Got interested in this cartridge which I used to call the 375 Belted Newton; bought an Adams & Bennett blank to put on a P14 Enfield action and would like to get some up to date loading data. So many forums have loads from several years ago, so I'd like to hear some late info on the round and how it's performing for everyone.
Dick C.

Hi Gatguy,
Your P-14 will take the factory 375 H&H, but here's an idea. There is something called the 375 Sundra. I found out that I could use my Boer 10.6mm F.L. reloading die to form my wildcat out of a factory 375 Ruger virgin brass case. So maybe you can do up a composite wildcat, along the lines of the Sundra. It would use 300Win Mag. brass necked up and be given more taper, or a full length 375 H&H case, which would blow out. Unlike the Sundra, you could give your chamber some more taper than the 300 Win mag's. Like the Sundras, you would be able to use F.L. 375H&H ammo, in a pinch. Your formed cases would have shorter necks, and your 375 H&H's would blow out, but not as far as the Sundra's. If the stock 375H&H has 95 grains of H2O to the mouths, then this would have 98-100 grs.. It would still have most of the Holland's taper, unlike the Sundra's. You can dial in enough shoulder to headspace on, instead of the belt, unlike the Holland's, and keep most of the Holland's taper for slick feeding. edit: The Sundra will take an unaltered 300 Win Mag Case, as it has the Winnie's minimum case taper. It still hovers around 88-90 grs. of H2O to the mouth. Firing a 375H&H round gives a case with a neck twice as long, but with the same shoulder angle as the Winnie Mag. So these two cases could be set up in your dies to head space off of this shoulder, eliminating double head space problems. Adapting this idea by re forming the Winnie Mag case just like I do with the 375 Ruger case, to a more Holland's like taper, would again let both lengths chamber, with the H&H case having the same increase in neck length, as the Sundras. In both of these, it's the magazine box length in your P-14 which rules the O.A.L. of both cartridges.

I was going with the 375 AI but at 73, that is to much recoil so opted for the 375 Taylor, I have a 416 Taylor that's all I can handle so imagine the 375 will be plenty.
Thanks for the reply,
Dick C.

Hi Gat Guy,
You may be off the mark here. The 375 std Mag. is or was, listed in S. Africa, as the 9.5 Afrikaner. It uses less powder than the longer 375 H&H, but equals or maybe even surpasses the Holland's velocities. It's a more modern bottle necked case, what! I was just trying to show you how to kill two birds with one stone. If you squeeze down a 375 Taylor case to near that of the sloping Hollands, then it will take a few less grains of powder. If you slightly blow out, a 375 H&H you will use somewhat more than the 95 grs. of capacity, but without gaining the efficiency of the sharper bottle necked Taylors. But this idea would feed nicely through your P-14 rifle. I was suggesting that you only blow out the Holland's chamber enough to produce a proper head spacing datum point on your wildcat. So, it would still have the lower efficiency of the Hollands design, but you could use re formed 300 Win Mag cases as well. John Sundra kept all of the Winnie Mag's capacity, but cut a longer neck so that the Hollands case would also chamber. So, the actual recoil of all of these, excepting the Sundras, will be nearly identical. If a more efficient case spits out the same bullet at the same velocities, then the felt recoil will be nearly identical too. I'm thinking that your P-14 would have pretty close to the capacity of the new 375 Ruger, but less than the Sundras or the very similar 375 Weatherby. Your P-14 is a CRF rifle, designed for a streamlined cartridge. They have been made up in 300 and 375 Hollands, for many decades. My other point is that if I can squeeze down a virgin 375 Ruger case body in my F.L. die, than so can you squeeze down the 300 Win Mag cases. The downside is that you will have to design a full length Hollands reamer, and send some blown out 375 H&H cases back to your die grinder, as samples. Only after you receive your F.L. sizing die, will you be able to re-form 300 Win Mag cases with it, to get your short necked variants. I am suggesting, tongue in cheek of course, that you name this kitty, the 38 Giglio, as something that can keel over a Whale of a Critter. It's a little less menacing than the 38 G.G. for Gat Guy. All things being equal, this number should be a bit more accurate than the same G.S.'ing effort in making up a sloping magnum wildcat, which head spaces on the belt, alone.