These systems use small rifle primers.

Any of the auto primer tools with the proper shell holder will easily prime the cases.

If your brother is a machinist, he can easily fabricate you a simple decapping tool.

FYI: Should be noted that the primary reason for this modification is for shot consistancy and thus accuracy improvement. The benefit of capturing blowback from ignition is a secondary benefit. Anyone willing to proceed with one of these modifications should be willing to work up an accurized load for thier gun, which IMO and almost all of the independant experts out there, includes only shooting a loose powder and one of the better spitzer style saboted bullets.

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