quote:

Originally posted by jeffeosso:
I wonder, of all the posts and posters on this topic, who owns AND hunts a big bore purdey.

If hunting with a cartridge were a prerequisite to posting, would you have any posts at all?

NOTE: I do not define shooting 90 pound does next to a pile of a corn bait as 'hunting'.

Again, after speaking to both Miller and Echols I will only say that its shocking how wrong some posters are about what calibers riflesmiths will and will not build. They Both will build a 375 Ruger, no problem, but some of the other " established " calibers, not.........................JJ

JJ, since what you wrote about ballistics of the 375 Ruger was inaccurate, and what you wrote about Mr. Echols was inaccurate, how can we be sure that what you wrote about Mr. Miller was accurate?

And how about Purdey?

Dan, my first post shows no edit marker. I was talking of the HH being a classic. Edited ????

Wrong about Mr. Echols ? I stated he needed to re-coup tooling costs before he would build. Lying ???

" Some are blinded by the sun and refuse to see light ".........Plato

To all..... ..................................JJ

quote:

Originally posted by JJ_Miller:
Dan, my first post shows no edit marker.

The software does not leave an edit marker.

quote:

Originally posted by 500grains:
JJ, since what you wrote about ballistics of the 375 Ruger was inaccurate, and what you wrote about Mr. Echols was inaccurate, how can we be sure that what you wrote about Mr. Miller was accurate?

And how about Purdey?

Dan,

This is the most factual field data I've been able to pull together to date:

Handloading the 375H&H in an attempt to reach 375Ruger exterior ballistics w/ a short 22-23" barrel appears to be a hard one to do. Even w/ R-15 you'd be hard pressed to get a 270gr bullet out of a 23" barrel over 2700fps in a 375H&H. I don't think I'd go much over 73gr and you'd be maxed out around 74-76gr. Using H4350 you'd top out around 83gr. Either way, you'll need at least a 24" barrel or would need to drop down to a 260gr bullet. There is tons of published data available on this and most who break 2700fps are beyond max pressure and/or have longer barrels.

The published velocities for the Hornady Heavy Mag 375H&H is for a long barreled rifle, 26" IIRC. From what I've seen through a chronograph it appears that Hornady may have downloaded the H&H Heavy Mag as of late. You may have difficulty reaching those velocities now w/ a 26" barrel, I doubt you'd ever hit those velocities w/ a 22-23" barrel.

Jeff Quinn has already tested and published data using a factory 23" 375 Ruger barrel. Without any signs of excessive pressure he clocked the following:
- factory loaded Hornady 270SP = 2758fps
- hand loaded Hornady 270SP = 2875fps
- hand loaded Barnes 270XLC = 2975fps
- hand loaded Barnes 270TSX = 2856fps
- hand loaded Barnes 300TSX = 2757fps

End results are that Quinn showed that the 375Ruger can be handloded w/out excessive pressure and shoot a 300gr Barnes TSX faster than a 375H&H can shoot a 270gr bullet.

It does appear that there is more to the equation than just the overall raw water capacity of the two cartridge cases. Depending on bullets and powder, you may have over a dozen grains difference between top efficient powders in each and it's possible that neither will have compressed loads using 100% cartridge capacity. Based on what I've seen, you cannot load a 375H&H and shoot the same top velocity as you can w/ the Ruger.

In the end, we'll have a better grasp of the potential of the 375R when pressure tested load data is published by the main players. For me, I intend to follow Quinn's lead and work up a load w/ H4350, but, I'm only shooting for standard H&H velocities.

GVA

GaryVA,

What did Jeff Quinn consider a sign of excessive pressure? I take it he did not measure it directly with a strain gauge.

It is well established that traditional "pressure signs" do not become evident until pressures are, in fact, quite excessive.

I am suspicious of any data that show that kind of increase over a factory load for a new and highly touted cartridge and that claim no excessive pressure.

GaryVA,

How did Mr. Quinn achieve that when the Ruger has just 3.5 grains more capacity than the H&H? It seems he must have loaded the Ruger to significantly higher pressure or the velocities would be very similar.

Dan is right, JJ is right, and jeff quinn is right... and PO ackley is right

Notice, I am agreeing with EVERYONE on the matter, because they are all correct, to a point.

quote:

Originally posted by GaryVA:
...375 Ruger
- hand loaded Barnes 300TSX = 2757fps
....
GVA

quote:

Originally posted by 500grains:

quote:

Originally posted by JJ_Miller:
I got 2659 fps with 375R 300gn RN.

Compared with:

quote:

.375 H&H Magnum Heavy Magnum Centerfire Rifle Cartridge, 300-Grain Full Metal Jacket Round Nose Bullet, 2705 fps

The case is approaching 6.75% larger than the 375 HH (per rip)

The rule of thumb is 25% of the case gain for velocity gains, at the same pressure
((.0675/4)+1)*2705 = 2750.647 (rounded up)

WOW..

If we accept
1: dan's statement of 2705 FPS in a 375HH
2: Rip statement of 6.75 average greater capacity
3: the rule of thumb for case capacity increase to velocity increase

we find a HUGE 7FPS "over pressure"

Now, if we accept
4: PO Ackley's position that an "improved" case is more efficent

We find what?

PII

Absolutely nothing worth talking about in terms of PRESSURE and CAPACITY.

Now, How'd got a purdey turnbolt bigbore rifle to compare to?

besides, it's not like saying you can take a 458 lott WAY past 2300 FPS with a 500gr bullet or anything