I recently shot one of my M48’s for the first time about a month ago (after I got all the cosmoline out.) I was using some Portuguese surplus my friend gave me.
I didn’t find the recoil to be severe enough to cause a flinch, but I did notice I wasn’t too keen to keep shooting after about ten shots. The barrel was also quite warm. I usually bring a little camp pillow along to absorb the recoil, but I forgot it.
I gave the rifle to my friend (wearing a PAST vest) to try. He fired only five rounds before it was closing time. He showed me the insert in his PAST vest and it had a perfect indentation in it of the buttplate of my M48 and the bottom screw. We both had a good laugh, especially since he had been shooting a sporterized No.4 Mk.1 up until then.
The next weekend I shot a varmint match with a friend’s Remington 700 VS in .223 Rem. I probably shot a hundred rounds over the course of a few hours and I hardly even heated up the barrel. The recoil is so mild it is almost non-existent.
I like my full power cartridges, but I’m seriously considering buying a .223 Rem target rifle to play with. I like to be able to go shooting and put about a hundred rounds downrange accurately. It gets pretty hard to do that with a hot barrel and a bruised shoulder.