Thread: My 260AI Load Development Begins

Originally Posted by Tikka7mm08

How will I know if over-bumping the shoulder? Or will it be so minor it doesn't matter... or do I screw adjust the die until a tight case no longer is and lock it at that setting I guess...

If you don't have a gauge - I have a Sinclair 40 degree one - the best way is to remove the striker/firing pin assembly from your bolt and with the bare remainder chamber your cases. This way you can feel the bolt closure against the case without the influence of the main spring. For my target rifles I set the FLS so there is just resistance (need to ensure locking lugs are kept well lubed) as the bolt handle is reaching the bottom of its closing stroke. For field/sporter rifles I set the FLSing so there is no resistance on bolt closing. Need to be careful though you don't over size and create a new problem. If you size a case and it is still too tight, make an adjustment but then use another unsized case to check your adjustment. Don't just keep adjusting and sizing the same case as you will get a nice fit with it but too loose for all subsequent cases sized.