Which neck do I need. .270 or .276? 243 AI

[Magical_Merlin]

I am ordering a Pac-Nor BBl for a Savage 12 and I need to know which neck I need for the 243 AI. If I go with the tight neck, what does that mean for reloading. I dont mind turning necks, but I was wondering what else this includes. Thanks.

 

[Wild_Bill]

HI if you are going to neck turn for a tight neck chamber that is all you have to do and you only have to do it once to each casae then reload as usual. Now if you go with a 276 neck you will have a neck that is verry close to being fitted to the chamber as some cases measure .2755 . So in this case i would still turn your necks set the turner for a turned case to measure .274 and you will have nice cleaned up necks that will have 1 thou clearence around the whole neck and you can turn in one operation. If you want a thin neck you will have to turn in multiple steps. I would reccomend the .276 neck as the necks will be thicker andnot dent as easily. The first thing i would do is purchase the brass i would reccomend Lapua 243 brass ans debur 5 and seat the projectiles you are going to shoot in them and then measure the necks with a good micrometer that go's to tenths of a thou. make sure your cases are 274 or larger. then set up your neck turner to make a small cut to reduce the diameter to 274 measure the necks with a projectile in them again. This is what i would do if you want to go without turning i would look at 277 as it gives better clearence with Lapua brass.

Cheers Bill
Australia

 

[Magical_Merlin]

Thanks so much for the response. It sounds like you have done this before. I think I will stay with the 276 neck.

 

[Wild_Bill]

Thats ok i have just spec'd a reamer with my gunsmith friend at 277 after measuring brass for a close fitting neck to shoot with 105-107gr bullets it is a pacific reamer and cuts beautifully.We came to that dimention as being optimum without turning and being tight enough to make the expansion as small as posible. Good uck on your rifle i hope it shoots well.

Cheers Bill
Australia