Powder for .270 Win.

[Ron AKA]

I prefer Hodgdon powder (made by ADI in Australia) over IMR (made in Canada) due to the temperature insensitivity of the Hodgdon branded ADI. So H4831 would be my choice for the 270.

That said, I see IMR now have two powders which are said to be temperature insensitive - the 4198 and the 8082 XBR. Perhaps they are moving to make all their powders temperature insensitive...

IMR Rifle Powders

While I have shot a lot of the 4831 army surplus powder, I no longer have any. I do still have some of the H4831 that was made in Scotland. I would say the Scottish H4831 develops a little more pressure for the same load, compared to the Australian ADI. I've measured increased velocity with the older powder.

 

[H4831]

You should also bear in mind that H4831 has a different burning rate than it did years ago. That is the prime reason that I have favoered IMR as it seemed more consistent lot to lot.
Neil

I used mostly the old, original war surplus H4831.
When Hodgdon's acquired new H4831 and sold it in the regular one pound cannisters, they stated the same loading data for the surplus powder could be used with the new powder.
I tested the new powder against the old, using a Oehler 33 chronograph. I loaded six rounds, 270, 130 grain bullet and 60 grains of war surplus H4831.
I then l oaded another six, everything the same, only 60 grains of their new H4831. Here are the results, right from my notes.

The old war surplus---average 3078, with an es of 33.
The new H4831 ------average 2960, with an es of 45.

I guess that was why they stated you could use the old loading data with the new powder, they knew the new powder was slower burning=less pressure, less velocity.

 

[H4831]

Years ago I read somewhere that Jack O'Conner's scale was out a grain or so?Perhaps that is why his load has been backed off a tad? Could be hooey ,don't rightly know?Are the IMR line of powders as temperature tolerant as Hodgon's?Harold

O'Connor's scale was not off a grain or two. He worked close with other big names in the industry, like Vernon Speer, Hodgdon's, Barnes, etc, as well as with his shooting buddies, such as Parker Ackley.
In a former posting I stated how the original load was 60 grains, later he said 62 grains was great, but it never went over because it over filled the case. In some publication that I have, somewhere, Bruce Hodgdon states that when they tested their surplus H4831 powder for making loading charts, they never even tested the 270, because O'Connor's loads were so widely accepted, they just added his figures to their loading charts!
I suppose there were many reloaders in north america who tried 62 grains, I know I did, and I never heard anyone talk about excessive pressure. Bruce

 

[Eagleye]

Here's another guy who used 62 grains of H4831 in, not 1 but at least 4 - 270 rifles. All digested the load without complaint, and all were quite accurate using this recipe. I found that it was easier to put 62 grains of H4831 in a Winchester case than it was to put it in a Federal case, however. [I'm not a fan of Federal brass anyway, so no tears shed there, lol]
Eagleye.

 

[dizzy dan 1]

If you have H4831 on hand, there is no use getting 4350, as it is not as good for the 270, as is H4831.
For the last about sixty years, the classic load has been 60 grains of H4831 with 130 grain bullets.

x2 Same load here in my #1.DAN>>>