Hello, I am new to this. I have a Remington model 700 in 7mm RUM I took in on a trade. As I've seen the ammo is hard to come by, and barrel life is short. I want to convert it to something that's just all around more convenient. And in simple English as if you were explaining to someone who had no clue. I'm wondering what I would need to change, i.e. barrel, bolt, etc. as I've said I'm new to this and wanting to get into long range shooting. Just clueless here
I understand you wanting to convert and as you took it on trade you don't know how many rounds are down the tube so. Here are the steps to convert and do it right so as you progress you can just replace barrels, upgrade the trigger now or later and even upgrade the stock or switch to a chassis. The Rem 700 is a great base receiver to build from.
1: find a reputable gunsmith for your area
2: get a quote on a bolt and receiver truing
3: select a barrel in the caliber you want to shoot. You can order barrels on line distributors like ALTUS shooting supply, Mile High shooting, Bugholes southern precision etc and get them in a few days! I prefer this method and usually acquire them faster and less expensive then through my gunsmith.
It can be any caliber you wish you don't have to stay with 7 mm and you have a long action magnum bolt face so you will select the chambering for the case cartridge based off that.
For example, if you select a 30 caliber barrel blank you could pick the 300 PRC or 300 Winchester chamber. Switching to a non magnum would require a new bolt as your bolt face is opened to a larger diameter. Smaller bolt faces can be opened up to magnum size but material can't be added back to go the other way.
4-"prefit" barrels or "remage" barrels are barrels already chambered for a specific cartridge case. They might be an option after a gunsmith trues your bolt and receiver. That said, with a factory receiver I would probably have my smith chamber each barrel with your receiver. You can buy a barrel vise for under 100 and a rem 700 action wrench for less than 50 and if you want more than one barrel chambered, let's say rem 7 magnum and 300 win you could simply swap barrels with a common torque wrench, rezero and away ya go..
Have fun with the process and enjoy shooting your new gun!!