Velocities 70gr TSX, CFE 223, 16” 223 barrel

[d31tc]

Considering loading, as the title states, 70 gr TSX with 223 in a 16” 1:7 barrel. Curious if anyone has chrono data for various charge weights.

Barnes does have load data in a 24” barrel for CFE 223. They also have 70 gr TSX 5.56 load data for other powders in various barrel lengths.

 

[Another_Kelley]

No chronograph experience on that particular combo, but we do know a lot of lead-core 77gr ammo will be topping out around 2750fps. Given that, if you could get anywhere north of 2800fps without destroying those primer pockets I'd say you've done well.

 

[AJC1]

Considering loading, as the title states, 70 gr TSX with 223 in a 16” 1:7 barrel. Curious if anyone has chrono data for various charge weights.

Barnes does have load data in a 24” barrel for CFE 223. They also have 70 gr TSX 5.56 load data for other powders in various barrel lengths.

Curious why so heavy. The 50 is considered a great barrier bullet, and if you have 100% weight retention why go so heavy? Monos are velosity hogs for good operation and terminal performance.

 

[d31tc]

Curious why so heavy. The 50 is considered a great barrier bullet, and if you have 100% weight retention why go so heavy? Monos are velosity hogs for good operation and terminal performance.

Before reloading, I had used the Barnes Vor-TX 70 gr 5.56 factory ammo. It was devastating on a deer I shot, so when I bought my reloading components, I bought 70 gr TSX. Next bullets will likely be 62 gr, though.

Situation is short range, so the terminal velocity with 70 gr is likely going to be above 2,400 fps on the low end; more likely around 2,500 to 2,600.

 

[Anchorite]

Have shot several pigs with the 62 gr Speer. Works like magic. I prefer a little more barrier penetration or “oomph” with critters that might charge me and try to bite.

Softer skinned, like coyotes, gimme a 55gr pill every day of the week.

 

[d31tc]

I was curious, so I did some plots of Barnes Load Data and did some interpolating/extrapolating.

The orange line represents Barnes 223 load data for 70 gr TSX from a 24" barrel.

The blue line represents taking the max charge weight from Barnes 223 load data for 70 gr TSX and interpolating/extrapolating velocities for those charge weights from Barnes 5.56 16.5" barrel load data for those powders that were in both 5.56 and 223 load tables (Varget, TAC, H4895, RL 15).

The black line, not having CFE 223 70 gr TSX load data for 5.56, represents a relative projection for an estimated velocity using CFE 223 load data and firing a 70 gr TSX from a 16.5" barrel.

The yellow line represents Barnes 5.56 max load data for 70 gr TSX from a 16.5" barrel. Since 5.56 NATO runs at approximately 58,000 psi max pressure vs 55,000 psi for 223, I would assume higher velocities could be achieved with CFE 223 in a 5.56 barrel if load data for that existed (2,750 to 2,800 fps).

Just an observation. Not going past published data. Sure wish Barnes had that data...

 

[AJC1]

I was curious, so I did some plots of Barnes Load Data and did some interpolating/extrapolating.

The orange line represents Barnes 223 load data for 70 gr TSX from a 24" barrel.

The blue line represents taking the max charge weight from Barnes 223 load data for 70 gr TSX and interpolating/extrapolating velocities for those charge weights from Barnes 5.56 16.5" barrel load data for those powders that were in both 5.56 and 223 load tables (Varget, TAC, H4895, RL 15).

The black line, not having CFE 223 70 gr TSX load data for 5.56, represents a relative projection for an estimated velocity using CFE 223 load data and firing a 70 gr TSX from a 16.5" barrel.

The yellow line represents Barnes 5.56 max load data for 70 gr TSX from a 16.5" barrel. Since 5.56 NATO runs at approximately 58,000 psi max pressure vs 55,000 psi for 223, I would assume higher velocities could be achieved with CFE 223 in a 5.56 barrel if load data for that existed (2,750 to 2,800 fps).

Just an observation. Not going past published data. Sure wish Barnes had that data...

View attachment 1184478

223 I agree is 55kpsi.
556 is 62kpsi.
When hunting with tiny bore it matters.

 

[d31tc]

Range report - I chronographed 223 REM with 70 gr Barnes TSX and 24.9 gr CFE 223 with two rifles.

Savage Axis, 22” 1:9 twist barrel: Avg Velocity 2842 fps

Aero AC-15, 16” 1:7 twist barrel: Avg Velocity 2605 fps

This was my first outing with my $12 (after rebate) Walmart clearance Savage Axis with the scope that came with it. I shot a bunch of 55 gr through it to sight it in and groups were around 1.5”. I switched to the 70gr TSX and made final adjustments with two 3 shot groups shown here. lose Close enough for the day as I ran out of time with my tests but I was very happy with the results.