Before I get started, let me first say that the design for this breech is heavily based off FA_24’s “demon breech” used in his Countess writeup. My design is basically taking that one and making it work for those with CPVC couplers.
Ok, now let’s get started. I was recently commissioned to design a breech with a 9/16 main barrel that worked in the ½” CPVC coupler of his BBB. What I had known previously as many do as well is that ½” copper has the same or similar OD as CPVC, yet the same ID as 19/32” brass. It was therefore the perfect candidate to make the breech.
Alright, so first, you need to cut yourself 7” of ½” Copper tubing. This is all assuming you’re going to have an 8” main barrel. If not, it’s all proportional. (9” barrel; use an 8” piece of copper. So anyway, get yourself 7” of Copper tubing, and 8” of 9/16 brass. I lost the cool pics of it next to a ruler for some reason…but I have it from now on. Next, you need ½” of 9/16” brass:
And half an inch of 17/32””
And one full inch of ½” brass:
And finally, 6 ½ inches of ½” PVC. If you have Sch 20, that'd be the best, but if you had Sch 40, like I did, you’ll see how we deal with that in a bit:
Now, time to cut the breech opening. Trace yourself a breech opening with pencil 1” from the back of the PVC. I use a little paper template to trace this. You can just put some glue stick on the back and stick it where you want it on the PVC, and then trace from there. It works very nicely. Once you have it drawn, it’ll look like this:
Now, you can reverse this and the last step if you’d like, but this is the order I did them in. What you want to do now is drill out the PVC to fit the 1/2” Copper. The copper has an OD of about 5/8, maybe a bit less, but that’s the most accurate that I could achive with my drill bits available. Once drilled out, the copper should fit inside the PVC:
Now that it fits, you want to superglue it in place, as in the picture above. You should have about an inch of copper sticking out the back. Once it’s super glued (I used Zap-a-Gap, by the way), cut out your breech opening. It’s nice and easy, because you’re cutting through both at once. You want to be careful with your cutting though, make sure it turns out clean through the copper, or the 9/16 won’t slide through correctly.
Here’s a picture of the finished breech opening cut:
(It is yet to be cleaned up. That will come in part two later (Cosmetics)).
Now, you want to combine your little assembly of smaller pieces of brass. 1/2” inside of 17/32” inside of 9/16”. Here are a few pics of what it should look like when you’re done (Again, this part is heavily based off the “demon breech” and I take no credit for this part of the design):
Now, put a bead of superglue around it, and push it into the rear of the Copper, with the ½” facing inwards:
While that’s drying, take the chance and put a few tightening rings around your 9/16” brass that’s going to be your main barrel. Once you’ve finished that and your glue has dried, congradulations! You are almost done. Test it out, see how the 9/16 is sliding in the Copper, make sure there are no restrictions in motion. Here’s a pic of where you should be now:
And open with a dart:
Now, this part is for those who are definitely using ONLY CPVC COUPLERS with this breech. This is for added stability, and will make sure your breech stays on correctly. Note, once you do this, the breech CANNOT be used with PVC couplers. Since I was specifically commissioned though to have this work with a specific gun using a CPVC coupler, I did this step. What you do is take a PVC coupler, and superglue it slid onto the back of the breech:
That will keep it extremely stable when used, as the copper will slide into the CPVC coupler, and the ½ PVC coupler will slide over it, creating both a double seal, and double the stability. Here’s a picture of the finished back of the breech:
And that’s it, you’re done. By the way, just to prove stability, I stuck the breech on this:
And shook it around like a maniac. It didn’t budge. Though it is also not difficult to remove from your gun if you please. Cosmetics will come much later as I need some more paint, but I figured I’d present this to the community. The lucky owner to be of this is also going to have his first time seeing this in the works when he reads this write-up, but I just couldn’t wait. I hope this helps those of you with CPVC couplers on all your guns wishing to use brass breeches.
Also, due to the fact that this is a variation of the “demon breech,” it shotgun loads like a dream. If the buyer requests, I will add some sort of grip to the front for opening and closing the breech, but personally, I prefer it like this. It keeps the weight of the breech towards the back, and helps even more to keep it from dislodging when you don’t wish for it to (Although I doubt this could happen anyway. Like I said, it’s very sturdy).
I hope the future owner as well as the rest of the community like this; Questions, comments, and criticism are appreciated.
EDIT-I'm not sure if this should've gone in the Modifications or Homemades section, as it was built for a modified blaster. If it's in the wrong place though, if an admin would please move it, that'd be great.
Edited by diamondbacknf1626, 08 September 2009 - 05:21 PM.