Was just looking at the SSK site and saw a picture of this monster and it reminded me that they made such a beast. Anyways I'm thinkng that unless one was to win the lottery that this was about the only way that anybody would be able to get into anything that size. A couple of things though, does anybody have even a remote idea how much this conversion on a Ruger #1 would be. I've emailed SSK before and their response time was measured in fortnights so I'm reluctant to send one off. Also with the #1's being so popular around here and there being so many big bore fans it's kinda a surprise that no one here has one or at least mentioned it before. I mean how many people here wouldn't want anything like a .600 One last thing, One would have to wonder about the actual shootability of the rifle. I've heard horror stories about .577 conversions and the brutal recoil that they generate. I just don't think that a person could stash enough weight on a #1 to make it tolerable. Although a break would help. Any thoughts on my ramblings?

J.D. recommends a large muzzle brake, (his own design), as well as a countercoil recoil absorption device. They are available in a hydraulic style or spring style. Both are rather unattractive.

I talked with him at great length about this conversion and ended up deciding it was too impractical. Same with the 577 3" Nitro.

The total cost we were bandying about was around $2200. This will vary depending upon the brake, recoil absorber, and sight selection. The sights I wanted jumped the price to around $2500.

The 500 3" Nitro is a great way to go on the #1, IMO. No need for the brake or the recoil absorber; just use a good pad.

Bullet selection is much greater also for the 500. What fun is a rifle if a working stiff cannot afford to shoot it?

Regards,

~Holmes

Too impractical because of cost or the fact that the recoil reduction systems are ungainly? No offense but I've never turned down a gun or project because it was impractical. Thanks for the low down!!!!

I should not have used the word impractical as even a 500 cannot be considered such! There are other cartridges just as effective that are easier to live with.

My goal was to have a British style single shot big bore and appearance was a major part of the attraction.

For my taste, the brake and compensator detracted from the spirit of the project. And shooting a "lightweight" 577 or 600 regularly without such devices was not going to be enjoyable thereby interfering with my play time.

Can't have that, eh?!

Regards,

~Holmes

I found a picture of the recoil reducers that they use and agree that they are not too easy on the eyes. Although I imagine that I could live with it. I've wanted a .600 somethin' for a long time. Appreciate all the info Holmes.

It sounds as if you are hooked on 900 grain gobs of lead, eh?!

Seriously, give J.D. a call. You will find it easier to get him on a voice call than by email.

He truly loves to build the 600s and wishes more shooters would try it. He is VERY opinionated so be prepared!

Everything I have seen out of SSK has been of excellent quality and their build time is less than you might imagine.

I cannot think of a better way to get a 600 without mortgaging one's home.

Do you cast bullets at all? This calibre would be a great way to try your hand at paper patching if that is of interest to you.

Good luck and keep us posted.

~Holmes

Sorry Holmes!
Paper patch and muzzle brakes is a no no!
Henrik

Hello Henrik,

I had not thought of that but I see where it could be a real problem!

Thanks for the heads up.

~Holmes

The .600 JDJ is a .577 NE blown out to .620. That out to be able to crack the 10K ft-lb level. In a
Ruger No.1 that out to exceed the 160 ft-lb of recoil level. That is the point where most folks are seriously unable to control the weopon anymore. With an extremely effective muzzel break and a "hydraulic recoil absorber" I'll bet you will only suffer minor retinal detachment once you wake up! What a recipe for a really first class Flinch. The cracked stock aside, for $2500 you could easily build a real .600NE or .700NE rifle on a Mcmillan .50 BMG repeater action that will weigh about 16 lbs and actually have something thats shootable.-Rob

Rob, your idea has alot of merit and I believe that you are right. While the #1's are great they just are not made to deal with that kind of horsepower in a way that is acceptable to the shooter. I have not looked into the Mcmillan idea but 2500 for just about everything sounds very low. Wouldn't the action alone eat up a good portion of that, not to mention stock, barrel, and any other smithing work that would go into a project like that. I have always thought that a project like that would run upwards of 4k or so. Give me the lowdown if possible. Your the man when it comes to this stuff!!!

Here is the way you could apoach this. First make sure you can legally own an over .50 Rifle in your state. If so, proceed as follows! Mcmillan repeater action $1700 ( cheaper if you can find a used one or $1000 if you use a Mcmillan single shot action. Barrel- Pac-Nor( I'll even give you the right contour) Have them Chamber it for a .600 NE, fit the barrel and install a INTEGRAL muzzel break-$500. Mcmillan Tactical stock- $400 and a shilen trigger( or a good old Rem 700 Trigger. The neat thing about this conversion is that the .600NE has a .810 rim which should fit the McMillan boltface perfectly. Pac-Nor might charge you a little more to machine in a barrel slot to allow the extractor to snap over the rim ,but thats simple mill work and I see no major problems other than getting a .600 NE case to feed properly from the Mcmillan magazine. Figure way under $3000 for everything. Now you have a 3 shot repeater in .600 NE that will easily take the Gaff and weigh much less than 20 lbs. Believe me, this will be shoulder fireable, accurate and reliable. You can do all the fitting and steel bedding yourself. Another good idea is to have Pac-Nor make you a matching .50BMG barrel at the same time and set the thing up as a switch barrel. This seems one heck of a better idea to me than hot rodding a Ruger No.1.-Rob

Hey Rob,

Where did you come up with all these awesome ideas? It sounds like one heck of a rifle for $3000. Man, I need to stop eating lunch for a while to save some cash for this rifle. Cheers! Ming

This route seems much more practical in terms of recoil, and the price is reasonable too. I just saw a Heym 600 Nitro a couple weeks ago, and I think it used a mauser action, but I don't know specifically how they did the fitting. It weighed about 13 pounds and the whole outfit was used for $6700. The BMG action, kind of like Saeed's 700 would be a smart way to go. I had no idea the rim fit so well in the bolt face though. It would be an interesting shop project. The brass isn't cheap, but Beartooth Bullets makes a hard cast bullet for it, and they are very reasonable compared to plinking with woodleighs.
300H&H

Now you guys really got me going! First of all I have to say that IMHO the whole idea of using a .600 or .700NE Rimmed case makes No sense to me. This would only be an interesting experiment in firearms machining as far as I'm concerned. It is not what I would personally do.The reason I say this is that if you look at the price of .600 or .700 NE brass, they cost a fortune. More importantly, they actually have major ignition problems as they use Fed215 primers and you just can't reliably ignite 180 grs of powder with this small primer. Everyone winds up having to use a couple of grains of Bulleseye for ignition which works until the cartridge gets dropped or banged around, then it's hang fire time again. IMHO the most productive thing to do if you want a really big bore is go the .50 BMG action route. The .50 BMG cases are dirt cheap, provide reliable ignition and have been successfully blown out to .600 and .700 calibers. With respect to recoil, if you use slow powders like H50BMG and a 900 gr bullet, with about 250-280 grs ( no I'm not kidding) you can match the ballistics of a .600 or .700NE ( 1900fps) or load faster powders like H4891 and hit 2700-3000 fps ( this will produce big time recoil -14,000 ft-lbs.. When you go to bores this large ,the expansion ratio increases dramatically and you do burn huge amounts of powder. With a good muzzel break these guns are shoulder firable, reliable and controlable. You also don't have to spend a fortune if you know what your doing.-Rob

I'm not sure but are you a little worried about getting a rimmed case to feed right? I'm just wondering this because of your comment about this being an interesting machining expirement. Now I know the Heym's feed ok, so how do they go about getting it right? Any magic tricks in getting rimmed cases to feed?

The issue with a rimmed cartridge is that the Mcmillan action uses a coned barrel shank like a M-70. I'm certain a good machinist cout circumvent this, but a flat barrel shank, and flat locking lug system like a Mauser would be much easier, assuming you just had to have a real .700 NE. I suspect this is exactly what the Heym action has. Personally, I'd go with the .700 Improved on the .50 bmg CASE. RELIABLE AND EASY TO MAKE. I think Dennis olsen as actually made a few of these.-Rob

Robgunbuilder...!

A .700 NE is not good if it dont can handle more than around 180 grains of powder. The velocity will be around 1900-2000 f/s with a 180 grain load. So the .600 NE then can it make 2400 f/s with a 900 grain bullet in a modern bolt action like the HEYM Express rifle...? The .600 or .700 BMG IMPROVED would be very fun to have. But 17 pounds?? isnt that a little to light for a rifle with a caliber that can push a 1000 grain bullet at 3000 f/s ??? And what will the reloading things cost to a .700 BMG IMPROVED??

Have you done any shooting with your .585 NYATI last time?? I think that my big bore will be a .585 NYATI in the future. At what velocity do you think it can push a 900 grain Hawk bullet.( custom made)

Overkill- I have another idea for you. Did you know that 585 Bertram Nyati brass apparantly is identical to rimless .600NE brass? Yes, the basic 3 inch long Bertram brass will take a 900 gr. .620 Diameter bullet beautifully. If you make and then solder on a Belt, you can have a full blown belted .600NE that will headspace on the belt and probably work just fine in a CZ550 Magnum. Just think of this! We can call it the .600 Overkill!-Rob

Robgunbuilder..!

How do you short the .585 Nyati cases down to orginal lenght of a .585 Nyati??

If I ever go over caliber .585 Nyati then it will be a .600 or .700 BMG IMPROVED But the .600 Overkill would also be good if it is possible to have it on a Brno CZ 550 Magnum action.

How will a .700 BMG IMPROVED look like?? like a long target .50 BMG??

OK,

to get the basic bertram .585 Nyatti Brass down to size and to form the small shoulder you run it through a trim & file die, then you proceed to cut the protruding brass from the top of the trim & file die with a sharp hack saw and then file smooth with a bastard file.

Rob, why would you need to solder the rim on for the .600 Overkill ?? it could be left with the gibbs rim and one would still have a tiny bit left on a cz 550 bolt face??

Is there something I am missing??

PC- A .620 bullet in the 585 Nyati case doesn't look like you could make enough shoulder to headspace on. I don't know for sure, but it would be like a .400 Brown -Whelen. It would have the same .640 boltface as the Nyati and take up just a little more mag space. Soldering on a belt would result in a simple way to headspace the cartridge and it should still work in a CZ action. This is a very intriguing idea. It's probably the largest bore you could get to work on a CZ action and IMHO it would in fact be more practical than the NYATI. If it works I believe we could get Bertram or Horneber to make some brass. You could also make a switch -barrel out of your CZ550 or Zkk-602. Now that would be cool! -Rob

[ 07-31-2002, 20:54: Message edited by: Robgunbuilder ]

Rob,

You are onto something, pity it is to late for me my .585 is almost done, could I still have it coverted to a switch barrel later on for this cartridge ??. I assume by belt you meen like the magnum belts that run around the base of 7mm rem mag, .460 weatherby etc.??

I would have built this if I had of known about it !!

What velocity's could we expect from the .600 Overkill ?

Would we leave the Bertram basic Brass at 3.25" as you get it or would we need to trim it to 3" to allow a little more room in the mag??

This might actually be a bigger thumper than the .577 or .585.

Rob, I reckon you should build one and see if it can be done

If down the track Rob this idea seems to work how much work would be involved in getting my .585 Nyatti converted to a switch barrel to fire the .600 Overkill, can it even be done after threading a barrel or is it something that needs to be done at the begining of barrel work ??

Would the feeding need to be altered at all ??

PC-I've got to do the final measurements, but my first thought is to go with the 3.25 inch brass and 900 gr Woodleigh and adjust the length until it will just fit in the magazine. For a switch barrel you will simply need a .620 barrel with the exact same breach to shoulder dimensions as your current barrel , threaded with a 2mm thread and the barrel profiled to be identical to your current barrel so it will fit into the stock without any changes to the bedding. It would then have to be reamed to the .600 Overkill. I've built Switch Barrels before that were so closely machined that all you had to do was screw in the new barrel and load the ammo. Such a set-up with a properly dimensioned barrel needs only to hand tightened to headspace properly. Your gunsmith already has the critical barrel dimensions and with the right reamer could literally knock you out a perfectly fitting barrel without even having your gun present. I'm seriously going to look at this possibility as I agree with you, it could trulysurpass the 585NYATI and T-Rex in power and avoids most of the problems with both of them. I wonder why I didn't think of this before. Just think of this as a scaled-up 458winchester magnum capable of firing 900 gr bullets at 2400fps or more. I'm going to profile this on quick load tonight and see what results I get.-Rob

[ 08-01-2002, 04:54: Message edited by: Robgunbuilder ]

Rob this sounds really interesting and it is something I might look into doing. Is there as much action work required as there is for the .585 Nyatti ??.

I am thinking if I got this rifle built I would like to make it in the African style with 1/4 rib express sights and the whole bit. I would not scope this one.

Would Hornber be able to make this brass for us Rob ??

Rob,

One thing I forgot to mention, I was thinking today and I wondered why the .600 Overkill would need a belt to headspace off, the 45/70 case does not have a belt nor does the .44 rem mag. What am I missing here ??

PC- The 585 NYATI doesn't headspace off the rim like a 45/70 or .44 mag or a .600 NE for that matter. The 585 Nyati brass is in fact slightly rebated at the rim ( .640 Rim and .653 at the case) and headspaces off the shoulder just like a 30-06. When you use the Bertram 585 Cases and go to .620 there is no longer enough dimensional difference between the bullet diameter and the case to support a shoulder. There would be a Ghost shoulder, but this brass is so thin, I would bet that on recoil it would collapse and I would not trust it to headspace on. The .600 NE uses a .800 Rim and as you know getting a rimmed case to feed through a Mauser Action is extremely difficult and requires a very specialized magazine box ala the Siamese Mauser in 45-70 ( I have built one of these and never again). You could do this with a Mcmillan action or perhaps a Heym, but this case would be lost in such a large action. Thus, my idea is based on simply adding a belt to the 585 NYATI BB case. The case will need to be shortened to 3.00 inches and a loaded round with a 900 gr Woodleigh will be exactly 3.600 and will fit lengthwise in the CZ 550 action as it's no longer than a .375 H&H. THe width of the cartridge at the belt will be .681 and is the only dimension I have not yet checked. The NYATI width is .653 and we know that fits No problem. Worst case I believe is that the magazine may have to be ported ala a Remington .338 ultramag. Once a CZ550's action rails have been opened up for a 585 NYATI, they should also work for a .600 Overkill. My goal is to have the .600 Overkill as interchangeable as possible with a gun built for a 585 NYATI. A switch barrel if possible. I ran the case dimensions and powder capacity data on Quick load last night and this data suggests with a 27 inch barrel, that this cartridge with a 900 gr bullet will do 2347 fps with 163 grs of H414 for a Muzzel Energy of nearly 11,000 ft-lbs at about 53,000 PSI. While there is absolutely no reason this thing would not work extremely well in a Ruger #1, the Recoil would be physically dangerous and potentially uncontrollable IMHO. Quick load is very conservative, thus I have no doubt that a realistic 2400 fps is obtainable. This does fall well within the maximal design capabilities of the CZ550. I didn't run the recoil energy numbers, but it will be substantially more than the NYATI. Today I'm going to either turn a brass belt and solder it on to check dimensional toterances or just turn a complete case from brass. I do have some trepidations about firing such a cartridge with a case head that has had a belt soldered on with full power loads due to concerns about the heat annealing the head. However, if this dimensionally works, I'd first just machine up some cases, and de-bug the thing, then get Horneber or Bruce Bertam to make some cases. If this isn't the ultimate you could stuff in a CZ550, I don't know what is.-Rob

Robgunbuilder...!

If the .600 Overkill get 2347 f/s with a barrel lenght of 27" with 163 grain powder. What velocity would be possible to get in a .600 NE with a barrel lenght of 28" and load it with 180 grain powder...???

Overkill- Beats me- I really don't like Rimmed cases. Now you could make a .600 overkill limproved by chambering the CZ550 for a Full length 3.35 inch BELTED NYATI case. The COL would then be about 3.950. This would hold 180 grs of powder, but would be a single shot only as it's way too long for the CZ magazine. A 28 inch barrel sounds good to me. Will you do the honor of firing it first? -Rob

Robgunbuilder...!

I would be if I could be the first to shoot the .600 Overkill but I live so far away from you and I dont have the money to fly over the world to visit you.

Rob this is a project that could realistically work. And you certainly would have a thumper, you do not envisage any problems at all with the strength of the cz action to be able to handle the .600 OK.

Just by the way Rob is the .585 Nyatti with full powered loads detrimental to the 550/602 action or is the .585 well within it's capabilities. I would not like to have a .585 on an M98 action.

Rob if you send a case to me I can ring Bruce from Bertram Brass as he is only 1 1/2 hours from were I live and see if he might be able to make a sample for us of the .600 OK.

Rob do you forsee as many problems with our Horneber brass as far as paper thin around the shoulder and therefore recoil setting the shoulder back in the magazine ??

Rob,

In regards to doing this cartridge on a Ruger #1, would there be a enough metal around the Barrel ??

And if one were to stuff 3 mercury recoil reducers in the stock & make sure they had a 26-28" barrel with a full diamter of 1" at the muzzle, a magnum xxx pad and perhaps a break, would this make it bearable ??

I am thinking with the above features that it should weigh around 12 pounds.

PC- Yes it would actually work quite well in a Ruger Number 1 if you stuck to slow powders like H50BMG or 20N29. Velocities would be around 1800 to 1900 fps and of course you could go slower with XMP5744. It really appears to hit the mark with H414 , IMR4831 or the like. I would still worry about the stock on a Ruger Number 1. By the way I made some cases just to see what problems would occur in the CZ action and posted them for ha ha's.-Rob

[ 08-02-2002, 16:55: Message edited by: PC ]