Re: remington model 7 243 question
Hi the barrels that can be fitted to your model 7 are exactly the same as that can be fitted to a Rem700, you can take a rem varmint barrel from a 700 and headspace it to your model7 their is no strength diference in the actions. the only diference would be that the model 7 has a smaler diameter rear takedown screw so a realy heavy target barrel around 7 pounds would probabl;y be a bit to much unless the bedding was perfect. the 243 and 6mm rem have the same dimensions as for the internal and they can differ in twist rates depending on the age and manufacturer but if they both have the same twist they can fire the same projectiles. The 6.8 SPC is an awsome cartrige but it has a smaler case so the extractor sometimes will not work if you were to change over from a 308 sized bolt. If you want to build a 6.8 you can either swap the bolt over or have a sako extractor fitted and the bolt bushed to the correct size when the barrel is fitted. The M16 type extractor is actualy a bit better than the sako but either will work.
Hope this helps? with my model 7 it is a Short mag and i fitted a 338 WBX barrel that is a 338-300 ultramag improved with 60 degree shoulder, to it it was a rem sendaro 338 ultramag barrel i rechambered and use to form my cases in.
What are you looking to do with the rifle? if you have shot the barrel out and are looking to rebarrel it that is great bui if you are just looking to play you could buy a model7 or 700 tac in 6.8 with a heavy fluted barrel off the shelf and sellt he 243 for less than building a custom but that is not always the way to go because we all should be able to play and see where it takes us. One thing i would recomend is to extend the inside dimensions of a 6.8 spc mag in a rem tac 6.8 i was loading the 135gr MatchKing at 2600fps using Benchmark and rem cases they were amasing and i shot the rifle to 1000 yards it is comparable to a 223 with 80gr MatchKings in drop and windage pretty amasing from such a short case but you cant use those loads in an AR. Also it duplicates a wildcat used here in Australia for many years the 303-270 and the 303-270 is legal to shoot all deer species here but the 6.8 is not.
Also the 6.8 in a 20" barrel will launch the 90gr projectiles over 3000fps. it is a great all round varmint and medium game round if the correct projectiles are used.
