458 win mag loads with TAC powder....anyone?


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Feb 14, 2021
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Has anyone loaded the 458 wm using TAC? I see a lot with AA2230 but didn't find any around.
I want to load some 450 TSX in the .458 win mag and found some Ramshot TAC locally so bought a few pounds. This will be for a distant buffalo hunt. I want a reliable round with good velocity in my Model 70. I know the gurus @TOBY458 and @Michel458 will have some good direction......at least I hope so.

Has anyone loaded the 458 wm using TAC?
In 2022 we renewed and reviewed some of the earlier Data done in 458 Winchester, and with good success, and yes, TAC was tested, but the problem is, we tested with 400 gr bullets only, and not 450 gr.......

450 gr we tested and retested of course AA 2230, IMR 8208, X-Terminator, V-N530, and touched H-4895.

I was working to confirm that you could have viable results with a 20 inch 458 WInchester, which we did confirm that you can very easily use Bullet Tech to your advantage and work with a 20 inch gun and do anything you wish on the planet.

But, one of our main interests in the 2022 work was with 400 gr bullets, and we did use TAC and had some great results with it. But no 450 gr work with TAC. TAC is a great powder, it is #1 with my own 458 B&M with 450 gr #13 Solids and others...... It is also extremely good in some other 458s I have, and even 223.......

The work also took us to learn that the data we did in 2013 with AA 2230 would be different than the new 2022 AA 2230, the granules were not even the same and had been changed completely. However while finding that 2013 AA 2230 gave on average 5000 PSI more pressure than 2022 AA 2230, unless you were pushing hard to begin with, you would not blow to pieces on the first tests....

8/7/22450 #13 Solid75/AA 2230Fed 2152263224617225560100 PSI—COL 3.282
2013 VintageMatch6100059200180060100
8/7/22450 #13 Solid75/AA 2230Fed 2152238221424222655600 PSI—COL 3.282
2022 VintageMatch560005510090055600

Do keep in mind, this is in my 20 Inch 458 Winchester................ You can look for about 30-40 fps in 4 more inches of gun.......

In reality I am not a AA 2230 fan, it is extremely good for 458 Winchester, probably overall top powder for 450 gr weight bullets, but I can't find much of a use for it in my other big bore rifles.

If you are looking for best results, you really probably need to get a few lbs of AA 2230..........

If you cannot find it local...... Get on Midway, they currently have plenty in stock, ready to order, deliver to your doorstep, I am sure probably Graf, Midsouth and some of the others have it as well.
This is from Barnes's online load data, 24" test barrel. I have not used it. Though at some point plan to try it with the few 450's that I have.

Definitely a fan of the Accurate 2230 and those other 400's !
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Excellent LD........ That should get him started properly....... Note the big difference in 450 TSX and 450 Solids.......... The TSX must have to be seated much deeper in the case....... I never used a 450 TSX for anything. ?

I do find the X-Terminator 450 Solid data above interesting......... I tested with 450 CEB #13 Solids and hit this.......Note my Data is 20 inch barrel..........
8/13/22450 #13 Solid75/X TerminatorFed 2152246223411224059900 PSI
102021 Blend601005960050059900COL 3.285

Bullet Tech has taken things to the next level, no doubt about it......Today you have a 400 gr bullet that can out perform heavier in 458s........ I have always considered the 458 Winchester a 450 gr Cartridge to give optimum performance on the heavy stuff, elephant, buffalo and hippo.......... Today in many cases, because of bullet tech, that can be dropped once again.......
That 450 TSX is definitely a long bullet. And their COAL is loaded to 3.340" for it, and 3.310" for the solid. Which, I am assuming they are crimping in the uppermost groove for both.

Today's non-conventional 400's performance level is certainly amazing. As has been reported on this forum and other ones.
My model 70 does have the standard 24" barrel. I have not taken possession of it yet even.... I was planning on measuring the bore length to see if I can load longer after altering the mag box. I understand going to 3.360 is often possible and gets good results. This should give me some better case capacity.
I love a handy rifle and may have the barrel cut down to 21".
I will look for some AA2230..... I hesitated on buying the TAC but the way powder is these days I bought it since they had it and Barnes manual listed it with good velocity.
Hoping I get the around 2250 with the 450 TSX.
My thought was get the 458 wm over the 416 rem mag to shoot a heavier bullet. Now thinking I should have just bought the 416.
Heck maybe I still will.
The old 458 vs 416 debate.
Maybe I just make it a 458 Lott .
Thoughts on all of this?
My thought was get the 458 wm over the 416 rem mag to shoot a heavier bullet. Now thinking I should have just bought the 416.
No, you made exactly the right choice, 458 Winchester is first class........ and far more capable when it comes to the larger species, and with the right bullets extremely versatile ......

Maybe I just make it a 458 Lott .
Absolutely NOT............ keep it as is, you can do anything you ever need to do with the Winchester. I have both, have been to the field with both, and 458 Win does not come up short.

Hoping I get the around 2250 with the 450 TSX.
Should not be an issue at all............. Try the TAC loads first as listed in the book, then go from there. COL makes a difference as well...........

You did well....... you can make the 458 Winchester do what you want and then some.......
From what I have seen TAC is bit slower so may be able to do more than AA2230.
I will see what happens. AA2230 is available on mail order but I will see what happens with the TAC first as it is slower on the chart by just a little so I may be able to get to 2250 in compressed or at least less compressed .
I have been testing TAC in my Rem 798 458 Win Mag with good results. My rifle likes a charge of 72.5gr which gave me a velocity of 2240fps out of the factory 24" barrel. I had the barrel shortened and threaded so I can mount a suppressor and the same load now gives me 2150 out of a 20" barrel. I have also had good luck with AA2230, which I use with 500gr softs.
I used x-terminator powder in my loads with CEB 420 and 450 grain bullets. This was going off of data sent to me by @michael458 . In my 21” M70 and my 22.5” R8 I’m getting around 2250 fps with both bullets.
As to the 450gr TSX, I’ve had trouble getting much over 2175fps with that bullet. It’s an extremely long bullet, so it takes up a bunch of powder space in the short-ish 458 WM case. Maybe a 24” barrel would get you a bit over 2200 fps with the same loads.
That said, in my R8, I can load bullets out long, due to the longer magazine length. I can easily get 458 Lott performance with the longer TSX bullets with that set up. I used TAC for that application, and it worked very well.
I’d try Benchmark. It is available from sources like Powder Valley. It is an excellent powder for the 458 WM and it is temperature insensitive. Asking questions and hunting for answers that agree with pre-determined ideas is not the best method for gathering objective info.
Got on to Tac in the past when looking for a powder to replace IMR 4320 in my 458 Lott. Called the company for a max load. It was more then I needed as I have found a vel of 2250 with the 500 gr will do all needed. Using the Swift AFrame in 500 gr the charge is approximately 1/8 “below base of bullet for my Labrader vel of 2250. So no compression of powder.
This is from Barnes's online load data, 24" test barrel. I have not used it. Though at some point plan to try it with the few 450's that I have.

Definitely a fan of the Accurate 2230 and those other 400's !
View attachment 615315
Though I have not used TAC in the 458wm I have great results with H335
I’d try Benchmark. It is available from sources like Powder Valley. It is an excellent powder for the 458 WM and it is temperature insensitive.
I had CEB make a 400 gr #13 Solid in 2022, which tested with IMR 8208 poor results, AA 2460 ok results, TAC gave excellent results, some better than even AA 2230, RL 7 Ok results, and then some older Benchmark in 2023, dated before 2013 for reasonable results. I later ordered a couple of lbs of new Benchmark, and just have not got around to testing, other projects took priority.....And never got around to 450 gr weights either in 2022/2023........ Just so many avenues one can pursue and try to keep up.

So no compression of powder.
I hear a lot of concerns about compressed loads. Don't get overly concerned about compression alone. In fact, many times you should actually welcome compressed loads. Consider a Bolt gun and how recoil effects the bullets in the magazines....... You sometimes get "set back" of the bullet, driving deeper in the case right....... Well, if you have a compressed load, this is not a concern any longer. I use mostly compressed loads in all my big bore rifles. Sometimes, it is so compressed that I have to be careful not to BULGE the case....... Some might have concerns possibly of "Caking up" powder in the case over time. This might be a concern if your ammo is kept in a high humidity environment for a few years, or other long term environmental negative conditions. But under any sort of normal conditions I have never had that happen, and I have ammo that has been compressed for years. At times when doing pressure data I will test some of it, and it tests the same, or near the same as it did when new. Below is some data on TAC with 400 CEB Solids that is very compressed, to the point of having to be concerned about bulging the case.

Reminder; My gun is a 20 inch gun, reflecting 20 inch velocities.............AND, this is 400 gr Bullets.

11/3/22400 #13 Solid80/AA 2230Fed 2152407239017239961100 PSI— COL 3.290”

11/3/22400 #13 Solid86/TACFed 215242124147241858700 PSI —- COL 3.290”
5920058200100058700Loaded Carefully for No Bulge

10/13/23400 #13 Solid75/BenchMarkFed 2152352234210234761600 PSI—COL 3.175”
6250060800170061600Winchester Brass

Back in 2000 I used 458 Winchester and 400 Swift A Frames to take 3 lions, two in Zimbabwe and 1 in Mozambique, I used 70/RL 7 for 2325 fps in a 22 inch gun at that time, and the Swift just slammed all three to the dirt, hammered......

In 2013 I tested the 400 North Fork Premiums with the same load and got excellent results, this is a 24 inch WInchester M70 test gun in 458 Winchester........

11/18/13400 NF-Soft70/RL 7Fed 215237023682236958105 PSI--Excellent Load

Testing the 400 Swift again in 2022 with the 20 inch Winchester yielded excellent results, very low pressures with TAC.

8/28/22400 Swift A85/TACFed 2152355233224234452400 PSI—COL 3.262

I hope this does not get confusing, going back and forth, but when I looked just now at the 2013 data, I did test some BenchMark with 450 gr bullets........ OK, once again, this is a 24 inch Winchester M70 458 Win....... 2013 Data.

12/18/13450 #13 Solid70/BenchmarkFed 215226622606226360208 PSI-Magneto Muzzle Vel Max Safe

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