Today I worked on the Thimble which contains the Barrel Port and Loading Tray.... The 3/8" diameter stub on the barrel fits into the front of it to insure alignment with the bore, and the joint is sealed with an O-ring, which also seals it into the Breechblock in front of the Transfer Port.... I haven't yet machined the O-ring groove behind the transfer port in it.... The barrel port in this part was machined with a 3/16" end mill starting at 30* to match the transfer port at the back of the port, and then angled to 45* to make the front of the port longer to match the bore area.... The port ends up just over 3/16" wide x 5/16" long at the boreline, but blends into the 17/64" round transfer port.... The finishing touches were done with a Dremel....



The hole at the back fits over the head of an 8-32 screw in the bottom of the Breechblock, that takes the end load from the barrel screwing against it, and the air pressure inside it.... You can see that screw in the bottom of the loading tray in the photo below....



Once again, I am extremely pleased with the way everything fits and lines up.... This relative small part took about 6 hours to make.... Next up is the Bolt, which will carry the O-ring that seals the breech inside this Thimble.... It is the retractable style I developed a while back, with no probe to restrict the airflow.... Then comes the complicated job of machining the "J" shaped bolt slot in the Breechblock and Monocoque tube.... I'm not looking forward to that....

Bob