the lighter (slower) one? I remember that made a big difference before with the SGM mags. The factory spring was reacting so quick, it was returning the bolt to battery faster than the fully loaded SGM mag could keep up, resulting in the bolt going right over the top shell in the mag. Just that split second seemed to make a lot of difference before. I think some more work could be done to the mags to help this. You already smoothed them up inside, allowing better follower travel. Maybe shoot some silicone spray in there again to lube them some. I have some here if you would like to join me for some shooting this afternoon. I plan to do some rifled slug choke testing in the S-12s, and also have a couple of prototype shotgun mags (12 and 20 ga) I need to test, as well as a .308 mag from ProMag. I also have a Paradox rifled 410 choke that I want to try with some slugs to see how it does.

Back to your mags though...I think it will help a lot to put a stronger mag spring in the SGMs...or at least add some to it by straightening (stretching) it a little, or adding a few more coils to it from another spring. I don't have one apart in front of me right now but I wonder if you could even replace it with an AK mag spring?

As a very last resort, may even want to try adjusting the feed lips a little on one mag to see if we can get the shell rim up a little higher in the back for the bolt to pick it up better....

 

Happy Independence WEEK everyone!

 

[ticknc 5]

I was shooting the Winchester Xpert Game/Target Steel Shot, 410, 3", 1400 FPS, 3/8 oz, 6 Shot, Gunfixers #2 on these FTF's.

 

Yes, it has the lighter recoil spring. I swapped it back because after we field tested it, the lighter one seemed more reliable.

 

These Surefire Mags are the 15 rounders. I'll try the silicone spray. I don't have any extra mag springs unless I tear one apart and make it unusable.

 

Surgery on the feed lip area, so that the back of the shell rides higher, appears to me to be the best solution.

 

Cobra, I would love to come out and do some "testing" today, unfortunately I'm hung up on some family obligations.

 

• Happy Federaly Designated Holiday

Edited July 5, 2010 by TickNC

[Cobra 76 two 2,677]

Well good luck and know you're always welcome to come out again if you want me to help you tweak those mags. When these mags first came out they were 10 rdrs as I recall, and would not feed the steel hulled shells. I modded some that MAA sent me and got them working fine with all shells. I think SGM listened to what I had to say to Nate about the feed lips being too long on the original mags, and changed the molds. I've had good results with the new 15 rd mags using the Barnaul steel hulls and the Golden Bear. I think the Silver Bear they have now is the same as the Barnaul I bought years ago.

 

[ticknc 5]

Did the surgery on the Surefire Mag (center of photo) to the feed lips today. Narrowed off the feed lips as much as I dared. You can see the back of the shell is riding a little higher. Still need to field test.

 

 

I put 2 rounds in each Mag again for the photo.

[Vermiform 26]

Did the surgery on the Surefire Mag (center of photo) to the feed lips today. Narrowed off the feed lips as much as I dared. You can see the back of the shell is riding a little higher. Still need to field test.

 

Well, please share! Did you field test?

[ticknc 5]

Well, please share! Did you field test?

 

...Sorry, not yet.

[ticknc 5]

Field tested today.

 

Test firing Golden Bear Buck-shot Brass Plated Steel Case, 410, 2 3/4", #4 Buck - 5 Pellets.

10 rounds in the Surefire 15 round Mag that I Modified.

 

Gunfixers setting #2

 

Shot nearly flawlessly. I had one hang fire towards the end, because, I believe the lighter recoil spring did not push the bolt back all the way.

 

I think I'm going to go ahead and modify all my Surefire Mag feed lips. I don't think it will hurt anything unless I shave off to much.