The Loads:
1) .375/300gr GSC FN @ 2526 fps MV--375H&H
2) .375/270gr GSC FN @ 2921 fps MV--375RUM
(both of the above have identical nose shape)
3) .474/500gr North Fork Cup Point @ 2125 fps MV--470NE

It was 25 yards to this contraption:


The ratio of wood to water:
1": 7"
(2 plywood boards of 15/32" for every 7" thickness of water in 2.5 mil plastic bag)

Remember last time it was 1.5" to 6.5", wood:water (3 boards instead of 2 per compartment) and there was a tie between the .375/300gr at roughly 2500 fps (impact velocity) and the .375/300gr at roughly 2700 fps. Both went through 7 bags of water and bounced sideways off the 7th wall of wood.

Results today:

The 300 grainer at 2500 fps was captured in the 8th wood wall, with about 3/4 of its length sticking out of the down range side of the boards.

The 270 grainer at 2900 fps bounced off the 8th wood wall sideways, leaving only a shallow dent in the wood, on which you could make out the marks of the driving bands from the side of the bullet.

However, the entry (target dot) board (1 thickness of plywood) was broken completely in half and the top half somehow squeezed /flexed out of the Steel Mistress and landed 16 feet uprange toward the shooter. More violent initially. The slower bullet just cracked the entry board slightly, but penetrated farther.

It seems the faster bullets just lose their initial speed surplus within the first compartment of wood and water, rather violently then settle down to behaving like the slower load of same weight: Non deforming bullets only!!!

The third load was a North Fork Cup Point, as above.

It made it through 7 bags of water and bounced off the 7th wood wall sideways. Like above, leaving an imprint in the wood from which the driving bands could be "read." The nose of the Cup Point was only slightly expanded.

The initial entry/target board was cracked more vigorously than the .375 H&H load above, but not broken in half. The water splash was about as spectacular as the .375RUM load, however, by my visual impression.

Scoring the bullets on a scale of 0 to 25 for penetration, each board penetrated completely by the nose of the bullet gets one point:

1) 17
2) 15
3) 13

Then index this for us simple minded folk:

1) 100%
2) 88%
3) 76%

I suspect that most premium soft point or expanding bullets will be in the 33% to 50% bracket, regardless of velocity, with weight having more bearing on penetration, and most dependent on toughness of construction.

Keep in mind that #3 is the .474/500gr Cup Point, a limited expansion large hollow point at only 2100 fps so need to keep that in mind: Apples and oranges. It did some notable entry splash violence surprising for its low velocity, and penetrated almost as well as the GSC FN's.

The Cup Point is neither soft nor solid, but more solid than soft.

I regret that I did not have time to do the .475/500gr North Fork Flat Point Solid at 2100 fps for comparison to the Cup Point.

That will be next time.

RIP,

Keep up the good work.

Hog Killer

RIP,

Hey I'd love to see what some of these smurf blue round nosed Barnes solids do out of the .470.

I've got a piloe of them sitting on my shelf if you need a few give a PM.

Thanks, Hog Killer, and surestrike.
Chief Thunderstick (pictured above) is wondering the same thing, about the Smurf Bullets, as surestrike, so it is on the agenda.

RIP.
Keep up the fantastic work you are doing. I look forward to see the results of the solids in the heavy calibers compared to the 375´s..

While I hate to read too much into a single un-repeated test, it certainly looks like you've just settled the "momentum vs. SD" argument. SD won-- look at the momentum of the two .375 bullets. The higher SD bullet penetrated a little more. The higher momentum bullet penetrated a little less. Sooooo.... one could argue that SD is more important than momentum. As many do.

Pertinax

My 2c worth.

The 270 v. 300gr test above could have gone either way. The last couple of centimetres in water invariably results in a tumble as the bullet is almost at rest and shoulder stabilisation and gyroscopic stability has all but disappeared. Had the 270gr bullet arrived at the last board nose first instead of sideways, it could have poked its nose through instead of leaving a drive band print. Ditto for the 300gr bullet arriving sideways. I base this statement on results from a number of wood, plastic and steel devices used and destroyed over the years. In reality, in this particular test, after 60 or so inches of penetration, both bullets wound up within an inch of each other. Given the tie of the previous test, both with 300gr bullets at varying speed, I would say that the difference in penetration between the three, in this medium, is insignificant.

What is significant is that, in both tests, the higher speed bullet created visibly more damage. This is consistent with what we see in game when a cylinder shape is used. Given similar momentum levels (plus or minus 5%), the bullet with the higher energy value creates a larger wound channel.

When RIP first asked for a vote on the three bullets, I posted:

"With the amount of building material involved, the 270/2900 and the 300/2700 will be pretty close and both will be better than the 300/2500. On game the 270/2900 will be best. It will give the largest permanent wound channel and would be first choice."

If the sample size of the test is increased, I would be surprised if my prediction is proven to be much out of line. Tune the Steel Mistress to a finer pitch with thinner wood boards at the far end, and the differences will be more readily apparent. Speed up the 270 gr FN to 3100fps, and the penetration will reduce by a small amount. Take it down a notch, to around 2800fps and the penetration will increase marginally. Neither will be of significance on game. Observation will also show that, at 3100fps, the 270gr bullet is spectacularly superior in total damage caused to the stopping medium or device, compared to slower bullets. On game the additional energy visibly translates into faster knockdowns.

As an aside, the Steel Mistress could be used to truly lay the Sd argument to rest. Shoot her with a 350gr .375 monometal bullet at a Mv of 1000fps and count the boards and bags penetrated. There are many factors that go into the equation that makes up terminal ballistics and Sd isn't one of them.

RIP this is good work and, as I previously said, I salute your efforts. If one has not done this, the amount of effort and money expended cannot be appreciated. Thank you.

I suppose that was more like 4c worth.

Thanks all, for the kind words.
This is fascinating play.

Consider this: the two stops of the same bullet (300grain .375 GSC FN at 2500 fps) with different media, namely 1.5": 6.5" versus 1": 7" (wood to water ratios).

Ignoring the 2.5 mil plastic garbage bags holding the water, equal resistance to stop the same bullet was given by:

A. 19 x (0.5") wood(X resistance/inch) plus 7 bags of 6.5" deep water (Y resistance/inch) :

Total resistance A = (9.5)X + (45.5)Y

B. 17 x (0.5") wood(X resistance /inch) plus 8 bags of 7" deep water (Y resistance/inch):

Total resistance B = (8.5)X + (56)Y

TRA = TRB

9.5X + 45.5Y = 8.5X + 56 Y
X = 10.5Y

So does 1 inch of wood equal 10.5 inches of water, on avearge, in bullet resistance, for the zero to 2500 fps range of velocities?

Too simplistic, I know, and calculus with Resistance varying as a function of velocity is needed ...

But just for simplification sake in this contraption, If I use a single 1/2" thick plywood board per 7.5" thickness of water bag, as required by the bracket spacing in the current contraption, I get:

Medium C: 0.5": 7.5" wood to water
1 entry board
1 board backing each water bag
12 water bags:

TR of C = 13(0.5)X plus 12(7.5)Y = 6.5X + 90Y

Assume Y = 1, then X = 10.5 resistance units.

TRA = TRB = 8.5(10.5) + 56 = 145.25 resistance units by SWAG: Approximates what was required to stop the champ penetrators so far.

Then:

TRC = 6.5(10.5) + 90 = 158.25 resistance units by Swag.

So 12 water bags with one board per bag might stretch out the bullet stop to about 8 feet long and leave room at the end of the trap for an extra several inches of wood to catch any bullet that got through the 12 compartments, by Scientific Wild Assed Guess!

So it looks like I need to shoot them all again with one board per bag of water, 0.5": 7.5" wood to water thickness ratio, i.e., 1:15 ... ... If I hope to distinguish between the loads more authoritatively.

I'm not insane yet, but I may soon be ...

Just as a suggestion, I'd pick a .375/300gr load and tweak the Mistress till you get to your goal of consistant penetration into the tenth chamber and call that 100%. Then see where all the other flavors of caliber and bullet salad land.

FWiW I use an old PASGT vest (kevlar) in front of a large sand bag to stop bullets that make it through my row of gallon jugs when I'm playing with bullets.

Paladin: Have Gun Will Travel?

Your suggestions are good ones. My shooting has been tweaking along those lines so far.

10 compartments would be nice.

Applying the simplistic math to the previous pine box/RIP Bullet Coffin that was defeated by the GSC FN .375/300gr at about 2500 fps:

11 plywood boards ~ 1/2" thick (no entry board, bag of water was entry target), plus 11 water bags 6" thick, "TR0" = 123.75 units for Pine Box, and the bullet zipped right on through.

TRA = 145.25 for 3 boards per bag of water as above, previous RIP post: < 7 full compartments

TRB = 145.25 for 2 boards per bag of water, as above: 8 full compartments

So 10 full compartments with one board would be:

(1+10)(1/2")(10.5 resistance units per inch of wood) + 10(7.5")(1 resistance unit per inch of water) = TR"10" = 132.75 units. Not enough.

11 compartments of 1 board/bag as in the Steel Mistress above: TR"11" = 12(.5")(10.5) + 11(7.5")(1.0) = 63 + 82.5 = 145.5 Resistance Units.

145.25 units of R stopped it before.

My 12 compartment Steel Mistress will have 1 compartment to spare, plus room for a stack of wood at the end of the contraption ... or a flak jacket and a sand bag.

11 is close enough to 10 for me.

That is about 7.4 feet of travel for the final calibration load if it goes as my estimate predicts.

RIP:

Thanks for testing the 470 Cup Points.

I will be "testing" them on Cape Buff in three weeks, however, I will be pushing the Cup Points just a bit faster at a nominal 2170 fps...

Out of 7 recovered Cup Points from buffalo from a 470 at a MV of 2020 FPS, they expanded to an average of 62 caliber..

Thats about what I am looking for...I don't think they CAN expand beyond that as expansion stops at the bottom of the cup, and that seems to be about 6o caliber, regardless of the original caliber, the 416, 375 and 404 all seemed to do this about the same..and penitration was about the same it appeared to me...but this also was complicated by how much bone was struck, if only rib was struck the expansion was more like .460 in the .470 with a very flat slightly expanded nose..

jjs,
Welcome.
I will shoot the 2100 fps 470 NE 500gr CPU/CUP versus FPS North Forks this weekend ... and try the North Fork .375/300gr CPU/CUP and FPS of same weight, at 2500 fps.

I've got a feeling the North Fork FPS bullets are just as hard and reliable as the GSC FN, for solid performance.

A comparison of CPU to FPS in big caliber at low velocity versus medium caliber at medium velocity will be interesting.

Ray,
Thanks for the report. Sounds like the perfect buffalo bullet. jjs should be well served in the .470 NE, ready for any shot.
My Steel Mistress is not live game, but it is fun to see what potential these loads have for application to big bone, etc. My one shot with the 2100 fps CPU only expanded the nose from about .40 cal to .45 cal on the .474 CPU. My boards and water must be about like buffalo ribs.

Higher velocity or harder target is required to get the most devastation out of a CPU. It would also be a great .470 Mbogo bullet at 2500 to 2700 fps.

Apparantly your steel maiden, mistress or whatever gives you about the same performance that I got by hanging those elephants up on my clothes line and shooting through them, but with a lot less work,

I also noticed that your steel Miss bullets performed about like mine did on live buffalo and dead buffalo...good show!

After inputs from various sources, here is a thought on the Cup Points:

Maybe the plywood entry board is limiting the initial expansion by making a seal of wood inside and outside of the "cup" like a plug of wood in a hollow point, and a wall of wood on the outside of the cup/hollowpoint that restricts expansion.

This would be a sort of stagnation of equal pressure on both sides of the rim of the cup, locking it into form.

To avoid this, I will make the entry target of the contraption into a hole in the board, that the first water bag bulges into.

A hydraulic water hammer inside the cup and flowing away outside the cup as the bullet passes may facilitate Cup Point Expansion.

Plugging a hollow point with wood before it started into a game animal would not be desirable either.

I will "retool" to shoot into a water bag as initiator on both softs and solids, maybe make it to the 12th compartment with some bullets, and have a stack of wood at the end of the contraption to catch any "superpenetrators."

I now doubt that any sporting bullet will make it to the end of the Steel Mistress backing boards.

4th of July Holiday: shooting suspended.
Chief Thunderstick and I will be back at it next weekend.

jjs has Ray's recommendation on the .470 NE Cup Points for buffalo. Sounds like there is no better buffalo bullet.

I can also say that the Steel Mistress is strong, and we fear no bullet. Not even a loosened bolt so far. Eventually I will get up to the Bridger brass solids with flat noses for the .505 Gibbs, and fear not.

For data correlation purposes:

From left to right:

1. North Fork 500 grain Cup Nosed Solid .474" - new

2. same, fired into buffalo - 56" penetration

3. same, fired into giraffe - 55" penetration

4. same, fired into giraffe (100 yards f/u shot) - 58" (penetration increased when expansion was less due to reduced velocity at range?)

velocity - 2300 fps

Thanks, 500grains.
That looks like perfect performance.

I assume the MV was around 2300 fps from a .470 Capstick?

From various sources:

Live game bone expands them well.
Live game soft tissues expand them weakly.

Water alone expands them well.
Wood alone does not expand them very well.

It is hard to reconcile this artificial media stuff versus live game, but you and Ray have obviously proven them to be great big game bullets. jjs should sleep well, Tanzania bound with a .470 NE Merkel.

Yes, a capstick. Anyone travelling on safari with these bullets can be assured of excellent performance and should have no worries at all.

quote:

Originally posted by RIP:
After inputs from various sources, here is a thought on the Cup Points:

Maybe the plywood entry board is limiting the initial expansion by making a seal of wood inside and outside of the "cup" like a plug of wood in a hollow point, and a wall of wood on the outside of the cup/hollowpoint that restricts expansion.

RIP,

My congratulations on your efforts.

A couple of suggestions I might offer to you:

While the plywood is great mostly as a direction and stability indicator along the way...... Maybe even giving you some bone comparison as a rib? (stretching it?).......

BUT, - - - - as Gerald states in so many words the initial performance is extremely important to look at. Here hydro-dynamic differences can be observed as well as non-game like materials messing you up!

In lieu of plywood at entry, or even a hole in said plywood.......... What about a couple of thicknesses of truck tire innertube or thicknesses of water soaked leather? Something closer to "hide" right where the "action" takes place the quickest I think would give you a more realistic reading for the cup points and especially expanding bullets..........

Good work! BigRx

BigRx,
I would consider wet leather covering the water bag entry hole in the board, but even that is not the same as live game hide, which is more elastic. Innertube is elastic, though, eh?

I gotta just pick one and go with it, consistently, for softs and solids.
Wood board entry is out.
Water bag entry will be tried next in the Steel Mistress.

This is an artificial medium, just to answer some basics about bullet momentum and caliber.

I will apply lessons learned from this to live game, where the truth is told about expanding bullets.

As such, this thing is best for testing solid bullets in a consistent way.

I have some CZ loads done by A-Square with their round nose brass solid, for the .505 Gibbs.

A comparison of those to the Bridger Brass Flat Nose Solid will be good data from my contraption. Coming up.

RIP,

The inner tube idea is a good one. I would look for a used, large tractor tire tube. Probaly get for free. Cut it into sections and bolt it to your "Iron Mistress". This being two thicknesses of rubber. This should come close to duplicating a fresh hide. If not may be two slices of tube, for four layers on entry.

Hog Killer

Weeeellldoggies! I'll use truck tube to cover the entry hole.
That'll do. Thanks y'all.
I think the bugs are out of this thing now.
Bring on the .505 Gibbs with Bridger Brass Flat Nosed Solids!
I'll endeavor to persevere, through pesky work and around family ...

First stop at a Tire Store along a 4-lane highway netted all the truck tubes I could haul for free. I just took a dozen home with me for now. I'll split up the "splits" for the entry hole. 4 layers of inner tube rubber banding the center-holed entry board. Thanks again for the suggestions, Big Rx and Hog Killer.

That should be enough rubbers for the Steel Mistress for the weekend.

Of course this eliminates any testing of the .45-70, as the bullets might bounce back at me from the rubber bands.

Rip,

We all know the real reason that you will not test 45-70 loads on the Maiden, it's to save her from distruction and complete penitration.

Hog Killer

how bout we all send ya ten bucks and you fill it with beef briskets instead of water. you will need about three per section. o.k., who's in?!

quote:

Originally posted by RIP:
First stop at a Tire Store along a 4-lane highway netted all the truck tubes I could haul for free. I just took a dozen home with me for now. I'll split up the "splits" for the entry hole. 4 layers of inner tube rubber banding the center-holed entry board. Thanks again for the suggestions, Big Rx and Hog Killer.

That should be enough rubbers for the Steel Mistress for the weekend.

Of course this eliminates any testing of the .45-70, as the bullets might bounce back at me from the rubber bands.

ouch!

o.k. now i demand satisfaction...

borrow a guide gun from someone with taste and put some good 500 grain hard cast big meplats through yer iron whore ( no insult intended to you or the bragging rights depth-o-meter )

boom stick,
Beef briskets would be barbecued and eaten instead of shot. I see I have a date with the Steel Mistress and a .45/70.

glad to see you turn a corner on the 45-70

please try some belt mountain and some beartooth and possiby some cast performance. start a thread on the lever action board and people will throw them at you, but be sure to duck, those lower velocities sure can penetrate