Home Forums Reloading Big Game Rifles IF the 30'06 was a 53K or 54K CUP ctg.

So subject to the big what if.
And knowing that the 50,000CUP standard is in respect to the 1895 Winchester.
What do you figure the actual velocities for the 30'06 would look like if, ran into the 53,000CUP relm, just like the 25'06 or 270Win.
24" bbl.

The old ballistic rule of thumb (which works pretty precisely with single-base powders, not quite so well with double-base) is that velocity increases at half the rate of pressure. So:

If we increase the pressure to 54,000 over 50,000, that's an increase in pressure of 8%.

If the muzzle velocity of a 180-grain bullet at 50,000 is 2700 fps, at 54,000 it will be 2808, an increase of 4%.

Funny thing CUP, The 06 at 50K CUP is rated at 60K psi ANSI, the same as the 308 which is 52K CUP rated.
The 53Kcup of the 25-06 is 63K psi and the 270 is actually 52K CUP but 65K psi......Hmmmm

PSI and CUP are not directly relatable.
You cant just plug in a conversion factor to convert from one to another.
PSI changes from caliber to caliber, even if the original CUP was the same.
Do a goggle search on this subject, I'd post a link but these danged filtered servers at work......

You can however plot one vs. the other for a variety of cartridges and do a linear regression on the data cloud to get an approximate relationship. Check Denton's posts, I believe he has done this.

Understood.
I was only trying to point out the that CUP of the cartridges he listed are not related linearly in PSI.
The 308 and 270 as example have the same CUP value, 52K CUP, but different PSI piezo rateings, 60K and 65K respectively. The 25-06 and 270 don`t equal out either in any apple to apple comparision. Loading to the CUP value of another cartridge may not change anything, or may change it in an unexpected direction
Probably didn`t express myself to well, sorry.........

MD's right on with pressure tested data I have on the 06. 2800 with IMR 4831, RE 19, RE 22, etc gives just about exactly 63-64,000 psi in a 24" barrel.

I've seen folks claim more - fast barrel technology <g>

As an FYI, a 200 gr can go 2675-2700 in an 06 at 63-64,000 psi as well.

I don't rely on what "published specs" tell me.. I rely on what my brass and rifle tell me... they are the ones using the load...

remember, SAAMI specs are lawyer specs....

on the other hand, handloaders have the option of loading their ammo for the game and the environment that they are going to hunt in... which many times doesn't need to be the max potential of a cartridge....

and many guys will give you a lame excuse to explain why they need a 500 yd load to hunt in an environment that they are going to take a deer within 100 yds tops...

if they are happy with it, so be it... but I taylor my loads to where we are hunting and what we are hunting...

Nice theory on selecting loads to game and conditions to be hunted, but that is not my querry.

I'm looking for information on what the increase in pressure will net.

The nuances of game rifles and load selection are not lost nor new to me.

I am working on something I can take and cite as almost sceintifically credable, therefore thanks for the input, but....................

I know where this is going........"If I could just load my 06/280 to 270W pressures--I would have a 270!...Also known as a 30-06 Improved

Ok, I couldn't help myself on that one.....

You could always do what my buddy who belongs to the cult of RL-22 does--pour large volumes of RL-22 into his 06 cases and produce 300WM velocites from 24-26 inch bbls......

...of course, his cases are toast after 2-3 firings....


Casey

I have a copy of "A Handloader's Odyssey" by Stan Watson, copyright 1999, wherein he did precisely that - take the .30-06 up to higher pressure levels to see what it would do. Stan used an Oehler System 43 and two .30-06 rifles, a Model 700 and a Model 70. Some folks here will remember him, he used to post as OKShooter.

Just as some examples (I'm not giving the charge weights):

150 grain Sierra at 63,800 psi gave 3133 fps with RL-15, 24" M70.
150 grain Sierra at 58,700 psi gave 3055 fps with H380, 24" M70

165 grain Hornady BTSP at 65,900 psi gave 3015 fps with IMR-4350, 24" barrel M70.
165 grain Hornady BTSP at 66,400 psi gave 2983 fps with IMR-4350 in a 22" M700.

180 grain Rem. PSPCL at 66,000 psi gave 2954 fps with H-4350, 24" M70
Same bullet at 61,900 psi gave 2872 fps, H-4350, same rifle.
Same bullet in a 22" M700 using RL-19 gave 2707 fps at 60,400 psi.

Hope that helps.

Now, just for the usual caution - I wouldn't go anywhere near those velocities unless I had an Oehler 43 myself. 3133 fps with a 150 grain bullet and 2954 with a 180 is flat out cookin'!. Stan was a ballistics consultant for the military for many years and knew what he was doing. I'd bet there's not one in a thousand handloaders who could really tell you with any precision (even within 5,000 fps) what their loads are really doing in their particular rifle with their component lots.

But this does give one some comfort to know that if you stay at 2950 fps with a 150 or 2850 with a 165 grainer, using suitable powders of course, you are very likely in safe territory. And everybody repeat after me, "and the animal will never know the difference!"

You can believe the lawyer spec BS if you want to. Watch a gun blow up sometime and get back to me on lawyer specs. I guarantee you'll be much more conservative after watching one blow up from close range.............

BTW: The numbers I quoted were from an individual using an Oehler and pressure testing equipment. He ran pressures up to 70,000 psi.

+1

I wish folks would run a ballistic program when developing loads to see what getting that last 50 ft/sec actually buys them. Using "normal" hunting bullets (BC 0.400 and above) amounts to a couple inches at 500 yards. I load all my rifles close to max levels but usually leave a few ft/sec on the table because I want to know I'm in the safe zone. If I want a magnum, I'll buy a magnum - and have.

Wasn`t the question answered by MD? 4% increase in velocity?

Like mentioned above CUP and PSI don't really translate the same. The 30-06 is SAAMI 60K psi. Since the .270 and 25-06 can be run at 65K, in a modern gun, it's reasonable to assume the 30-06 could be safely run at 65K. In looking at some QL data for my .280 I see that a 150 TSX over H4831 hits 2943fps at 59259psi. It hits 3008fps at 63516psi, and 3072fps at 68153psi. (24" bbl)

With a 160 and R-22 it hits 2953fps at 61533psi, and 3013fps at 66006psi.

The pressure curve will depend on the bullet wt and powder burn rate of course. I would suggest that running a 30-06 at 65Kpsi would result in 70-100fps increase in velocity with slower powders (H4350 and slower). You'd probably get the higher increase with the 150s and 165s.

Generally speaking, with my .280 QL data, it seems that a 55-60fps increase in velocity is good for 4.5-5Kpsi increase in pressure. That's with 140s, and 150s and powders such as N550, H4831, R-22, and the like.

FWIW, YMMV.