I've worked my way up to 170 grains of IMR-4350 behind a 900 grain Woodleigh and am only getting 2100 fps. Would really like to get to 2250 fps and the magical 10,000 ft-lbs of energy. Barrel is a 21 inch 9 groove Pac-Nor. Is this a reasonable velocity for this barrel, or do I need a different powder? Of course at 260 ft-lbs of recoil energy I'm not sure how much faster I want to push it.

Also here is a gratuitous picture of it levitating a 55 gallon drum.



And the video:

http://youtu.be/ktQd6iiCNJk

That's awesome. Wouldn't want to have to do any quick follow ups though!

Is that one of Wayne's rifle? What would be a slightly faster powder than IMR 4350?

I don't know how you guy's handle all that recoil. AND you're just wearing a t-shirt... Better man than I!

JDA, at 2,150 fps or less, it's just a big push...not bad at all.

Conversations and videos like this make me feel so inadequate!

quote:

Originally posted by Biebs:
Is that one of Wayne's rifle? What would be a slightly faster powder than IMR 4350?

Nah, I had a local gunsmith put it together for me. Not as nice as one of Wayne's, but a lot cheaper.

As far as the powder goes, I'm hoping someone on here will let me know what might work better. I've also got IMR 4895 on hand, but I'm worried that it might be a little too fast for max loads.

You can get there but that short barrel cuts speed. Start with lower charges of faster powders. I can hit 2200+ from my 20"r with Medium to medium slow powders---Varget-4064 up through 4895-4320 but be carefull on pressure. I also found best to use an over-powder wad on lower density loads to prevent hang fires.

Go here for some good info on how to get where you want to go.

Testing the 600 Overkill

Michael458 and srose did a great deal of testing of my 600OK with various bullets, powders and charges.

quote:

Originally posted by CCMDoc:
Go here for some good info on how to get where you want to go.

Testing the 600 Overkill

Michael458 and srose did a great deal of testing of my 600OK with various bullets, powders and charges.

Boy that was quite the trip down memory lane!

Sure does
Hey Doc, did you ever sell your Overkill? How's your dad & does he still have the 585?

As you know, it is an awesome caliber and Wayne built me a great bolt gun. I traded it to Beibs who then sold it and hopefully it's found a good home.

Pop still has his 585 and we shoot it a bunch of times every year with my nephews. It's amazing how, with some instruction and a little practice they can shoot it (and my 600OK) all day long with the only mark being a smile on their faces.

I have a SS PH action that I hope to someday have someone build another 600OK from.

.620 - my favorite!!!

Try H414 and use a 24 inch drop tube. You at have to recannelure the bullet and load it out more too . That 21 inch barrel kills velocity. With a 26 inch three groove you would be at 2250 now.-Rob

And the Dr is the guy who would know! :-)

quote:

Originally posted by Robgunbuilder:
Try H414 and use a 24 inch drop tube. You at have to recannelure the bullet and load it out more too . That 21 inch barrel kills velocity. With a 26 inch three groove you would be at 2250 now.-Rob

FWIW, I went as high as 180gr/H414 for 2325fps from a 24" barrel. Notes indicate a bit of drag on extraction so 175gr might be max. 170gr produced 2200 from same barrel in 30deg weather.

BL-C(2) was a little better with 170gr=>2280fps and 175gr=>2390fps. The 175gr load also produced a bit of extraction drag and was heavily compressed so 170 might be a better MAX.

Thanks everyone,
Looks like I need to find a new powder. Unfortunately I can't seem to find any for sale.

By the way, if single shot loading does the 600 Overkill have to be crimped? Don't really want to recannelure the bullets, but I don't want hangfires or other problems either.

If single loading no it does not require a crimp.just make sure your not jaming into the lands if you ever have to extract a live round. I have never had a hang fire although I worried about it quite a lot. The 3 groove guns with 26 inch barrels can easily hit 2400fps with H414. When the barrel
Gets shorter and the groove numbers increase so does resistance and you need a lot of barrel to burn a lot of powder. Using a bore rider bullet can give you almost another 100 FPS though. Most guys will shoot even a 2300gps load only once or twice then back down to 2150 or so. Survival instinct kicking in!-Rob

Finally got some H414 and tested some loads at the range today. Unfortunately velocity peaked at 160 grains of powder and I'm still only at 2100 fps. Any ideas? Should I try a faster burning powder like Varget?

4320 or 4064 would be a bit faster

quote:

Originally posted by Biebs:
Is that one of Wayne's rifle? What would be a slightly faster powder than IMR 4350?

These are what I thought was max in my 24" barrel:

145gr H4895 - 2250fps, slight drag on extraction
148gr IMR4064 - 2200fps, powder compression
170gr RL19 - 2100fps, heavy powder compression
140gr H335 - 2050fps, dirty cases (didn't go higher)

I thought H4895 was a bit too quick, perhaps that's why I didn't go higher with H335. RL19 was too slow and I ran out of case capacity. IMR4064 was a bit too bulky but showed promise. IMR4320 might be the cat's meow?

I am worried based on your H414 experience that with a 21 inch barrel you can burn enough of any powder to get 2250fps unless you use a bore rider bullet. You might try faster powders like 4320 and push the pressure as high as you are comfortable or until the cases start to stick, then back off. This cartridge was designed for a 26 inch barrel and it needs all of it to burn enough powder. Most folks run the 2150 Fps loads and are happy though.-Rob

quote:

Originally posted by PWS:
These are what I thought was max in my 24" barrel:

145gr H4895 - 2250fps, slight drag on extraction
148gr IMR4064 - 2200fps, powder compression
170gr RL19 - 2100fps, heavy powder compression
140gr H335 - 2050fps, dirty cases (didn't go higher)

I thought H4895 was a bit too quick, perhaps that's why I didn't go higher with H335. RL19 was too slow and I ran out of case capacity. IMR4064 was a bit too bulky but showed promise. IMR4320 might be the cat's meow?

Kind of funny about the 600 OK running out of case capacity.

If RL-19 will do 2100 fps,
I bet RL-17 would be a nice +2150 fps powder.
It might be more compact and energetic per weight of charge than RL-19.
And it sure worked well in the 12GaFH for me.
Even the 209 shotgun primer ignites it reliably too, no duplexed starter powder required, up to 180 grain charges I tried.
Filler wads used, no case capacity lacking there. Just got too brutal in recoil for me with + 1300-grain slug, even with a muzzle brake on my H&R NEF-er.

There is something special about that RL-17 powder,
the way the deterrent is mixed in throughout the powder, IIRC, not just a coating.
I bet it is relatively "ballistically temperature independent" too ...

hi.my 600 OK from Wayne have a 22" barrel and for top velocity around 2300 fps I've used the IMR 4895 x 145 - 150 max however you better make sure the chamber is cut perfect to allow cases to extract at these velocity which we had to attend to. the N550 gr is perfect for this cartridge and 150 grains will do the trick. I cast 935 gr lead bullets with 20/1 alloy and the best powder is AA 5744 x 50-60 grains without the need of fillers as prescribed by accurate arms. AA 4350 x 145 gr dose mid 1900 with mild recoil & quite pleasant to shoot. a 26" barrel will reach 2400 plus however recoil is beyond safe margin. why y'all trying to hot rod this cartridge? a 900 grain at 1900-2000 fps will do the job extremely well demonstrated by Mark Sullivan in Africa . be safe & shoot well

Originally by the cartridge's creator, (Robgunbuilder)

quote:

...unless you use a bore rider bullet.

Dr Rob again offers sage advise. I'll bet CEB
ends up being your bullet...

quote:

600 OK running out of case capacity

It ain't the capacity per se, but the shape for effiency gains, as load increases.,

IE.... the ratio of the diameter to the length of the powder charge.

If the ratio isn't perfect you can't make it up with too fast

of powders at the same bullet weight..

Like my 585 should be .20" longer to be perfect, the 600 should be .75" longer,

and so on...Ed

Forget the powder.

You need to add four or five more inches of barrel!

With fewer grooves!

Carbines, even in .600 OK, do not equal rifles.

I think you have maxed out on velocity with a short barrel. The .600ok needs a 26 inch barrel with a bore rider bullet to get a true 2400 FPS. Both my guns have 26 inch barrels so I'd be pleased to see 2300 with IMR 4895 with such a short barrel. My guess is the fireball is quite impressive too.