Barnes TSX 55 gr or 70 gr in AR

[ldlfh7]

Looking to let one of my nephews use my AR for deer hunting this year. Between the 55 gr and 70 gr TSX which do you think would be the better round? More speed with the 55 gr but more mass with the 70 gr. The barrel has a 1:8 twist so it should stabilize either.

I am not trying to start a thread about the effectiveness or ethical reason to use or not to use 223/5.56 on deer. Just wandering if I should select speed or greater mass for the nephew.

 

[GooseGestapo]

Either will work. Whatever shoots most accurate.

However, any soft point 60 grn or heavier will also work. I suggest some 63gr Sierra Semi pt over 25.5grn of RL15 or similar. Let him shoot a few dozen to get a feel for the rifle (practice) before hunting with the platform.
Practice, practice, practice, equals shot placement, shot placement, shot placement....
For price of 50 TSX, you can get 200 Sierra's. Shot 150, still have 50 to hunt with...

 

[ldlfh7]

Well I do have a good deal of 62 gr Hornady Interlock rounds but wanted to make sure he got good penetration with the 5.56 hence the Barnes. If the regular cup and core works with the 5.56 maybe I should save my money and just shoot those.

 

[jmr40]

Copper bullets don't need a lot of mass to penetrate, but they do need speed to expand. Either of those will shoot all the way through most deer. But once bullet speed at impact drops below about 2000 fps you might not get any expansion. I'd play around with a ballistics program and see where each drops below 2000 fps and let that determine which one.

But at the same time I think you'd be fine with the Interlocks too.

Yea, the copper bullets are more expensive, but they are hunting bullets, not plinking bullets. Buy 150 cheap bullets for plinking and 50 Barnes bullets for hunting. I can buy 200 Barnes bullets or 200 C&C bullets and have them last me 4-5 years for load development, practice and hunting. The money I save won't fill my truck with 1 tank of gas. With all I spend for licenses, and other gear a tank of gas every 4-5 years is nothing.

 

[vladamiraaron]

I like Federal Fusion 62 grain. I've been using it for years with my 582 series Mini 14 with perfect success. It is designed specifically for deer and they make a "MSR" version for the AR platform.

 

[azar]

As a general rule, Barnes bullets favor speed. You can't realistically push a solid copper bullet too fast and generally, the faster the better. That being said, the 70g TSX has a significantly better B.C. and will maintain it's velocity and energy further out.

Using Barnes here's some possible calculations for each bullet.

Bullet  	B.C.    2000fps energy
------		-----	-------	------
53g TSX		0.204	348y	472fpe
[b]55g TSX		0.209	328y	429fpe[/b]
62g TSX		0.287	404y	551fpe
[b]70g TSX		0.314	382y	622fpe[/b]
55g TTSX	0.272	426y	490fpe
62g TTSX	0.294	414y	551fpe

I generally lean towards the Tipped TSX line as the tip aids in expansion and the ballistic coefficients are improved.

 

[waffentomas]

I'd go with the 70gr. With such a small bullet, go with penetration.

When I hunt in Idaho I use my elk load on deer, kills 'em dead. These options have a degree of similarity. Go with heavy, and penetration. Put two holes in them (with one shot) and put them down.