.223/TAC/16" AR Velocities

[Potsy]

Ran the following a few weeks ago. Thought I'd get some opinions here. Should have saved some group pics, but I was shooting at electronic targets at 600 yards (couldn't use the 300's), and while my 6X SWFA did very well at that range (everything landed in about 1.5-2..MOA or a little more), I didn't trust my own groups. So, I'll just post my velocities.
16" Black Hole barrel, Mid Gas, w/9" SAS Arbiter Suppressor
R-P Brass, CCI400's, All Loaded w/TAC
Velocities per MagnetoSpeed.

Hornady 75BTHP
24.1 2635
24.3 2733
24.5 2759
24.7 2774
24.9 2795
25.1 2802
25.3 2819
25.5 2848

Hornady 73ELDM
24.1 2699
24.3 2765
24.5 2787
24.7 2827
24.9 2844
25.1 2851
25.3 2852
25.5 2882

Hornady 53V-Max
25.6 2964
25.8 3003
26.0 3018
26.2 3047
26.4 3049
26.6 3137


For the 75 and 73, I was looking at 24.6 and 24.4, respectively. The nodes were better at 25 grains for both, but primers were FLAT, and simply fell out of the cases when the decapping pin touched them at 25.3 and 25.5, so I know 25 is starting to get more than a touch warm.

The little 53 VMax is evil. I've been running it at 26.0 and it makes tiny groups and was under 1.5 MOA at 600 yards (which is pretty fricken' good for me with my AR, shoulda took a pic of the group, the wind was VERY calm, btw). I'm gonna bump it to 26.3 and see if that's an even happier place.

I tried a ladder with Hornady 55SPT's (having had good luck with 25.0 of H335), there's a good node around 24.5-25.6 with TAC, but it's only running about 2875, and I'd like something a bit closer to 3,000fps. I only ran it to 25.3 and was getting 2988, but there was no real node from there back to 24.7. I'll try from 25.3 to 25.7 and see what happens.

Shoulda measured OAL, but each load was seated just deep enough to function in an ASC magazine.

 

[never_summer]

You should try some thicker primers especially running that high of pressure, pretty impressed you had that good of luck with 400s

 

[Potsy]

I've never had a problem with 400's (not saying others haven't), and have ran around 600 of them through my AR. Before that, I've ran 7-1/2's, 205's, and some BR-4's, but this is my first attempted "ladder" with the AR, so, numberwise, I couldn't tell you which primer is "best". Some loads have grouped well, others, not so much, that's about it.
I bought a couple thousand of them before the last presidential election and only after I bought them did I start to read where they would give trouble in an AR. I've ran 400's with LeveRevolution, 335, and now Tac, and the only issue I ever had was when a primer fell out of a Federal case (that had a couple reloads on it, I knew the pockets were getting sketchy) loaded with 25.3 H335 and a 55SPT. Haven't used Federal cases since and pay more attention when seating primers.
I'm sure some with WAY more experience than I will disagree, but I've wondered if AR's are like Rem 700's where it comes down to the difference in bolt face and firing pin as much as primer thickness. Also, I don't run my AR hard (I nearly treat it like a bolt gun), and, between a heavy carrier (Bravo), spikes buffer, and the SLR gas block, I don't run it over gassed. If I were a "hard charger" I'd likely run 41's, based on what I know now.

After prattling on about all that, I DO WONDER if running 450's would help tighten up the lower "nodes" (no idea as to their relative thickness), as I've read that TAC likes a hotter primer.
I'm going to play with that after componentry becomes available again, as my precious stash of 450's is currently being saved for my .22BR.

 

[DownhillFromHere]

I found CCI 400s to flatten excessively in my Tikka T3X Varmint at even the mildest .223 loads with multiple powders and bullets from 55 through 77 grains. CCI 450s did much better as regards flattening. Winchester SRPs were in between.

The Tikka is gone, sold to finance a new .223 build. Since I have several boxes of 400s, I'll try them in the new one.

 

[308pirate]

@Potsy 25 grains of TAC under a 75+ grain bullet is pushing it regardless of whether you can keep the primer in the case or not.

Find a lower node. You're playing with fire.

 

[Potsy]

I never wanted to be over 2,700 with either bullet. A little would have been fine, but not 150fps worth.

Ramshot Data has a max load of 25.8 grns of TAC with a 75BTHP. It runs 2,994fps (24" barrel) with their data. I figured 25fps/inch times 8 inches would give 2,794 in my 16" barrel. I didn't even want to be at the the very top (and still don't), so I figured I'd run up to 25.5 and find my load somewhere under that.
But yeah, 25 and definitely anywhere above is too warm, at least in my inexperienced opinion.

Beyond the primers flattening and falling out above 25, my rifle recoiled noticeably harder, which is I supposed would be attributable to more pressure AND more gas coming back through the system, as my brass was flying farther as well.

I will say I was surprised that the 73's were that much faster than the 75's. My uneducated guess is that the 73's appear to have a touch less bearing surface that the 75's, ergo less friction running down the barrel. The 73's may have been seated a tick deeper, as they are a tick longer, but I'd not think the slight difference would be worth nearly 50fps at any given charge, speeds were also higher all the way back to 24.1, not just at the upper end.

I'll add that I've read BHW barrels run a bit fast, but I'm not really counting on that (and certainly not to the tune of extra 150fps!)

Probably back up to 24.4 with the 75BTHP's and load them. Not a great node, but I'm done with them after their gone. I'll go with 73's after that, as they shot VERY well at 600, have a better B.C. (so I've read) and are nearly the same price.

Next time I can lay hands on my Buddy's Magnetospeed, I'm going to run 23.3 to 24.3 with the 73ELDM's and 450's and see what happens.

 

[308pirate]

Ramshot Data has a max load of 25.8 grns of TAC with a 75BTHP. It runs 2,994fps (24" barrel) with their data.

That's for rifles chambered in either 5.56x45 NATO OR in a CIP (not SAAMI) 223 Remington chamber.

Are you sure your barrel is either?

 

[Potsy]

.223 Wylde, which, by all accounts, should be fine with 5.56 ammo.

But apparently not over 25.0 grains of TAC. I sorta suspect there’s not a rifle out there that 25.8 won’t be hot in, regardless of what’s stamped on the barrel or how deep the throat is........

 

[308pirate]

.223 Wylde, which, by all accounts, should be fine with 5.56 ammo.

But apparently not over 25.0 grains of TAC. I sorta suspect there’s not a rifle out there that 25.8 won’t be hot in, regardless of what’s stamped on the barrel or how deep the throat is........

I agree. That's why we do what we do.

 

[Nodayhunter]

My custom build .223 Wydle with 16 inch proof barrel loves the 53 grain vmax as well. It averages 3150 at the muzzle with factory Hornady superformance rounds. It is a sub half moa shooter out to 200 yards, haven't tried anything further yet.