11.5" upper would any 556 FMJ fragment at any distance?

[ARCHIVED THREAD] - 11.5" upper would any 556 FMJ fragment at any distance?

mike45acp Joined Apr 2003 Posts 2058 EE Offline USA	Posted: 3/13/2005 2:12:57 PM EST I like using FMJ and it seems like a 11.5" upper would be a great home/ranch defense rifle. easy enough to carry in my atv or jeep while cruising along the US MEX border. But would it basically be a .22lr? Would i have to use hollow points to cause damage? M193+11.5" upper good plan? mostly concerned with 20-100 meters.

Kharn Joined Nov 2000 Posts 2897 EE Offline MD, USA	Posted: 3/13/2005 2:14:31 PM EST 20m with M855, IIRC. Kharn

mike45acp

Joined Apr 2003
Posts 2060
EE Offline

USA

Posted: 3/13/2005 2:15:06 PM EST

Originally Posted By Kharn:
20m with M855, IIRC.

Kharn

wow anything past that and its ice pick?

TheFreepster Joined Jan 2005 Posts 192 EE Offline ME, USA	Posted: 3/13/2005 2:16:10 PM EST [Last Edit: 3/13/2005 2:17:04 PM EST by TheFreepster] Try this 12-15 m with M855

gotm4 YOU SAID MEMBER! Joined Jul 2001 Posts 4555 EE Offline VA, USA	Posted: 3/13/2005 2:16:28 PM EST Go with a 1x7 twist barrel (LMT makes the entire uppers ready to go with that twist) and Black Hills blue box 77gr ammo.
	Slow is smooth, smooth is fast, fast is deadly, frontsight press, always bring extra ammo, every plan is a good plan until the timer goes off.

Happyshooter

Joined May 2001
Posts 3933
EE Offline

MI, USA

Posted: 3/13/2005 2:20:00 PM EST

Originally Posted By TheFreepster:
Try this

12-15 m with M855

Here, I got the answer for you:

Q. At what range will M193 fragment? How about M855?

Assuming true M193 or M855 ammo, velocity is the key. Velocity is dependent on barrel length and environmental conditions.

As barrel length increases, the bullet is propelled faster by the expanding gasses in the barrel, imparting more velocity on the bullet, resulting in a longer range before a fired bullet drops below 2700 fps. A shorter barrel imparts less velocity, and therefore the bullet has less range.

Temperature, altitude and humidity are other factors. As temperature or altitude increases, air becomes less dense and bullets travel faster. Contrary to common conceptions, as humidity increases air also becomes less dense and helps bullets retain velocity.

It is important, then, to keep in mind that any statistics given can only be approximate and can be affected by a wide range of factors. But as a baseline, these numbers are what you could expect for 75° F, 25% humidity, at sea level, from various barrel lengths:

Distance to 2700 fps
20" Barrel
16" Barrel
14.5" Barrel
11.5" Barrel

M193
190-200m
140-150m
95-100m
40-45m

M855
140-150m
90-95m
45-50m
12-15m

As you can see, barrel length and ammo selection make a major impact on fragmentation range.

mike45acp Joined Apr 2003 Posts 2063 EE Offline USA	Posted: 3/13/2005 2:28:22 PM EST wow 50 yards they look cool but they dont work so good huh?

FredM Joined Aug 2003 Posts 697 EE Offline TX, USA	Posted: 3/13/2005 2:38:44 PM EST They will still yaw at longer distance. Especially the longer bullets.

DarkNite Joined Feb 2001 Posts 986 EE Offline WI, USA	Posted: 3/13/2005 2:47:52 PM EST MACV-SOG Recon Teams used the Shorty all the time, quite lethally, too. But jungle work is short range. The 16" barrel looks like a good compromise.

mike45acp

Joined Apr 2003
Posts 2065
EE Offline

USA

Posted: 3/14/2005 7:32:38 AM EST

Originally Posted By gotm4:
Go with a 1x7 twist barrel (LMT makes the entire uppers ready to go with that twist) and Black Hills blue box 77gr ammo.

so with those they wont ice pick em

SHIVAN

Amateur Troublemaker....

Joined Jun 2002
Posts 16408
EE Offline

USA

Posted: 3/14/2005 7:36:20 AM EST

Originally Posted By mike45acp:
wow 50 yards they look cool but they dont work so good huh?

You are taking "home defense shots" outside of 50yds {150'}????

Seems like a great tool to me.....

TexasSIG

Ammo Burner

Joined Oct 2004
Posts 257
EE Offline

TX, USA

Posted: 3/14/2005 7:38:50 AM EST

[Last Edit: 3/14/2005 7:45:50 AM EST by TexasSIG]

Get thee some 75gr TAP. If you want to joust with 55gr, leave thy shorty barrel at home.

So says the Oracle (well, it sort of says that

)

Not sure why you want to stick with an FMJ though.....in a short barrel, fragmentation
is not your best friend, at that point you're depending on bullet design.

If you insist on the short barrel, don't go with more than 75gr in a 1:9 twist. The 77gr
tumble for me at 1:9 but the 75's don't. Must be right on the ragged edge there...... (11.5" bbl)

Best to get 1:7, but I already had this 1:9 laying around so.....paid for is a good thing.

Your village called, they want their idiot back.

[ARCHIVED THREAD] - 11.5" upper would any 556 FMJ fragment at any distance?

General » General Discussion

Warning

Confirm Action

Stay Connected

Newsletter

Contact Us