The only job of the barrel pins is to hold that light, skinny forearm to the barrel. That's it.
Recoil happens at the breech, where a good wood to metal fit is extremely important. And when recoil happens at the breech, the whole stock moves in turn. So the pins aren't absorbing the recoil.
They are supported in their whole length by wood, a barrel lug, and wood again... So it's not like they're supported only on the ends, and have to absorb recoil in the middle. If they were subject to a lot of recoil, it would be the wood (being the weakest link) that would fail.
The pins on my twenty eight year old .58 caliber longrifle are still as good as ever. Come to think of it, I've never heard of a barrel pin breaking or bending. I've heard of them falling out, but never compromised.