I want to build a 500 A Square for fun gun (rock buster). I'm tired of being asked if I have a "50 caliber" I already have a big laminated stock and action for 110 Savage. I can easily modify bolthead and it will be single shot. My question is in regards to action strength. Bullets up to the 750 AMAX will be used. Please advise opinions on action strength and safety. Thanks, RandyB.

should work fine,, it will be a hassle to eject a live round

The Savage has as locking lugs as strong
as the big long actions, Enfield, Ruger, CZ.
And action diameter makes reciever just
as strong.It would work for 550 mag that is
based on Weatherby case.Ed

Use it like a "shell holder" action for those near 5-inch long A-Max and milsurp loads, single shot style.
Use the shorter "500" loads through the magazine.
Remove the bolt if any of the loaded rounds are too long to eject.
Sounds like a fun rock buster.
You can try 1000 yard targets with a 5-mil holdover and the BMG bullets, 750-grain A-max at 2150 fps.

Use a fat barrel with 3" to 6"-long cylindrical shank Knoxform of 1.2" diameter.
Taper from there to muzzle as much or as little as you want.
About .850" minimum muzzle diameter at 23-24" muzzle for a portable sporter.
Or 1.000" to 1.200" at 26" to 28" muzzle for a target piece.
Stainless barrel of course.
Twist?
Anything from 9" to 15", average = 1:12" twist.

The Savage action will handle the 500 A Square as long as you don't go loosing your head as far as pressures are concerned...staying below 63kPSI for safety sake. It will handle more but all you do is set yourself up for problems.

I'm doing a similar "thing" with a Savage except I will use a slightly modified 505 Gibbs case...basically blown out to minimum taper and taken out to 0.510"...single shot...for shooting milsurp 50 BMG bullets.

I have a barrel and reamer coming for doing my own version of a 50 cal Rigby based cartridge for starters, using an old Tang modle Ruger receiver. It will have a be very slightly larger case capacity compared to the 500 A-Sq...I like a non belted cartridge...makes it slightly easier to get to feed (highly argumentative tho')

I opened up a standard 0.532" mag bolthead to 0.600" leaving a 0.045" rim and the Gibbs case bases can be turned down the 0.032" difference easy enough...you then have a "slightly" rebated rimmed cartridge, but not enough to go nutz over. The bolthead will handle an unmodified Rigby base.

You can get the magnum length magazines still some places or can take two standard mags, cut and weld together to make a longer mag...(done that several times)...and make a mag that will handle almost 4". Doing so gets into the area of usefulness...and depends on the bullet design and seating depths...a lot of work for only a few extra f/s and not necessarily of any real gain.

You will need to have a gunsmith or machinist do some mill work on any of the newer receivers to handle the longer mags or find one of the Lazzaroni or early 375 H&H receivers that are already set up.

The upshot is...the conversion can be done using one of several very nice 50 cal already available cartridges or you can make your own...

How much you want to spend is the second question...if you can't do the work yourself you are looking at a bit of expense..."depending".

For a simple single shot it is nothing but opening up the bolt and screwing on a chambered barrel basically...if you want to use the mag then you are getting into another very large can of worms...again...depending.

My 510 Gibbs "Imp" will be a single shot, I will make a follower to make it easy to single load, you can insert cartridge almost 6" long into the chamber without having to pull the bolt, BUT, you will have to pull the bolt to remove it unfired.

I picked the Gibbs case for a number of reasons including it being one of the largest capacity cases without going totally bonkers...

BUT, if you really want to get hairy legged and macho, pick up a Sav 210 shotgun and research Ed Hubels offerings, and just do a 50 BMG and get into all the controversy.

There is lots of very good information already available on this forum and lots of "NOWAYJOSE"...if you really want to do a Savage conversion you need to do a ton of homework, research, net crawling, measuring, load calculations, etc...and pick out the easiest way...dreams can turn into day AND nightmares. You also have to consider cost and availability options for brass, dies, who has what, etc...lots of folks forget about this end when dreaming or until it's too late.

ANY conversion is easy, but not always all "that" easy. Buy a subscription to Ammo Guide, it is chucked full of excellent 50 cal cartridges to drool over and pick from.

Anyway...luck on your quest.

I built a 22-378 AI several years ago on one. It was a real hammer,; 60gr Nosler Solid Base HP's at 5200+fps. But a barrel only lasted about 150 rounds. You don't have much of a lip after milling the bolt face to take the Wbee case.

Rich

A savage would definately not be my first choice for a 500 a2. But it certainly can be done.you will need to mill the rear action bridge back for ejection clearance and rail work will be complicated as most savage actions will start out as narrower cartridges. The easiest 500a2 conversion is a CZ 550 in .416 rigby. The ramp angles will also need someone who knows what they are doing.-Rob

and, just for the sake of being fully informed, my 500 AR is a bit easier fit!

click on my signature if you've never heard of it.. its a shortned, improved blown out 416 rigby case, necked to .510, and a 3.45 OAL .. and 4.13 or so with 650gr milsurps!

use a HEAVY barrel, you want 12 -15# for a rock buster

I agree with both Rob and Jeffeosso...the 500 AR would be a much easier cartridge to fit...IF...you want to mag feed, it's basically a shoe in. Dealing with the Savage magazine tinware is a PITA to get the lips bent right to feed a cartridge the size of a Rigby or Gibbs...

For a Gibbs size case you really DO need a full diameter barrel...1.35" OD...the same OD as the Savage receiver. A 1.25" OD barrel will work fine for the 500 AR...plenty of meat for that one. If you want weight go with a 1.5" but that will set you back the cost of a new rifle almost...and is relative to your pocket book

And the way the Savage magazines are made the case holding rails are built into the top of the magazine and the feed ramp is almost non-existant and built into the front of the magazine also, with a small ramp in the receiver...for single loading none of this is a problem.

I guarantee if you haven't done much mag or receiver work you DON'T want to start...it is much cheaper, easier, a lot less headaches and so on, to start with something that is already designed for the cartridge you want to use than to do it the hard way...unless you just have a hankering to want to learn...then it's just plain fun.

I wouldn't recommend doing much over a Rigby size case if you want to mag feed anyway in a Savage or many other M98 size receivers...I've been futzing around for over a year, off and on, working to come up with usable magazine for a shortened Gibbs case and a full length case...the Gibbs case is definitely a single stacker.

To get the right size magazine for a full length Gibbs you need to add length to the mag by sectioning two 300 Win mags, just in front of the feed lips on one and just behind the indent on the other mag...then tig the opposite pieces together and add tabs with holes to each end, drill and tap a hole splitting the distance in front of the rear mount hole and using the front mount hole to hold the front of the mag...gets a bit complicated to explain but relatively easy to do.

I didn't have much trouble getting 500 AR dummies to feed fairly reliably from a standard 300 Win Savage magazine or a 375 H&H mag, but the Savage is NO DGR by any stretch of the imagination, so I wouldn't use the Savage for anything other than a single shot at this case size anyway.

The size and strength, unique design and ease of conversions make the Savage action amenable to many standard and wildcat conversions, but it is also limited as far as pressure is concerned and has other issues that need to be understood and corrected or lived with...and the design of the bolt also leaves some weak points...you need to be sure to use the small diameter firing pin and bolt head retaining pin with the small hole otherwise that pin will break at the wrong time. I think Savage quietly solved that problem with later model belted mag size calibers, but I have two older magnum bolts with the large diameter pin that needed new small diameter firing pins and bolt pins installed.

If you want a single shot, simple, very useful, fun and cheap to make (relatively speaking) shooter, pick a Savage, order a 32-36", 1.35" OD barrel from PacNor, and he will do the chamber, threads and crown (check online) open up the bolt face and use the Gibbs case and trim the bases to 0.600" OD...CH4D has 1"-14 510 Gibbs dies for $182, and change plus the required adapter for your press for $15 bucks, PT&G will do the reamer for about $150...Great deal for less than $500 bucks.

If you want a mag fed hunting rifle, then go with Robs suggestion and what I would do if I wanted a hunter, or pick another PH style receiver, there are a few very good ones around the $600 range.

I almost went with a 500 AR, it's a nice efficient design and produces very respectable ballistics, then Ed came up with his 499 HE for the NEF 500 S&W, I couldn't get a barrel and so on. I had talked to Jon at McGowen about the 500 AR but they were swamped and getting ready to move so I decided just to do my own thing this time and go with my own case design and have a reamer made.

Sometimes the simplest things get rolled over and turned into Mr. Hyde without hardly any outside help and "stuff" happens all the time.

What you want to do is nothing but a set of problems to solve, one problem at a time, no harder than waking up, making coffee(or not) and dealing with the rest of the day....So GET'R'DONE.

Luck on your quest.

Thanks guys. Lots of good info. Rifle will indeed be single shot. Going to go with the A Square as I already have the WBY brass. Considered the 510 Wells as Quality Cartridge makes brass for it. Settled on the A Square as I seemed to be able to find more load data for it. While builing dummy rounds for my buddies I realized I am going to need a different press. And I thought I had it all figured out!

The beauty of the 500a2 is that you just expand a .460wby to .50 then drop in a full power .500a2 load, load a bullet and go shooting. Out pops perfectly fireformed .500a2cases. Some loads will definately get your full attention too. -Rob

Randy,

I'm fixing to send my 500 A2 reamer to McGowen for a Savage barrel here shortly.

Its a PTG reamer, .511 throat - with enough length for BMG projectiles.

If that suits you, you're welcome to have them make another while they've got it.

Another vote for the mean little bastard AKA 500 AR.

why not the 495 A2?

Fireball, Thanks for the offer but I"m going to build it myself. PTG reamer, Pac-Nor barrel. Already have one buddy called asking about this so I know this is going to lead to more of same. I really appreciate everyone"s input. I only hope it turns out to be as much fun as my 44-06 (30-06 necked up to 44 cal for hogs)!

Randy
You might call McGowen and see if they have barrels on hand .. they might, and that might speed up your order. I have plenty of pacnor, douglas, shilen, ab, and even a shaw barrel .. the first 3 are great, for varous reasons .. i just wish i could make myself "hate" an AB barrel.. if they made .475 and .510, they would be the blaster KINGS