autogun

Military Guns and Ammunition

Hosted by autogun

This is intended for people interested in the subject of military guns and their ammunition, with emphasis on automatic weapons, particularly in larger calibres (12.7+mm).

  • 3165
    MEMBERS
  • 179789
    MESSAGES
  • 3
    POSTS TODAY

Discussions

Exploring The Design Space   Ammunition <20mm

Started 25/7/15 by NathanielF; 91996 views.
QuintusO

From: QuintusO

30-Jun

View the screenshots in detail? Knock yourself out.

poliorcetes

From: poliorcetes

30-Jun

I meant, just like here in the forum but without site search using google or bing. 

QuintusO

From: QuintusO

30-Jun

Aren't they all available in this thread?

Mr. T (MrT4)

From: Mr. T (MrT4)

4-Jul

End of the day biggest gains in lethality are to be found in optics and integrated ballistics  not it more rounds per target hit.

QuintusO

From: QuintusO

4-Jul

Yes I believe that's correct.

QuintusO

From: QuintusO

10-Jul

Been working on my <5lb 18" barreled bullpup a bit:

Mr. T (MrT4)

From: Mr. T (MrT4)

11-Jul

Am working on my own carbine in times of kung-flu

Integraliy suppresed .300BLK ,9x39 bolt action Carbine

QuintusO

From: QuintusO

1-Aug

A group of a few of us have been tossing around a few cartridge ideas, and one we consistently come back to is a 7mm derived from the old .30 T65E1 case. The scholars among us may recognize this as essentially identical to the T65/7mm experimental round from the early 1950s. 

The interest in a round like this is that it exists on the junction where the maximum power and performance is achieved within the envelope of the existing 7.62x51mm round. 7mm is barely big enough to accommodate a large, general purpose steel penetrator (.277 is not too small, but a bit smaller than is desirable, and unlike the jump from .284 to .308, the ballistic performance difference is not substantial), and if you have an API requirement as well it becomes very close to the minimum practical size. All of this "depends" of course, if you sufficiently reduced requirements you could go much smaller, say to 6mm, but what you find when you play around in the space long enough is that the jump from 6.5mm to 7mm does not cost you very much in terms of trajectory and drift, but it gives you a considerable boost to bullet volume. The jump from .284 to .308, on the other hand, has you sacrificing velocity to get enough sectional density, and making other tradeoffs you'd rather not have to do. Any of these rounds from 6-7.62mm would be suitable of course, but 7mm looks like the best brokered compromise, given the constraints that you use the 7.62mm parent case or similar, that you have a steel-cored API bullet requirement, and that you are trying to achieve the highest overall performance within that footprint. A different compromise becomes desirable if those constraints change (for example, the 7.62x57 Blasphemy is better if you are not constrained by the 7.62x51 footprint, a 6.5 or 6.8mm like 6.8mm GP is better if you are not planning to use steel-cored AP or API at all, and other rounds are obviously lighter than 7mm while approaching its performance in many respects).

If you've been following my journey through the small arms ammunition sandbox, then you'll know that I've been playing around a lot recently with dedicated "Hi" calibers intended to be paired with a "Lo" caliber. Where I see the T65/7mm fitting in is as a "reach-down" Hi caliber intended to be used in lower echelons as well as higher ones. It's small enough to be used comfortably in DMRs within fireteam level units, without being excessively large or too different than a regular squad rifle caliber. This takes the pressure off the "Lo" caliber to fill that role, allowing it to be more well optimized for the close fight role.

This raises interesting questions about what kind of platoon organizations would be best suited to a combination like this (say, T65/7mm or similar, plus something like 5.56 Super). To me, the most obvious is the heterogeneous squad, with 9-12 members and three or four fireteams, one of which is a support fireteam with LMG, DMR, and ammo bearer/AG. This is sort of like the US Army platoon organization writ small onto the squad, and to be honest I am not sure what I think about it. It doesn't seem obviously poor to me, but I wonder if a homogeneous squad would simply outperform it in most relevant environs.

You could make a case for this round combination in a homogeneous squad organization as well. Assuming you could accept DMR capability out to only a few hundred meters, and emphasized mobility instead, the T65/7mm could be used in Weapons Squads with a combination of GPMGs and "heavy" DMRs providing a longer-legged and more capable overwatch if needed.

The most obvious application to me, however, is the idea of the "arms room" concept, where squad organization remains the same, but weapons are traded out as environments change. The idea here being that squads are "reconfigurable" and potentially any of the above systems could be emulated. Based on their press releases, this appears to be close to the model being pursued by the US Army with the 6.8mm GP, and I suppose that makes it no surprise that the two calibers are fairly similar. However, the Army seems more interested in delineating use of these weapons by personnel role, rather than according to the tactical environment. This, to me, feels like a mistake, as it invites all the complexity of the "arms room" system without the flexibility of allowing small unit commanders to make their own decisions about what weapons will be used where.

The worst application for the T65/7mm, I think, is the USMC's homogeneous platoon model, where the "Hi" caliber is only used at the company level with "attachable" MG teams, and the DMR capability is provided by "Lo" caliber weapons (the M38, in their case). 7mm provides only a weight benefit here, and while that may be appealing, there's a case to be made that the superior performance of rounds like the 7.62x57 Blasphemy would be a better fit.

autogun

From: autogun

2-Aug

A couple of thoughts: your 7 mm/T65 sounds rather a lot like the 7 x 49 FN offshoot of the 1950+ NATO trials which actually saw service in Venezuela, until they presumably decided that being the only country in the world to use it, wasn't very practical. (see page 22 of this for a group photo).

In terms of squad makeup I am way out of my zone, but I've tended to think that "fire and movement" called for two "weapon teams" based around an AR or LMG, so that "half-squads" can cover each other as they leapfrog forwards.

TOP