Knockout Brass Breech bases
thingiverse
Update: 12/20 Redesigned barrel piece to seat the exact amount of 9/16 brass you need. Cutting guide for 17/32 brass added. NStrike attachment updated with new design and reuploaded Update 12/16 Increased the length of the barrel piece as well as attached an Nstrike attachment I got from https://www.thingiverse.com/thing:3427635 Designed these to make modifying knockouts easier. Hopefully you guys find them useful as well.
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