How's your form?
I've been training on the Starting Strength 3x5 for about a month and a half now with decent gains in Back Squat, Overhead Press, Power Clean, and Deadlift. However, my Bench Press has progressed very little. I lifted weights before I started this program, but not under any specific training regime. So I've had an adequate idea of what my 5 rep maxes should have been starting out. I started at 80% of my estimated 5 rep max and built up from there. The problem is my bench press is not too far from what it was before, and now I am failing to successfully complete 3 sets of 5, while every other lift is progressing normally. What should I do from here?
How's your form?
Step 1: Get a form check.
Step 2: Check the first three questions.
Step 3: Increase pressing programming complexity.
Also, that’s not how starting weights are determined, ergo you likely started too heavy.
I agree that's not the typical protocol, but if he can already bench a weight for 3x5 with good form then there's not much point to finding a "starting weight", because we define said weight as that at which form starts to break down and bar speed markedly decreases.
This pretty much answers it. Regarding Step 3 written above, start with microloading 1-2 lb jumps between workouts. Failing that, try 3x3 instead. Also, there is nothing wrong with having 1 lift be on a different level of programming while the rest progress linearly. From my understanding, a lot of people end up with squats and deadlifts continuing linear progression while presses and bench presses can be progressing using something like the TM.