@guardian7
I've done a lot of PTTP side pressing and it is a lift I really enjoy. A few observations and considerations based on my experience:
--There are a lot of versions of the side press, from "almost a military press" to "almost a bent press." Some traditional definitions specify that both knees stay locked. The PTTP version allows a bent front leg. It also borrows from the bent press in starting with your elbow back against the lat (imagine you are picking up a heavy sack by holding the gathered top of the sack and slinging it over your shoulder -- that's the start of the side press, not a squared up military press rack position) and in pushing yourself away from the weight (instead of just pressing the weight up). However, it is much more upright than the bent press, with less folding under the weight, and it is a real press rather than a support (the weight should always be moving upward throughout the ROM).
--It is important to find the right balance point to grip the bar. With the wrong balance point and groove, bar will tilt and wave around all over the place. There is a learning curve and some experimentation in getting it right, so be a little patient. With the right balance point, the bar will be extremely stable. You don't even have to grip it tightly (although you may want to to generate tension). With the right balance point, and the right groove for the lift, the bar will just go straight up and down almost like it is locked in a Smith machine.
--The right balance point will NOT be with your hand centered on the bar. Move your thumb side a little closer to the collar, so the balance point is a spot on the base of the hand approximately below the pinky finger. Experiment to find the right spot for you and practice so you can reliably find that spot.
--I have never liked shouldering the bar as shown in the book. I either take the bar off a rack at shoulder height, or one arm snatch it to overhead and lower it into position for the first rep. I will also snatch or clean and push press the bar overhead with two hands, then adjust my grip to one hand with the bar overhead, and lower the bar into position for the first rep. This way, the bar is always horizontal and there is no extra stress on the collars. I have never had plates slip at all when side pressing.
--As alluded to above, I like to LOWER the bar into position for the first rep. Even when I take the bar off a rack at shoulder height, I will jerk/push press it overhead and then lower it into position. I find this allows me to generate more tension for the first rep, and get into a better starting position.
--I can lift a lot more in the barbell side press than the KB military press. My KB MP 1RM is 36kg (a little more than 79lbs), but I have done 95lbs x 5 and 105lbs x 1 in the barbell side press.
--In planning your cycles, the side press is lift you have to be a little patient with. You won't necessarily make fast linear progress. So step cycles and wave cycles with lots of backcycling work better. You are not going to be able to just slap on 5 more pounds from session to session to session.