7mm stw reload question

[Petersen]

I was using rem brass with 80 gr. h1000 with 160 grain accubond. I just picked up some win brass that are heavier - 3 or 4 grains.

Is this a big enough difference to be concerned with using the same load in the new brass?

 

[Lefty7mmstw]

I was using rem brass with 80 gr. h1000 with 160 grain accubond. I just picked up some win brass that are heavier - 3 or 4 grains.

Is this a big enough difference to be concerned with using the same load in the new brass?

You should be fine. Was your old 7stw brass win though, or rem??? Rem brass sometimes likes a grain or two less charge as the neck is thicker.

 

[Petersen]

Thanks. The old brass is rem. new brass is win

 

[trueblue]

You need to rework your load with the different brass.
The new brass is heavier and therefore the wall thickness is different. This could creat pressure issues for you if you use your normal load.
Start a couple grains lower and work up your load looking for pressure signs.

 

[Petersen]

That is what I am thinking, but was asking because of the large case size and large amount of freebore typical with this chambering. Is the difference (3+ grains) significant for a STW? I understand that a case/design like a 22.250 would be sensitive to these differences, but is it enough in a large magnum with a lot of freebore?

 

[Lefty7mmstw]

trueblue is correct that you need to back off and work up again. The two(rem and win) are close in the 7stw, but rem does have a bit thicker neck and that may change things. Your win brass may actually want more charge, but you can only go a grain or so more with that load so your pretty well topped out.

 

[Petersen]

Shot the load this morning and no issues or signs of pressure. Thanks for the help.