Originally Posted by Riflecrank
Sir Russ,

After your excellent work with the King of Cartridges, .458 WinMag,
I can only understand your new rifle by remembering that I was once young and impetuous too,
tried a lot of new toys too.
The increased recoil which you note, I can only understand by considering either stock fit or the weights of rifles compared,
so similar otherwise in ballistics.
If your .425 Express rifle is only 8.5 pounds with the scope mounted as pictured above, that is pretty light.
Your stock profile looks great for handling recoil.
Light weight stock too, eh ?
Beautiful rifle all around.

Is that about a No. 4 sporter contour ?
And what twist did you choose, please ?

Your choice of H4895 aka AR2206H at a midrange load is wise.
In the A-Square manual they loaded the .425 Express with up to 73.3 grains max of that powder and 400-grainer bullet.
26" barrel, .423"-grooved, 1:10" twist
H4895 73.3 grains (max) >>> 2396 fps <<< 63,000 psi
RL-15 at 78.0 grains (max) >>> 2437 fps <<< 59,500 psi

I can usually beat RL-15 by substituting Varget aka AR2208, close to same charge.
Varget was tops for me in the .404 Jeffery, for accuracy and MV with better ThermoBallisticIndependence (TBI).

H4895 is a one-powder do-all for reduced loads to maximum/compressed loads in the .458 WinMag.
Probably has better TBI than the AA-2230 ball powder which allows faster MV with non-compressed loads,
around 2500 fps MV with 80.0 grains AA-2230 and 404-gr Shock Hammer, even in a 23" barrel length with .458" grooves and 1:14" twist.
I have used 87.0 grains of H4895 compressed under a 400-gr Woodleigh PSP for well over 2600 fps in a 25" barrel.
I worked down from there.


Sir Ron,

It is so good to hear from you.

I actually have no idea on the specifications of my barrel, I let my builder take care of that! I will ask him next time I'm on the phone to him and let you know.

I love H4895/ AR2206H powder. It is fantastic in the 425 Express and is equally fantastic in the .458Win Mag...

When test firing the .458 Win Mag and the 425 Express side by side, the 425 definitely has snappier, sharper recoil. As you say, 8.5lbs is pretty light for such a powerful rifle and that must bump recoil up. If memory serves me right, my .458 weighs in at 9.5lb.
When l was googling the 425, unpleasant recoil was often mentioned - with people stating that even compared to other cartridges of similar power, the 425 just seemed to kick more...? It might just be a quirk with the cartridge...

In a head to head comparison my .458 Win Mag seems to have an edge over my 425 Express.
My 2 loads that l use in the .458 are;
550gn Woodleigh RNSP at 2080fps
450gn Woodleigh Hydro at 2280fps
Both these loads are putting out more than 5200ft/lbs and there's not an animal alive that l wouldn't feel confident hunting with one of these two loads...

My 425 Express is firing a 400gn Hornady DGX at 2300fps for 4700ft/lbs of energy. Still enough for anything that can be hunted (provided the right projectile is used) but half a step behind the .458WM...
But today gave me a chance to do some more playing with the 425 Express...

A friend of mine very kindly gave me some projectiles to try in it - thank you Justin.
These projectiles were some Bertram 400gn soft-points and some Atomic 29 360gn all copper
hollow-points.

Both of these projectiles are Australian made and I was really keen in particular to try the Atomics as they were a bit lighter and l was keen to see what increase in velocity l would achieve.

[Linked Image from i.imgur.com]
Atomic 29 360gn projectiles.

I tweaked the powder charge slightly and loaded up 10 rounds. The finished round looked great.

[Linked Image from i.imgur.com]
425 Express with 360gn Atomic 29 hollow-point

Once l had some rounds loaded up it was to the range to see what velocity we were getting...

[Linked Image from i.imgur.com]
425 Express firing 360gn Atomic 29 hollow-point

These loads showed no sign of high pressure and delivered good velocity. Awesome.

Once l got home l punched the data into my ballistics calculator and this is what l got...

Caliber: 425 Express
Ammunition: Atomic 29 360gn HP
Muzzle Velocity: 2450 fps
Ballistic Coefficient: 0.376
Muzzle Energy: 4799 ft/lbs
Recoil Energy: 57.0 ft/lbs (approx.)
Firearm: Zastava M70

50mtrs = 1.75 - 4326ft/lbs
100mtrs = 3.0 - 3891ft/lbs
150mtrs = 2.0 - 3491ft/lbs
188mtrs = 0.0 - 3221ft/lbs
200mtrs = - 1.0 - 3124ft/lbs
250mtrs = -7.0 - 2789ft/lbs
300mtrs = -16.0 - 2484ft/lbs

This load is punching out 4800ft/lbs of energy and has a usable trajectory out to 300mtrs.
I think that this would make a fantastic all-round load in the 425 Express - and in fact, this will be the load that l now use in my 425 Express provided they are accurate of course.

So this new load gets the 425 Express a little closer to the .458 but still doesn't quite match it in regards to energy.
But this new 425 load shoots flatter than either one of my .458 loads and l can't wait to try it on a big Sambar stag!
The more and more l play around with the 425 Express the more and more l'm liking it...

But can it topple the .458 Win Mag off it's perch as my favorite cartridge? That's a big ask for any cartridge!!!


Russ

You'll probably never NEED a gun. In fact I hope you never do. BUT IF you do, you will probably need it worse than anything you've ever needed before in your life...