I've finally found a .375 bullet my old FN Browning seems to like. It's the 260-grain Nosler Partition. Problem is, the faster I push it, the tighter the groups.

The best groups I've fired have been with 81.5 grains of IMR 4350 (the max load listed in the Swift manual for the 270-grain A-Frame). This load Chronoed between 2720 and 2754 with 1"-1.25" groups. The problem is that a few of these shots produced a little bit of a sticky bolt lift (though most shots did not).

So I tried the same bullet with IMR 4064. Started with 68 grains at around 2550 and ended with 70 grains (the max in the Nosler book), at 2640. Again, as speed goes up, the group comes down, exponentially. At 70 grains, the bolt opens as if with an empty chamber, and groups are around 2 inches. I really feel that If I can get 4064 to produce somewhere in the neighborhood of 2700 fps, I will get the accuracy I need to have enough confidence in the rifle to use it as my primary leopard and plains game rifle on my next safari (as well as a back up DG gun with 300 grain solids).

So I'm asking if somebody would please be so kind to run Quickload for me utilizing 260-grain Nolser Partitions, WW brass, CCI 250 primer and both IMR 4350 and IMR 4064 powders, all fired in a 24" barrel.

Thanking ya'll in advance.

GAH

I don't have Quickload but do use Loadtech. I can't get loadtech to show your 4350 load . It thinks the case won't hold that. Is your OAL longer than 3.6? Extrapolating looks like 66-69,000.

As to 4064. It calculates a max of 71.7 at 62000. Each .5 grs raises the pressure around 600PSI and 10-15fps. Above and below that point.

I get great results in my 375 using the 270CT and RL15.