Ok so I will ask this question a different way with more information.
INFORMATION : Shooting the 55gr. Federal TRU BTHP (T223E) ammo through my IWI Zion 12.5 1:8 rifle, I am getting an average of 2491 fps. muzzle velocity. Federal website states a BC of .25. I put this through the Hornady Ballistic Calculator and it says I should be above 1800fps out to 200 yards.
QUESTION: what is the max effective range for reliable performance:
DISCLAIMER: this is all of the information I have, and understand there are a myriads of external factors which come into play.
With that round, acceptable performance is simply hitting the target. If you go to the federal website, you can see the gel test results. The bullet frags and separates. The BTHP round is oriented towards precision, hitting where you want to hit, not terminal effects on target. Once it hits something, there’s no telling with reliability, where it’s going to go and in how many pieces it’ll go there.
https://le.vistaoutdoor.com/ammuniti...ls.aspx?id=681
AQ planned for years and sent their A team to carry out the attacks, and on Flight 93 they were thwarted by a pick-up team made up of United Frequent Fliers. Many people look at 9/11 and wonder how we can stop an enemy like that. I look at FL93 and wonder, "How can we lose?". -- FromMyColdDeadHand
tk390 are you bound to the T223E round through the department? We were issued the Federal V Shock round 55 grain BTHP from 2002 to 2010. Our DRMO M16A1's wouldn't stabalize a 62 grain rounds so we ran 55 grains. We thought is was a good round as it was very accurate. Then we had an OIS where the suspect was pacing back and forth with a handgun and turning while swinging his arms. An officer fired two rounds from 28 yards and hit the suspect in his right forearm as he was turning and swinging his arm in front of his body. It pretty much blew his right forearm in half. It was a nasty looking wound but neither 55 grain round continued through the forearm and hit the suspects torso. Right after I that I pushed for a faster transition away from the 1 in 12 twist rifles and to a better round.
We ended up with a FBI contract round which is basically the Winchester RA556B round. That has been a good round for over a decade. Also if you are LE you can contact the FBI Firearms unit on letter head and request their ballistics CD they publish. I used to get one every other year with all ballistics data test they have done over the years. David
Last edited by dwhitehorne; 10-31-21 at 19:52.
So our county is a bit of a quagmire. We have a county police department and a county sheriffs department. The two have different roles. The PD, which is bigger and therefore drives the bus when it comes to equipment specifications, chose the RRA 1:9 twist overs a decade ago. We are still using 870’s And are trying to get patrol rifles. we tend to follow suit, as to not reinvent the wheel, however I believe the weapon chosen,as well as the ammo can be updated, if not at the very least reviewed and vetted to assure it is right for our application.
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That BC is rather optimistic. It does not match the projectile manufacturer’s BC, not even close. I wouldn’t be surprised if its a typo, since the pictured round in the LE site shows a completely different, heavier projectile. The BC would be believable for a 60-62gr bullet.
Using your 2491 fps velocity (is there any chance that this might be a typo?) and Sierra’s BC (its their projectile), I get the following velocities:
25 yds 2393 fps
50 2283
75 2176
100 2071
125 1970
150 1872
175 1777
200 1685
I don’t know the minimum velocity for this bullet, but it shows suboptimal performance in the gel tests on Federal’s site. Maybe someone more familiar with that bullet will have something.
RLTW
“What’s New” button, but without GD: https://www.m4carbine.net/search.php...new&exclude=60 , courtesy of ST911.
Disclosure: I am affiliated PRN with a tactical training center, but I speak only for myself. I have no idea what we sell, other than CLP and training. I receive no income from sale of hard goods.
I apologize when I looked at my readings I saw the last thought it was my average. The average was 2538 ft./s. I looked at the box of ammo and it says T223E.
When I look at that on the website it shows a ballistic coefficient of .25 and a bullet weight of 55 grains.
I know when I look up the projectile on Sierra‘s website the ballistic coefficient is much lower. I do not know where the discrepancy comes from but the ammo came out of the box in the above picture. I’m not sure who’s information is more accurate and I am not a guru in this area that is why I need help deciphering all the information any help would be appreciated
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clearly the reason one should choose an expanding round instead of 193 or other fmj rounds is that they have almost no shot of stopping in the perp which in turns means that its not dumping even half of its kinetic energy in them. Yes if you hit someone in the heart or brain with a 193 it very well may drop them DRT and then it may not. I like 193 for training because its cheap but I do keep mags full of either tsx or fusion/gold dots. Just saying
If a person is shot twice in the torso with with the same bullets at the same velocity with one projectile coming to rest exactly on the far side skin layer, having perfectly "dumped all its energy" into the target and the second projectile passing straight through the torso and "keeping some of its energy" how are the wound tracks different up to that last point of differentiation (exit or retention at the far side skin layer,and assuming paths of the bullets through bone/tissue are similar)? How does energy kill? If the projectiles pass through similar structures how is the first wound track more lethal because of "energy dump"? What does that look like when observing tissue?
I don't disagree with your conclusion. I'd rather have Fusion in my rifle that 193 for defense. I've just never understood the idea of energy as a wounding mechanism.
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