.495 A Square

[Big_Easy]

It is barreled, I have 500 pieces of brass. I am 1/2" from having the action inletted AFTER paying Wenig $300 to inlet a blank! I do not have a climate controlled shop, so that slows things down a great deal. Need to weld up the duck pond - have the plug. Plains game safari in 2021 kinda slowed things down a great deal. About to get back int to he saddle on it though, as the weather warms.

Just wondering how this project turned out? Was thinking maybe I need a .495 A-Square as well? Surely you have some brass to spare good sir?

 

[USMA84DAB]

I do have brass to spare. You can use .460 Wby cases for US use, but getting 100 for use going to Africa is what I would recommend. I could sell you them for $3 each.

The project is nearing the top of the project list again. Lots of drama I will spare you, tied to my time in the service. It appears to be clearing out now, so I should be getting to it soon. Have been focused on a barreled receiver I purchased from the CMP on 2003 and am now finishing the stock on it. It is a re-constructed parts rifle, but it will be a functioning example of an M1917. Also restored a bubba-ized M1916 just to get a functional .30-06 up and running - put a nutmeg laminate Boyds stock on it in place the 1950s Ward Cleaver white spacer, plastic black fore end tip monte carlo stock. I need to open up the space for the Timney trigger on that one and it should be done for this phase. It needs to have the metal re-finished at some point.

Have wrestled with a 7mm-08 on a yugo-24 mauser action as well.

Also, the .375 Ruger gets ALOT of my attention, so that has slowed the work on the .495 as well.

It is bubbling up the hit list though. Great situation to have several projects to work on at once/in sequence! I have slowed down as well due to funneling the vast majority of the $ into Namibia next SEP, assuming WWIII doesn't kick off, our 2nd civil war, etc..

 

[Jefferry404]

FWIW, when I use the Asquare manual data to fit Quickload, can never find the bullet lengths. For the 570 asquare mono (which is naval bronze), I use Barnes brass mono-solid and scale the length by the densities, which is 95%. If anyone has large bore A^2 mono measured length, let me know and will see how this matches up. thanks
steve

 

[analog_peninsula]

Not to be negative, but the .500 A2 seems so much easier, assuming access to an appropriate action. Loading it down to maybe 2200 fps is so simple…

 

[Jefferry404]

The same, if you want to use the Asquare manual loads as it is the only published source of pressure data.

 

[Big_Easy]

Not to be negative, but the .500 A2 seems so much easier, assuming access to an appropriate action. Loading it down to maybe 2200 fps is so simple…

Thats my issue, lack of affordable left hand actions. Even 375 H&H are getting exp. Ill Proabably wait until the next economic downturn and then look to buy one.

 

[Riflecrank]

Not to be negative, but the .500 A2 seems so much easier, assuming access to an appropriate action. Loading it down to maybe 2200 fps is so simple…

A confluence of inspiration from this and another forum made me fall off the Gunndoku Anonymous wagon, again.
Thanks to multiple enablers.

Like the .450 Watts Magnum was Jacked into a SAAMI .458 Lott
and the .510 Buhmiller Magnum became the .500 A-Square,
I started doing unto Art Alphin as he did unto others when I did the .510/460 Wby Mag Improved back in 1999: .500 A-Square with slightly different shoulder angle and a wee bit longer throat.

Now in the works is the .510 Winchester Magnum made from the .495 A-Square by giving the 2.800" case a 2.820" chamber length and a scaled-up .458 WIN MAG throat:

Make-do dies and no annealing used in making the feed-trial dummies from old 460 WBY brass.
Proper handloading dies, annealing and fire-forming will be a cosmetic enhancer.

There was initial thought of building it on a .375 H&H-length action like Art touted for the .495 A2.
But that would be un-Winchester-Magnumly-like, as bad as with the .458 Lott's usual crowding.

Moving from .458-caliber to .510-caliber:
A 2.5" case scales up to 2.784".
A 3.4" magazine box length scales up to 3.786"

2.8" case in a 3.8" magazine box length is good.
Otherwise the cartridge is cramped like a SAAMI .458 Lott.
Ditto the original throating of the .495 A-Square, tight and short near identical to a SAAMI .458 Lott.
Now we might see a 21"-barreled .510 WIN MAG able to deliver the ballistics of a 26"-barreled .495 A-Square.

The .458 WIN MAG is the Game Field Superiority Rifle.
Train with the .510 WIN MAG and you will never flinch or short stroke your .458 WIN MAG.
They make a great team, like an F-35 fighter jet and a B-2 stealth bomber.

 

[Riflecrank]

The .495 A-Square might have been Art Alphin's first and best proprietary cartridge.
A-Square data from ANY SHOT YOU WANT,
Art really played up the low recoil to high muzzle whomp ratio:

Hyperbole on ghost shoulder and parallel-sided throat advantage is amazing,
as is a passing mention of one shooter who uses cast bullets !
Maybe that one guy re-throated his .495 A-Square and he had a slower twist than 1:10" that A-Square used, or he was just a plinking wanker
The .510 WIN MAG will be a much better cast bullet shooter, with .512" to .513" hardcast PCP-GC bullets for best accuracy.
Maybe a 1:14" twist homage to the .458 WIN MAG will be slow enough for cast, fast enough for everything else useful ?

 

[Riflecrank]

Scaling up a 3.340" COL for the .458 WIN MAG to a 3.720" COL for the .510 WIN MAG:

No difference in cartridge case.
Use same handloading dies for .495 A-Square and .510 WIN MAG.
Cartridge Overall Length is whatever you want in the .510 WIN MAG, not limited to 3.6".

Chamber is lengthened by 0.011" to allow a full 0.020" for case stretch and spring-back on firing,
just like the .458 WIN MAG.

Throat is a scaled-up .458 WIN MAG throat by a factor of (0.510"/.458").
Leade-only throat, base diameter 0.521", leade hemi-angle 0*29'30".

Found another drawing of the .495 A-Square in Ken Howell's book:

Proper .495 A-Square/.510 WIN MAG handloading dies when available will make it
much easier to make pretty brass for the .510 WIN MAG.
Fire-forming will iron out those ugly shoulder wrinkles from the 460 WBY MAG very nicely
when the cases are annealed before fire-forming.

 

[Riflecrank]

I have two .500 Mbogo rifles, so to undo the duplication,
I can now let the first .500 Mbogo get un-barreled,

 

[Riflecrank]

Get a load of the "figure" on the left side of the stock. Hubba hubba.

 

[Riflecrank]

The second .500 Mbogo (below) is the reason I un-barreled the first .500 Mbogo:

That would make a nice conformation for a .510 WIN MAG,
though nowadays I prefer a peep rear sight, nix the island rear sight.

 

[Riflecrank]

Keeping it alive, the dream of the .510 WIN MAG,
here is the bolt face of the CZ 550 Magnum organ donor rifle:

Compare to the leading surface of the .505 Gibbs CZ 550 Magnum that will not allow push-feeding-snap-over-rim,
and the MRC PH action that will:

And if you want to use a Winchester M70 for a .495 A-Square-Unimproved:

Yep, my CZ 550 Magnum action for the .510 WIN MAG allows 4+1 by push-feeding one round into the chamber, closing the bolt over 4 in the box.
I am on it,
26"-barreled 1:10" twist .458 WIN MAG with 3.4" mag box for varmints and 1000-yard match shooting.
21"-barreled 1:14" twist .510 WIN MAG with 3.8" mag box for larger varmints.

 

[Riflecrank]

Essentially,
the .495 A-Square can do with 570-grain bullets
what the .500 A-Square can do with 600-grain bullets, MV-wise.

The .510 WIN MAG can do more than the .495 A-Square of Art Alphin can do.
Also, easier to load down to 2200 fps with either 570-grainer or 600-grainer than the .500 A-Square is.