Neck sizing new brass and rifle

[UndFrm]

The rifle is in the process of being completed and I was looking at things that I might still need to reload for it.
Have some Alpha brass for 6 Dasher. Would I need to size the neck (or adjust) to get the proper load data or should I just go ahead with the publisher data and not worry about seating right now?

The brass has never been fired before. I do have the neck sizing die but no bushings for it yet. From this point, how would I determine what bushing(s) to get?
Or, should I just seat it, charge with a safe amount and see what the grouping is like before jumping into the neck sizing?


PS: Brand new to reloading, please let me know if I'm missing something that might be too obvious for you.

 

[straightshooter1]

The rifle is in the process of being completed and I was looking at things that I might still need to reload for it.
Have some Alpha brass for 6 Dasher. Would I need to size the neck (or adjust) to get the proper load data or should I just go ahead with the publisher data and not worry about seating right now?

The brass has never been fired before. I do have the neck sizing die but no bushings for it yet. From this point, how would I determine what bushing(s) to get?
Or, should I just seat it, charge with a safe amount and see what the grouping is like before jumping into the neck sizing?


PS: Brand new to reloading, please let me know if I'm missing something that might be too obvious for you.

Not long ago, I bought some Alpha .308 brass to test and see how I liked them. First think I did was load 10 of them up that I would fire and then measure the case volume to see how my previous loads might work (they were loaded below what I normally use, to be safe). The first thing I noticed was that the case OAL's were very consistent. But, there were burrs on both the outside and inside of the case mouth. Burrs on the inside is not good for seating. So, I deburred the outside mouth rim and chamfered the inside. I did not try to size the necks, though the neck tension was ~.003". When I fired the 10, they did so well I loaded up the remaining 90 with my favorite load to fire form them and they did outstanding; the best I ever got with virgin brass.

So, the first thing you should do is make sure your cases don't have burrs on the case mouth rims. Most likely, they do. If they do, take care of it. You may not need to size the necks for your first firing. To find out what bushing you want to use eventually, seat a bullet in the case and measure the OD of the neck; subtract the diameter of the bullet from that measurement and divide that number by 2. This will give you your thickness of the neck. Now that you know those numbers, to find the bushing you want, decide on your neck tension you want. If it's .002, then add .0005" to that for springback and subtract from the size of the neck with bullet seated.

If you don't have a bullet puller, now's a good time to get one. A Hornady collet bullet puller will be my best advice.

Good luck.

 

[Chris1972]

Couldn’t you just measure the OD of a loaded round and subtract .0025? It seems you’re over complicating things.

 

[Rocketmandb]

Comments:

- Get a mandrel die. They are inexpensive and very useful. One such use is to open up the case necks on new brass as they always tend to be tight.
- Do not do load development with new brass.
- Do not do load development on a new barrel.
- Instead, load up 100 rounds at a load in the middle of the range your reloading manual tells you and use them to speed up the barrel. Then, with once-fired brass, you can either do it again (some people like to have twice-fired at a minimum to start load dev) or just start load dev.
- No matter what, you definitely need to chamfer/deburr the case mouths. Any crap on the inside of the neck messes with, well, everything. Any crap on the outside of the neck can cause chambering issues.
- Get a full-length sizing/bushing die instead of using a neck sizing die. If all you do is neck size, you will eventually either have to full-length size or you will get stuck cases. If all you do is full-length size every 4 or so firings, you have to keep the brass sorted by firings, or you will have consistency issues.