Keltec RFB not accepting several metric FAL magazines

[JNA]

Hey Guys,

I recently purchased a Keltec RFB with several metric FAL magazines. I looked it up online and all of them appear to be metric FAL magazines, however some fit and function fine, while others will not lock in at all. I tried them both at the range and at home. Do any of you have any recommendations on how to get it to fit. I am assuming it would probably require some filing, but would request some more insight as I am not the most mechanically inclined. The only thing that appears somewhat different between the magazines is the back of the magazine, but I am not sure if that would cause a problem. Thanks in advance and all the best.

 

[cr5]

As long as they don't have a big lug on the front side they are metric (non metric can be turned into metric by grinding off the lug).
If you drop the lower from the upper like you would when you strip it to clean it you can insert a mag and see where it is binding up.
If it will lock in empty or with 4 rounds or less but not with 5 it's just the mag was pinned to tightly. Just lock the bolt back before inserting a mag if that is the case.

I good smack on the bottom of the mag also help. Some are tighter than others.

Good luck

 

[JNA]

Bolt is locked back, magazines are metric and a good smack does not keep it in place/lock (empty and with ammunition).

 

[petermoo999]

put the working one next to the non-working one, look closely at the back where the mag catcher is? Are they the same height and size? Are the mag lips at the same height?