View Full Version : mr4 bolt action mod

10-29-2011, 03:58 PM
What is needed to convert to bolt action?

11-01-2011, 06:37 AM
Almost most importantly, you need a valve pin that does not have the material removed from the rear end of it. The T1 valve pin did the job for me, though I imagine it's relatively difficult to find at this point.

You can visit our own beloved Vike's page on this type of valve pin here:
Click me! (http://vikingshadow.webs.com/modifyingthevalvepin.htm).

As mentioned in the site, the purpose of this is to eliminate blowback, which 'deletes' the semi-auto aspect of your blowback Spyder.

From there, you need to disconnect your striker (or hammer) from your bolt, but maintain it's orientation otherwise it will not catch the sear. This is function is pretty obvious, as you need to be able to pull the bolt back to 1. Cock the marker, and 2. load the chamber, but then 3. be able to push the bolt back forwards to close the chamber without the striker.

There are a number of ways to achieve this. You can slot the striker such that there is a channel for the bolt pin to slide back and forth in, or you can permanently affix a pin coming up from the striker, and have the bolt catch it on it's way back.

Lastly, the bolt action mechanism, meaning you need a way to twist pull back, push forward and 'lock' the bolt for firing. It is also important that you either relocate the ball detent, or have a good paint to bore match otherwise in the forward position, it is likely your paint will roll out of the barrel.