New to Neck-Only Sizing ... How to Handle New Cases?

[Syncrowave]

Hey, all,

Recently got a rifle in 300WSM and, since it's the only gun I'll probably ever own with that chambering, I decided to get a Lee collet neck-sizing die (Lee #91019) to use for those loads.

I bought a case of loaded Hornady ammo for it (since loaded ammo was quite a bit cheaper than any new cases I could find), so those cases will be fire-formed to my chamber when I reload them, but then I also found a decent price on some unfired (new) cases, so I bought those, too.

How should I handle the first loading with these new cases? Should I full-length size them, just to make sure I'm starting from a known state, or do you think I can get away with just neck sizing them? (I do also have a FL resizing die for 300WSM.)

This is the first time I've ever used a neck-only sizing die, so I've never run across this situation before.

Thanks in advance for any advice.

 

[jr600yd]

FL size everytime.

 

[ChrisNZ]

Agree. The FL die will do the complete job always, you won't be left wondering which die you should use/first/..

If you haven't seen it, search out the Cortina item on YT, something like "Stop neck sizing". He'll show you how to set up the FL die so everything will chamber properly without over-working the brass.

 

[Coyotefurharvester]

They should chamber fine(new brass) I would (dry lube inside necks first)use a mandrel to make sure the necks are round and inside neck diameter is 0.002 under bullet diameter. Prime,charge,seat,shoot.

 

[Big Mc]

Hey, all,

Recently got a rifle in 300WSM and, since it's the only gun I'll probably ever own with that chambering, I decided to get a Lee collet neck-sizing die (Lee #91019) to use for those loads.

I bought a case of loaded Hornady ammo for it (since loaded ammo was quite a bit cheaper than any new cases I could find), so those cases will be fire-formed to my chamber when I reload them, but then I also found a decent price on some unfired (new) cases, so I bought those, too.

How should I handle the first loading with these new cases? Should I full-length size them, just to make sure I'm starting from a known state, or do you think I can get away with just neck sizing them? (I do also have a FL resizing die for 300WSM.)

This is the first time I've ever used a neck-only sizing die, so I've never run across this situation before.

Thanks in advance*

Hey, all,

Recently got a rifle in 300WSM and, since it's the only gun I'll probably ever own with that chambering, I decided to get a Lee collet neck-sizing die (Lee #91019) to use for those loads.

I bought a case of loaded Hornady ammo for it (since loaded ammo was quite a bit cheaper than any new cases I could find), so those cases will be fire-formed to my chamber when I reload them, but then I also found a decent price on some unfired (new) cases, so I bought those, too.

How should I handle the first loading with these new cases? Should I full-length size them, just to make sure I'm starting from a known state, or do you think I can get away with just neck sizing them? (I do also have a FL resizing die for 300WSM.)

This is the first time I've ever used a neck-only sizing die, so I've never run across this situation before.

Thanks in advance for any advice.

FL ***** E V E R T T I M E Tommy Mc

 

[K22]

I Full Size all cases, all the time. However, I am very careful to only bump the shoulder when necessary. In my experience, full sizing produces the most reliable chambering reloads, an important consideration for hunters.

I use nothing but virgin brass from the same lot and dedicate a group of cases to a specific rifle. I rotate their use, so all cases receive the same number of firings and sizing's. I found this is the best way to maintain case consistency.

For virgin cases, I measure a sample of cases with a bump gauge and caliper to obtain the unfired case head space. I then set my F/L die to size the cases to zero bump. The reason I size virgin unfired cases is to uniform them to the same radial and head space dimension. I spot check them in the rifle (firing pin assembly removed) to assure optimum fit.

After the first firing, I measure a sample of fired cases (primer removed) to determine the fired case head space. I repeat the same process as above. Often, I can go several firings without having the bump shoulder. I believe this is because the F/L die is also sizing the radial dimension of the case which is often the culprit creating chambering difficulties. This also the reason I stop Neck Sizing about 25 years ago.

The process of making F/L die adjustments can be simplified greatly by using either Skip Shims or Redding Competition Shell Holders. This allows to one to make sizing changes without have to change the lock ring of the F/L die which can become tedious.