5.56mm 70gr TSX (aka "Brown Tip") and a 20" barrel

[ABNAK]

Talking full power 5.56mm NATO pressure loading here, not .223. Obviously not the military "Brown Tip" stuff as it's not readily available to us civvies, but the commercial equivalent.

Would this be perhaps the ultimate 5.56mm load for a 20" barrel? I've read it performs well out of short barrels so *should* do even better out of a full-sized weapon. IIRC it hits close to 3000fps out of a 20" barrel. You'd have the uber combo of range/ballistic coefficient as well as terminal performance. The damn thing's a loooong bullet....looks like a lawn dart!

[Digital_Damage]

Talking full power 5.56mm NATO pressure loading here, not .223. Obviously not the military "Brown Tip" stuff as it's not readily available to us civvies, but the commercial equivalent.

Would this be perhaps the ultimate 5.56mm load for a 20" barrel? I've read it performs well out of short barrels so *should* do even better out of a full-sized weapon. IIRC it hits close to 3000fps out of a 20" barrel. You'd have the uber combo of range/ballistic coefficient as well as terminal performance. The damn thing's a loooong bullet....looks like a lawn dart!

I could never get them to group that well for me. .9-1.2 out of a rifle that can shoot 77g SMK .5-.7. I wanted to like them, but they just did not work out for me.

[.46caliber]

I could never get them to group that well for me. .9-1.2 out of a rifle that can shoot 77g SMK .5-.7. I wanted to like them, but they just did not work out for me.

I had a similar experience. I was using some leftover 69gr BTHP match ammo to get my scope close for my TSX hand loads. The PPU match grouped much better and my hand load charges are individually weighed. 1/7 twist.

Next on the list is Hornady's 70 gr GMX. I'm curious if that will fair better.

Sent from my Nexus 4 using Tapatalk

[Onyx Z]

I could never get them to group that well for me. .9-1.2 out of a rifle that can shoot 77g SMK .5-.7. I wanted to like them, but they just did not work out for me.

Was this with a clean, copper-free barrel?

[Digital_Damage]

Was this with a clean, copper-free barrel?

Ya, completely cleaned with an ultrasonic cleaner and followed up with Copper Cutter, then back in the Ultrasonic. Went way beyond Barnes instructions.

It is not like I was getting incredibly bad groups with it, just not better or the same than I was getting with the cheaper SMK.

[Failure2Stop]

I really like the 70 and 50 gr TSX, but I don't expect it to be highly precise.
1.5-2 MOA works for me for the application of the guns I am stuffing these into.
For precision, the SMK is hard to beat, but the variability in terminal performance and less than optimal barrier performance (especially auto glass) makes me prefer something else for use in guns with shorter barrels.

[ABNAK]

Ya, completely cleaned with an ultrasonic cleaner and followed up with Copper Cutter, then back in the Ultrasonic. Went way beyond Barnes instructions.

Did not know there were special cleaning recommendations for the Barnes TSX bullets. You have to use a copper cleaner every time you clean?

[Onyx Z]

Did not know there were special cleaning recommendations for the Barnes TSX bullets. You have to use a copper cleaner every time you clean?

Yes, Barnes bullets require a copper-free barrel for top external ballistic performance. Standard metal jacketed bullets use gilding metal (sometimes referred to as gliding metal), which is 95% copper and 5% zinc. The 100% copper construction fouls more.

[ABNAK]

Yes, Barnes bullets require a copper-free barrel for top external ballistic performance. Standard metal jacketed bullets use gilding metal (sometimes referred to as gliding metal), which is 95% copper and 5% zinc. The 100% copper construction fouls more.

Wow, just that 5% more copper makes a difference, huh? Or is the zinc what keeps the copper fouling down?

[vicious_cb]

Wow, just that 5% more copper makes a difference, huh? Or is the zinc what keeps the copper fouling down?

Copper + zinc = brass. Guilding metal is form of brass alloy.