Vike's Complete Guide to Building a Spyder Pump


Slotting the Striker

        This is my striker prior to cutting the slot in it.  On the top, you can see the hole where the side cocking pin screwed into.  On the side facing us is where the pin that connected the bolt and striker together rested.

This is probably the most strenuous part of this entire modification.  Before I finished it, I was about 80 bucks in the hole!  I had gone through several carbide drill bits, bought a new clamp for my drill press, some cutting oil, and a few other things.  After about 3 hours of work, I had barely scratched the surface of the striker!

I learned a HUGE lesson on this modification, so I'm going to pass it along to you - and it's not going to cost you even HALF of what it cost me, depending on what equipment you already own.

Why slot the striker?

The reason you need to slot the striker is that you want the bolt to move independently of the striker when it's cocked.  Normally, when the striker is cocked back, the bolt is also in the back position and locked into place with the striker.  What we want now is to be able to cock the striker back, then move the bolt forward, sealing off the breach.  That means when it's cocked and there's no pressure on the bolt, tipping the marker forward and backward will make the bolt move back and forth on it's own. 

What you need to do this modification

  • Dremel
  • Grinding stone (for me, the cone-shaped one worked the best.)
  • eye protection
  • benchtop clamp
  • gloves

How to do this modification

NOTE:  When using tools, be sure to follow ALL safety procedures.  If you are a minor, be sure to get parent permission first and have parental supervision.  Never leave equipment on and unattended, and be aware that while bits are very tough, they do tend to shatter when drilling on other metals.  Be sure to wear proper safety goggles and go slowly.

Remember, the striker material is hardened steel.  It's extremely tough!  Using a drill bit will just result in shattering it (I had several chards in my fingers and hand at one point), or at the very least dulling it quickly.  Either way, it will take a very long time to do.  After working for a couple of hours, I finally asked the people in the Voided Warranty forum on what I could use to cut this slot.  They suggested using a high speed dremel and a stone cutting bit...I was very skeptical as I had never had any luck with a dremel, but sure enough, it worked like a charm! 

   Dremel with three of the stone ginding bits I used.  The silver residue came from the metal of the striker and is nearly impossible to remove.  You can see the bit already in the Dremel tool is misshapen - it was a cone shape to begin with, but provided the best cutting surface for this task.

So after spending nearly $80.00 on bits, cutting oil, a special clamp for my drill press, traveling all over town asking for help from different machine shops, and spending nearly 3 hours but hardly making a scratch on the striker - I was pretty upset.  Once I started with the dremel (and a bit I already had in my possession) it took all of about 20 minutes to finish it.  And it didn't cost me a thing since I already owned them.  Yeah - I felt pretty silly!  I did learn that those cutting stones can cut through anything, it seems.

So, step by step, here's what I did: 

1.  First, remove the oring from the striker. 

2.  Clamp the striker (with the hole for the pin that connects the striker and bolt together facing up) tightly in the table top vice.  Make sure to use some leather or cardboard in the vice to protect the striker from scratches. 

3.  After putting the bit in the Dremel tool, and putting on safety goggles, start cutting the slot.  Start at the pin hole and work your way towards the oring slot cut in the front of the striker, stopping just short of the slot.  You will have to add a little pressure to the tool as you cut to move it along.  I also found that angling the bit towards the front of the striker helped get through the material a bit faster. 

GO SLOW. Unless you have an extra striker laying around, you won't have a second chance! Here is a picture of the striker after I finished with it.  (It looks much better in person - must be the lighting,  I guess.  It doesn't really matter what it looks like, though as it's hidden in the actual operation of the marker.)

  Striker after being milled with dremel and cutting stone.

From time to time, check the cut against the pin that fits in the hole.  Make sure it can slide freely back and forth without binding. 

4.  Make sure to cut all the way through to the hollowed out section of the striker as the pin should, and will, fit into that space. 

5.  About half an inch from the front of the striker, the hollow part ends and you should be cutting into solid steel.  It'll be a bit harder to cut now. 

From time to time, you need to attach the bolt and striker assembly back together again and insert it in your marker to check that the bolt completely blocks the feedhole in the marker. (Look down the feed tube and move the bolt back and forth.   If the bolt doesn't move past the feedneck opening, you should keep cutting away material in that solid part of the striker until the bolt can completely seal the breech). 

6.  Once you've cut the slot long enough, go back with your cylindrical grinding stones and smooth the rough edges so you don't cut your hand or damage the inside of your marker.

Caution:  Use gloves as the striker will be EXTREMELY hot!  Don't try to cool it with water, just let it cool on it's own.  It's already hardened - you don't need to harden it more.

  Here is a comparison picture of two strikers - one with a slot cut in it.  As you can see, move from the pin hole to nearly the oring hole.

To test this mod out, reassemble the striker and bolt system and slide them into the maker, make sure to use the spring, the striker buffer and have the frame attached.  Cock the striker back, then tip the gun forwards and backwards - the bolt should slide back and forth and you should be able to see the bolt sealing the feedtube when it's tipped forwards.

If all checks out with this test, then you're through with the striker.  You can either move on to the bolt modification or the valve modification now.