FS: LM 6

[ikor]

WZ...I admit that I am basing that info on velocities gotten from multiple AR's at 10 1/2 and 11 1/2in. Actual chrono figures from LM6's are something I do not have access to here.

SA military ball is good ammo and full 5.56 power, which is well above standard .223 FMJ. Perhaps the figures you quote are commercial .223 rounds?

Also, fragmentation predictability depends upon a bullet designed to fragment, and not all 55gr FMJ (or 62gr either) bullets are so designed. S&B for instance, makes a steel jacket 55gr that almost never fragments, and the Swiss military bullet, while extremely accurate, is deliberately designed not to fragment.

Soft points and the Barnes TSX are designed to wound via expansion and do not frag.

[Wanderin' Zero]

WZ...I admit that I am basing that info on velocities gotten from multiple AR's at 10 1/2 and 11 1/2in. Actual chrono figures from LM6's are something I do not have access to here.

SA military ball is good ammo and full 5.56 power, which is well above standard .223 FMJ. Perhaps the figures you quote are commercial .223 rounds?

Also, fragmentation predictability depends upon a bullet designed to fragment, and not all 55gr FMJ (or 62gr either) bullets are so designed. S&B for instance, makes a steel jacket 55gr that almost never fragments, and the Swiss military bullet, while extremely accurate, is deliberately designed not to fragment.

Soft points and the Barnes TSX are designed to wound via expansion and do not frag.

To be entirely honest, I do not know what ammunition they used to determine the velocities. These are apparently officially quoted muzzle velocities – whatever that means. The point about the bullets though is a very good one. When the AR was first deployed on the battlefield, what were they using? I have seen photographs which show absolute snowstorms of fragmentation.

[DS]

There are various special forces units in the world using the very compact Sig 553 Commando with it's 9" barrel and 5,56 caliber for real world applications. I doubt that they would use it if it was not significantly effective. The 553 has 1:7 twist and thus allows for heavier bullets, which do not rely on frag, to be used.

The LM6 has a slower twist rate of 1:12 I believe, and that means one can shoot 50gr and most probably 55gr Barnes bullets accurately enough out of the LM6. This would be a premium sd bullet.

At CQB distances (the LM6 is a CQB rifle) and legal practical urban SD distances the LM6 will be gtg with 55gr FMJ 5,56 mil surplus ammo imo. It will any way grossly outperform any handgun at any given distance.

It will most probably outperform a heavier caliber at CQB distances purely because the average user will be able to impact more rounds quicker on the subject than he would be able to do with a heavier caliber rifle.

Imo even the M&P15/22 will be a force to be reckoned with at CQB distances purely because of the rate of fire at which bullets can be accurately placed on a target subject.

The 2" or so that the LM5 barrel is longer than the LM6 barrel will most probably account for around 100ft/sec increase in muzzle velocity with appropriate increase in practical efficient range.

If you intend to carry SD ammo in the LM6 or even the LM5 it would be prudent imo to use soft point or monolithic bullets. That will change the specs significantly from those of the 55gr FMJ and you will have a whole different ball game. Soft point bullets or monolithics at muzzle velocities of around 2200ft/s - 2500ft/s will be very effective SD tools.

Military FMJ bullets are designed for mil use. As a civilian you are not stuck with those bullets and you can definitely make even a 9" barreled 223/5,56 rifle a deadly and reliable performer at reasonable urban SD distances.

[Davidc]

Vector manual says twist rate is 1 in 12 for 4,5 and 6 and velocity is 980, 920 and 900 for the 4,5 and 6. They quote the twistrate as 1 in 305. 305/25.4 = 12

[Brendank]

Thanks for the kind words guys. I had an LM6 a couple of years back that I had to sell for a variety of reasons, so this is extra special

I know the feeling dude... had to part with my pristine LM5 some time back too...
Congrats and enjoy her! Unlikely to find a better specimen than Khumba's

[DS]

So according to Vector (and most probably with good quality full mil spec 5,56 ammo) the

4 = 3215ft/s

5 = 3018ft/s

6 = 2952ft/s


which is plenty for intended use with 5,56 ammo.

The difference in mv between the 5 and 6 is marginal at only about 65ft/s.

With .223 ammo I would still consider going SP or Barnes for SD in the 5 or 6.

[Brendank]

With .223 ammo I would still consider going SP or Barnes for SD in the 5 or 6.

Is Barnes .223 TSX available locally Khumba?

[SSP]

Is Barnes .223 TSX available locally Khumba?

The bullets are. Ive loaded some 53 grainers with pretty good accuracy results. Better than minute of man.

If I recall correctly Hiland AX 55gr SP ammo does 2950 or so out of my 6.

[Paul]

The current State issue 5.56 is VERY enthusiatic. Lots of flattened and pierced primers.

[Brendank]

The bullets are. Ive loaded some 53 grainers with pretty good accuracy results. Better than minute of man.

If I recall correctly Hiland AX 55gr SP ammo does 2950 or so out of my 6.

Thanks SSP. Did you get them from Camdix?