Brand New Brass Prep

[picone]

This relates to .260 Remington, 26" barrel, 1:8.3" twist. My next load with be with 139 Scenar's and IMR 4451 (you get what you get these days). I need 300 rounds for a class and I now have a range reloading setup to build up a load as best I can. My rifle shoots 1/2MOA with my old reloads not really trying to hard for anything but consistency and minimal jump. I'm going to buy all new brass and start over. Feel free to make recommendations if you feel strongly about something being cheaper and equal to Lapua brass.

Case Prep:
Do I need to size and trim new brass or is it good to go right out of the box? Also, regarding trimming, does anyone have a good recommendation/video on reaming so I don't over-do it? I have an RCBS trimmer and hand reamers.

Thanks!
Dom

 

[Krob95]

I found with new lapua brass in 308 that neck tension was sporadic. Mainly tight but some took a lot less pressure to seat than others. Started load dev and then tried it again by running the other 50 I hadn’t prepped and ran them through my Type S FL bushing die to set neck tension to a constant. Didn’t seem to bump shoulders as virgin brass was about 2-3thou smaller than my resized 1x fired brass. Got good results with just setting neck tension on the virgin brass, but will know more when I load the 1x fired brass.

I did not trim my brass as it didn’t need it. I did however chamfer the necks. I would also stick with the lapua brass as it’s going to give you good consistency with out having to sort brass by volume and all that BS.

 

[BigOldPhatboy]

Lapua or Peterson are my go to brands. Peterson being slightly less expensive usually. I always run a sizing mandrel to remove any dings and set a consistent neck tension. New Lapua Brass seems pretty tight.

 

[Steel head]

I run a .263 mandrel through the neck and a slight inside chamfer.

New neck tension is always stupid high even on great brass.

 

[picone]

Thanks for the help and info!

 

[picone]

Now that I have everything and ran some tests. Factory neck tension was like .007". When you say "run a mandrel thru to open it up", does that mean I use a typical Redding sizing die that has the expander nub and just run that thru it to open it up? I did do that and it opens it up to about .003" neck tension. Seems like that does the trick, but...

 

[davethedog]

Now that I have everything and ran some tests. Factory neck tension was like .007". When you say "run a mandrel thru to open it up", does that mean I use a typical Redding sizing die that has the expander nub and just run that thru it to open it up? I did do that and it opens it up to about .003" neck tension. Seems like that does the trick, but...

Search for a Sinclair or 21st century expander mandrel and mandrel die. That's what you want and should be considered part of the essential precision reloading toolkit.

 

[salks]

I just FL size like fired brass. The only difference will be the shoulder is already set back more than I would set it.

 

[picone]

Search for a Sinclair or 21st century expander mandrel and mandrel die. That's what you want and should be considered part of the essential precision reloading toolkit.

Only another $150, why not! LOL!! Thanks

 

[picone]

I just FL size like fired brass. The only difference will be the shoulder is already set back more than I would set it.

Thanks, that works for now and gets me thru what i need to do!

 

[Shoots 700's]

The last dasher brass i bought from Alpha was just loaded right out of the box. No prep, no issues out to 1135 yards

 

[davethedog]

Only another $150, why not! LOL!! Thanks

Nah like $50.
Just get the body and then whatever mandrel suits your caliber.

GENERATION II EXPANDER DIES | Brownells

Our Generation II Expander Dies completely capture the mandrel within the die so the mandrel cannot pull out. An O-ring in the die cap allows the mandrel to float a bit and find its own center within the case neck. All three Generation II dies are...

www.brownells.com

 

[Rocketmandb]

Nah like $50.
Just get the body and then whatever mandrel suits your caliber.

GENERATION II EXPANDER DIES | Brownells

Our Generation II Expander Dies completely capture the mandrel within the die so the mandrel cannot pull out. An O-ring in the die cap allows the mandrel to float a bit and find its own center within the case neck. All three Generation II dies are...

www.brownells.com

You can also spend a little more for a nitride mandrel. I got mine recently and have used it on 100 cases so far. It seems to be smoother to use than the stainless I was using before.

 

[davethedog]

You can also spend a little more for a nitride mandrel. I got mine recently and have used it on 100 cases so far. It seems to be smoother to use than the stainless I was using before.

Yeah if you’re going to use them as they are it’s not a bad idea. I buff mine on a polishing wheel and use a bit of graphite cause I’m cheap

 

[Simonsza1]

New brass, fl size, flash holes, uniform primer pockets, light chamfer and load

 

[picone]

Nah like $50.
Just get the body and then whatever mandrel suits your caliber.

GENERATION II EXPANDER DIES | Brownells

Our Generation II Expander Dies completely capture the mandrel within the die so the mandrel cannot pull out. An O-ring in the die cap allows the mandrel to float a bit and find its own center within the case neck. All three Generation II dies are...

www.brownells.com

Oh I see now. I was looking at the whole kit that goes up in .0005". Regular one should be fine. Their website seems to speak higher of the black nitride than the TiN. I'm going to call around and see if I can find something local. Need ASAP.