Century cast reciever magwell

[hulygan]

Can anyone help me out? on my century cast ss reciever, the mags won't fit flush and catch the mag release so they just fall out. Can anyone with experience for this tell me what and where needs grinding. Thanks

Tyler

[the_weasel]

Can anyone help me out? on my century cast ss reciever, the mags won't fit flush and catch the mag release so they just fall out. Can anyone with experience for this tell me what and where needs grinding. Thanks

Tyler

Just finished a Century cast G3 build and noticed there is a lip on the rear of the trunion that catches a groove in the magazine. Is your trunion too far forward in the receiver?

[hulygan]

no, its at the back of the mag, when i take out the mag release you can see the catch on the back of the mag does not penetrate far enough.

[pigpen]

Do those little doo-hicky's on the side of the mag need filing? I had to take a dremmel to just about every one of my g-3 mags so they would fit in my stamped receiver.

[cimmaronkid]

:ttiwwop:

[hulygan]

unfortunetly every pic i take gets blurry on the close up

[rustypirate]

Try filing on the front inside of the mag well.

On the ones I bought, they all worked just fine, but I noticed that the Century people cleaned off the front inside face of the mag well with an end mill. chances are that on yours, they did not take off quite enough and it is not letting the mag rotate forward enough at the top/front, so the rear is hanging too low.

[Optimus Prime]

I picked up some of the G3 mags for cheap a while back, and they did the same thing, but CETME mags fit fine, so I figured it was a better idea to mess with the $2 mags than the rifle. Just took a dremal to the top of the catch on the mag and they fed fine for me. I can get a picture tomorrow if you wanna see what I mean.

[SSwee]

I have two of the century cast receivers that are the same way. I fitted the buttstocks where the rear of the receiver was too long but haven't gotten to fitting the mag well yet.
SS

[hulygan]

Optimus, i first tried cetme mags but they didn't fit either, just had the same problem. thanks for the input though.

[M1 Tanker]

unfortunetly every pic i take gets blurry on the close up

Set your camera to the M for macro mode. That will give you clear pictures.

[rustypirate]

Sometimes the macro mode is also represented by a little flower icon.

[SSwee]

hulygan,
Measuring with a dial caliper and looking at the two cast compared to a JLD that fits good, the thickness of the front wall of the mag well is too heavy by .050" to .065". Should be able to fit by filing the inside of the front mag well wall. Looking at the left side with the latch hole, it'll let the mag rotate CCW and bring the rear of the mag up.
SS

[TJ71]

what I did with mine was remove the mag catch and insert a mag and you will see where and if you need to file, on my century ,I had to square up the bottom of the hole where the mag catch engages the mag.hope this helps

[hulygan]

Swee,
You had it dead on. i filed the front of the mag hole on the reciever and it fits in great now, plus it actually catches on the catch. imagine that. Thanks for the help guys.

[silverbear]

Swee,
You had it dead on. i filed the front of the mag hole on the reciever and it fits in great now, plus it actually catches on the catch. imagine that. Thanks for the help guys.

I have the exact same problem, and the picture you took of the mag not seating is exactly what's happening to me.

So basically you fixed the problem by filing down this???
29120

It makes me nervous touching the receiver because some of the g3 mags fit (you really have to beat it in there though). The CETME 20 round mag I have fits in with a moderate slap of the palm. The 3 5 round magazines (which i believe are cetme) fit in butter smooth.

Update: Link to relevant thread: http://www.militaryfirearm.com/Forum/showthread.php?21584-g3-Magazines-difficult-to-load-into-the-cetme

[SSwee]

That is it. Roughly a 3/16" high boss. I know about being nervous on taking material off. I checked fit with a number of different mags including thermolds before removing any material. Something else to look at. On the bottom edge of the trunnion is a rectangle boss that should mate with the front of a mag. If the receiver is not letting the mag rotate into place, the front of the mag cannot locate on the trunnion boss. I would wager the 5rd mags may lock in easy but they are not locating on the trunnion like they should.
SS

[spectre]

pull the camera farther away and zoom.

[silverbear]

That is it. Roughly a 3/16" high boss. I know about being nervous on taking material off. I checked fit with a number of different mags including thermolds before removing any material. Something else to look at. On the bottom edge of the trunnion is a rectangle boss that should mate with the front of a mag. If the receiver is not letting the mag rotate into place, the front of the mag cannot locate on the trunnion boss. I would wager the 5rd mags may lock in easy but they are not locating on the trunnion like they should.
SS

I find it odd because SOME of the g3 magazines are in fact fitting, and the cetme mags are much easier.

can you take a pic of the trunnion boss?

[silverbear]

Here are some pics:

1) G3 Mag - one that will NOT SEAT

2913429135

2) CETME 5 round magazine. Fits like a dream, the way god intended. I can easily eject the mag by pressing the mag release button with my index finger.

2913629137

3) CETME 20 round magazine. Fits after I smack the bottom of it. I need to REALLY press down hard on the mag release to get it to eject. Like I don't even have enough strength in my finger, gotta go thumb.

2913829139

[bladeworks123]

SSwee is right on here with the mag well length on the cast receivers. The aluminum G3 mags are right at 2mm longer front to back, than a steel CETME or even the steel G3 mags. The cast receiver was dimensioned to fit the Steel CETME mags, and even at that sometimes the casting leaves a little extra material up front where he shows in his pics, and also in the rear sometimes. If you have a mag that does fit in and lock like the five rounders you show above. Measure them with a set of calipers and compare them to the dimensions of the ones that won't roll in and lock. You will find that all the ones that won't lock in are longer. The aluminum ones that will lock in you will find have either been squeezed down and are bent in slightly in the front and have had the dimple at the back of the mag flattened out. I have built several CETMES on the cast CAI receivers now, and on every one of them they would not easily accept aluminum mags until I worked over the receiver inside the mag well.

BTW The front fitment of your magazines to the trunnion is perfect. Nice to see a CAI gun that the trunnion is clocked right in.