Those who know their stuff about Remington 7400 some help please

[TaperPin]

The ones I’ve been around are solid 2” to 2-1/2” guns. Other than that I don’t know much about them. I do know you would want to use small base dies so reloads chamber easily, or at least only reload a few times and then toss cases when they start to fit the chamber tightly since the locking lug design has very little caming force.

You should get one, it might turn out to be a keeper. Since many people don’t clean and lubricate guns very well it is probably where most jams come from.