Build Help - Cycling Issue

[Klem]

+1

As long as the dimple on the barrel is also exactly opposite the gas port, otherwise it will pull the block in the direction of the centre of the dimple as you do it up.

[shannerdrake]

[Klem]

Shanner,

That should work.

By now you'll have a pretty good idea of all the measurements, bearing in mind some blocks are still designed to leave a credit-card gap for the 'old-school' clamping foreguards.

If it doesn't work I recommend an adjustable clamping block, or if you prefer a non-adjustable clamping block, or at least a cheaper set-screw block than AA. SLR Rifleworks is a popular choice on this forum.