270 Win water capacity

Anyone have the water capacity differences of 270 Winchester vs Remington brass? I m pretty sure Winchester brass is more spacious but don't know actual capacities.

Lastly does anyone have experience with how much less powder to use in the smaller capacity case to achieve similar pressure/velocity? Are we talking 1/2 grain or ...???

Thx for any experiences or knowledge.

just fill them both and compare to start.

lhsako, I quit being lazy and did as you suggested... used small kernel H 4895 since cases already primed...
Results:

WW brass averaged 63.2 grs filled to top
Rem averaged 62.3 filled to top

9/10 s of a grain average difference.

Can anyone QL the two capacities with IMR4831, 130 BT at 3.320 OAL and CCI250 to illustrate what difference in powder charge I should use in Rem brass ?? ( as an FYI my load in WW brass has been 57.3 grs of IMR4831and its yielding 3150 fps in my 24" barrel)

Thanks for any help!

Lots here are more qualified to reply but, someone correct me if I'm wrong saying QL data is NOT "load data" per se but a powder comparison display showing APPROXIMATE charges, pressures and velocities that are strictly mathematical in nature.

It takes but a quick look at the comparisons, and reading the "warning" on such to know they suggest the user to start low and work up loads after picking a powder or two from the list.

Depending on your rifle chamber, powder lot, primer used, etc etc......it all will vary and can do so in a BIG way.

As I understand it, you have picked your powder and that minor of a change in capacity should only show up as also a minor change, but not always. ( I dont claim anything, ever to be "always" lol)

I'd never tell anyone what to do but........just saying I WOULD take the safe road (always) and work up to the velocities you wish (within reason) with the components you have in hand..........and if ANY of them change. Start over.

God Bless
Steve

My load is 63 of RL22. above book load but I slowly worked up. yields 3,180.
I use a drop tube and ad powder very slowly. H4831SC is a great choice in some rifles.
I use WW brass of course. let me know if you need any help. PM me.
with the 130 AccuBond at 3,100+, its a hammer that is a joy to carry!

Thx for R22 data you use. That's moving along!

Ended up chronoing my load of IMR4831 of 57.3 in WW brass and velocity was 3150 with 130 BT in 24" barrel. Shoots under MOA. I also chronoed Rem brass at same range session with .3 gr increases and it took 56.8 grs in that brass for similar velocity. Same PZoI so I m a happy guy.

Once IMR4831 gone will probably use my stash of R22 or maybe try some R23 or R26 as they seem to be temperature stable and give really good velocity. 270 is a solid big game getter with correct bullet selection/useage!!
Thx

good deal frank. go smoke those whitetails buddy. with that longer barrel, slower powder may improve ths speed alittle. seriously, get a drop tube for the slow stuff.....

I use 57.5gr imr 4831 with 130ab in nosler cases and found that 58gr in Winchester cases results in similar velocity. Remington cases produce very similar velocity as nosler with 57.5gr

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Theddguide, thanks for posting. Sounds like your charge weight differences (.5 grain) between cases fall right in line with what my findings were!! Good to know.

Happy New Year to all !