| Kalunga |
| (.333 member) |
| 23/12/06 01:31 AM |
Customizing a Winchester 70 .375 H&H. Any suggestions ?
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Hello everybody ! I plan to do some improvements on my Winchester 70 Classic Stainless in .375 H&H mainly because the accuracy is below my standards. For this reason I plan to invest in a high quality barrel combined with a new and better stock. The stock of my choice would be from Accurateinnovations, the model Accurate Hunter Laminate. The brand of barrel is easy, because here in Germany anything else than Lothar Walther will be difficult to obtain. But since I prefer heavy bullets of at least 300 grains and also don't need nor like velocities over 730m/s ( 2400 fps ) I am not sure about the best rate of twist, which could be ordered to my wishes. As far as I know, the standard rate of twist is 1:12 inches, so a somewhat shorter rate would be better to stabilize the long Barnes TSX 300 grainers or even heavier bullets. Has anyone here on the forum some advice or suggestions ? Thanks in advance and a happy christmas and a successful hunting season 2007 !!!
Kalunga
| 500grains |
| (.416 member) |
| 23/12/06 03:09 AM |
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Re: Customizing a Winchester 70 .375 H&H. Any suggestions ?
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If you want to go over 300 grains in bullet weight, then I suggest that you increase the twist rate from 1:12 (standard) to 1:10 or even 1:8. Woodleigh offers a 350 grain .375 bullet, and Rhino Bullets of South Africa offers a 380 grain bullet. Overly long bullets will tend to destabilize when they strike an animal unless the twist is fast enough.
And you are correct that the Barnes TSX 300 grain bullet is very long and is likely to show instability when it hits a game animal if fired from a standard twist. That has historically been a problem with the Barnes X .416 400 grain bullet and the Barnes X .458 500 grain bullet.
Good luck!
| allenday |
| (.333 member) |
| 23/12/06 03:12 AM |
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Re: Customizing a Winchester 70 .375 H&H. Any suggestions ?
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I have found that the standard 1 in 12" twist is ideal for 270 and 300 gr. bullets in the 375 H&H. A high-quality custom barrel, such as the Lothar Walther, should shoot just about everything well. My own custom 375 H&H has a Kreiger 1 in 12, and it shoots premium 270 and 300 gr. bullets all to the same POI up to 200 yds. I've seen this trait before with various quality 375 H&H rifles, such as the original pre-64 Model 70.
Other than that, I'd try to closely match Winchester's barrel contour at a 24" finish length, as I consider it just about ideal for a 375 H&H.
I'd also carefully select good open sights (I have EAWs on mine) as well as quality detachable mounts with bases that are custom-built to match the dimensions of your receiver exactly.
AD
| Kalunga |
| (.333 member) |
| 23/12/06 08:32 AM |
Re: Customizing a Winchester 70 .375 H&H. Any suggestions ?
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500grains, thanks for the advice ! I think 1:10 twist rate sounds good for my purposes, I will discuss it with the gunsmith. BTW, I didn't know that 400 grains Barnes X have a problem with stabilizing after impact. I used them on two buffaloes with success. They didn't perform as promised in those ads, which means the petals broke off more than expected, 86% weight retention on a X-bullet used on Cape buffalo and 76% with the newer TSX version used on savannah buffalo in Benin, so nowhere near the expected 99,98%. From the savannah buff the boys recovered another TSX that was bent at the tip and practically not opened up at all, but this propably happened when I had to shoot through some bush. It was a special hunt, the old warrior took ten .416 and two .378 bullets before he gave up, so many shots where follow ups. The cape buffalo died within seconds after receiving the X-bullet, Buzz Charlton said he had never seen a buffalo die that fast from a hit in the boiler room. Looked like premium performance to me !
Allenday, there are EAW mounts on the rifle already but with the open sights I'm not sure. I got a catalogue from Recknagel(ERA) and some of their open sights are looking usable. They make a universal front sight ramp that allows changing and adjusting of front sights, this combined with a fixed standing rear sight should work. What do You guys think about it ?
Kalunga
| Boomer |
| (.300 member) |
| 30/12/06 02:28 AM |
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Re: Customizing a Winchester 70 .375 H&H. Any suggestions ?
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500grains posts some good stuff, but he is incorrect about the 380 gr Rhino bullets needing a fast twist to stabalize. I have used these bullets for some time now, and accuracy from my short barrelled .375 Ultra with standard 1:12 rifling is excellent.
| Kalunga |
| (.333 member) |
| 30/12/06 02:40 AM |
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Re: Customizing a Winchester 70 .375 H&H. Any suggestions ?
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Hi Boomer, that really looks like an accurate rifle ! Do You have any experience with those bullets on game ?
Kalunga
| Boomer |
| (.300 member) |
| 31/12/06 01:02 AM |
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Re: Customizing a Winchester 70 .375 H&H. Any suggestions ?
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Kalunga -
I have not used the 380 gr Rhino on game as yet, although I did some testing prior to my trip to Tanzania which you might find interesting. When I was at the final preparation stages prior to leaving for Tanzania I became concerned about transiting the rifle through the US, and I received a great deal of contradictory information about how I could do so. In the end, not wanting to loose the rifle I left it at home.
The purpose of the test was to see which bullet gave the best results at close range. I lined up a row of 5 gallon pails filled with wet drill mud. If you are not familiar with this stuff, just imagine a very wet, slimy clay. I narrowed my choice of expanding bullets to the 300 gr Barnes X and the Rhino 380. In the test I compared the Barnes 270 gr XLC, a 300 gr original Barnes X, and the 380 gr Rhino. The bullets where chronographed at 2800 fps for the 270 gr, 2600 fps for the 300 gr, and 2300 fps for the 380 gr. Shooting was conducted at 20 yards. Interestingly, penetration was nearly identical for all bullets at about 32", no doubt the result of the spread in velocity. The 270 and 300 gr X's both lost their petals, and the shank of the 300 gr shows signs that it was beginning to bend. The 270 gr X measured .63" and the 300 gr X measured .50". The X's retains about 72% of their original weight. Both X's produced similar wound volumes in the drill mud. The Rhino expanded to .92" and retained better than 90% of it's weight. The wound cavity was large enough that the plastic oil pails failed.
The Rhino bullet is a bonded core soft point with a solid shank. I recovered several from a snow drift which show the beginning of expansion with the jacket opening in 4 distinct petals similar to an X bullet. The expansion is limited by the length of the bonded core above the solid shank.
The bottom line for me is that due to the high impact velocity the X's failed. The 380 Rhino expanded as advertised to a very large mushroom, this extent of expansion resulted in very large wound cavity.
I have the 570 gr .50 caliber X bullet which killed my buffalo. Expansion was perfect, and the bullet measures .97". Muzzle velocity for the .500 Nitro is 2100 fps. This bullet penetrated about 4' of buffalo and made a big lump in the skin of the off side on a quartering toward shot.
Based on this performance, I dare say that the 380/.375 would of performed very well.
