Why Old Timers used smaller gloves to hit the Bag ?

Some fighters today also use those kind of old-school small gloves while hitting the bag, at least at times. I remember seeing Andre Berto do it for example.

I'm not a boxer so take it with grain of salt, but I used to like to hit - pretty light - bag with bare hands, while putting some vaseline on my knuckles to get cut. I felt that it was making me more disciplined/conscious about keeping might hands squeezed on impact - and I was more confident later hitting with full power with gloves without having my hands hurt - so that's what I think is a logic behind it.
Maybe it's my bro-science though, I'd like to see some coaches comment too.

 

I always do a half round to a round with wraps just to be conscious of how my knuckles are landing. Power needs to be managed while I do this. Usually ramping up in speed and power towards the end.

After that, I do my regular bag rounds with 10oz. gloves.

For me, the no glove time is useful for me to make sure I'm punching well, which has the double benefit of reducing likely hood of injury and also making sure I'm not getting any bad habits with my punching.

With the 10oz. gloves and hands wrapped well, I feel that is good for developing punching power/protecting hands.

Anything over 10oz. feels like a lack of feedback to me and doesn't do anything for strengthening hands to absorb impact.

If I am nursing a hand, I'll just add a gel insert to the affected hand.

 

I would guess it had something to do with Velcro not being invented until 1948 and it being even later before it ended up on training gloves, the smaller bag gloves were likely just elastic or at least involved less lacing up than larger boxing gloves

 

this, faster easier on & off while training, also they were often called Bag Mitts, which also suggests the ease...