I am planning a 500 AR with .510 approx freebore to shoot milsurp and standard (copper) bullets. Whats a better donor action: M98 or CRF Magnum Model 70? The M98 is a 30-06 from century international, presumably hardened. The Mod 70 is a 7mm mag.
By the way, Mcgowen has Husqvarna CRF actions, and I asked if one could be used for the 500 AR build. Got reply from a dan wynne

"Not available in that cartridge. it will handle 30-06 length cartridges with a .473” bolt face."
i was under the impression the bolt face could be opened up, or do I need a .589 Rigby size bolt face? Can the .534 magnum bolt face be opened up to accomodate the 500 AR? Will there be need for extensive work on rails etc for feeding? replacement of follower?

Appreciate any input from the AR afficianodos

Emron,

I believe the M77 Ruger Mk II or Hawkeye is the most popular action for the 500 AR and likely the most cost effective. Nothing wrong with using the M70 CRF action just likely a bit more expensive. M98 Mauser actions have been used but that's the most expensive way to go.

Any of these three actions can have their bolt face extractor safely opened to accomodate the Rigby rim diameter.

use the model 70 -- the huskie isnt "really" a 98, though cool

Emron,

There’s no need for a .510” freebore with the 500 AR for use with milsurp bullets – but especially with monometal hunting bullets.

Check out the ‘500 AccRel throat, reamers, and freebore’ thread
http://forums.accuratereloadin...043/m/3061083571/p/3
and leaf through page 3-6 or so… Via diagraming it was verified that the 0.255” freebore of the 500 AR Nyati is more than sufficient to handle the various milsurp bullets and the 2.550” long 750gr Hornady A-Max UHC 5165 bullet.

The 1.25” freebore 500 AR finish chamber reamer and the 0.255” freebore 500 AR Nyati finish chamber reamer are housed at McGowen Precision Barrels along with the Go and No-Go Gauges. Pick your action and send to McGowen for a barrel and the relating gunsmithing work.

Freebore:
Surely the Ruger M77 Mk II/Hawkeye would be easiest.
If you go with an M70 Winchester you can have a single loader until you get your box worked out.
Two-down without the drop-belly magazine,
or three-down with,
feeding the short loads of 3.2" to 3.6" COL from the box.
Like with this 12.7x68/49-10 M70:



The standard Mauser 98:
This one almost became a 12.7x68/49-10, but has been rededicated to 500 Bateleur.

Mcgowen will also sort out your feeding issues. Yes without a custom box it will be 2+1. Easy fix to get feeding.

Thanks gents
Ill go with Ruger Hawkeye
The M98 might become a 9.3x66 AKA 370 sako mag
And surely the M70 can become another 404
But any suggestions on bottom metal to make the 500 AR a 3+1?
regards

quote:

Originally posted by emron:
Thanks gents
Ill go with Ruger Hawkeye
...
But any suggestions on bottom metal to make the 500 AR a 3+1?
regards

Here you go - he goes by 'kcscott' here on the AR forums; here’s a link to his website and the pocket floorplate he made for the M77 Ruger MKII:
http://www.klstottlemyer.com/k...es/Pocket_Plate.html

I commissioned the prototype pocket plate for my stainless MKII Ruger. The economy has derailed its conversion to .470 AR but I would be happy to answer any questions about it or take any pictures one may want of it on my rifle. It is a simple idea that so far has worked very well as a 7mm Remington. Kcstott does very nice work and is a straight up guy to work with.