Barrel steel question

I was browsing Remington’s last catalog (nostalgia, you know) and was looking at all their rifle specs. For the Model 783 line, all models barrel material is listed as “carbon steel”.

The lone exception is their 783 Varmint Laminate (26 inch heavy barrel). Barrel material is listed as “A151 4137 Modified” steel. Not sure why this would be any different than all the other 783 variants. Is this essentially carbon steel?

Yes it is.

AKA 1022, small increase in carbon and manganese content over 1020. Still a low carbon steel. I think it is Remy’s standard stock.

It’s a low-alloy carbon steel similar to 4140 (ordnance) steel. It’s a common and inexpensive steel for rifle barrels.