bolt hold open

[recumbent]

A friend's MKIII bull barrel will lock the bolt open if you pull the bolt back on an empty magazine but only locks open 1 out of 5 times when shooting.

Where on the bolt does the bolt hold open engage the bolt?

This pistol has about 8000 rounds thru it and we always sling shot the bolt to load the pistol.

Any ideas?

Thanks,

Recumbent Bob

[Bullseye]

Bob,

A couple of things come to mind. The bolt stop components are not timed correctly, possibly due to dirt or grit under the hold-open components or the grip panel is interfering just enough to delay its operation. I don't know how new your friend's pistol is, but it may need the shipping preservative cleaned out from underneath the bolt hold open components.

Here's where the bolt stop hits the bolt face.



You might also check to see if the bolt stop lever is slightly rounded and allowing the bolt face to slip off of it under the forces of recoil.

Hope this helps.

R,
Bullseye

[Bullseye]

Bob,

I did think of another area to look at for that pistol. Be sure that the bolt and inner receiver are clean. Any build up will add drag to the bolt and it may not cycle fully rearward. This is especially true if firing standard velocity loads, as they are on the lower end of overcoming the recoil spring. Also check to see that the recoil rod assembly is smoothly operating. Sometimes the little half circle stop in the end gets flipped over and drags on the guide rod. Simply rotating the rod 180 degrees reduces the drag. You rotate it by turning the end near the bolt stop 1/2 turn.

Hope this helps.

R,
Bullseye

[recumbent]

It was a LOT of dirt and crud between the frame and the hold open lever and the return spring in the front was just packed with crud not allowing the spring to work freely.

Thanks,

Bob