Anyone have any experience with this? (.416-.375 ultramag) I realize it is synonymous with a .416-.404 Jeffery and with ultramag brass relatively cheap and available it seems like it might be a fun project. I am only interested because I enjoy wildcatting and having something a little different, I am sure a .416 Rigby is much more popular etc. Anyway, any comments would be appreciated.

IV

you are darn close on the 416-404...

it's sold today as the 416 dakota.

jeffe

Like jeffe said.
And to that effect, it would to just great. The Dakota gets an easy 2400fps with the 400g, and could be pushed over 2550 should you so desire. Or more to the point a 350g would run somewhere around 2700 fps? More or less, 30-06 trajectory with some bigass bullets.

I think there is a a company call Ultacats or similar that has all the dies from the 300 Ulta necked from 6.5 to 458.

Would be real easy to do and a lot more interesting than the 416 Remington.

Mike

mike,
it's "z-hat" that makes the ultracat... same company as the 411x3006

jeffe

jeffe,

I think if the 416 Reminton would have come out as the 416 Winchester or as an Ultra size 416 Winchester and also chambered in the CZ we would have seen quite a few bullets fom Sierra, Hornady and Speer.

The chap that runs the Wby custom shop was telling me a couple of interesting things the other day.

Firstly, after the 300 Wby the 270 Wby is the main seller.

From what they can tell a much higher percentage of 416 Wbys are sold to people who buy the rifle for exlusive use on very big game. In relation to the number of rifles sold the 416 Wby sells a lot more factory ammo.

While they can't give the 416 away in the standard Mark V Deluxes when it comes to the custom shop it does as well as the 378 but in the custom shop the 460 does more than the 378 and 416 combined.

Lastly, in the custom shop done up Accumarks the 30/378 leads the way.

I would have always thought the 257 Wby was the number two after the 300 Wby.

I think the problem with the 416 Wby and I certainly fall into this area is that it lacks the bullets, does not have the big 460 thing about it and does not give the 7mm and 300 Mag velocities of the 378.

A few years ago Hornady was going to bring out a 340 grain Spitzer for 416 but canned the idea.

Of course if you were only using this stuff on very big game then the bullet situation for 416 would be as good as the 375 and 458 bore sizes.

Mike

Thanks for the replies, I'll search "Z-hat" on the net!

IV

The site is Z-Hat.com. Give Fred a call.

The 411 Hawk is based on the 9.3x62 case. Scovill changed the base to .470 to use '06 cheaper brass. Fun gun.

Snapper

Idaho Vandal I got talked into building one and have been shooting it for a while now. John ricks put the 26 " SS Pacnor barrel on an Olymic Arms action, BBK-01, I think. John stamped 416 Ultramag on the barrel.

I got dies from Huntington, spendy, but had them in a couple of weeks. They call it a 416-300 Ultra-Mag, and it's in their new catalog

It's very accurate, I put a VA-Comp, on it from BP-Tec. So the recoil is very manageable, and it has a slight negative muzzle jump, the barrel dips instead of rolling up on you.

Extremely accurate. With bullets seated to 3.747 OAL and 103 grains of H4831SC, I got 2600 FPS w/ 400 gr Swift A-Frame.

97 grains of the same gave 2390 to 2408 FPS with a 450 grain Woodly.

I used the Hornady data for the 416 Dakota as a guide. Although the Dakota has slightly less capacity and has the bullet seated deeper, more of a standard magnum length, I can't get the 107 grains of this powder they list as max in mine. Maybe without the bullet.

I backed off to 100 grains of the H4831SC behind the 400 gr A-Frames and get 2530-2540 RPM out of that load.

Been using 375 Remington Ultra-Mag Brass. Wayne

Amazing, We have finally after some 100 years of expermintation, duplicated the original 404 Jefferys, even though we had to use the same case and screw it up by taking the taper out of it so extraction can now be problematic!! Simply amazing!

Actually the .404 Jeffery has less case body taper than the RUM cases do. The .404 Jeffery gets its overall taper from the gradual shoulder angle and looooong neck.

Where they really screwed up the RUM case was in rebating the rim.

That alone makes Saeed's .375/404 superior to the .375 RUM ... and the .416 Dakota superior to the .416 RUM ... and the .375 Lapua superior to all of them!

Well i would imagine that they rebated the rim so they could just grab a magnum size bolt out of the parts bin instead of spending all the money to tool up a comlete new bolt, and only a few thousands different.


Also, maybe they figured it was easier to cut brass than add steel, maybe they just wanna be different.

One guy will argue that more taper is superior, another argues that less is better.

Whatever it would most likely take some really fine scientific measurements to really quantify and define any differences. One round may be superior in one way and inferior in another, and sometimes it's all in someone's imagination.

My brass is 25-30 % of the dakota and lapua and Jeffery brass, and seeing as to how I don't have Saeed's money that makes my gun better than his. to me at least.


I'm extremely happy with my rifles performance so far, and I',m not using it's full power potential.

But---I'm not gonna set Jack off by saying my 416 Ultra whizbang is better than his 416 Rem Mag, because maybe his 2400 Fps may perform better for him than the Whizbang Wildkats 2600 plus he can get a box of ammo at the corner store in Africa, or Montana or one of those wild and wooly places. Waayne

Ja, und dat reminds me why .375 Weatherby is best .375 cartouche of all time! Except cool factor or nostalgia factor, but who care?

Rip xcept for the curvy shoulder is the 375 weatherby any better than the 375 ackley improved or the 375 Barnes supreme? Wayne

Walex,
The main advantage of the .375 Weatherby over the .375 AI and BS is the easy availability of Norma made properly headstamped brass. I don't think the shoulder differences are important.

The .375 AI has 0.2000" freebore and a more abrupt leade of 2.5 degrees. The Weatherby freebore is 0.3700" and 1 degree 2 minute leade.

I know the Weatherby works well at 3.600" COL or 3.800" COL in either the H&H box or a Rigby length box.

Shorter and more abrupt throat in the .375 AI. The .375 BS I have no knowledge of throat, though I do shoot both a .416 BS and .450 BS: blasts from the past, circa 1949.

Brass availability and throat differences are the only differences I would consider worth considering.

I like the .375 Wby best, but the .375 AI is a big winner too, as a shooter. Can you get brass for it with proper headstamp?