Which press???
If one of the HF's, will find it very lacking, even in the 12 ton range.

Truth is for gun smith work, find it easy to use a 3 ton arbor press for most press work (easy to make the needed punch and suports), and in regards to working on rifle like the HK and AK where you need to press the barrel in and out of the trunion, better off with a DYI screw press instead.

As for bending barrel blanks, then a press like the 12 ton unit will come in handy, but look into adding  a pneumatic assist with foot control to it.  This will free up both hands to hold the jigs in place as you start to set ram tension.
Note, the plates on the 12ton HF are cast units, and if you get into something else that you will need the full 12 ton pressure of the press, bank that your going to snap the plates.