Speer .308 125 gr TNT with AR Comp

[redcon1]

I had a hundred rounds of this stuff loaded up since 2019 and I finally got around to shooting it today. It was loaded up as a ladder test with 20 rounds having 44.2 gr of AR Comp (Speer's start load),. 20 rounds at 44.5 gr, 20 rounds at 44.8 gr, 20 rounds at 45.1 gr and 20 rounds at 45.4 gr. Speers max is 49 gr (C). I'm using Lake City Once fired brass so case capacity is reduced. My notes indicate that 45.1 gr was probably lightly compressed and 45.4 was definitely compressed. Spe 2,995 fps with this start load) Speer notes that 49 gr gave them 3,231 fps. Sadly, they don't state what barrel length they used.
My accuracy node was immediately and undeniably identified at 45.1 gr. I don't think I've ever seen an accuracy node pop out that dramatically. As I worked my way up to those 45.1 gr loads, I was very unimpressed with it all. Then I saw that beautiful 5 shot one hole group after shooting the 45.1 gr load and I immediately became concerned that I didn't have more AR Comp. I will have to remedy that ASAP. I over adjusted my scope after 44.8 gr which is why groups shifted to the right.

Anyways, here are the velocity numbers from my DPMS Gen II Recon with a 16" barrel as measured by my new magnetospeed. I find them to be pretty interesting especially considering that I'm allegedly 3.9 gr below max. I really like these light for caliber bullets in 16" barrel battle rifles. I had thought that the Nosler BT was going to be the preferred bullet here but after this, I'm liking the TNTs a lot and they are much cheaper.

44.2 gr: 2,873 fps SD: 9.4 ES: 21 MOA: 1.6 (Speer got 2,995 fps with this start load)
44.5 gr: 2,871 fps SD: 11 ES: 30 MOA 2.4 MOA
44.8 gr: 2,884 fps SD: 8.1 ES: 20 MOA 1.5 MOA
45.1 gr: 2,894 fps SD 7 ES 17 MOA: .54 MOA
45.4 gr 2,922 fps SD 7 ES 18 MOA: 1 MOA (excluding a flier) 1.6 MOA including the flier

I also shot quite a few 125 gr Nosler BTs loaded up with either Ramshot Tac or AR Comp today out of the 16" Recon and the 24" AR10T.
Accuracy was just not there. I had loaded these rounds back in 2016 actually and the ones I shot in 2016 weren't any more accurate as I recall. These bullets are good but they're pretty expensive. I have a a few hundred left and I will look for an accuracy node later but, for now, I think the TNT is the clear winner. The TNT has a .341 BC incidentally and the nosler is .366 so you're not gaining a lot for the extra money. The Noslers are $64/100 and the Speer TNTs are $29/100. I think the 125 gr TNT would be absolutely devastating as a SD round.

I have the Nosler velocity data and it's 2869 fps but, unfortunately, the load data was lost. I'm not even sure what powder was in those cases let alone how much (although I'm sure it was safe).

Bottom line: I need more AR Comp and a bunch more 125 gr Speer TNTs which I will be ordering here after creating this thread.

 

[2ndtimer]

Glad to see someone else has discovered the Speer 125 gr TNT in a .308 AR. Definitely the best bang for the buck for accuracy available. I use Ramshot TAC, and found my accuracy at just under 48.0 gr. I have been fortunate to find the bulk pack of 500 for under $100 recently. I haven’t shot a coyote with it yet, but since they leave my 18” barrel at over 2900 FPS, I am sure they will do the job!

 

[redcon1]

I have one of those 500 bulk packs too (-100 rounds now) and I just ordered a couple hundred to replace the ones I shot yesterday. I also have a few pounds of Ramshot Tac and about half a pound of AR Comp left. Unless I can find a jug of AR Comp, I'm gonna have to try to find a sweet spot with the Tac. I am not seeing AR Comp for sale anywhere unsurprisingly. I found it interesting that the AR Comp groups tightened up as soon as the base of the bullet started to compress the powder at 45.1 gr and then when the compression increased a little more, it opened back up. I have to wonder how much the load density had to do with it and if a similar load density behind a similar bullet might yield similar results with different powders as well.

 

[IALoder]

I may have to try some of these 125 TNT's in my .308 AR. AR Comp seems to be it's powder of choice, so that's covered! Those are some pretty darn good velocities!

 

[redcon1]

Velocity out of a short barrel is what I was after here- something that shoots as flat as possible out to 400-500 yards so as to not have to worry about drop and wind so much. Those carbine length barrels really suffer in the velocity department. Not sure if I can squeeze even more velocity out of this and still maintain that kind of accuracy and SD/ES. I want to try to though.