Ballistics on Speer 5.56 ammo

Printable View

05-01-15, 01:19
stx.dead.I

Ballistics on Speer 5.56 ammo

I have been talking with a buddy about building a new duty AR. This will be primarily for building searches (CQT). I have been looking into a 7" barrel but am worried about the ballistics of this length. I have read a lot of info on the 7" barrels not giving enough velocity to get good fragmentations. We use Speer gold dot 55grn soft point for duty and I was told that this has different ballistics than the standard m855. Supposedly 5.56 doesnt fragment only mushrooms. Does anyone have any knowledge on this ammo?
05-01-15, 05:39
Tigereye

There is probably good info in the "Terminal Ballistics" sub forum.
05-01-15, 07:11
Voodoo_Man

Ive got numbers at home for a 7.75 inch pws upper. Ill post the chrono range when I get home.

Note that speer shot about 4-6 inches high.
05-02-15, 14:16
turnburglar

Most here are not fans of the 7" AR and pistol length gas systems. 556 just wasn't meant for a barrel that short. Personally I'd go with an 11.5" carbine gas from a reputable manufacture. It's still under a foot of barrel length and has less blast, better reliability, and better ballistics.
05-02-15, 15:35
vicious_cb

Quote:

Originally Posted by turnburglar

Most here are not fans of the 7" AR and pistol length gas systems. 556 just wasn't meant for a barrel that short. Personally I'd go with an 11.5" carbine gas from a reputable manufacture. It's still under a foot of barrel length and has less blast, better reliability, and better ballistics.

Agreed, pistol length barrels are fun toys. I wouldn't recommend them for serious use due to their finicky nature, too much blast and flash and too much velocity loss.
05-02-15, 17:03
Eric

Quote:

Originally Posted by vicious_cb

Agreed, pistol length barrels are fun toys. I wouldn't recommend them for serious use due to their finicky nature, too much blast and flash and too much velocity loss.

Exactly. It really has no place in LE, in any capacity. I can't believe that your agency would approve such a thing. An 11.5" carbine is plenty compact for movement inside buildings.
05-08-15, 11:46
Vegasshooter

This is the ammo we use as a Dept. We issue the .223 not the 5.56 though. I can tell you that it did print 1" high at 50yds. from our old ammo, the Federal TRU 55gr. I have personally shot this ammo into 10% ballistic gel out of my DD MK18. It penetrated 14" and did mushroom, not frag. Based on all our testing, it is an excellent round. Far more barrier blind than the old BTHP we used before.

I would echo the above statements about the 7" barrel. Too much lost for virtually no gain. The 10.5-11.5 barrels work very well now. My DD will do very well out to 200yds. In civilian LE, I am of the opinion that shots further than that are not realistic enough to worry about. In 18 years of LE, I haven't seen it, or even heard about it. The 10.5-11.5 are a good compromise. This is just my opinion, I have been carrying a rifle for 16 years, and have run the Colt 16's down to the DD MK18.