I'm going to put together a .450 Remington Ultra Magnum, I have the dies and the reamer and I decided to go with a Brux stainless fluted cut rifle barrel. I was looking for input on the barrel contour and the length. I want the minimum length possible to completely burn the powder charge.

Smack,

The answer to your barrel length questions is: depends upon what load you want to shoot. If you give me your load details I can calculate what barrel length you will need to achieve 100% powder combustion.

Thanks Scott,

This is all new to me and I haven't been able to find any load data on it. I will be necking up a .375 Remington Ultra Magnum case to form my new case(450 Ultra Mag) I want to shoot the 350 & 500 grain Barnes TSX's. I would like to be able to stick with IMR7828 as my powder due to the fact it works so well in my .375 Ultra Mag. Any help with barrel length or a starting load for either bullet weight would be appreciated.

Smack,

I just ran a mockup through QL using compressed charges of your IMR 7828 powder with 26” barrel. QL indicates that you’re getting basically a 99.24% burn rate in your 375 RUM with 300gr TSX but will only get a 76.0% burn rate with the 350gr TSX and 84.5% burn with the 500gr TSX both with 26" barrel in the 450 RUM. It looks like IMR 7828 is the wrong powder for the 450 RUM cartridge.

However if you use compressed loads of IMR 4895 you’ll get:
• 350gr TSX: w/21” barrel length = 99.3% burn rate; w/26” barrel length = 99.8% burn rate.
• 500gr TSX: 100% burn rate with barrel length of 21.0” through 26.0” length.

SMACK;

I'm thinking that IMR7828 will be on the too-slow side of things. Check out Barnes' manual #4, the .460 WBY section. The .375 Ultra is a slightlt smaller case than the WBY. Powders in the medium range are used by Barnes in the WBY case. And, for the 350 TSX (which I use as my N.A. hunting bullet)IMR7828 would be WAY too slow!

I like your idea though!

Bob

www.bigbores.ca

http://www.accuratereloading.com/450vl.html

That is the loading data in Saeed's reloading section for the 450 Vincent Long which is a 404 Jeffery Improved necked to 45 and essentially the same as the 450 Ultra.

You could also search on Google for 460 G&A (Guns and Ammo) which is another 404 Jeffery Improved necked to 460.

There are also a group of wildcats which I think are called UltraCats or similar (they have a website) and might have loading data for there 450 Ultra.

And lastly a search on this forum will probably get something for 450 Ultra, 460 G&A, 450 or 458 RUM etc.

Thanks gentleman.....

http://www.z-hat.com/Ultracat.htm
email fred, he's a gret guy ..

there's NO .458 bigbore load that burns 100% .. what you are looking for is as close to 100% loading density as possibile.

my 458 AR is a 375rum based round, that can far exceed what users can shoot

Fred(Z-Hat) might be a good guy but I have been e-mailing him for two years regarding this 450 Ultramag thing of this and he has yet to respond. Jeff, do you have an e-mail address that might be different from the one on his web site.

quote:

there's NO .458 bigbore load that burns 100%

Jeff, the 458 Winnie will get there and in a 22" barrel too.

Smack, I can mock something up, but your powder choice (IMR7828) is WAY TOO slow for the cartridge you are describing. Something in the IMR3031 to IMR4064 burn rate would most likely work best. I will run those through QL and see what it predicts. Stay tuned.

Thanks Scott,

Can the QL estimate a ballpark figure on velocity for the two bullet weights(350 & 500gr)?

Smack,

QL (Quick Load) says that with IMR4895 you can get by with a 22" to 23" barrel if operating above 55 ksi with the 500gr Barnes TSX while achieving a calculated 100% powder burn. If you go to IMR3031 QL says you can cut the barrel back to 21" to 21.5".

I do not have a 350 gr TSX in the database, unfortunately. I did look at that standard X bullet in 350gr flavor and adjust the initiation pressure to simulate a TSX, and it would appear that it will be very difficult (probably impossible) to achieve 100% combustion with this bullet weight in a case with the volume of the 450 Ultra mag.

Yes QL can and does predict a muzzle velocity. I will get those to you in the morning.

Thanks for your time Scott, I have never used Quick Load. Looks like I need to start.

Are You going to use a bolt action or a doubarrel? I know a guy that made a 45/70 using
a doubarrel. And you talk about acturate man that gun was at 50 yds.

Smack,

Quickload velocity outputs.

Cartridge overall length: 3.650"
Case volume: 120 gr if water
Bullet: Barnes 500gr TSX
Powder: IMR 4895
Case fill: 103%
Barrel length: 22"
Muzzle velocity: 2201 fps
Chamber pressure: 63000 psi (rounded to nearest 1000).
Powder combustion: 100%

Cartridge overall length: 3.650"
Case volume: 120 gr if water
Bullet: Barnes 500gr TSX
Powder: IMR 3031
Case fill: 103.7%
Barrel length: 21"
Muzzle velocity: 2178 fps
Chamber pressure: 63000 psi (rounded to nearest 1000).
Powder combustion: 100%

Cartridge overall length: 3.540"
Case volume: 120 gr if water
Bullet: Barnes 350r X (using TSX initiation pressure)
Powder: Reloder 7
Case fill: 95%
Barrel length: 22"
Muzzle velocity: 2573 fps
Chamber pressure: 63000 psi (rounded to nearest 1000).
Powder combustion: 99.99%

I would consider all of these to be maximum loads.

With numbers liike the above, I would not bother. Just buy or build a Lott or jeffe's 458 AR. Both prefrm better.

Keith

quote:

Originally posted by Hog Killer:
With numbers liike the above, I would not bother. Just buy or build a Lott or jeffe's 458 AR. Both prefrm better.

Keith

Check the load data on Saeed's 450 Vincent Long.

quickload can be pretty wrong ...

I don't have a better email from fred, sorry

the vincent long is a graet round, and nearly the same, as mike says

vincent long data
http://www.accuratereloading.com/450vl.html

jeffe

You might consider using 404 Jeffery's brass instead. A bit more $$$, but the ID mikes around .424" so you are only necking it up .034" and blowing it out.

This should be a pretty nifty round.

Rich

My recent real world test data on my 458 win mag using a 500 gr bullet ahead of 74 gr of 2230 yield 2190 fps 10-12 ft away from the muzzle. (Measured with Oehler 35).
This cannon you are considering will probably exceed these results but these match the "suggested loads" above with I suspect far less recoil and of course ease of brass availability.
I have a Lott that I may be selling with these new found results with my 458 Win Mag.
It would appear my load is 4 grains under max by Hornady and recently supported by Accurate arms by a board member.

EZ

quote:

Originally posted by Hog Killer:
With numbers liike the above, I would not bother. Just buy or build a Lott or jeffe's 458 AR. Both prefrm better.

Keith

I assure you the referenced info from Scottieboy is wrong!
He only works from imagination, and he got the case capacity wrong for starters.
Nevertheless, the .458 RUM is a boring idea.
The equivalent has been done many times over.
What we really need is a ragged-edged .458 Ruger that will make up into a 6-pound rifle delivering .458 Lott ballistics.

DRG says: "Kiss my liberal grits!"

quote:

Originally posted by RIP:

quote:

Originally posted by Hog Killer:
With numbers liike the above, I would not bother. Just buy or build a Lott or jeffe's 458 AR. Both prefrm better.

Keith

I assure you the referenced info from Scottieboy is wrong!
He only works from imagination, and he got the case capacity wrong for starters.
Nevertheless, the .458 RUM is a boring idea.
The equivalent has been done many times over.
What we really need is a ragged-edged .458 Ruger that will make up into a 6-pound rifle delivering .458 Lott ballistics.

Only if they leave recoil lugs too small or maybe even eliminate them entirely and don't add any crossbolt(s) so they'll split stocks like three of the .375 Rugers my friends shop has sold this fall/winter to people that actually shot them a lot with heavy loads...currently being warrantied by Ruger, theoretically.

quote:

Originally posted by eezridr:
My recent real world test data on my 458 win mag using a 500 gr bullet ahead of 74 gr of 2230 yield 2190 fps 10-12 ft away from the muzzle. (Measured with Oehler 35).
This cannon you are considering will probably exceed these results but these match the "suggested loads" above with I suspect far less recoil and of course ease of brass availability.
I have a Lott that I may be selling with these new found results with my 458 Win Mag.
It would appear my load is 4 grains under max by Hornady and recently supported by Accurate arms by a board member.

EZ

You can use any powder you like in the 458 Win and the 460 G&A/458 RUM will do the same velocity in cruise mode.

Mike,

I do not doubt your statement. I was referring to the loads listed in dialog prior to my initial post.
If you are a hand loader like so many on this forum. The 458 Win Mag has gained new life with a number on new powder offerings that make it all the better for its intended purpose (Close range stopping power).

I like more velocity as well. Most will say a 450 / 400 (400 gr) @ 2100 FPS is sufficient for its intended purpose however I like a 400 gr out of my 416 Rem. @ 2450.
I believe I have a realistic recoil threshold in the way of a 470 nitro or 458 Lott and my 8.0 lb 458 win mag at full house loads is pretty eye opening as well!

Merry Christmas!

EZ

quote:

Originally posted by Mike McGuire:

quote:

Originally posted by eezridr:
My recent real world test data on my 458 win mag using a 500 gr bullet ahead of 74 gr of 2230 yield 2190 fps 10-12 ft away from the muzzle. (Measured with Oehler 35).
This cannon you are considering will probably exceed these results but these match the "suggested loads" above with I suspect far less recoil and of course ease of brass availability.
I have a Lott that I may be selling with these new found results with my 458 Win Mag.
It would appear my load is 4 grains under max by Hornady and recently supported by Accurate arms by a board member.

EZ

You can use any powder you like in the 458 Win and the 460 G&A/458 RUM will do the same velocity in cruise mode.

One of my wishes is for the 460 G&A to be produced by one of the factories...Hornady would be nice! I think it would be about the perfect 458....maybe next year

eezridr, I followed your and 465 H&H posts on the Browning Safaris in 458 and decided I had to have one...found a really nice one that I am having tweaked. Hopefully, should have it back from Roger Farrell next week. Those FN long extractor Browning Safaris, of the late 1950s and early 1960s, are really nice stuff!

Ron,

I did not use the 458 Ultra as there were no case dimensions provided for it, it is a wildcat afterall. So I used the 460 G&A, which should be close. The results are what Quickload spit out. So pray tell Ron, the all knowing know it all, what is the correct case capacity of the wildcat 458 Ultra mag?

Smack,

Be warned many of those posting data for there 458 whatever are in fact greatly exceeding SAAMI or CIP pressure specification. They do not believe they are due to their interpretation of "pressure signs" but the fact is they are. These large cases can typically take a great deal more pressure without showing ANY "pressure signs" than the smaller case heads can.

If it were me I would not waste my time with a Ultra mag or 404 Jeffery based case as the volume increase over a belted magnum case is not sufficiently great to allow moving up to the next slower powder and then pouring in a great deal more of said slower powder to get a big increase in velocity. If it were me, I would just build a 450 Dakota, 450 Rigby, 460 Weatherby, or a 458 wildcat off of the 505 Gibbs or 500 Jeffery case (ala 450 AHR).

Have fun with your project.

I built a 460G&A about 15yrs ago, too many headaches for the performance it can deliver. R15 is/was the powder to use, my hunting loads did 2350fps with 500gr bullets. Some years ago I rechambered the rifle to 450 Dakota and haven't looked back. If the 458 Lott isn't enough, the 404 based rounds won't be either.

JohnS,

since I own a CZ 450 Dakota I am obviously in agreement with you there. It gives me an easy 2470fps (factory equivalent) with 500gr bullets, and the pressure is below the smaller cases trying to get close to those numbers. That said, this does look like a project well worth pursuing. I will be interested to see how it works.

Rich

A noble endeavor w/o doubt, but I can't see reinventing the wheel as the G&A is basically the same thing. And it has the full diameter head, not the rebated version Rem. chose, which is not something I'd want on a dangerous game cartridge. And then there is that thorny issue of headstamped brass. For a gun that will actually be taken overseas and hunted with, I demand having properly headstamped cases.

John S,
Glad to see you are still with us.
Regarding your advice here: You are a smart man.
I got a 450 Dakota too.

I think I am wildcatted out, will finish my experimenting days with shotgun slugs and brass hulls,
until I go blind!
Right now lusting after a
Connecticut Shotgun Mfg. Co.
RBL Professional
20 Gauge Double Rifled
Sabot Slug Gun

"SOLD OUT"
Shucks! I was hoping to take a 3.5" reamer to it!
Even if just a 3-incher, 900-grain slugs could pack some whomp and whump at both ends of a light gun.
Double trigger option is standard, you pay extra for the single trigger ...
"Heavy-fill" fiberglass stock from McMillan is not offered, however ...



DRG says: "Kiss my liberal grits!"