Brass from one gun to another and bushing question.

[OzzyO20]

I'm VERY new to reloading, so please keep that in mind. I'm reading the Hornady reloading book before I bolt down the first piece of gear, but I've already got a question.

Ok, long story short I ended up with my shooting buddies full reloading set up. Forster Co-ax, Redding competition die set, powder, bullets, etc. Part of the lot included 200 pieces of Lapua 6.5 CM brass. 100 are once fired in his Surgeon and 100 were once fired in my old custom Remington 700. I know for certain that's all the use the brass has seen because I was there when the boxes were opened, loaded, and shot before being put up for almost a year. I've also since parted with the R700 and picked up an AI AT in 6.5 CM. So I have a few questions:

1. Should I get a Redding full length bushing die and try to 'reset' the brass before I load for the AT? I know the chambers will be different, and all I currently have are a Redding Competition bushing neck sizing die, along with the body die and seating die. From what I gather, if I just neck size them the body will still have the dimensions of the other two rifles chambers. I'm aware there is a pretty passionate debate between FL and neck sizing, but I'm just trying to figure out what to do in this particular instance.

2. How do I determine what bushing to get to size the neck with the already fired Lapua brass in either die set up? I'm going to practice on some once fired Prime that was fired from my AT, and I was able to mic the neck of a loaded round, subtract the .001 for 'spring back' and another .001 to get neck tension and came up with .289". I know the Lapua is thicker brass, but how do I know what it will be loaded since it came once fired? For that matter, how do I know what to use even with new Lapua brass since it's not loaded? I'm guessing it may come preset to have good neck tension, but that's purely a guess. I do have a .290" and .291" bushing, but I'm not sure if they are correct or not.

I appreciate everyone's help up front, and I'm sure you'll see more posts from me over the next month or so while I learn all this stuff.

 

[TX_Punisher]

Lapua is thicker than my hornady. I'm using a .290 bushing which puts the lapua at .262 inside neck dia for .002 neck tension. Ymmv

 

[spife7980]

1. Should I get a Redding full length bushing die and try to 'reset' the brass before I load for the AT? I know the chambers will be different, and all I currently have are a Redding Competition bushing neck sizing die, along with the body die and seating die. From what I gather, if I just neck size them the body will still have the dimensions of the other two rifles chambers. I'm aware there is a pretty passionate debate between FL and neck sizing, but I'm just trying to figure out what to do in this particular instance.

2. How do I determine what bushing to get to size the neck with the already fired Lapua brass in either die set up? I'm going to practice on some once fired Prime that was fired from my AT, and I was able to mic the neck of a loaded round, subtract the .001 for 'spring back' and another .001 to get neck tension and came up with .289". I know the Lapua is thicker brass, but how do I know what it will be loaded since it came once fired? For that matter, how do I know what to use even with new Lapua brass since it's not loaded? I'm guessing it may come preset to have good neck tension, but that's purely a guess. I do have a .290" and .291" bushing, but I'm not sure if they are correct or not.

1. I would measure which of the set of 200 cases are smaller and then see if either or both will chamber in your rifle. If they do chamber then you can go ahead and load up making sure that loaded rounds chamber before you make 200 of them. If they dont then you can body size down until they do chamber. Once you get some brass fired out of your new barrel you can then get your stuff set up for that and be good to go. The only way to know what exactly needs to be done is to sit down, measure and see. Dont just size all the way down to saami minimum specs unless you find out that you have to.

2. You know what bushing you need when you measure a loaded round. So that means size one of your fired pieces down and load a bullet or load a bullet into the new brass. You can also mic the neck diameter, double it to account for both sides and add in the bullet diameter for your loaded round diameter.

 

[Supersubes]

First things first. Take your neck sizing die, and hide it somewhere so you won’t be tempted to use it. You should always FL size. In this specific case, it will be a requirement just to get the brass to enter the chamber.

I use a .289 bushing with lapua brass. When in doubt, use the bushing that’s close to load up a test round for the purpose of measuring for loaded neck outside diameter.