Gday slideshow
@Fordy definitely no offence taken, I find this fascinating a little bit like a crime scene or a good who done it and why/how.
Cool & that’s a different kind of explanation on the subject but I tell you what that makes a huge amount of sense for me I love it
That’s why I asked the question thanks for a more updated answer.
But have I got this right? You are saying SD and counting in velocity as the bullet reaches each step in its flight path ie at 5y velocity equals 20y v etc?
Not from my reading
I’m sorry I don’t understand the above but potentially I know what I did which is probably the way I’ve wrote it ( I only got 2 % points above a failure in English @ school so I understand I’m not clear on my writing skills & apologies for that )
I’ll keep on trying to relay in a better way & thanks for asking for clarification as it’s important in my eyes
So take 2 on the following
SD
5yards &20 yards
SD I believe I should’ve been more thorough on my description as SD can be interpreted in a few ways
Standard deviation is potentially what i think you’ve thought my SD was about where I’m meaning sectional density that’s related to the projectile itself & nothing to do with velocity
If that’s the case Sectional density ( SD ) was in the era gone by a good measure of the ability of penetration ability which that is what Kevin Robertson often talks about in today’s world where the terminal sectional density (TSD ) gives us a better indication of penetration ability .
A easy hypothetical equation for this to be seen is let’s take 2 identical weight bullets in the same calibre one a expanding the other a true solid in a double rifle ready to shoot , the 2 bullets have exactly the same Sectional density prior to being fired
Now if one pulled both triggers @ once & the bullets hit the critter @ the same time the expandings Sectional density decreases where the true solids sectional density remains the same
That above is completely separated from the 5&20 yards as that relates to how the projectile leaves the barrel muzzle
Which we have been lucky to see due to extreme slow motion cameras catching this wobble as it leaves the muzzle the bullet takes a little time to settle that wobble down
So @ the said 5yard mark one just can’t get a consistent point of impact that is the same ea shot & why to understand the bullets capabilities this 5 yard mark is hard to get a true understanding of what the bullet is actually doing where if we move to the 20 yard mark ( I think 22 was the distance I was told years ago & recently used 25 yard as the distance ) the wobble has settled & now the bullet is @ a point on the impact where the wobble that dosent give us a potential false indication of what just occurred ( variability I guess is a better word? )
Now those numbers are what I base things off on the explanation I have been given but others may have way more beneficial information on those yardages re wobble of the bullet
Now on this yardage’s in testing a apples vrs apples bullet vrs bullet or pattern of the zones one gets a good idea in test media @ those 20 yards I mentioned where in real life testing in the field you see the better bullets still preform @5yard just like they did @20 yard where the lessor pill will give us erratic results @ that 5 yard mark
Now one needs numbers to fully see this but it’s one that puzzled me why I got the odd results of poor preformance on those in close results
Now another interesting part is the smaller the caliber the greater the less than ideal results occur on those real close shots compared to the big bores which I believe is where
@michael458 research confirms the meplat size & caliber size just give a self stabilisation where as he calls them the rat calibers (375 especially lol ) needs a lot more going for it than say the .510 cal
In my experience you can get a slightly sloped meplat in the .510 & yet it will still track pretty straight where in my beloved 375’s you get the same slight angled & you’ll often see a turn
Turns can still kill well but a turn is also very close to a tumbling occurring & those tumbling are one that are totally erratic on where they end up & how they kill , so one may accept a turn or tumble but for good consistency a dead straightline bullet gives us the highest level of consistency
On the velocity side I don’t know what else to say other than its finding a bullets limits under various situations has proven to be very valuable in understanding & be wary of what some companies will tell you as just like bullets some poor some ok some good
Hopefully I have explained that in a better way ? If not ask away or if I’ve cocked up on anything above please point it out & explain why would be good as then I can learn a little more ( that goes for anyone who has a different view or better still facts as then we all raise the bar on a knowledge level together
I think the failures are sometimes more interesting than the ones that don’t “ohoo it worked Again”!! (A Frame, CEB)
Looking forward to more discussions.
Cheers Sideshow
x2
Cheers Fordy