gatnerd

Military Guns and Ammunition

Hosted by gatnerd

This is intended for people interested in the subject of military guns and their ammunition, with emphasis on automatic weapons.

  • 3271
    MEMBERS
  • 185570
    MESSAGES
  • 0
    POSTS TODAY

Discussions

NGSW Phase 2 Consolidation and info   Small Arms <20mm

Started 30/8/19 by gatnerd; 280267 views.
smg762

From: smg762

24-Sep

Going back to the safety aspect, if one had a TKB022 or steyr ACR with NGSW ammo, surely youd need a lot of steel round the chamber to protect from kabooms...

as for compressed powder, im surprised noone has tried to reduce 556 down to 5.7x28 size.

also the 4.6hk has 65k PSI as well.

I wonder if reverse feed guns like the PKM or boberg pistol could cope with ultra pressure ammo....in principle i mean

  • Edited 24 September 2021 15:56  by  smg762
roguetechie

From: roguetechie

25-Sep

Somebody has, and it's been posted in this thread!

Gatnerd showed the Knox engineering design. I'll repost just so you see.

As far as needing "lots of steel"... Not really.

You need to use very good steels and well optimized bolt head designs or etc.

smg762

From: smg762

25-Sep

Yeh i saw that but the document implies that its using an advanced propellant....they didnt mention compressed propellant.

 My new thought for reducing throat wear  (most of my pet projects are very overbore) is to cut the barrel in half...the first 6 inches is separate from the rest and the user can do a quick change...

Its like a m249 quick change exept your only swapping out the throat.

The round itself is a .23 caliber FABRL which is only 42grains but has 4900fps. Hence the concerns with throat wear. 

Apparently revolving chambers wouldnt help much so the only other approach is cool propellants

  • Edited 25 September 2021 13:27  by  smg762
EmericD

From: EmericD

26-Sep

If your goal is to achieve very high MV, why not going for a conical adapter or a "Gerlich" conical tube?

smg762

From: smg762

26-Sep

If you mean a squeezebore adaptor, its likely to deform the bullet enough to affect accuracy.

The concept works as planned - use the .23 / .243 caliber to get a high ME....and then add a 43grain FABRL to allow your 5000fps

Velocity related wear is easier to solve but it really needs a cool propellant otherwise this round will eat away at the throat

smg762

From: smg762

26-Sep

What would be the approximate BC of this 43grn FABRL...assuming a .243 diameter?

Note that the shape is much more refined than the original fabrl - the ogive is actually slightly inverted inwards

  • Edited 26 September 2021 12:01  by  smg762
roguetechie

From: roguetechie

26-Sep

You wouldn't want to do a "swappable barrel throat" think about all the supporting gun structure you'd need to build up around that in order to ensure precise alignment etc. That's a recipe for an unreasonably heavy gun.

Also as useful as 4900 fps would be, it's just kinda not worth taking it to that extreme In a full caliber bore rider projectile configuration.

If you're going to go to all the trouble to launch something that fast you might as well take it all the way and send something with a 10-25:1 length to diameter ratio and just figure out acceptable parasitic mass ratio sabots.

smg762

From: smg762

26-Sep

Isnt the 6.8 fairly overbore?  Im sure the LMG would have less barrel life than a 762 equivalent

smg762

From: smg762

27-Sep

Going back to the FCS on 6.8, i was surprised that all the guns have a recoiling barrel... if one wanted 700m precision shots, is this going to be a handicap...

surely its better to have a sensor on the barrel and a smart optic that reads the sensor

roguetechie

From: roguetechie

28-Sep

Actually, barrel life is well in hand.

As far as the recoiling barrel thing, the answer is no.

TOP