Production run of breech plug will be made with overall length in excess of installed length for custom fitment.

Rifle owner will need to supply me with breech plug face sealing surface to primer face sealing surface dimension. To obtain proper primer crush (headspace).

Step 1:
Choose your preferred primer and measure primer length with dial caliper. Example .299

Step2:
Install primer in existing breech plug and measure overall length from breech face to primer battery cup surface . Example 1.889

Step3:
Install breech plug in gun with same test primer . (Please remove firing pin assembly from bolt body for this step) next install bolt handle and close bolt completely.
Remove primer and measure primer length if primer is crushed by more than .002 example.297
You have the 3 dimensions in steps 1-2-3 to have your custom fit breech made and delivered .

If not proceed to step4.

Step 4:
Put primer back in bolt and take a feeler guage and place .002 feeler between rear of bolt and action where bolt handle contacts action when closed to headspace primer .
continue this process increasing feeler guage until you obtain.002 primer crush.

So now you will have possibly 4 measurements.

Example
step1 = .299
step2 = 1.889
step3 = .297 Done if .299 go to step 4
step4 = .005 feeler guage installed you obtain primer crush measurement .297
Done ready to order your custom fit knight bolt rifle breech plug.