Greetings - I would like to convert a CZ550 in 416 Rigby to 500 A-Square; I hope to keep this a fairly low budget rebuild, nothing fancy - initially, the rifle will have iron sights, later may add a scope - I have no gunsmithing skills or tools so my thought is to send the action to someone to rechamber / rebarrel to 500A2 -- any suggestions on this project would be appreciated -KMule

The conversion is relatively straight foreward, and Pac-Nor probably has the most experience. Ive done this exact conversion myself, however since you say you have no gunsmithing experience, here is what I suggest you should do. First send Pac-Nor your gun. Have them fit a #7 contour barrel, chamber it for 500A2 and make darn sure you have them machine in a muzzel break. If you go Stainless steel have it bead blasted, and if you go Chrome-moly then add $100 for blueing. Figure this will cost $500. Without a break believe me you are not going to ENJOY a 500A2. You then need to order a Express stock from Mcmillan to fit the CZ550 and have it inletted for the #7 contour barrel. Figure $350. You could make the original CZ stock work for awhile, but it will split with full power loads. Now you need a good gunsmith. He needs to slightly open up the rails, modify the feedramp, fit open sights( NECG fronts and rears are nice), install a second recoil lug( don't even think about a 500A2 without one), double crossbolt your stock and glassbed the whole thing. Figure another $400-500. There you have it. This is the stripped down version. You can spend more if you want a fancy stock. Figure on spending about $1500 and waiting and waiting and waiting.-Rob

Rob,
you said it all. I would suggest a lam stock, from
www.rifle-stocks.com if our chap is at all handy. You'll need to add checkering if you go this way.

let me sugegst 470 mbogo if you are going to start with a rigby...

jeffe

Rob and Jeffe - thanks for the response - I have been following various threads on the A2 and your advice is right on the money - I am considering a 25" barrel with a 3" removable brake and a finished weight of approximately 13-14 lbs - in your experience, does this barrel / weight combination seem ok? I currently shoot a 450 Ackley at 11.5 lbs and it is a sweetheart - the gunsmith I've chosen is Dave at Chimo Guns in Wasilla, Alaska; Dave has built many big bores and does superb work, a very straight forward practical guy - and yes, Chris @ Pac-Nor will be the barrel maker as his barrels seem to appear quite often here in Alaska - thanks for all your help - KMule

A finished weight of 13 or 14 lbs, you say? Loaded up and slinged you're talking some 14 to 15lbs, or so. Is this to be a hunting rifle or primarily for bench shooting?

KMuleinAK,
I have a gun very similar to what Rob is describing. A good recipe. It weighs 10#10oz empty, with a 23" barrel and thread protector on the muzzle. The muzzle is 0.875". Add ammo and it is close to 11#. Add to this the rings, 2.5X Leupold, sling, and it weighs about 12.5#. Add Muzzle brake to this and it weighs about 13 pounds and overall barrel length is close to 26". The chunky muzzle brake is for 750 grain target bullet shooting. You can go "lightly" into the bush or heavy to the range with the same rifle.

Nickudu, how much does your big stick 505 Gibbs weigh when you go lightly with it?

I'm just curious, how many rounds can be held in the magazine box of the CZ?

Nickudu - you bring up a good point and the honest answer is that I will bench shoot first and then hunt (moose,bear) - I assumed increased weight would be a good idea in this caliber although I have not actually pulled the trigger on a 500A2 - the charts indicate it will bark some on both ends and I needed some real world feedback - you are correct in that a 14-15 lb. hunting rifle is heavy, as I am just starting down this path I appreciate your questioning the use of the rifle - DaggaRon - your rifle at 23" and then a brake reads more like what I would like, since I have been using a 11.5 lb. 450 Ackley and it carries well for me - again, my concern is the felt recoil increase moving up to the 500A2 - I bench shoot the 450 regularly with no problems and it absolutely hits moose like a Greyhound bus - I will ponder the weight question so more - The Cool Guy - three rounds in the magazine and one in the chamber; I believe that the same capacity is available once chambered to the 500A2 - thanks again for the feedback - KMule

Kmule,
email me

fsrfr@uaf.edu

I forgot to tell you to have it throated for a 650gr .50 BMG bullet. this is lots of fun in this caliber and the throating doesn't seem to effect the accuracy with 570 gr woodleighs. As if you could tell! This makes for cheap practice and will empress everyone at your local range. I prefer longer barrels in the 500A2 and think 26 inches or more would be about right. This thing burns alot of powder and needs the barrel length. The weight increase also helps alot.-rob

Yep,
Special throating works well. I started with a Ruger No. 1 and the standard 500 A2 reamer plus a throating reamer from Dave Manson. That barrel is 27" plus muzzle brake, so almost 30". The muzzle diameter is 1.000".

The second gun (on a BRNO ZKK 602, described above somewhat) was cut with a custom reamer with an integral throat for the 700 grain AP bullet for target work. Reamer by Dave Manson. This is the "510 JAB" which has only 0.300" total throat.

Even the Ruger 500 A2 with "add on throat" of .588" total throat, freebore plus leade, to seat the Hornady A-Max out to 4.76" COL is capable of good accuracy with shorter bullets, as Rob says. It can put 3 Harlow 705 grain match semi-bore riders into 0.190" at 100 yards, IIRC.

Of course you got to have a good smith to chamber the rifle. Concentricity runouts in millionths of an inch?

[ 07-16-2002, 06:26: Message edited by: DaggaRon ]

McMillan told me that they would not inlett their Express stock to a barrel profile larger than a number 5. This means somebody else will have to do this if desired but I probably would not take a chance to get a thinner and weaker stock. McMillan also told me to use their Target model stock called Baker Special because it can accomdate a barrel profile up to a number 8. Unfortunately, this stock has an adjustable cheek piece built into so it does not look much like a typical hunting stock. Is it weird to use this stock? Any opinion? Thanks. Ming

I am satisfied with the standard McMillan Express stock with barrel channel enlarged and reinforced with glass bedding and hidden cross bolts.

[QUOTE]Originally posted by KMuleinAK:
Hi KMuleinAK,
As mentioned before the weight of your rifle is really something you will have to take into consideration. My 500 A-Square is on a Bruno 602 with a 23 inch Pac-Nor barrel and open sights only. It weighs in at 10.5 pounds and will produce just over 2400 fps with a 600 grain bullet. This combo will do anything you could want and will dish out enough recoil that you'll remember what you did. Here are a couple of pictures of the 500.





Take care,
470 Mbogo

[ 07-16-2002, 10:41: Message edited by: 470 Mbogo ]

Mcmillan will inlet the express stock for the #7 contour Pac-Nor barrel. The problem is making sure that whatever stock you get, that it will take the CZ-550 action. You will still need crossbolts and a second recoil lug. Don't leave home without one! Guns in this power class will split their stocks in a hurry without proper reinforcement.
470 MBOGO- I'm going to shoot my 470- this weekend. The stock is a left hander because I'm left eye dominant. However, I can cycle a bolt pretty damn fast with my right hand.-Rob

Hello everyone !
When the heck are we going to see some load data on the .470 Mbogo, hope this cartridge safely will manage those "famous" 8000 fpe !
I hope also someone will give me reloading tips with the .500 A2(with a 26 inch barrel, will this cartridge do 2600+ fps with the 570 grain woodl. solids ?) Hope someone endures these kind of questions.

11 or 12 lbs, without a break, would be shootable... and 12-13 borders on what a strong fella CAN carry all day, and be able to shoot. 13lbs is 500 ne, light 577 double weights.

I can tell you that 11 is tough to carry, all day, without a sling, and 13.75 is even harder, but it can be done.

jeffe