- Category: Performance
- Published on Friday, 09 November 2012 22:58
- Written by OMW Jun
- Hits: 19086
A sealed breech mod allows you to use a tighter barrel and changes your blasters operation from open bolt to closed bolt. Only blasters with a direct plunger have enough air volume to utilize a closed bolt system.
With streamlines this is more for the cool factor but, this mod can be adapted to be used with stefans for maximum performance.
Use the pipe cutter to cut your stock breech along the middle seam.
Cut a 1 ¼” long piece of ½” brass and 1” pieces of the 17/32” and 9/16” brass.
Mark off ¼” on the ½” brass then heat it with the heat gun and press it into the front of the rear half of your stock breech. It may take multiple re-heatings to accomplish this. Once it is in place slip the 17/32” brass over the ½” brass followed by the 9/16” brass.
Take the 19/32” brass tube and cut a 5 ¾” long piece. Mark off 2 ¼”. From that mark draw a 3 ½” long rectangle extending forward. This long “nose” will ride along the top of your barrel during use and will act as a guide for your darts. Without this your blaster will jam.
Cut out the rectangle.
Cut the lower half of the front of your stock breech off.
Use the heat gun to soften the plastic and fit it over the piece of 19/32” brass you cut in the previous step. Be extremely careful when you do this. A heat gun can reduce your breech to a squishy lump of plastic in no time. You only get one chance at this. Take it slow. You will have to heat the breech then press it to the brass and you may have to do this 20-30 times before it is the correct shape. Next you will wrap sandpaper around the 19/32” brass and sand the breech down for a perfect fit.
Use the cutting wheel on your dremel to form the front of the 19/32” brass to fit the plastic breech.
Scuff the outside of all of the brass pieces you have been working with up till now in preparation for gluing. At this point it is also a good idea to wash all the parts you plan to glue to get rid of any oils that may be present.
Epoxy everything together. I did this with three separate batches of epoxy. Do not try and mix on big batch and try to glue everything in one go. Take your time. I would also recommend that you use a scrap piece of cardboard to protect your work area from any epoxy spills.
With the front half of the breech you are going to have to apply pressure until the epoxy sets. Use both hands to keep the brass and the plastic pressed together for at least 10 minutes before setting them aside to dry.
As the two halves of your breech are drying start work on the barrel. For this barrel I used 6” of 9/16” brass.
Take your pipe cutter and press some tightening rings into the back of your barrel. This will prevent your darts from falling out and will allow pressure to build behind the dart. I would recommend that you try some test rings on a scrap piece of brass to practice not cutting all the way through.
Use the small grinding bit for your dremel and widen the back of your barrel slightly. This will help the darts load more smoothing and should reduce jamming.
You can use the same grinding bit to clean up the front of your barrel too.
Dry fit the two halves of your breech together to make sure that the overall length from the plastic tip to the bottom where the o-ring goes is 5 1/8” then take the two halves of your breech and epoxy them together.
Use the file, sandpaper, or dremel sand down the plastic at the forward half of your breech so it fits inside the plunger body.
Test fit! You may find areas where more plastic needs to be shaved down at the front of your breech for smooth priming. Also, don’t forget to remove the dart tooth from your blaster.
You want the lip of your barrel to protrude no more than ¼”. Any more than that and it will interfere with the darts in your magazine.
Mark how far up on your barrel the brass nose portion of your breech reaches when it is in battery.
You want to make sure you do not apply tape below this line because it could cause your breech to bend during use.
Tape around your barrel above the line you marked. Once there is enough tape for a good friction fit nest your barrel with the barrel extension included with your Retaliator.
Double check you make sure enough of the brass protrudes into the magazine well for a good seal.
Now assemble your blaster and use the stock spring to test it out. At this point you may need to make minor adjustments to get it to work the way you want to don’t put in all of your screws just yet.
Once everything is working smoothly and you have tested your breech with the stock spring install an OMW 5kg for maximum performance.