mini 14 cycling and bolt lock open problems

[Blade&Bullet94]

im working on a mini 14 a friend recently purchased. its one of those 200th year of american liberty rifles, so its fairly old. the problem it keeps seeming to have is the bolt likes to lock open occasionally during firing. i dont know alot about high powered semi auto rifles yet, so i cant figure out what is causing this. i tried cleaning it and the magazines, helped a little. then i saw the brass was flattened on one edge of the case mouth. i thought it might be effecting how the bolt cycled. found out it was from the low mounted little red star scope that came on the rifle. i put a higher mounted scope on there and the deforming stopped., and the gun seemed to cycle a little better, but it will still occasionally lock open. i am using the cheapest ammo, pmc bronze and american eagle, if this may matter. the only last thing i can think of is the spring that pushes the bolt hold open plate down may be too weak, and so the recoil of the gun is causing the plate to pop up and hold open the action. any help would be welcome, the mini 14 is supposed to be a rugged and reliable rifle, but so far it jams more than my ruger 10/22 when its dirty running bulk ammo out of an eagle mag >>

 

[Centurion75]

Ae you using Ruger factory mags? If not I would try one of those and see if the problem goes away. The next thing I would do is remove whatever scope and mount currently on the rifle and give it a go

 

[TurtlePhish]

It's possible that the hold-open spring has weakened. See if you can find a replacement and try it out. Might fix the problem.

 

[rule303]

This is a 180- prefix rifle I assume? They had some issues, and were updated. Many of the parts are out of production, and won't interchange with the newer minis. Check for galling of the rails and bolt, and make sure everything is clean and lubed. If you can't get it running right, I bet if you sent it to Ruger they would either fix it or offer a replacement at a greatly reduced price.

 

[Blade&Bullet94]

i dont know if any of them are factory mags to be honest, theyr all unmarked second hand magazines, 2 20s and a 10, the only one that seems to work properly is one of the 20 rounders. and as i said, i put on a higher scope and the deforming of the brass stopped. also it is a 180 rifle

 

[Blade&Bullet94]

looks like the bolt hold open spring was the culprit. went to my local hardware store, got a spring that was the right diameter, snipped off a section and replaced the old spring. emptied a mag without a hitch, even with cheapy pmc bronze. as a bonus, this has become my first paid repair job. (being 18 and an apprentice at a gunshop, friends have started to come to me for firearms advice)

 

[Art Eatman]

Good that the problem is solved.