Robgunbuilder...!

I have the load info my self.

The velocity that you say over 3000 f/s with a 1000 grain bullet is with a barrel lenght of 36" Whit a barrel lenght of 26" for more practical use for hunting the velocity is going to be 2865 f/s with a 1000 grain bullet.

So I am sure that the .700 NITRO EXPRESS will have almost the same velocity with a 26" barrel. The .700 NE here on accuratereloading have a barrel lenght of only 23" and it still get over 2400 f/s with a 1000 grainer.

The 50 BMG case is 99 mm long and the .700 NE case is 87 mm long. I think that the .700 NE case is more fat than the .50 BMG

Robgunbuilder....!!!!!!

Does the .700 BMG take more powder than the .700 Nitro Express...?

Please answer this time....

Oh... I am sorry for that Rob. But I am a little DRUNK just now

The problem with the .700 NE is that the case takes standard primers and thus gives unreliable ignition. Thus, you need to add some bullseye powder on top of the primer to ignite the charge. Guess what happens when the case is shaken and the bullseye moves in the case? NO BOOM. This is bad when old MBOGO is after you! Just ask Mark Sullivan who l;earned the same lesson I'm told with his .700 NE double.
The .700 BMG uses standard BMG primers and will go Boom every time. This is good!
The .700 NE is also a rimmed case and a single shot is all you get even on a .50 BMG action. you could have a double made for $60K-70K and have it still not fire reliably.
A .700 IMproved on a repeater action will hold three down and works every time.
Finally,As for barrel length, no way your gonna burn 250-330 grs of powder effectively in a 26 inch barre anywayl. For me a 1000 gr bullet at 2600 fps should be more than enough. Doe this help?-Rob

And not to mention that brass for the 700 Nitro will probably be about as hard as low tensile plastic on a hot day

Mike

Thanks for the info Rob...!

How long does the barrel have to be on a .700 BMG so it can burn 250-330 grain powder..? minimum lenght???

Does Mcmillan have any web site?? please give me the adress...!

I stand corrected!. I Talked to the developer of the .700 BMG IMPROVED last night and he told me that with some faster powders he could indeed hit 2980 fps with a 26 inch barrel plus a clam shell brake with a 1000 gr bullet. He originally started out with a 36 in barrel and then cut it back as his load development proceeded and he moved up to faster powders. Nevertheless, he was burning 330-340 grs to get 2980. I would expect that you really want a 30 inch tube at a minimum for this bore size. I was cautioned, that this combo will dish out all the recoil any human being can stand plus some and I believe it!-Rob

Rob.!

Yeah a 1000 grainer at 2980 f/s will have recoil

A last question about this...! What will the weight be in a .700 BMG IMPROVED rifle with muzzle brake and what will it cost...?

Thanks...

Mcmillan repeater action- $2000, Mcmillan Tactical stock $500, Pac-nor barrel $300, Trigger ,$200, Muzzel Break, $300 , Reamer and guages$ 300. Gunsmithing-probably $700. Custom reloading dies $300, open sights/scope $1000 I'd estimate about a $5000-$6000 gun depending on your additional needs. You will need to cover the reconstructive retinal surgery costs. Weight can be as light as 15 lbs or as heavy as you want.-Rob

[ 07-10-2002, 03:21: Message edited by: Robgunbuilder ]

Another problem for non-US citizens is finding the parts. The barrel and action Rob talkes about requires a export permit from the US State Dept., but after 9/11 they will not approve permits for Title II firearms (like DD) unless they are from a Military or Govn't agency. So Overkill, you'll have to find an European barrel supplier.

It is not so bad.. 40 000-50 000 swedish "kronor" for a rifle in caliber .700 BMG IMPROVED

But I dont know if it is legal in sweden???
I have heard that 20 mm is max diameter on a bullet for hunting. The .700 is 17,7 mm

Rob,

What do you think a .585 NYATI wil cost..? It will maybe be better for me.

Overkill !

Stop dreaming. When they were shooting the .475 A&M Magnum or the .475 LTD they loaded very hot,,to the limit of sanity,,ballistics: 2980 fps with a 500 grain bullet,,or over 3000 fps with the .475 LTD ,and using the dsame bullet. What hits me is that you will be able to hit 2980 fps, doubling the weight of the bullet(1000 gr.)in a 26" barrel. both muzzle blast and the "kick" will convince you.( I just like the tought of seeing you standing there, reaDY to pull the trigger of the .700 Improved, with a 1000 gr. going 2980 fps, and a 15 pound rifle without muzzle break and a steel butt, .It would be a sight to see !
I think the .585 Nyati will do the same thing, with even the same weight using the same lenght of barrel and a 750 grain bullet traveling at 2575 fps, or 2600 fps !Will knock you BIG TIME !
I'd be "happy" with 11.200 fpe,,,19.723 fpe is tooooo BRRRRUUUUTTAAAAL !!!!(, BUT THE SHOOTING RANGE WOULD BE YOURS FOR REST OF THE SEASON)
Or get the early version of the .585 Nyati,,the .475 L.T.D,,FIRING 500 grainers at 3100 fps.The dream rifle is still the .577 T-rex with 750 barnes mono,,going 2715 fps,,and 12.280 fpe !
Overkill,,,With all 'respect',,stop saying ,,"the .577 T-rex is my favorite",,,mean it !,,and don't say ,,"now the .700 Improved is my favorite",,cause when the tech comes up with some new shit,,,f.ex the .900 NE,,YOU PROBABLY would say that's your favorite,,made my point i think. The .700 Improved and 20 x 139mm,have MUCH more POWER but they lack personality, and cannot be used in an hunting application,,and you know as well as me that 10.000,11.000,12.000 fpe will be overkill,,OVERKILL !sO GO GET YOUR NYATI !
i THINK horneber will continue distribute components for the really large bores, so it is relly not impossible to get what you want !
Overkill,,set at a cartridge you wish and think you can handle,,go to the .585 Nyati,,i have yet to try the .460 Wby,,,it will be more than sufficient,,in the right firearm. Nothing is better than a firearm that your confident with and vice verca !

I still like the idea of a .620 rimless.

Take a 50 bmg case, turn the rim down to .640.

Swage the case down to something reasonable that will still leave a shoulder with a .620 bullet seated.

Trim the case back to 2.8 inches.

Run case through forming die, drop in 180 grains of powder, seat 900 grain bullet, and achieve 2300 fps.

Enjoy!

Robgunbuilder, will you build one for me?

Personally- The full length .50 BMG case improved and necked to .620 is my favorite design. I don't like the shortened versions at all as they are too much work and what action are you going to use that will hold more than 1 round and feed reliably? The Mcmillan repeater will hold three .50's down in the mag with a little trimming. This action is Ideal IMHO as it's relatively cheap and if .50's are ever made illegal, you can change the bolt to a .378 WBY boltface and be perfectly OK. The full length .600 BMG shouldl also fit and feed flawlessly in this action. Frankly, a .600 Improved on the full length .50 BMG case burning 280-300 grs of a slow powder like 24N41 or H50BMG will only generate about 2200 fps with a 900 grn bullet. This is only slightly above the .600 NE in power( about 8000 ft/lbs ( same as a 460 WBY and in a properly constructed rifle will be NO PROBLEM at all to shoot. Last time I checked my 460 WBY didn't weigh 15 lbs and I don't consider it's recoil even with full power loads punishing in the least. I'm more afraid of my steel butt .45-70 lever gun! Change powders to H4831 or faster and you can get darn close to 21,000 ft/lbs and undoubtably exceed 3000 fps with a 900 gr bullet according to my calculations with a 26 inch tube.. This should be an incredibly flexible cartridge.
500 grs- I'd love to build one for you and me and for Overkill, but I live in Kalifornia and they won't let me! Wait till I retire and move to a state like Nevada where it's legal.-Rob

[ 07-10-2002, 23:36: Message edited by: Robgunbuilder ]

Per577...!

Yeah I know that a .700 BMG IMPROVED will have a BIG recoil and I dont understand how a muzzle brake can be so effective. A 15 rifle " 7 kg " With a 1000 grains bullet going at 3000 f/s. If the weight is around 40 pounds "20 kg" then it would not have so much recoil, but who is going to have a rifle like that on hunting A .585 NYATI or a .577 TYRANNOSAUR would maybe be better. If A-square start again then I will buy a .577 T-rex if not I will go with the .585 Nyati and with a 28" barrel it will go over 2600 f/s with the Woodleigh 750 grain SP bullet I think. Enough even for me. But a .577 TYRANNOSAUR with a 28" barrel will be my dream I think that it is easy to find a used Brno BBK 02 rifle here in sweden. And then buy cases from Hornebear. I am going to hunt moose with my .460 Wby this autumn and with Hornady 500 grain RN SP at 2600 f/s. And then I will tell you how the effect was. I am going to do a little "STOPPING POWER" test soon. I will put up a 20 l how do you say it in english? you know a "dunk" as we say in sweden. Were you have GAS you know. It will maybe have weight of 50 pounds. when I put sand into. And then I put it up on something and then I shoot. It will be fun to see if it go down fast, or if it go down.

Robgunbuilder...!

How can 280-300 grain powder not give more velocity than 2300 f/s with a 900 grainer??? Then the .600 NE is the same there you can even get 2400 f/s+ I think in the Heym Express rifle. I think that a .700 BMG IMPROVED will kick HARD if the rifle weight is only 15 pounds even with a muzzle brake. What do you think

How much velocity do you think a .577 TYRANNOSAUR can give with a 28" barrel and with a MAX load with vvn-550 powder And what velocity can be possible in the .585 NYATI with a 28" barrel...?

Overkill- the point is that by intentionally using a powder too slow for the case capacity and bullet weight, that you can control velocity down to very managable levels while avoiding the potentially dangerous situation of a large volume case with a squib powder load. you can readily change performance levels by moving up to faster burning powders. thus, you can throttle down to .600 NE performance or up to T-Rex plus plus plus, while still maintaining a nearly full case of powder. It's all about understanding the relationship between powder burn rates, case volumes bullet diameter and pressure. If you ever pull the trigger on a .50BMG with a clam shell brake on it and without one you would instantly understand the incredible effectiveness of these brakes.
I think we have previously covered the whole T-Rex/ NYATII thing. There is not enough difference once you get past the practicallity to matter.
It's just like the difference between a 425 and 500 HP car. Past 400 HP the main difference will be determined by the driver. -Rob

Rob,

I was thinking of building the .620 rimless with an extra deep mag box on a Cz550 or Olympic arms action to fit 3 cartridges down and one in the tube. The gun should weigh 13 pounds and have a 26 inch barrel, no brake. Iron sights only, english walnut stock. I envision 2100 fps with a 900 grain bullet for hunting purposes, and 2400 fps with a 900 grain bullet for "guest shooters".

500 grains- you could reduce the .50 BMG rim easily, but I believe you'd need a hydraulic press to swage the .50BMG case body down. Even then I doubt you could get it reduced enough to feed thru a CZ550's rails ( assuming there would be any left). You'd need a Schuler type single stack mag made to feed and you might also be forced to open up the internal locking lug ring. I think by the time you were done you'd have a very expensive and potentially marginal .600 NYATI equivalent. I thought about this also and the 600 improved would still be my choice.-Rob

OK, so we need the 50 BMG action.

Is it a push feed or controlled feed?

Rob.!

Now I understand better. powders is different one powder burn slow and another fast. And it give different pressures. A calm shell brake is effective. What is a "Calm Shell"...?

Why build a .600 BMG IMPROVED when the .700 BMG IMPROVED have more power. I mean that cartridges at this power around 19 000 foot pounds energy then it is better to build the biggest that is legal for hunting. But sure it is more for fun than for hunting that I will buy a big bore like that.

"clam shell brake" - look at the end of a tank barrel or the end of an artillery piece to see the kind of brake thay have. It is a clam shell.

A .620 rimless have a couple of advantages over a .700.

1. Bullets are more readily available.

2. Bullets are cheaper.

3. Recoil will be less.

4. Penetration will be deeper.

5. Medical bills will be lower.

I hope you'll move to Nevada soon,,robgunbuilder !I hope you could show me some drawings of the .600 Imp & .700 Imp. It really is satisfying to get ot know thru this forum that one could actually own one of this beasts(1000 gr. at 2980 fps from a 26" barrel ,,,jjeeezzees !!).It's really not far behind the original 14,5x114mm, when it comes to energy figures.26.750 joules muzzle energy from the .700 Imp,,,and 31.700 joules from the 14,5mm Russian.I think one could achieve much more power from the Russian round if one blew that round out to accept even bigger diameter bullets, and experimenting with powders.

Do you think the brass is of high quality, the .700 IMP ?
What velocity is possible in the .700 Imp using 1200 grain bullets and 26 inch barrel, where caan one get these 1200 gr. bu�llets ?

The .700 BMG IMPROVED have couple of advantages over the .600

1. Penetration will be better with a 1200 grainer.

2. It will have more power.

3. It will kill any game better.

Per577 and Robgunbuilder...!

A 1200 grain bullet will have a much better penetration than the 1000 grainer if it is a soft point. But I dont think any one make 1200 grain bullets...

Waht is a .700 JDJ...?

500 grains- The Mcmillan is a push feed with a big Sako extractor on it. The .50 BMG brass is tremendously strong and very very cheap compared with anything else.-Rob

Robgunbuilder.!

What velocity does the .700 JDJ get...? And is it easy to find cases to it?

I really don't know much about the 700 JDJ. I hope it's not one of those blown out and shortned 505 Gibbs things JDJones was fooling with.
I should point out that it's not trivial to blow out any of these cases. Once you loose the original shoulder, you either need to design in a sub shoulder ( which I have done successfully a few times) or figure out some type of initial headspacing on the case mouth etc. People have also loaded bullets out till they jam in the lands, but this has always seemed incredibly dangerous to me. I try and stay away from proprietary cases as much as possible because of all the standardization issues. This is another reason why the .50 BMG case is so attractive. Why mess with success! The 585 NYATI is a case in point.-Rob

Overkill,

Any game that survives the 1000 grain .700 loading deserves to live. Don't shoot it with the 1200 grain load.

Overkill,,,i have said it before. The .700 JDJ is a shortened 50 BMG to dish out 1200 gr. 2300+fps and 14.000 fpe !
Of course the .700 Imp with 1000 gr. to 2980 fps from a 26 " barrel sounds more interesting, to say at least. 6000 ��,,,i really have to stop use my money on CD's !!!!!