Failure to feed

[RyanN]

This is a Century that takes metric mags. It will not feed reliably. When trying to chamber a round, the nose of the bullet hits the breechface and stops. I have tried two different metric mags with similar results. This receiver won't take Inch mags.

I must say that I am tempted to break out the dremal and try to bevel the area that the bullet is hitting.

Any ideas or suggestions?


Bullet being stripped from left side of mag and hitting breechface


Bullet being stripped from right side of mag and hitting breechface

[garyd1961]

If you pull the bolt all the way back and let it fly will it chamber the round? If so it may be ok. If not check to make sure bolt carrier works smoothly. Also check the recoil springs for gunk. If it still doesn't load you could try ggiilliiee's rail modification. Some will tell you not to try the rail mod and others will say it works great, I will leave that choice up to you. I do know it will let the cartridge pop up quicker and maybe missing the breech face. I wouldn't go too far with the mod if you decide to use it. I have done a few and I only took a little off the rails. You could just try smoothing the sharp edges on the bottom of the rails first.

[C. M. Wolf]

Can you post a pic that shows the inside of the recv'r looking straight from the top-down, without the mag in place and then with the mag in place?

I suspect either the feed ramps are too small or the recv'rs mag feed window is too small. But don't cut anything until you are sure. It could be something else, like both of your mag feed lips.

.

Michael

[paolo.orange]

Mag seated too low??

[RyanN]

I actually attempted to fire this gun for the first time on Sat. There is definately a problem. I was using a mag that I know works. I got more failures and only one sucsessful round down range. The bolt is definately cycling freely(free enough that it pushed several bullets back in the case when the bullet hit the feedramp).

I will take photos like Micheal suggested and post them soon.

[Mosin Guy]

Lots of info in this link http://www.falfiles.com/forums/showthread.php?t=108077

[tsmgguy]

Wish I could be of more help, but I would not dremel anything as the portion of the breech that the bullet is lodging up against contains the cartridge base and provides support during ignition.

[JackA]

Your gas piston is also sticking too far into the bolt carrier / bolt area . Also looks like it was built on a Coonan receiver by the little pad on the left rail side close to the chamber . Maybe holding the carrier and bolt from going completely home to chamber a round . Push on it to sse if it will go back into the piston tube , if so the piston spring may be weak also . Don't carve on any thing till you thorougly check things out , lot harder to add back metal !!!

Jack

[RyanN]

Thanks for all of the advice guys. I about ready to just part with this thing. I have been told that the reciever is a Imbel and likely worth $350-$400. Any truth to this?

[hagar]

Originally Posted by JackA

Your gas piston is also sticking too far into the bolt carrier / bolt area . Also looks like it was built on a Coonan receiver by the little pad on the left rail side close to the chamber . Maybe holding the carrier and bolt from going completely home to chamber a round . Push on it to sse if it will go back into the piston tube , if so the piston spring may be weak also . Don't carve on any thing till you thorougly check things out , lot harder to add back metal !!!

Jack

Ditto on that gas piston, try an OEM one. Might just have enough resistance to keep rounds from chamering.

[RyanN]

Originally Posted by hagar

Ditto on that gas piston, try an OEM one. Might just have enough resistance to keep rounds from chamering.

I really don't understand how the piston can have anything to do with the nose of the bullet getting caught on the feed ramp area.

Come to think of it, I haven't even tried adjusting the gas port. It was set on 5 the day I was attempting to shoot it. But I still don't see how it could affect the bullet jamming into the feed ramp.

[JackA]

Post some more pics of the receiver to determine manufacture , although as I have mentioned it might be a coonan as Century bought from them also.

Jack

[C. M. Wolf]

Originally Posted by C. M. Wolf

Can you post a pic that shows the inside of the recv'r looking straight from the top-down, without the mag in place and then with the mag in place?

I suspect either the feed ramps are too small or the recv'rs mag feed window is too small. But don't cut anything until you are sure. It could be something else, like both of your mag feed lips.

.

Michael

Or... you can part it out... or you can send it to a Gunsmith that will,(in no uncertain terms), fix it for you... or...

Post some more pics so that people here can better what the true problem might be.



Michael

[RPBII]

This is a US receiver made for Century not an IMBEL.

[kennaquhair]

It does look like a Coonan featured receiver.

As far as the appearance of the end of the gas piston sticking out of the breech face of the upper, remember that its desired position is relative to the face of the tab at the upper left, not the breech face of the casting. It doesn't look horribly out of spec at this time and certainly shouldn't be recessed into the breech face.

C. M. Wolf might be on to something as it looks as though the distance from the end of the feed ramp cuts to the breech face might be a little short. It is hard to tell what is going on under the nose of those bullets.

From the pictures it looks as though the chamber chamfer might use a little adjustment. The chamfer angle looks to be too vertical. It could more closely approximate the angle of the feed ramp and might use a little more width. Judicious use of a file followed by a polish might provide a fix to this problem. At the link that Mosin Guy provided:

3. New cartridge jamming against back of receiver
...
b. This can also be a problem caused by a slightly out of spec barrel. The barrel around the chamber cut should have a bevel about 1/8" wide. You can widen it slightly with a small file and polish it with fine sandpaper and then a felt tip and rouge on a dremel.

Don't touch the feed ramps. Frankly it looks as though someone has been in there with a grinder already.

I would look at the chamber chamfer with an eye towards modifying it. The inside edge of the chamfer should not extend farther into the chamber than the chamber edge of the extractor cut, but it may extend that far. That should be your limit line for safe operation. At worse, the bullet nose should impact on the chamfer. If it doesn't appear that you can correct the problem within the constraints of the description above, then best to stop now. When removing material in this area always approach it with the idea that you want to remove too little and continually check to see if you have made sufficient change before deciding to remove too little again.

All of the above is based on the assumption that I am properly interpreting the images attached. A picture of a clean feed ramp and breech face without the cartridges would help.

[RyanN]

I sure appreciate all of the help and suggestions. I am now seeing why there are comments like, "Oh no, its a Century".

Originally Posted by JackA

Post some more pics of the receiver to determine manufacture , although as I have mentioned it might be a coonan as Century bought from them also.

Jack

Here are some photos that I already have on hand:

Originally Posted by C. M. Wolf

Or... you can part it out... or you can send it to a Gunsmith that will,(in no uncertain terms), fix it for you... or...

Post some more pics so that people here can better what the true problem might be.

I still plan to post photos of the top view with and without the mag and perhaps with a bullet chambered.

[kennaquhair]

After sleeping on it, while I am fond of neither your rifle's feed ramps nor barrel chamfer, I really don't like the fact that the round is still being held in the mag at this late point. The chamber chamfer shouldn't be employed to prise the round out of the magazine.

Open the feed rails. It is a ggiilliiee mod and seems to be the proper first answer to all FTF problems involving Century receivers wherein the round impacts the barrel face. Employ the search facility and go slow ... again removing too little material before checking.

So far the best surviving thread with pictures documenting the mod that I've come across is at Receiver rail mods improve feeding

Other wiser members will be along shortly to properly chastise me for youthful impetuousness.

[RyanN]

Originally Posted by kennaquhair

After sleeping on it, while I am fond of neither your rifle's feed ramps nor barrel chamfer, I really don't like the fact that the round is still being held in the mag at this late point. The chamber chamfer shouldn't be employed to prise the round out of the magazine.

Open the feed rails. It is a ggiilliiee mod and seems to be the proper first answer to all FTF problems involving Century receivers wherein the round impacts the barrel face. Employ the search facility and go slow ... again removing too little material before checking.

So far the best surviving thread with pictures documenting the mod that I've come across is at Receiver rail mods improve feeding

Other wiser members will be along shortly to properly chastise me for youthful impetuousness.

Thanks for that info and link. I think that this will be my next thing to try.

[RyanN]

Here are the photos that I promised you guys. Looks like the rails have already been done. The cuts look factory to me.

I am not really sure what my next step is. I would like to get it going, but I don't really want to put any money into it.

[C. M. Wolf]

Hummm... Off hand, I'd say that the mag-well feed window in the recv'r floor looks to be cut correctly. I would still recommend running your finger on the edges of this window to 'see' how smooth the edges are. If they are a bit rough or sharp, I would recommend carefully smoothing the edges with a bit of 400gr wet&dry sand paper,(be careful to not take too much off this area on the sides of that window).

Then it looks to me as though the feed-ramp-scallops are a bit shallow,(these could also stand a bit of polishing too). I would recommend that you also check all your mags for sharp/rough edges at the top, slightly closer towards the front. (If you look closely, you can seen the top-front lips of the mag's mouth through the recv'rs mag-well-feed window, these are the areas that should have smoother edges on the mags, just buff them again with some 400gr w&d paper).

Only remove enough of these area's edge surfaces to gain smooth, non-resistant operation in feeding as possible,(if you remove too much, it's a b!tch to put it back). Go slow in polishing these and check it often by separating the recv'r halves, inserting a partially loaded mag into the mag-well, and replacing the bolt/carrier assembly into place. using only your hand to slide the carrier/bolt system, slowly push the round into the chamber while watching carefully how the round moves out of the mag and into the chamber. Also feel for resistance as the rounds are being moved up-into the chamber and exactly where the most resistance is during this travel. Are the rounds being slid smoothly up-onto the bolt face and smoothly under the extractor claw of the bolt?

I have a feeling that the problems may rest more with your mags than with the recv'r,(other than those feed-ramp-scallops being a bit shallow and needing smoothing).
Are all your mags a very tight fit once they are locked into the mag-well? Do any of them move around within the mag-well once they are locked in?

If any of them move within the mag-well, exactly what directions do they move most in? (Up & down on the mag lock? side to side? front to back? etc).

Oh one more thing, approximately how many rounds have been fired through that recv'r? (I'm thinking by the looks of the surfaces, not many, to the point that the recv'r may still be in the process of being 'broken in' on this rifle. That's a good thing that simply keeping it clean, well lubed and shooting the sweet lil' thing will eventually take care of mostly on it's own.)

Take your time, pay attention, and answer the above questions as best you can, one by one.
Please let me know what you find.



Michael

[garyd1961]

Heck it's a Century ,open up the feed rails. It's not gonna hurt, lots of us have done it. You don't have to go all the way just take some off each side. It may just fix your problem.
Is that a unibrow?
Edit- I was just checking my Century receivered rifle and I noticed the tips of the bullets were hitting in the same spot. The only difference is the breech of my barrel has a little bit of a bevel and the bullet jumps over the spot where it's hitting. It still hits hard enough to deform the tip of the bullet. I tried opening the rails some more but it didn't help. So maybe what you need is a tiny bit of a bevel on the breech face of the barrel.

[RyanN]

OK fellas, I have finally gotten the feeding issue worked out. Thanks to everyone for thier input and support resolving this.

First off, I ended up smoothing the edges on the mag and receiver rails with some 400 grit sand paper. Next, I pushed the bolt by hand and watched what the round was doing. I noticed that the receiver rails were not contacting the bullet as it moved toward the chamber. Finally, I also had to take a dremal to the feed ramp on the barrel. I was very careful not to modify the chamber length. I made it more steep so the angle would extend down closer to the "unibrow". At this point, bullets cycled through the gun manually. A quick range trip verified that the feeding problem is fixed.

The only issues I experienced today was that a few times the bolt wouldn't pick up the next round. After thinking about it, I bet I need to adjust the gas system.

[red caddy]

Hey Ryan, would you post up a pic of the compleated fix ?

Thanks, Paul

[W.E.G.]

post up a pic of the compleated fix ?

Thanks, Paul[/QUOTE]

[RyanN]

Here you go.