I read an article about forming '06 brass up to .338. You may have contributed, not sure.
Do you think going from 308 to 324 to 338 is better, or all at once. Respective bushing sizes of course
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338 Mega
- Thread starter Idaho Trecker
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Do you think going from 308 to 324 to 338 is better, or all at once. Respective bushing sizes of course
elkaholic
Well-Known Member
Its certainly safer to go in steps but can be done in one step with a good tapered expander, depending on brass used?
Monkeygoat
Well-Known Member
Using your brass - I found some Hornady 336 and 346 expanders, but nothing in the 320 range. Good to know on the bushing. Brass and dies still arriving this week?
elkaholic
Well-Known Member
they're stuck in Illinois!!
nimrod_gn
Well-Known Member
Ready to start load development. I have several powders to try. Has anybody found a rule of thumb to find starting charge weights for the 338 Mega by taking say something like the 338 Lapua Mag data and adjusting it?
Idaho Trecker
Well-Known Member
More like 338 win mag for a baseline. Looking at hodgdon data my initial fire forming loads with h414 line up with their data pretty well for the same bullet weight and having my bullets jammed. Use the low end data fore fire forming and go from there. There isn't much shoulder or body taper to shoot out but still enough it needs to be done with lighter loads and the bullet jammed since the shoulder doesn't head space after necking up to 338 from 30. I was surprised how accurate a 225 sierra was at my 515 yard steel while fire forming from the deck.
If you've already fire formed I'd just start from an area of the 338 win mag data you feel comfortable and work up from there. I've almost exclusively used rl 26 with all my testing since I received adg brass so can't say much as to where you may end up with other powders. Early on I did pressure testing with hornady brand 33 nosler brass Rich and I formed so capacity and toughness are not close to adg brass. If I was going to focus on another powder I'd be looking at hybrid 100v for most bullet weights. You canalso drop to just a bit faster burn rate and there are a ton of options in the 4350 area to try but won't give the speed. If best temp stability is wanted that is a good area to try out. Depending on bullet and which reamer you used 4831 may also work well.
If you've already fire formed I'd just start from an area of the 338 win mag data you feel comfortable and work up from there. I've almost exclusively used rl 26 with all my testing since I received adg brass so can't say much as to where you may end up with other powders. Early on I did pressure testing with hornady brand 33 nosler brass Rich and I formed so capacity and toughness are not close to adg brass. If I was going to focus on another powder I'd be looking at hybrid 100v for most bullet weights. You canalso drop to just a bit faster burn rate and there are a ton of options in the 4350 area to try but won't give the speed. If best temp stability is wanted that is a good area to try out. Depending on bullet and which reamer you used 4831 may also work well.
nimrod_gn
Well-Known Member
Great info and advice. Thank you. A buddy and I are just finishing our 338 Mega rifles. We'll post some findings here as we try some different things.
Idaho Trecker
Well-Known Member
Which reamer did you use? Long or medium? What bullets are you going to focus on and powders do you have available?
nimrod_gn
Well-Known Member
Used the medium reamer. Leaning towards starting with the Badlands Super Bulldozer 2 in 250 grain. Can't find RL26 but have Hybrid 100V, H4350, H1000, H4831, RL19, H414, Retumbo, N570, Varget
Idaho Trecker
Well-Known Member
What are your build specs? I personally would not start with that bullet. The medium reamer with that long bullet will more than likely max out your magazine and be buried in the case a long ways. Out of your list of powders I would think 100v, h4350, h4831 would be your best bets. I would imagine rl 19 may work but I've never owned any. H 414 probably would be ok also just not very temp stable nor is 19.
nimrod_gn
Well-Known Member
My gun is a bartlein barrel on a Tikka action. My friend's is the same bartlein barrel on a Bergara action. We talked with our smith about this and he suggested we start with the medium reamer and if it didn't work well we can always lengthen
Idaho Trecker
Well-Known Member
That was a good plan and with the Tikka you have plenty of room to go further out if you decide to. I look forward to see what you end up with.
@nimrod_gn,
So it''s been about 6 months any updates on your handloads. Very interested in how the 250 SBDII's worked out? Vel? Accuracy?
So it''s been about 6 months any updates on your handloads. Very interested in how the 250 SBDII's worked out? Vel? Accuracy?
