Expansion ranges for Barnes 50 and 70 TSX

[BallisticHarmony]

Could anyone help me out with this calculation or point me in the right direction to do it? I’d like to know the max expansion distances for both the Barnes 50 and 70 TSX rounds, specifically the improved Black Hills 50 TSX load which uses a slightly different projectile.

The BH 50 TSX has an expansion velocity threshold of 2300 FPS.

The Barnes 70 TSX has an expansion velocity threshold of 1800 FPS.

Given this, I’m trying to figure out the maximum distance for expansion with the following barrel lengths:

50 TSX (Black Hills)
11.5”
14.5”
16”

70 TSX
11.5”
14.5”
16”

Any and all help would be greatly appreciated. Trying to find the most optimal barrel length and ammo combo.

[ggammell]

Could anyone help me out with this calculation or point me in the right direction to do it? I’d like to know the max expansion distances for both the Barnes 50 and 70 TSX rounds, specifically the improved Black Hills 50 TSX load which uses a slightly different projectile.

The BH 50 TSX has an expansion velocity threshold of 2300 FPS.

The Barnes 70 TSX has an expansion velocity threshold of 1800 FPS.

Given this, I’m trying to figure out the maximum distance for expansion with the following barrel lengths:

50 TSX (Black Hills)
11.5”
14.5”
16”

70 TSX
11.5”
14.5”
16”

Any and all help would be greatly appreciated. Trying to find the most optimal barrel length and ammo combo.

Some one of the TOD did some work ups on this. I have the spreadsheets saved. I’ll DM them to you later today/tonight.

[1168]

I can tell you some of what you can very roughly expect, but you’ll have to shoot it yourself, through your barrels to be definitive. What I have done is, downloaded a ballistic calculator, such as Ballistic AE, and found reputable internet sources for velocities. This data comes from several people and several different brand barrels.


50 TSX 2300fps? Expansion floor
Note that the BC on this bullet is pretty low; I got it from Barnes. Also, velocity is extremely barrel length dependent.
10” 2759fps@muzzle 105yd limit
11.5” 2940fps@muzzle 140yd limit
14.5” 3250fps@muzzle 200yd limit
16” 3268fps@muzzle 205yd limit

62 TSX 1900fps expansion floor
10.5” 2654fps@muzzle 270yds limit
11.5” 2775@muzzle 300yds limit
14.5” 2939@muzzle 350yds limit

70 TSX 1800fps expansion floor
10.5” 2559fps@muzzle 290yds limit
11.5” 2649fps@muzzle 320yds limit
14.5” 2746@muzzle 355yds limit
16” 2788@muzzle 370yds limit

70TSX looks best, number wise, if your barrel can spin it fast enough.

A thread to read on this exact subject:

https://www.m4carbine.net/showthread...defense-round&


Some of my sources:

https://sofrep.com/85495/suppressed-...14-5%e2%80%b3/

https://www.m4carbine.net/showthread...s-70-Grain-TSX

https://www.m4carbine.net/showthread...m-50-grain-TSX

https://www.youtube.com/watch?v=0ZhuazCahMw

https://www.youtube.com/watch?v=S3xgcu2yNRs

I did not link any sources on LF or TOS, but I did use them.

Edit: see my chronograph thread.

[BallisticHarmony]

Thanks so much to you both!