gatnerd

Military Guns and Ammunition

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

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True Velocity .308 Weight and Teardown pics    Ammunition <20mm

Started 15-Aug by gatnerd; 1507 views.
EmericD

From: EmericD

16-Aug

Thank you very much for sharing those data.

5 g for a .308 case is very good, that's 1.2-1.9 g less than a 5.56 mm brass case. That also means that you can have an equivalent of a 6 mm / 6.5 mm CM for less than 15 g with a 7 g bullet, maybe 13-14 g if you aim for a shorter 6 mm / 6.5 mm BR equivalent.

Now, if the owner of the TV rounds could:

- measure the case capacity,

- load the powder from the TV case in a brass case and measure muzzle velocity compared with the same powder load in the TV case, in the same weapon,

then I think we would have all the results needed.

Mr. T (MrT4)

From: Mr. T (MrT4)

16-Aug

Its actually better than i expected,as you are only replacing the part of the case with plastic, the case bottom remains metal, bullet stays the same.

That is why any drastic gains would only come with smaller caliber lighter bullet.

smg762

From: smg762

16-Aug

If TV did a 300 win mag, but with a 160gr .308 or 7mm bullet, what do you think the weight would be. 

gatnerd

From: gatnerd

16-Aug

EmericD said:

Thank you very much for sharing those data. 5 g for a .308 case is very good, that's 1.2-1.9 g less than a 5.56 mm brass case. That also means that you can have an equivalent of a 6 mm / 6.5 mm CM for less than 15 g with a 7 g bullet, maybe 13-14 g if you aim for a shorter 6 mm / 6.5 mm BR equivalent.

I was stoked that the guy went though all this effort; I had just asked for him to weigh the loaded cartridge.

Probably the lightest '7.62 class' option for this would be a 6mm Creedmoor using the 88gr Flatline or similar VLD 85-90gr lead free bullet. 

That would weigh in at 13.86g. 

EmericD

From: EmericD

16-Aug

gatnerd said:

I was stoked that the guy went though all this effort; I had just asked for him to weigh the loaded cartridge. Probably the lightest '7.62 class' option for this would be a 6mm Creedmoor using the 88gr Flatline or similar VLD 85-90gr lead free bullet.  That would weigh in at 13.86g. 

According to the reloading tables found on Warner Tools website, the 88 gr could reach 3400 fps from a 26" barrel with the 6 mm CM case.

The Powley computer predicts something like 3340 fps at 52 kpsi from this same barrel length, and still 3060 fps from a 16" barrel with 2480 J of ME and a cartridge specific energy of ~180 J/g (not bad given the 16" length). With a .258 G7 BC and a bullet length of >31 mm, that would make an interesting AP round.

gatnerd

From: gatnerd

16-Aug

EmericD said:

According to the reloading tables found on Warner Tools website, the 88 gr could reach 3400 fps from a 26" barrel with the 6 mm CM case. The Powley computer predicts something like 3340 fps at 52 kpsi from this same barrel length, and still 3060 fps from a 16" barrel with 2480 J of ME and a cartridge specific energy of ~180 J/g (not bad given the 16" length). With a .258 G7 BC and a bullet length of >31 mm, that would make an interesting AP round

Thank you for running the numbers; I was very curious how that would perform from a 16". 

As far as 'nearly off the shelf' cartridges go, I think the TVx6mmCxFlatline has a lot of potential - I think it would be a pretty fantastic LMG round for the new FN EVOLVYS. 

In terms of lead free VLD's, I recall you mentioning some work on bringing back pressed/swaged/ cold formed brass projectiles? Did that ever come to fruition?

I'm curious whether something like the Flatline could be produced cheaply and at scale for military applications. 

QuintusO

From: QuintusO

18-Aug

6.5 grams lighter in the case isn't light enough for you?

I got mine in today as well.

In reply toRe: msg 8
gatnerd

From: gatnerd

10-Oct

Well seems like TV cases are out in the wild now, and so we're starting to see some good testing on Youtube.

Heres a super test of Heat Transfer using FLIR. The polymer case does indeed result in a cooler weapon then brass.

https://www.youtube.com/watch?v=0G_FSmpaeVo

True Velocity .308 Winchester Keeps Chamber Cold?! | Thermal Images

True Velocity's polymer ammunition is known for keeping temperatures down compared to brass ammo. The composite casing insulates the heat from the powder, ke...

And some basic accuracy testing:

True Velocity vs. Federal Gold Medal Match, Sierra Matchking, more | Virtus

True Velocity claims their polymer-cased, Nozzler Custom Competition .308 Winchester can stand toe-to-toe with the best match-grade factory ammunition around...

And from another test by those guys using the same Desert Tech bullpup boltgun:

smg762

From: smg762

11-Oct

If heat loss is the goal, could one use an open bolt gun and somehow solve the drawbacks of the open bolt design

For instance the gun jerks with each shot, but is there a way to solve this?

Such as delayed blowback and a lighter bolt

Farmplinker

From: Farmplinker

11-Oct

A well designed API (Advanced Primer Ignition) gun is very controllable in full auto, but it only works for pistol cartridges.

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