My brother just picked up a wasr 10 converted to hicap. He was trying to use some of my drums in it but none fit they will go into the mag well but stop before they are latched in. All the mags i have fit in it though. Any quick fixes? Also does the wasr have the same receiver as the sar 1?

Depending who converted the wasr 10.  Some of them are known not to be converted properly due to sloppiness.  Who may I ask is your wasr 10 made by?

 

I think century converted it. I dont really know though it didnt come with any paperwork other than the CAI instruction book. The widening of the mag well looks to be decently done no really large machining marks.

Well there's your answer.  Century will use the crappiest components. If I were you, take it to a gunsmith and have them make the adjustments just to play it safe. :)

It may be as simple as shaving a little bit of metal off the inside of the mag well.

The culprit is probably the receiver at the rear edge of the mag well, the edge in front of the mag catch.  This edge sometimes had burrs from the mill cutter that hogged out the mag well during the conversion.  Sometimes this rear edge of the mag well was not cut back far enough, and just a little careful filing on that edge is all that it takes.  

Try to insert the drum and look closely at all edges and surfaces to try to understand where the interference is located.

Noah