Sizing new brass

[thisismyboomstick]

Ok, I know this is probably a dumb question but is it required to size and trim brand new cases? The specific cases I'm curious about are Winchester .300 WSM cases.

[ar15barrels]

It's generally recommended to size, but trimming should not be necessary.
Try loading a couple rounds without sizing and verify that they fit your gun.
If not, then they will obviously need sizing.

It really varies from brand to brand.

Remington brass from Midway comes with a tag in the box telling you to size them before use.
Lapua brass is supposed to be good-to-go right out of the box.

[dw1784]

Unless you're using match quality brass, I would size them first. Sometimes the case mouth may be ding'd or out of round. Plus I inspect flash hole and off center/out of round brass before I use them. It's good to size them first and establish a basis to work from.

[rksimple]

Even my Lapua brass came with some dings in the necks. I just neck sized them. Most other new brass gets fl sized.

[Prc329]

What is more important for consistent match quality reloads, neck sizing after the first reload or full length sizing?

[Timberwolf]

After the first firing the brass is now fireformed to your chamber. Old rule of thimb is that to neck size after that and it will be more accurate as FL sizes takes it out of spec (smaller) than your chamber hence not as consistent.

It depends, however, on your competition - BR guys neck size all the time and go to great lengths to make sure each and every case, compenent, etc is the same. But their comps are won by thousands of an inch. In LR Prec its a matter of accuracy and speed.

I personally F/L size every loading as I don't want tight cases, especially when I'm in a timed event. WIth F/L sizing I get between 6 - 7 loadings per case and my reloads stay between .75 and 1.0 MOA all the way out, if I do my part.

[Fjold]

What is more important for consistent match quality reloads, neck sizing after the first reload or full length sizing?

If you set your FL sizing die to just touch the shoulder of the fired case then it would be equal but it's a lot easier to just neck size. If you use the FL sizing die you will need a comparator to measure the shoulder height of your cases.

I use a FL die but it is adjusted to just fit my chamber. Usually I'll neck size the cases until the shoulder has grown forward enough to make chambering difficult and then I'll set my FL die by adjusting it down just enough to where I just feel the resistance when the bolt handle gets about 3/4 of the way down. Then I lock the die down and never adjust it again.

[rksimple]

Nayt, I bump the shoulders back .002 every time. It makes for pretty accurate ammo, and I never have tight cases. I have the expander ball removed and the correct bushing to give me .002 neck tension. That makes it so the brass doesn't get overworked in the neck and less runout without the expander ball pulling the neck to one side or the other (depending on neck thickness throughout).

Like twolf said, its all about accuracy and speed for us. You could give the best shooters black hills to shoot with and they'd still win. If you can get a load thats reliable (not too tight) and accurate (~.75MOA) thats all you need. Brass life and such is an afterthought once reliability and accuracy are there.

[Prc329]

Like twolf said, its all about accuracy and speed for us. You could give the best shooters black hills to shoot with and they'd still win. If you can get a load thats reliable (not too tight) and accurate (~.75MOA) thats all you need. Brass life and such is an afterthought once reliability and accuracy are there.

I am mainly working on consistence between loads now. I know the bullet, powder and velocity will make for an accurate load, just looking to improve the consistency from round to round, batch to batch and taking out any variables as possible. If I can get everything to be solid and consistent then I can know for sure if I pulled the shot or not.

[rksimple]

I am mainly working on consistence between loads now. I know the bullet, powder and velocity will make for an accurate load, just looking to improve the consistency from round to round, batch to batch and taking out any variables as possible. If I can get everything to be solid and consistent then I can know for sure if I pulled the shot or not.

Are you having problems with repeatablity from batch to batch? If you're doing the same thing every time, you shouldn't have an issue. Have you gone as far as weighing cases?

[Prc329]

Not really but I just feel like the loads could be better. I think my Lee sizer was just throwing something off so I moved to the Redding bushing sizer (on the way). I also decided just because I think it will help improve my workflow the RCBS seater. I like the idea of dropping the bullet from the top.

It is not so much of a problem I am having with inconsistency but me wanting to make sure everything is as consistent as it possibly can be from the jump.

[ocabj]

Lapua is the only brass I will load up straight out of the box with no case prep. I've had only one box of Lapua brass that had dinged necks that needed to be run with an expander ball.

Most guys I know like to at least neck size virgin Lapua brass with a standard bushing die (i.e. Redding Type-S neck only sizer) to get better neck tension since out of the box, neck tension is actually pretty tight. I've had no problems with virgin neck tension.

[rksimple]

Not really but I just feel like the loads could be better. I think my Lee sizer was just throwing something off so I moved to the Redding bushing sizer (on the way). I also decided just because I think it will help improve my workflow the RCBS seater. I like the idea of dropping the bullet from the top.

It is not so much of a problem I am having with inconsistency but me wanting to make sure everything is as consistent as it possibly can be from the jump.

Understood. You're on the right track. Did you get the fl bushing die? Get a comparator and adjust the die to fit what your rifle needs/likes. The seater will be a good addition.

[Prc329]

Not yet, waiting for my Lapua brass so I can load a few rounds and measure so I can get the right bushings.

[Timberwolf]

The bushing size on Lapua is generally either .336 or .337 depending on your rifle. WHen I used Lapua I used .337 when I neck sized and .336 when I FL.