I was going to post on 500's pole, but thought I'd start a new thread.

If we accept that the fn's penetrate deeper, and I agree with that premise, then the question has to be why?

I contend that the fn punches it's way through vs "mushing" it's way through as a rn does. I believe the rn get's resistance from a larger dia of material, though that doesn't necessarily reflect in a larger dia wound channel.

Take a sheet of sheet metal and wack it with two punches, one rounded and one straight. The rounded one will have the rounded indentation, as well as causing a larger dia very shallow angle depression. The flat punch will create a deeper dimple, but overall disruption will be over a smaller area.

I believe the question is whether or not the round nose or the flat nose would travel in a straight line and not deviate off-course. From the impromptu tests that RIP has done, they both seem to penetrate about the same. The major diff is that the flat nose will not deviate off-course where the round nose will veer off-course and tumble. Another thing is with the flat nose, the "cookie cutter" effect is evident. This all comes from the old sixgunners who shot truckloads of critters with semi-wadcutters over the roundnose lead bullets.

Paul,

The mechanics of an FN solid in animal tissue is discussed here:

http://www.grosswildjagd.de/fundamen.htm

And here:

http://www.grosswildjagd.de/penetrat.htm



The bottom line is that on game, larger wound channels and more bleeding are observed with FN solids than with RN solids. The mechanics of punches on sheet metal are not analagous because ductile solids (sheet metal) behave markedly differently than aqueous media (animal flesh).

quote:

Originally posted by 475Guy ... From the impromptu tests that RIP has done, they both seem to penetrate about the same. ...

NO NO NO.
Flat Noses penetrate about twice as far overall and in a straight line.

The Round Nose bullets penetrate half as far and follow a curving path after tumbling.

Flat noses don't tumble until slowed way down.

Round noses tumble at higher speeds and slow down much faster after they tumble.

In the Iron Buffalo, Monometal Flat Nose solids go three times as far before tumbling than do the tipsy Round Nose solid bullets, whether solid brass or steel jacketed lead.

Just beating a dead horse, or a dead buffalo.

This is a simple explanations from Garrett web page:

"Since wound channel diameter is much more a product of meplat diameter than actual bullet diameter, it is our view that all non-expanding hunting bullets should utilize very broad meplats. Broader meplats result in larger diameter wound channels, which increase the speed of incapacitation. Another benefit of broad meplated bullets is increased penetration depth. This relationship of penetration depth to meplat diameter is quite interesting, and fundamental to proper full-potential bullet design. It is commonly believed that bullets with less meplat diameter, such as truncated cones, offer less resistance to penetration and, therefore, provide deeper penetration. This would be true if terminal stability was not influenced by meplat diameter. However, bullets such as truncated cones with less frontal area, and greater front to back weight disparity, are far less stable upon impact, and, as a consequence, provide less penetration. It is always easier to observe than explain, but clearly as the weight disparity between the front of the bullet and the rear of the bullet increases, there is a tendency for the heavier end to overtake the lighter end upon impact. This takes the form of the rear of the bullet moving forward faster than the front, resulting in yaw which greatly inhibits penetration. Simply stated, the bullet goes sideways. However, when the weight disparity between the front of the bullet and the rear of the bullet is minor, or non-existent, this tendency to yaw is greatly reduced and the bullet penetrates deeper. However, once the issue of front to back weight disparity is corrected, and bullet yaw is substantially eliminated, further increases in meplat diameter result in reduced penetration depth".

The above explanation is pretty clear that broader meplats are desired vs. a RN to maximize penetration, but if you have a broader meplat than needed to correct front to back weight disparity, you will begin to reduce pentetration. So the ideal meplat diameter for maximum penetration (non-expanding) for a given bullet would be that which is just wide enough to correct the front to back weight disparity and no more.

Gary

quote:

Originally posted by GaryVA:

The above explanation is pretty clear that broader meplats are desired vs. a RN to maximize penetration, but if you have a broader meplat than needed to correct front to back weight disparity, you will begin to reduce pentetration. So the ideal meplat diameter for maximum penetration (non-expanding) for a given bullet would be that which is just wide enough to correct the front to back weight disparity and no more.

Gary

Wrong explanation and false conclusion. I designed many FN, much slimmer and with greater weight disparity than the RN. But much more stability in penetration. Explanation on my website.

Norbert,

I read your posts and looked at your web page. I'm doing a poor job expressing my opinion, I'm trying to say the same thing you are. There is nothing I read on your web page that is new, other than if you've created a more efficient design. The more efficient and smaller you can make the meplat and still have stabilization upon impact (result of the desired cavitation), the greater the penetration potential. The end result is that the cavitation is what allows the bullet to remain stabilized.

I'm speaking in just basic terms of basic meplat design compared to a RN. There are numerous variations of this design and you may have one that is very effective and still have great front to rear disparity, but whatever the design...once you've reached that point of stability, if you increase the meplat beyond that point...you'll begin to loose potential penetration. Also, keep in mind that if a bullet design has too great front to rear weight disparity and it is effected by the impact due to lesser cavitation, yaw will be introduced and the bullet will attempt to turn ass first.

Gary

OK, RIP. You know what I was trying to say.

If you shoot a buffalo with a Bridger flat nose solid, you will first get an entrance hole much like a 38 special wadcutter makes in a sheet of paper, and clean caliber size hole in other words, you will also notice if your observant to these things that the hard cutting shoulder on the Bridger shaves the hair clean and close for about an inch around each entrance hole, you will observe large funnels of blood spewing from the entrance holes, sometimes like a wather hose, and sometimes every time the front feet hit the ground the blood spews out from both sides as much as 10 feet..then you will note that internal damage is about 1 to 1.5x times more tramatic than a RN solid and about like what one would expect from a soft, then you will note a caliber size exit hole...

With a Northfork cup point you can about double the effect of a bridger flat nose solid but with a larger exit hole and certainly at the expense of penetration, and more blood...On a Buffalo the cup point will win on broadside shots and the flat nose wins lenthwise..

A Woodleigh RN solid, makes a smaller hole, does less damage internally, and makes a smaller exit hole, but with a capable caliber that good penetration and straight penetration kills Buffalo well enough, and they normally make few tracks and spew a lot of blood from the mouth and nose, sometimes from the sides also...

None of the softs or hollow points compete in this arena, they just punch a small entrance hole and expand to double size and stop on the off side skin, and this is what they are designed to do..They kill well from the easy angles. My problem is with softs you sometimes only get nose and mouth blood and thats not good in high grass, I like blood on both sides shoulder high...