Turn your delrin-bolt without o-rings into a gas-efficient o-ring bolt! Also- you can remove that pesky built in venturi found in shocktech pre-alias bolts! I made my detent groove as big as the dragun stock bolt has, so it wonít trash the ball detent! Read-on.
DONíT BLAME ME IF YOU HAVE TROUBLE DOING THIS/MESS-UP YOUR MARKER AND/OR TOOLS IN THE PROCESS! I AM PROVIDING HINTS AND SUGGESTIONS ON HOW TO IMPROVE YOUR MARKER. BE SMART. IF SOMETHING DOESNíT SEEM LIKE A GOOD IDEA, ITíS YOUR RESPONSIBILITY TO MAKE THE CALL.
I am not responsible for any damages you may do to your property*
What you need:
ANY crappy delrin bolt w/o o-rings
A drill (not absolutely necessary) and a few bits, or a pencil.
A dremel (>god) and tips
The venturi is the star thing in the end of the bolt. It supposedly reduces turbulence. Youíll notice high-end bolts donít have it. Itís old technology. It restricts air flow. TAKE IT OUT!
1. Take a dremel, get a cutter like this:
2. Chow-away at the venturi, being careful not to cut into the outside walls of the bolt:
Wear safety glasses!
3. Get an abrasive stone that will fit inside the end of the bolt. Run it around gently to de-burr and smooth the inside of the bolt so air can flow well.
It should look like this when youíre done:
Thatís it! Just wash the bolt to get-rid of the delrin filings. Also- you can get-rid of an aluminum venturi by un-screwing it with long needle-nose pliers. If itís an aluminum bolt with a bunch of holes, the above method should work*
O-RING GROOVES!!! YEAH, BABY!
Though people have probably done this, Iím the first one I know of, so I call it the agitator mod, lol!
One note before you start this awesome mod. If you start with a bolt thatís too thin, you may weaken it excessively and cause it to break once you start using it. Iíll let you guys know how mine works out, but I havenít, at this time, thoroughly tested it.
1. Chuck a large drill bit into your drill (you canít do this, unless you have a bolt without a venturi). Wrap the bit in a rag and stick it snugly into the front of the bolt: (I disassembled mine to do this, but you donít have to if your bolt is a one-piece one... thatís no problem.)
2. Make sure the bolt is centered ie; when the drill turns, the bolt doesnít move from side to side. This will ensure that the grooves are the same depth all the way around. This step is very important. If you donít have a drill, you can rotate the bolt by hand while dremeling. This will take more time/effort and probably wonít be as good. Then again- not all of us have drills.
3. Put a cut-off wheel on a mandrel and chuck it into your dremelís collet. Wear safety glasses! On a slow speed (3/5), cut into the material on either side of the air inlet as the drill rotates at a slow speed. Go slowly and make sure you donít cut too deep, or your bolt will break in half, which is bad! To make a wider groove, turn the dremel, so the wheel is rotating on a different axis than that of the bolt. If you donít know what I mean, feel free to pm me about it. I started on the forward groove of the two, since the seal of that particular ring isnít as important as far as blow-by is concerned.
It should look like this:
4. Do the other groove, and make both grooves a little shallow. Test fit Ďem a few times and take the material off slowly. The bolt should fit in the gunís bore snugly, but it should be effortless to slide it. There shouldnít be any free play and the bolt should drop outtaí the gun if you tip it... You donít want a lot of friction.
5. Once the grooves are the right width/depth, wash+dry the bolt and re-install it. Also- if you do make the grooves a little too deep, wrap some teflon tape in the grooves to act as a shim. This will make the o-rings tight enough again*
tired of your bolt pushing and wearing your ball detent? If it has a groove thatís too small, make it bigger! Some guy tried this on my bolt with a (jackknife?). LOL! Iím gonnaí use a dremel!!
1. If possible, compare the bolt to your stock one, so you know how it should look
The delrin bolt is shorter, so the groove doesnít have to be as long in this case.
2. Using a dremel and tapered stone, carefully remove the material at a medium speed. Wear safety glasses!
3. Check the groove as you go. Make sure itís even and also that it doesnít get too big. Wipe the bolt occasionally and re-install it to see if it pushes the detent. Itís okay if it bumps it. You just donít want it hitting the detent and/or depressing it very far. The groove may be a little rough when you finish. Some 400 grit sandpaper and patience should smooth-out the marks. ONLY SAND THE GROOVE. The outside of the bolt is smooth and nice. You donít want to damage the finish.
4. The bolt should look like this when you are done. Wash it and re-install it when itís dry.