I have been wanting a 50 bolt rifle for some time, and have decided to go ahead with a 500 AS, as opposed to a 500 j or Gibbs, going on the advice of several of the posters here ,that on a CZ ,it is the easiest and least expensive route to go on .There is a few questions , and some advice i need before i get started ,thanks .1.Which is preferable a BRNO 602 or a CZ550 ? 2.Where and how large is a barrel mounted recoil lug ? 3.How do you bed the barrel with a recoil lug on it ? 4.How do you fireform 460 w cases to 500 AS ? 5.Which are good reloading dies ? are there 7/8 dies ? 6.What is the performance of a 500 AS on game ?as compared to the 500 j and Gibbs ? is there any noticeable difference or not ? 7.How does it compare to a 577 NE on big game ? 8.Is a muzzle brake a good idea ? and is there a brand which is removeable ? Thanks for any advice cheers

I can't help you with anything really, but you'll have to let us know how you like it when it's finished (i've wanted a 500 A2 for a while, but it is one of those things I really don't need or can afford right now. I don't even know if I could tollerate the recoil on one yet).
I haven't heard of it's killing power vs the other 500's, but I have heard it has a noticable difference over the .458 calibers

Do a search while you're waiting for replies. Go to the top of the page, click on "Find", type in 500 A Square. It'll give you some info.

1.Which is preferable a BRNO 602 or a CZ550 ? CZ 550 unless you prefer a backwards acting safety. 2.Where and how large is a barrel mounted recoil lug ? At least a 1/4" thick and the width of the barrel ~ 6" forward of the front of the the receiver recoil lug. 3.How do you bed the barrel with a recoil lug on it ? It should be bedded just like the receiver recoil lug. 4.How do you fireform 460 w cases to 500 AS ? Neck the cases to .475" and then 0.50" at this point anneal the case necks. Then run them through your 500 A Square full length sizing die. Fire them in the rifle with ~ 50ksi pressure loads and you will be more than fine. 5.Which are good reloading dies ? CH4d makes the most economical dies, but they are 1"X14 tpi. RCBS makes 7/8"X14 tpi for almost twice the price. are there 7/8 dies ? 6.What is the performance of a 500 AS on game ?as compared to the 500 j and Gibbs ? Loaded to the same pressure the Jeffery and the Gibbs provide a ballistic advantage. That said, if you load the A Square to 55 ksi it works very well, if not quite as impressively as the Jeffery and Gibbs when loaded to that pressure level. is there any noticeable difference or not ? Depends upon how you load it. Equal pressure the Jeffery and Gibbs have an advantage, but you most likely will not notice it. 7.How does it compare to a 577 NE on big game ? All the fast 50's when loaded with 570gr bullets to about 2300 fps are the magazine rifle equivalents of the 577NE 3" 750gr. 8.Is a muzzle brake a good idea ? and is there a brand which is removeable ? If loading the 500 A Square to better than a 570gr pill @ 2250 fps you may very well want to look into a good muzzle brake (Vias comes highly recommended). Thanks for any advice cheers

Good luck with your project.

I've picked up a CZ 550 in 416Rigby with the intention of also converting later on to 500A2. 'Smith straight out said he'd prefer the 550 to a 602 (I have both) as its less metal work seeing as the 550 is in 416Rigby. My CZ is the "American" model so I've saved a bit on the dual crossbolts and a stock that fits better than the hogsbacks style.
Cheers...
Con

You should e-mail Dudley Rogers at Tshabezi Safaris. He has used a 500 A.S. extensively now for several years. He is very enthusiastic about it as a PH's rifle. It is definitely more than is needed by a sport hunter tho. Make no mistake that a 500 A.S. is going to cause an emotional response when you light it off.

Checking the penetration of the 500 A-Square using 570 grain Woodleigh softs at pointblank range in soaking wet newspaper, got about 9-inches of penetation, 100% bullet expansion flat as a pancake, and complete confetti. With Woodleigh solids got about 4 1/2 feet of penetration in the same media.

Same bullets from a 500 Nitro Express at 2,150 fps (350 fps slower than A-Square) penetration of the softs increased to 24 inches with good expansion and weight retention. Solids penetrated 4 feet but had noticeably smaller diameter wound hole than the 500 A-Square.

Like them both, but would hesitate using softs in the A-Square on dangerous game.

Now I have to trot out some old pictures again to defend 500 A2 penetration.

Do not use Woodleigh softs nor those obsolete round nose FMJ solids!!! It is all in the proper bullet:

Best: GSC FN solid and HV soft.
Barnes only if you can't get the GSC bullets in time for your hunt.

Woodleigh softs are indeed just "punkin balls" when it comes to 500 A2 velocity.

Use a tough soft and it will hold up to any buffalo, and end up under the hide on the off side. I used the Barnes XLC .510/570-gr because I did not have any GSC HV's loaded at the time. Both the XLC and the GSC FN 570-grainers impacted this bison at about 2400 fps.

The FN's were not recovered, they zipped through from rump to throat and kept going, about 8 feet of penetration. One while the bison was still standing after the first XLC in the ribs. The other as a test after he was dead. It passed completely through from rump and out the neck also.

A second XLC was fired broadside into the dead bison at point blank range, and it expanded more, but still stayed under the off side hide of the chest.

It was iron sight shooting, and I missed the heart with the first XLC. It did knock the bison down, bowled him over, but he got up immediately and ran. The magazine was full of GSC FN's for followup of the single soft. The second shot, a GSC FN, went higher than the heart also, Texas-style, but that GSC FN dropped the 1830 pound bison (dead weight after bleed-out) dead in his tracks. He moved no more.

BTW, this was from my 10" twist McGowen stainless .510 caliber 23" barrel that is .850" at the muzzle, and a straight taper from a 3" parallel sided Knoxform, similar to the GS Custom Barrel Profile for the .395 barrels.

Anyone building a 500 A2 would do well to use a 10" or at slowest a 12" twist.

If the petals of a GSC FN could be made to blow off with even more velocity, then the "soft" bullet might exit.

Ron,

Those Barnes X bullets don't expand too much do they! How many buffalo/bison have you shot with Woodleigh 570gr SN and 600gr PPSP?

Hammer,

570 gr Woodleigh Softs loaded to 2440 fps went better than 18" in buffalo for me, and those where head shots (so the bullets went through several inches of bone too). I think you newspaper testing is BOGUS. Heck they go through 12+" of Osage orange too. Granted the bullets from the buffs were rather mangled, but they certainly got the job done.

The GSC FN .510/570-grainer at 500 A2 velocity (2450 to 2550 fps MV) is a most impressive penetrator, and the most experienced of elephant hunters cannot deny that, surely. That is what I would use for Texas Heart Shots on elephant. Maybe even Texas Brain Shots on elephant ...

My 500 A-Square barrel is a 10-inch twist, 26-inch long McGowen.

The Woodleighs are what my 500 NE are regulated for and happen to have them available for all my fifties. Know that I would want something tougher for the A-Square, but the Woodleighs work alright in the NE on cape buffalo.

The best media for testing bullets is a great subject for debate around a campfire. Bob Hagel used a 50/50 mix of sawdust and silt damp to the touch. Others have used stacks of pine boards. Wet or dry newspaper is recommended by others. Then there is Corbin's SIM-TEST and the Bullet Test Tube material as well as 10% ballistic gelatin. Speer used wet lap, maybe because they were across the street from a Potlatch Paper mill. I haven't reached a conclusion whether one material is great and another is totally bogus. Have seen hundreds of tests. Still sorting through it all.

CH4D DOES make a 7/8-14 500A2 die set, I got mine from Dave about two months ago....

You don't Texas heart shoot an ELE. It doesn't work! You try and break the thigh bones. ELE don't go far on three legs. A 500 a2 would be a good choice for that shot. By the waY ITS REALLY HARD TO DO. ELE going away move pretty damn fast.-Rob

And all this time I thought you were supposed to bust up the ball and socket of the iliofemoral hip joint, or hit the lumbering lumbar spine with the old root-of-tail shot.

I much prefer the foramen magnum shot for a departing elephant if at all possible.

quote:

I much prefer the foramen magnum shot for a departing elephant if at all possible.

You made me learn something....did not know what the foramen magnum was, so had to look it up.

Canuck

Gotta tell someone....

That beautiful brown truck dropped off my 500 A-2, .538 neck BMG throated PTG reamer today!!!!

My friend executed a classic Texas Heart shot on a departing ele with me two years ago with a .375 H&H. Unfortunately,for us it didn't work. Chased the ELE nearly 2 miles. Only caught up with it by running. We both shoot pretty badly totally winded! The lesson learned, no more Texas Heart shots on departing ELE and USE A BIGGER GUN with a 1:15 twist.-Rob

uh oh, somebody said the twist word

I've got the barrel in the vise and the ol pipe wrench clamped on real tight! The cleaning rod has a real tight patch on it( I drew me a 1turn in 10 inches MAGIC MARKER LINE on it SO'S I can line er up real good like and if I BEAT on it with my sledge real smart, I'm gonna get me a 1:10 twister fer sure!Wow, Had to Hammer the cleaning Rod into the muzzel to line up MY MARKER! WACK/WACK- Damn the sights are crooked now!! Maybe a reverse gain twist is EVEN BETTER!! WACK! WOW I'm fer sure onto something!!!! Sights are DEAD ON NOW!! Now if I butt shoot a ELE I'll get some GOOOOD Penetration. -Rob

Damn- My 1:10 to 10:1 Reverse gain twister shoots real good and penetrates ELE Butt like mad! You-all send me your guns PRONTO. I GOTS THE SYSTEM WORKED OUT fer SURE. I'm selling all my other guns.-Rob

Robert,

Seems to work if you start out with a 1:15 twist but does it work if you start with a 1:12?

When you can confirm that you can make it work for the 1:12 twist I may send you one of mine.

I can now go both ways, You just WACK the pipe wrench hard when you standing on the left for a 1:15 or 1:12 ( you adjust your WACKER accordingly) till you can follow the 1:10 Magic marker line. The trick is them pesky 1:6- 1:9 twist barrels you Ele Butt shooters like so much. You gots to stand on the right side and Adjust your Wacker in this case. Then you just clamp down HARD on the barrel band and WACK away till she eyeballs straight.Oh yes I gotta remember to heat the barrel now with a OXY/ACETYLENE torch till it glows bright ORANGE Then WACK Gently! Looks kinda wierd when you look down the hole in the barrel, but ELE BETTER watch out! YOU GET SUPER PENETRATION!15-16 ft on average!
SEND ME YOUR GUNS! -Rob

Glad to hear you have figured out the process for all the higher twist rates. There is still one thing keeping me from shipping my rifles to you for adjustment, and that is the added pressure and recoil the faster twist will undoubtedly induce. I just cannot decide the the added phenomenal penetration is worth the load development work and potentially greater recoil. I know I am a wimp.

For an Added FEE and SUBSTANTIAL delays I OFFERS to Drill HOLES in the barrel band to reduce pressures( thus compensating for your increased pressure loads), increase NOISE and maybe reduce RECOIL. SOME call this a Muzzel break! Your Penetration will be unsurpassed! SOME consider my three step program( send me guns, send me money, wait a long time) VIAGRA for GUNS! I ship UPS TOO!
SEND ME YOUR GUNS! Art ALPIN DOES! Oh NO! Maybe hes just trying to STEAL My SECRETS!-Rob

quote:

SOME consider my three step program( send me guns, send me money, wait a long time)

OK...that part did tickle my funny bone.

I was thinking it might be a little early in the day for though Rob.

Cheers,
Canuck

I'm opening my new store VFG( Viagra for Guns) Gunsmithing here in Las Vegas. My prices are HIGH, my Delivery schedule is Questionable, and I GUARANTEE NOTHING! Come visit us at our SCI Booth next to A-Square's next February! Expect to see our VFG TV commercials shortly! They will run day and night! The ads will feature BIG ELE BUTT Penetrators and a toll free number where you can send us your credit card numbers, birth date, SSN and Bank codes!
SEND ME YOUR GUNS

quote:

Originally posted by Robgunbuilder:
My prices are HIGH, my Delivery schedule is Questionable, and I GUARANTEE NOTHING!

And you'll still be one of the better gunsmiths!

The effects of

BORE-ENVY and TWISTOPHOBIA

will no doubt take their toll.

Rob,
If you don't stop doing that you'll go blind!!!!

RIP,
Rob has bore envy????????

Or is it you who have the bore envy?

RIP/SCott- SEND ME YOUR GUNS. I take Visa, American Express, Mastercard, CASH IS ALWAYS WELCOME if not PREFERRED. In fact, we take any form of money with both hands. While your waiting (and you'll be waiting a long time) I will work my magic on your guns. You will PRAISE MY WORK and come to finally understand what TRUE CRAFTSMANSHIP really MEANS. ART ALPIN DOES! The 1:10 to 10:1 reverse gain twister will become your weapon of choice assuming the following:
1. You can shoot straight
2. You actually are allowed to own guns
3. It doesn't blow-up ( I don't Test Fire)
Given the above I'm convinced this technological advance over all current twists will provide you with unsurpassed bragging rights at your local rifle range. ART ALPIN Endorses my PRODUCT! Should you ever actually hunt something, these weapons in an emergency also make a very good club as I in turn endorse A- Square style stocks too ( to lessen felt recoil)! In conclusion,
SEND ME YOUR GUNS and please visit my booth ( # 666) at SCI.-Rob

I hope anyone building a 500a2 and wanting to use 700-to-750-grainers will select a 10" or 12" twist to start with and have no regrets. Poor Rob has gone mad from his slow-twist melancholy!
He is delusional, grandiose, loose-associating ... the descent into schizoaffective-twistomania can be a hellish thing. Hopefully the men in white coats will be arriving soon, for his own good and the public's good, before he gets anyone else's rifle barrel in a vice! What a shambles he must have made of his own barrels with these latest "experiments!"

Rob,

As stated earlier I am a wimp and will remain with my 1:12 twist barrels for for 0.510 bores.

Ron,
When will you finally go hunting with me so we can see if the 1:10 or 1:12 twist is the better penetrator in the 500^2? My latest 500A^2 is just like your's ie. 23" barrel.

Tankhunter, I apologize for the thread hi-jacking, but I believe I have answered your questions (if no one else has).

Thankyou for the info ScottS and Fireball 168 that will help me alot towards my project

Hopefully this thread has emphasized the need for faster than 1:15" twist on the slower-than-a-50BMG 500a2.

It is really not such a difficult concept, really no need for a psychotic break over this. Just do it right the first time. Turning down a surplus 50BMG barrel is really not the way to go, unless you are building a 50BMG.

RIP- I was just having some fun ( spoofing you) with your mindless mewlings over the 1:10 twist. You already know what I think of that. I truly did enjoy myself and given the amount of PM's I've received, seems like a whole lot of folks on this site got a good laugh out of it too. You have to admit it was funny! Don't get your panties in an uproar. NO ONE CARES! -Rob

Rob,
I'd go commando rather than wear panties, any day. No knots here, all in good fun.

Maybe 12" is the best "minimum twist" for a 500a2, for 1000 yard accuracy with 750-grain A-Max bullets, but 10" is more than enough and that ain't a bad thing for any 500a2 hunting rifle.

Here is a lovely 1:10" twist stainless .510 barrel from Harry McGowen, waiting to be chambered as a 500 Mbogo:


Thanks for allowing me to emphasize this, again.

I'd give the new owners of McGowen Rifle Barrels, in Kalispell Montana, a while to get geared up before swamping them with orders for 10" or 12" twist barrels, but other makers are available, who make faster twists than 1:15".

Maybe the new owners will have a web site soon. 78 year-old Harry McGowen never did jump on the internet band wagon.

He created a new caliber for a faithful customer before he passed the torch: .395 with 12" twist

Please don't swamp the new makers with .395 barrel orders either.

A 750-grainer from a 50BMG at 2750 fps gives 2200 rps in a 15" twist barrel.

The same bullet from a 500a2 at 2200 fps gives 2200 rps in a 12" twist barrel.



2200 fps is asking a bit much for a 500a2 with a 23" barrel, hence I chose a faster twist: 10"

Faster twist is not detrimental in any way for the shorter DG hunting bullets at close range.

The .510 Whisper pushing the 750-grain A-Max at 1050 fps would require a twist of 5.73" to get rps up to 2200.

1 in 5.73" twist? What the hell were they thinking???

Even I would consider anything faster than 1:7.5" twist for a .510 caliber rifle to be highly "experimental."

Am I missing something here regarding the .510 Whisper?
Is the twist requirement for a subsonic velocity different than for a supersonic velocity?

Maybe loading the 750-grain A-Max in a .510 Whisper is just an advertising gimmick and it is really supposed to shoot only round lead balls of .510 caliber?

Please no PM's on this subject to me. I get enough seriously interested PM's on how to properly build a 500 A-Square already.

Only cowards guffaw at fast twist by PM's.

Please get it out in the open if you must guffaw.