Internal Magazine Questions

I am currently shooting a short action .223 with an internal mag. However, I am loading the 75 A-Maxs with a 5k jam and they are too long for the mag well. I was considering switching to a long action with an internal mag, but dont know if the 223 will feed properly. Most of the long actions are made with the 30-06, 270 case in mind. Will the feed lips of the long action be close enough to hold the 223 case? I have an older single shot, and was thinking about just switching barrels. But I would love to have the mag. If it will work, anyone wanting to trade a long action with blind bag for a long action single shot? ::)
Thanks,
Mitch

Are the A-Max's shooting well enough to warrant the extra trouble? How do they shoot when loaded to a short enough length to feed from the magazine?