Search results
Results From The WOW.Com Content Network
Considering what Ammo Oracle says about the 5.56/.223 round requiring at least 2700fps to garauntee fragmentation, would an expansion-type hollow point or soft tip bullet be more effective out of a 10.5" - 11.5" barrel in a combat situation ? 75gr OTM or 77gr Mk262 work out of an 11" barrel.
Actual chronographs of MK262 have shown the muzzle velocity to be approximately 2360 PFS from a 10.5” barrel. Quoted: The 77gr. 5.56 round will still fragment at velocities less than 2100 fps. A much more realistic threshold for reliable fragmentation with the 75-77 grain OTM loads is 2,250 FPS.
To determine the final results, I subtracted the minimum terminal ballistics velocity by the muzzle velocity and divided by the rate of change of velocity with respect to distance. This determines the distance at which the 55 gr 5.56 Federal bullet reaches 2300 FPS: Max Effective Range = (2300 - muzzle velocity) / -3.3.
For 500-600m shooting, go with the 18". Posted: 8/6/2016 12:36:24 PM EST. [#3] A 30-shot string of Hornady 5.56mm 75 grain TAP T2 chronographed over an Oehler 35-P chronograph from a 16” Novekse Recon barreled AR-15 had an average muzzle velocity of 2735 FPS.
TNVV/NG/PVS-14-GP – U.S. Gen3 Filmed Green Phosphor! $2599. [ARCHIVED THREAD] - Effect of barrel length on bullet velocity (5.56mm) ARCHIVED. Posted: 12/27/2015 12:22:52 PM EST. Was doing so research on 5.56m barrel lengths and how they relate to muzzle velocities. The table below is in the Wiki page that I have linked.
It is a 10.5 inch barrel and I'm using M855 (for now, mostly because I have a boatload of it and I use it in most of my other rifles). I normally run with a 50/~200 yard zero on my other 5.56 weapons. The data that I am seeing is that I will be getting about 2600-2700 fps out to ten yards from the muzzle (which is the very bottom of ...
But U do U. Shooting 5.56 out of a 5.5" barrels takes most of the efficiency out of the round. 77gr 5.56 isn't really faster than 110gr 300blk out of a barrel that short. But it is far flashier/blastier, rougher on parts, and carries far less energy, especially at ranges you will shooting things with a 5.5 inch barrel.
It seeems most people or "units" stick to 10 inches. The answer to your question is dependent on the type of ammunition used. Common fragmenting rounds will not fragment from a 8" barrel. Best current option out of a 8", 5.56 barrel is the 50gr.
BC= Ballistic coefficient. ** (all the data listed is for a 10.5 inch barrel)**. If using a 7.5 inch, typically they have about 300 fps less then a 10.5 inch barrel using the same round so you can subtract 300 fps from the ones listed and use a ballistics calculator to find a estimated range the threshold will be with a 7.5 inch barrel.
A 16" barrel will get around 3,100 - 3,150 fps at the muzzle with M193 so you'll get even more from an 18". In fact, in some cases you will get close to the same velocity for M193 and M855 out of an 18" as you will out of a 20" due to the fact that those rounds have most of their powder burnt out by 18".