Marine sniper
Well-Known Member
Had a .375 Lapua improved built, can I go from .338 to .375 in one step to open the necks up?
.338 to .375 expander question.
- Thread starter Marine sniper
- Start date
Help Support Long Range Hunting Forum
Decap
Well-Known Member
If it's new brass I would say a conditional yes with the caveat if they haven't already been annealed I would anneal them first.
I have a couple of neck up expander mandrel a but they are small steps up (6-6.5mm and 6.5-.308). When necking down I usually go no more than .006" steps. But that's a lot of mandrels and I don't know if you can get them for in between caliber sizes.
I'd go smaller steps too. That's a lot of movement, even with annealing.
I've necked down 300-400 375 rum brass to 338 edge in one step creating a false shoulder to form. Never annealed and had no problems. I would think you would be fine with a tapered expander mandrel but if it was me I would prob go .358 then .375
Guys using 308 win brass to form to 375 Raptor are sizing in one step with a sizing die that has a tapered expander and seem to have good results.
Guys using 308 win brass to form to 375 Raptor are sizing in one step with a sizing die that has a tapered expander and seem to have good results.
Just use the COW method
375ultramag
Well-Known Member
I take 300 saum brass to 338 and then to 375 using the tapered expander in the link and have had no problems so far. Only expanded 100 so far but works
www.midwayusa.com
Redding Tapered Size Button #16373 375 Cal
A long tapered expander for easy expansion of the case neck on bottleneck cartridges. Fits:FeaturesCases between 30 cal and 375 cal.
www.midwayusa.com
Buy a 358 taper button.
And a 375 taper button
Do NOT use the COW method, to size brass from 338 up to 375.
And a 375 taper button
Do NOT use the COW method, to size brass from 338 up to 375.
You built a 375 SAUM?I take 300 saum brass to 338 and then to 375 using the tapered expander in the link and have had no problems so far. Only expanded 100 so far but works
Redding Tapered Size Button #16373 375 Cal
A long tapered expander for easy expansion of the case neck on bottleneck cartridges. Fits:FeaturesCases between 30 cal and 375 cal.
375ultramag
Well-Known Member
Earnhardt
Pm sent.
Pm sent.
Mike Matteson
Well-Known Member
Interesting: I am looking taking some 300WM Lapua Brass and changing it to 338 WM brass. I hadn't realize there was taper sizing Button out there. Thanks, it always pays to read, and learn. I done the other way in reduction of necks for smaller bullets.
Don't see the problem? I expanded 270 brass to 338 for my Sherman with no problem using Bullseye and tissue paper?
hydehunter
Well-Known Member
when I had a 458 Lott built I took 8mm Rem brass and just blew it out to 458
That sounds like fun
