What's new
British Ordnance Collectors Network

This is a sample guest message. Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

Cartridge HEDP M-789 30mm cutaway

B

blu97

HONOURED MEMBER RIP
Ordnance approved
Hi all I showed a thread about a cutaway of this round but there was a lot of commotion about this, it is top secret. So here is a link from the manufacture and I must say it looks better as mine.
http://www.atk.com/ammo_PDFs/mediumcaliber.pdf look at page 41
Sorry for the moduraters for the inconvenience I made I hope this will make it up.
Sheers
 
No worries Blu and thank you for your link.
im glad all is sorted out,so please onward with the good work.B)

best regards


waff
 
Hi blu97,
That is a beautifully sectioned round. A bit to modern for me but fascinating to see all the same.
Weasel.
 
Ok first bit Blu97 and everyone else,as admin sometimes i have to make decisions and these can be right or wrong,,i am only human (allegedly),when i removed Blus image i only did it in the interest of the forum members and the site ,acting upon information i had received,this information may be correct or incorrect i dont know,im not going to go into it in detail as this is something I DO NOT KNOW ABOUT,,but having looked at Blu97s link to the manufacturers site i am more than happy to ask Blu97 will you please repost your original image that is if you want to..The following images are from the manufacturers site please read the bit at the bottom highlighted in red on the last image

first the manufacturers cutaway .
(the manufacturers stuff is "approved for release to the public domain")
screenshot2.jpg
 
I totally agree with you spotter.The post was reported by a member as possibly being dodgy therefore action had to be taken both to protect the members and BOCN.
well im glad all is sorted out then.:)

regards

waff
 
I agree on al of this, and i also want to ask Blu97 to post his Nice cutaway again.

Cheers Mad B)
 
Cartridge_HEDP_M_789_30mm_cutaway.jpg
At request, here it is again.
The M789 HEDP is an anti materiel and antipersonnel round. The projectile body is steel and is loaded with a 27 grams PBXN-5 high explosive charge and a spin compensated shaped charge liner that has a PD (M759) fuze. The cartridge case is aluminium. The fuze arms while the projectile is in flight and initiates the projectile's explosive filler upon impact. The shaped charge liner collapses with detonation that creates an armour piercing jet. Fragmentation of the projectile body also occurs that can produce antipersonnel effects within a 4-meter radius. Estimated penetration performance is in excess of 50 mm RHA at 2,500 meters. The round is fired from a 30mm canon from the apache helicopter.
 
Top quality blu97-bet that took ages to do ?

Carry on the good work as these cutaways are always very interesting to see.
 
Can anyone (without dragging us back into the classification morrass) explain what was done to the shaped charge to compensate for spin? I know the M230 uses a low rate spin - but that shaped charge looks 'bout like every other one I've ever seen - save for those marks on the liner.

PS: don't mean to sound like I don't approve of pulling questionable material - that was absolutely the right thing to do in the circumstance and obviously after some thought, returning the material was also correct!

Dave Mason
 
Herts meet.

Agree, cutaway is an excellent medium for teaching - very engaging and explanatory. Must be painstakingly difficult to do well.
 
Last edited:
Nice cutaway as has been mentioned before. I am attaching a photo of my M789 cutaway which is in a red anodized Amron aluminum case. Also shown are three variations of the 30mm WECOM HEDP projectiles. Point being that the design of shaped charge cones is wide open. The cone liner used in the M789 is called a "fluted liner". As was mentioned this design is intended to overcome the bad effects of spin on the formation of the jet and slug of a shaped charge. The flared variations of thickness in the liner provide excess copper that is distributed more uniformly when the rotation occurs. Not rocket science and still does not totally compensate for the spin, but it certainly helps. This design is mostly used in medium caliber designs and not larger caliber cones.
The WECOM designs show three different designs of cone liners, to include on identical to the M789. Thus the fluted liner has been around for years. All of these designs incorporate the nose impact spit-back fuze design to initiate the explosive charge.
I missed the discussion that led to the removal of the original photo, but given the rather wide public dissemination of the M789 design, the age and use of the "fluted cone" design and the wide fielding of the M789 there is certainly nothing classified about it at this point. I have some original design drawings some place for the M789 and they are not classified in any manner either. Not sure who originally designed or patented the fluted design, but I doubt it is currently even proprietary either so I am not sure what the concern was.
 

Attachments

  • 30mm Cones.jpg
    30mm Cones.jpg
    69.6 KB · Views: 161
You must log in or register to reply here.
Top