rcman50166 wrote:Also Ragnarok, that does sound optimistic... Sabot rounds are very unstable when they leave the muzzle of the gun. A sabot can deflect the direction of the round it carries up to 15 degrees. That's a worse case scenario though. An average sabot will cause about a degree of deflection, so in the end, you may be taking pot shots at something well beyond the round's effective range.
As predicted by Maxus, it's the (reasonably) long post that says why I think it's possible:
Sabot isn't
quite the right word, but it's the closest equivalent I can think of. Where sabot implies it supports the round, the basic principle matches JSR's idea from here, but refined a bit :
http://www.spudfiles.com/forums/viewtop ... tml#156690
To avoid the problem you describe, I've already got a smart plan that means the dart will separate from the "sabot"
before it's left the muzzle - don't ask how just yet, I'm still perfecting it. The dart will leave the muzzle slightly ahead of the sabot/wadding and because of this the dart's path will neither be affected by the muzzle blast or the sabot.
The design is not quite of the exacting military standards people are talking about, but is certainly a step up on what some spudders have used. Given I'm using a combination of stabilisation techniques to get the best result, I'm not that worried about the dart's stability - the only real concern I have about the accuracy of the dart is it's fairly high susceptibility to side winds, given it's large flank area, poor normal Cd and fairly low mass. However, that can be guestimated for.
If I can get accuracy of 3 MOA - or maybe a little worse - which isn't hopelessly optimistic, then with a handful of darts, I should be able to get at least one hit on the plate I have at 400 metres.
spudfarm wrote:that is something you will need a hybrid to do..
... quite fittingly, one of the original objectives for HEAL was that it would be able to "give a hybrid a run for it's money".
I think the objective was met - although HEAL doesn't have quite the same velocity capacity as a hybrid, the energy at 300 psi is almost the equal of what a 4x hybrid in this size range might achieve. At 30 bar, I have no doubt I could compete with a 5x hybrid.
Now, I couldn't begin to pretend that HEAL had the sheer energy of large cannons like the SCTBDC, but believe it or not, for it's size, HEAL is actually more powerful, being one of the few pneumatics capable under "non-extreme" conditions of generating more than 1 Joule of muzzle energy per cubic centimetre of barrel.
It would be hopelessly optimistic to put a similarly large hole to what DYI managed, so I'm not trying to manage more than about half the diameter on that front.
Even then, I'll be a little short on the energy per unit area to what DYI achieved, but considering the secondary damage he racked up, I don't think it's inachievable.
While we're here, we mustn't forget that Nova's Brass Bruiser nearly penetrated 5mm plate steel with his "Pimpin' Ammo".
And, no offence intended to Nova of course, but HEAL, by virtue of it's larger size, has a bit more muzzle energy than the Brass Bruiser.
So, getting HEAL to pierce 6mm plate at short range wouldn't be too much of a task. Now, what you're going to ask now, is: "What about at 400 metres?"
That shouldn't be too much of a stretch either. After drag, the dart should be able to carry over 80% of it's KE from the muzzle to the target.
I never said it was going to be easy. It's going to take what is a pretty powerful launcher, a truckload of patience, and a lot of work - but I think it can be done.
I wouldn't have said I thought I could do it if I didn't believe it at least possible.