Black Hills 5.56mm 77 gr TMK and 69 gr TMK Review

[pyrotechnic]

That's an interesting one. Do you know why? I would think that all it's looking for is an object breaking two radar planes, but I'll admit, my chrono-knowledge is limited to reading online and a base knowledge of physics.

The magnetospeed uses the magnetic field generated by the moving projectile to induce a voltage. Time between the voltage spikes of the two sensors is uses to determine projectile speed. Proximity of the sensors to the traveling projectile is paramount to the operation of the chronograph. Their Sporter model does not have enough adjustment available to allow for the large diameter of a can.

The lab radar is pretty slick and will track your round out to about 100yds.

[bfk4lyfe]

wow that stuff moves.

[markm]

I'm really enjoying your experiences here, so much so that I've ordered some 69 gr. TMK to try myself.

The 69 gr is the surprise performer. I'd like to frag test it against the 77s in some water jugs.

[Spooky130]

Are you seeing any issues with the plastic tips and reliability in your tests? I wanted to grab some TMKs for my KAC LPR but was told TMKs don't play well with semi-autos... Seems weird that Sierra would bother with .223 TMKs if they couldn't be shot in semi-autos...

[markm]

Not a bit. I think we've shot some of the TMKs in my own hand loads too. No issues at all with the tips. My loads didn't fly as fast as this factory ammo, but none of what we've shot has been an issue.

[markm]

Ran the 77 gr TMKs out to this 1000 yard target today with Pappabear's 16" SPR. Wind was mild which is a huge help. Last week Pappabear clipped the cactus thing on the right with a TMK. It's tough to thread a bullet between the cacti.



With the mild wind, we racked up several first round hits at 900. The 77 TMK beat a hot (3014 fps) 62 gr boat tail hollow point by a full mil. (8.5 vs 9.5 mils) out of the 20 inch bolt gun.

I was able to go 3 for 3 with a red dot sight at 500 again today with the BCM 14.5 middy KMR. I was pleased to repeat these shots from last week.

[Pappabear]

Are you seeing any issues with the plastic tips and reliability in your tests? I wanted to grab some TMKs for my KAC LPR but was told TMKs don't play well with semi-autos... Seems weird that Sierra would bother with .223 TMKs if they couldn't be shot in semi-autos...

We have run TMK's out of 10 different guns with no issue. Buy with confidence.

[gaijin]

"I was able to go 3 for 3 with a red dot sight at 500 again today with the BCM 14.5 middy KMR. I was pleased to repeat these shots from last week."


Well done. Crazy well done.
2 minute dot on the micro RD? (Holosun?)
What size is your 500 yd. target?
Even with the desert terrain/coloration I'd have trouble picking up anything much smaller than a billboard at 500 with unaided eyes.

[markm]

Well done. Crazy well done.
2 minute dot on the micro RD? (Holosun?)
What size is your 500 yd. target?
Even with the desert terrain/coloration I'd have trouble picking up anything much smaller than a billboard at 500 with unaided eyes.

It's an IDPA size gong. Fairly large. Both times I shot it, I had 10 rounds in the mag and quit after 3 so I didn't screw it up.

Pappabear ran his 11.5" Sionics reduced gas port gun with ACOG out to 640. I think he was holding the 500 yard hash on the reticle at the top of the IDPA size gong to get hits.

[Pappabear]

It's an IDPA size gong. Fairly large. Both times I shot it, I had 10 rounds in the mag and quit after 3 so I didn't screw it up.

Pappabear ran his 11.5" Sionics reduced gas port gun with ACOG out to 640. I think he was holding the 500 yard hash on the reticle at the top of the IDPA size gong to get hits.

The black hills was dead on with my ACOG at both 500 and 640. It's nice to be able to put the reticle on the target and it hits. Our 77's require a slight hold over at longer ranges due to I suspect ACOGS being calibrated for lighter faster bullets. But the heavy BH makes up for the difference.

Whatever the hold is, you just need to learn it. But it's still cool.

PB