I am considering getting a .375 Flanged double rifle. It seems that they are usually regulated with 300 grain Woodleighs at 2400 fps. Does anybody have experience getting a double to regulated with 350 grain Woodleighs? If so, what powder, etc. did you use? Rifle make, barrel length, weight, etc.?

John Taylor wrote that the .375 Flanged was the one rifle that would regulate with multiple bullet weights, (ie., 235, 270, 300). Just wondering if one could go up in bullet weight from 300 as well as down.

Any info would be appreciated.

I have two DR's that I reload with lighter bullets,in my 470 NE I have shot many a 400 gr bullet when hunting small game,in my 458 Lott,I have used 350's,400's,450's & 500's,but I have not used heavier than what the guns were regulated with,I am going to assume that It can be done but you will maybe lose some velocity or if you can find ammo loaded with the 350's? maybe you can get the gun regulated for that particular ammo.

A quick look over some of my load manuals showed no bullet weight greater than 300 grains for the .375 HH mag and Flanged mag. The proper 300 grain bullet takes all DG, so I am curious what drives your interest in a .375 bullet heavier than 300 grains?

There is plenty of load data for the 300 grain .375 bullets though.

I'm not an expert or even a user of .375 magnums but, as I understand it, part of the reason makers were able get different bullet weights to regulate was because they loaded at least a couple of the flanged cartridges to the same velocity of about 2400fps. (The 235-grain bullet is not too far from three-quarters of 300, so I can imagine that one could work.)

However, if you were to use 350-grain projectiles, they would probably have to do 2400fps as well, and that might put a strain on things.

I'm sure to be oversimplifying the matter but that might be a consideration to start with.

I like Dr. Kevin Robertson's theory on deeper penetration resulting from the enhanced momentum of heavier bullets. Softpoints also expand to a greater diameter. Besides, it's fun to experiment!

No question that longer bullets penetrate more, if they they retain shape. Our tank penetrators prove this, being 30 inches long and less than one inch in diameter. No rifling.
But as stated, in a double rifle, other considerations are there.

My GUESS is that with the heavier bullet you would need slightly less barrel time to achieve the up and out recoils for regulation. That means more velocity and maybe loads that are too stiff. Don't think I'd try that, especially with an older rifle.

Then there's the question of twist rate adequacy to stabilize the longer bullets..?

Good hunting,

quote:

Originally posted by drongo:
I like Dr. Kevin Robertson's theory on deeper penetration resulting from the enhanced momentum of heavier bullets. Softpoints also expand to a greater diameter. Besides, it's fun to experiment!

Buy a larger caliber.

quote:

Originally posted by Emory:
My GUESS is that with the heavier bullet you would need slightly less barrel time to achieve the up and out recoils for regulation. That means more velocity and maybe loads that are too stiff. Don't think I'd try that, especially with an older rifle.

Then there's the question of twist rate adequacy to stabilize the longer bullets..?

Good hunting,

I did a virtual pressure and velocity software run using 350 gr Woodleigh and using IMR 4831 (propellant that Graeme Wright used in his test of 300gr Woodleigh .375 H&H flg NE in his book)
and the results were that the chamber pressure in order to get to 2400fps would be at least 6,000 psi over the MAXIMUM for the cartridge. I strongly suspect that in actual firing the pressure would be even more than predicted.

Data Point....A few years ago Norma factory loaded the 350gr bullet in the 375FM but I no longer remember at what velocity. If you contact them they might be able to help.

The Woodleigh loading manual has data for 350 grain bullets in the .375 H&H Belted Magnum.
Max velocities are variously 2295-2325’/sec using H4350, H4831, and Reloader 17/19/22

Woodleigh do not show loads for their 350 grain bullet in the .375 FL Mag.
Their quoted loads for the .375 FL Mag and the usual 235/270/300 grain bullets run ~100-150’/sec less than the .375 Belted Mag.

IMO Expecting to load a .375 FL Mag to equal a standard .375 Belted Mag in a double rifle would be expecting too much.

If you have a .375 flanged magnum double made, Drongo, and regulated for the 350 grain Woodleigh, then by the rule of 3/4 it should regulate a 263 grain bullet with the same charge of powder. That's close enough to try a 270 grain bullet or a 260 grain bullet and tweak a bit.

Regards, Tim

Thanks to all for the info. I have ordered dies from RCBS - special order 2-3 months - and will get started as soon as they arrive. Thanks again.

quote:

Originally posted by drongo:
Thanks to all for the info. I have ordered dies from RCBS - special order 2-3 months - and will get started as soon as they arrive. Thanks again.

Buffalo Arms has the CH4D .375 FL Mag dies in stock if you dont want to wait:
https://www.buffaloarms.com/37...-set-4d-4d375flanged

Ever since RCBS got taken over by “vista Outdoors” it has been a botch job.....

Just curious, but why wouldn't regular 375 H&H dies work? Isn't the only difference in the rim?

As an aside, I saw this the other day. No connection and I've never dealt with this company, but $80 for 40 pieces of Kynoch 375 flanged brass doesn't seem a bad deal!

https://www.libertytreecollect...d.asp?idproduct=8898

quote:

Originally posted by Omnivorous_Bob:
Just curious, but why wouldn't regular 375 H&H dies work? Isn't the only difference in the rim?

As an aside, I saw this the other day. No connection and I've never dealt with this company, but $80 for 40 pieces of Kynoch 375 flanged brass doesn't seem a bad deal!

https://www.libertytreecollect...d.asp?idproduct=8898

The brass might be berdan primed.

quote:

Originally posted by Omnivorous_Bob:
Just curious, but why wouldn't regular 375 H&H dies work? Isn't the only difference in the rim?

As an aside, I saw this the other day. No connection and I've never dealt with this company, but $80 for 40 pieces of Kynoch 375 flanged brass doesn't seem a bad deal!

https://www.libertytreecollect...d.asp?idproduct=8898

Those brass look to be the .375 Flanged Nitro Express 2-1/2” not the Flanged Mag.

As an aside: Berdan primers aren’t that hard to deal with “if” you can find a source of primers. Seemingly after Old Western Scrounger went out of business nobody imports Berdan primers into the USA.

drongo...If you need some brass, I have some WR once fired brass. Pack of 10, $15 & postage, have about 100 cases available.

quote:

Originally posted by Omnivorous_Bob:
Just curious, but why wouldn't regular 375 H&H dies work? Isn't the only difference in the rim?

As an aside, I saw this the other day. No connection and I've never dealt with this company, but $80 for 40 pieces of Kynoch 375 flanged brass doesn't seem a bad deal!

https://www.libertytreecollect...d.asp?idproduct=8898

Cases are not the exactly the same, overall length,neck length,shoulder angle,baseangle ,
case taper are all slightly different.
In a pinch you might ght get away with it, but with a tight chamber ,might not close in a DR

375 H&H dies (RCBS)work perfectly in my 375 Flanged Magnums; I use a standard PTG chamber reamer. No issues at all; no problems in chambering, etc. You just run them in to touch the shoulder. They are so similar that it works with my reamer.

Ive used the 350 gr. Woodleigh in my 375 H&H, my 375x62 and the 375 Ruger...Ive shot a few buffalo with the 375 H&H and the 375x62, and don't expect to get 2400 FPS from either..2100 to 2300 FPS is all you will ever need in the first place with that big bullet, and it seems to me your walking on the heels of a 404 or 450-400 as to results in the field...

I have a friend that we loaded his 375 flanged to 2100 to 2150 FPS with the 350 Woodleigh with both IMR-4831 and RL-15, best I recall. That was some years ago and he has since passed on. He shot both buff and elephant with it.

We only had to make a slight sight adjustment as his gun shot them into a 2.5" group at my house 65 yard target..

I think you will do fine, but you just have to load them up and see...I got his loads by reducing the recommended book loads by 10% and worked up very little..I looked for that data but couldn't find it for you..It was about 1982..

BTW, he was pleased with its killing effect, as I was with the 375 H&H and the 375x9.3x62, a big slow bullet penetrates like hell as its not a violent expander unless pushed too hard, but expands enough at low velocity was my take..

I shot my largest Cape buffalo with that bullet in 350 gr. Woodleigh softs, in my H&H, at 2200 FPS, It was my favorite buffalo bullet, hands down..

Reregulation is never an option, its to expensive, and not practicle at all.. but don't get regulation mixed up with sighting in..you can move bullet impact with the sights or by playing with the loads in a double rifle. the word regulation is misused often in reference to double rifles..