SOCOM looks to ditch 7.62

[danhr]

Mk19s for everyone

Problem solved

Danhr for President 2020.

[dkf]

I wonder how many personnel they are willing to lose when the poly cased ammo melts in the chamber and turns the rifle into a paperweight. Even more so now that they want to field more select fire rifles.

[FJW]

I wonder how many personnel they are willing to lose when the poly cased ammo melts in the chamber and turns the rifle into a paperweight. Even more so now that they want to field more select fire rifles.

Just because they toy with certain ideas doesnt mean they will certainly get around to implementing it. Many military proposals never make it past the testing ground, or take years of improvments done in the lab to finally meet expectations.

[Solaran_X]

I wonder how many personnel they are willing to lose when the poly cased ammo melts in the chamber and turns the rifle into a paperweight. Even more so now that they want to field more select fire rifles.

Depends on the polymer. I've had Magpul's polymer front sights mounted directly on railed gas blocks without any issue - and those gas blocks get HOT.

[dkf]

Depends on the polymer. I've had Magpul's polymer front sights mounted directly on railed gas blocks without any issue - and those gas blocks get HOT.

You didn't get it that hot then. There is reason it is recommended to NOT mount those plastic sights on railed gas blocks. The fill helps but most of these polymers they use are some kind of filled Nylon 6 which softens well below its melting point. Not mention the lack of dimensional stability you see with most "polymers". You should try to machine some of the plastics out there and hold any kind of decent tolerances with it. I've had plastic parts I've made expand several thousandths just from handling them.

[Ecclectic Collector]

The original caliber of the Garand was .276 or 7 mm.

Actually no, it is not. A 7mm uses a .284 bullet. Done enough reloading to know the difference.

Yes the round was called the .276 Pederson since back in those days the English speaking world didn't do metric anything. I think I remember reading a Phil Sharpe book where the army gave DCM thousands of free rounds to try in a couple of preproduction Garands at Camp Perry in the early 30s when they were set to roll the cartridge out as the official service round. These days you'd be hard pressed to even find an advanced cartridge collector who even has an solitary example of the cartridge.

Either way, the point is that 6.5 or 6.8mm, the US military's flirtation is not a new thing.

[Solaran_X]

You didn't get it that hot then. There is reason it is recommended to NOT mount those plastic sights on railed gas blocks. The fill helps but most of these polymers they use are some kind of filled Nylon 6 which softens well below its melting point. Not mention the lack of dimensional stability you see with most "polymers". You should try to machine some of the plastics out there and hold any kind of decent tolerances with it. I've had plastic parts I've made expand several thousandths just from handling them.

http://www.differencebetween.info/di...ic-and-polymer

Plastic is a type of polymer, but all polymers are not plastic. There are plenty of high heat tolerant polymers out there.

[dkf]

http://www.differencebetween.info/di...ic-and-polymer

Plastic is a type of polymer, but all polymers are not plastic. There are plenty of high heat tolerant polymers out there.

Congrats you can google. Look I've made and developed parts with high dollar exotic plastics and composites that you wouldn't even know to google. "High Heat" and polymers, plastics, etc is an oxy moron. You don't know what ya don't know.

[Solaran_X]

Congrats you can google. Look I've made and developed parts with high dollar exotic plastics and composites that you wouldn't even know to google. "High Heat" and polymers, plastics, etc is an oxy moron. You don't know what ya don't know.

So what you're claiming is that there doesn't exist a polymer that can handle the temperature of the chamber of a firearm?

[dkf]

So what you're claiming is that there doesn't exist a polymer that can handle the temperature of the chamber of a firearm?

Temperature is only ONE of factors here to making a casing that will hold up to and perform as well as a current brass casing. A chamber temperature could be -50 degrees F to over 500 degrees F depending on the conditions.