.223 Rem TAC and 75 ELDM Experiment - Range day update

Pharmseller

Sergeant of the Hide
Full Member
Minuteman
Nov 14, 2021
264
433
Oregon
I have a new-to-me stainless Tikka T3 Varmint in .223, bought it here on the Hide. It shot my previous 75 gr ELDM load okay, but not how I know Tikkas can shoot. I figure that if I have to do it over I’m gonna do it differently.

I did some research and decided to try TAC. I’m running it kinda hot so I’m not gonna post my load, but chrono testing gets me 3043, ES 16, SD 6, but only 7 shots. Brass looks fine, no bolt lift issues. I’m loading pretty long with Mountain Tactical magazines.

I put together a seating depth test starting at just kissing the lands (2.477”) and ending at 2.373,” which isn’t far from the ogive. Weather permitting I’ll be able to get an afternoon in maybe Wednesday.

AA628C0A-28D1-4B29-8752-92EEC02FD2F8.jpeg


I’m looking for Tikka accuracy. 3043 with a .235 G7 ain’t bad.



P
 
Last edited:

bunsen27

ACME Labs
Full Member
Minuteman
Jan 2, 2011
1,767
435
Raleigh, NC
I've been running 73gr and 75gr ELDM's over TAC since 2018. I use CCI 41 or 450 primers with Lapua brass. Using a Forster bump die with bushings, 21st Century mandrel and annealing every time has yielded excellent brass life so far. It's a really fun load for LR and PDogs.
 
  • Like
Reactions: MustangGreg66

Pharmseller

Sergeant of the Hide
Full Member
Minuteman
Nov 14, 2021
264
433
Oregon
I've been running 73gr and 75gr ELDM's over TAC since 2018. I use CCI 41 or 450 primers with Lapua brass. Using a Forster bump die with bushings, 21st Century mandrel and annealing every time has yielded excellent brass life so far. It's a really fun load for LR and PDogs.
How much TAC?

And what’s the velocity?
 

Pharmseller

Sergeant of the Hide
Full Member
Minuteman
Nov 14, 2021
264
433
Oregon
I sized some brass this afternoon from my chrono test. Primer pockets were as tight as a frog’s ass.

R-P brass, CCI 400 primers.




P
 

Matt_3479

Sergeant
Full Member
Minuteman
Oct 12, 2009
1,133
751
42
Awesome! I just ran out of tac and trying something else right now. Just did a pressure test and got to 3166 with 75 eld’ms. A sweet node between 3100-3140fps but it’s a little warm and a slight bolt clock. No other signs of pressure. Other node not as good looking at 2980 fps so going to start there
 

Pharmseller

Sergeant of the Hide
Full Member
Minuteman
Nov 14, 2021
264
433
Oregon
Awesome! I just ran out of tac and trying something else right now. Just did a pressure test and got to 3166 with 75 eld’ms. A sweet node between 3100-3140fps but it’s a little warm and a slight bolt clock. No other signs of pressure. Other node not as good looking at 2980 fps so going to start there


Keep us posted.
 
  • Like
Reactions: Matt_3479

TX_Diver

Private
Full Member
Minuteman
Feb 15, 2017
341
61
WI
How's the MT magazine treating you?

I had to send mine back because it wouldn't feed reliably. Waiting on a Gen 3 which is a little ways out but they've been good about keeping me updated at least.
 

Pharmseller

Sergeant of the Hide
Full Member
Minuteman
Nov 14, 2021
264
433
Oregon
How's the MT magazine treating you?

I had to send mine back because it wouldn't feed reliably. Waiting on a Gen 3 which is a little ways out but they've been good about keeping me updated at least.

4th round hangs up sometimes. Minor annoyance, push the tip down and the rim pops up and feeds.
 

Pharmseller

Sergeant of the Hide
Full Member
Minuteman
Nov 14, 2021
264
433
Oregon
Range day today and the conditions were great.

I started the seating depth test with the shortest rounds. Awful. The first 3 iterations were more like a shotgun pattern than a group. The next two lengths showed promise but then I got to the longest set, just barely touching the lands.

8B240355-B7D6-41BB-A0D3-688C4329135F.jpeg



I need to roll a few more but this is a pretty good first effort.
Safe in my rifle only, do not exceed published loads.
OAL is 2.477”
 
Last edited:
  • Like
Reactions: MustangGreg66

Pharmseller

Sergeant of the Hide
Full Member
Minuteman
Nov 14, 2021
264
433
Oregon
I rolled a few more today from the accuracy load to run over the chrono. Average of 10 shots was 3101, SD of 16,
which I thought was a little high. The original test load (3043) was a little shorter but the sd was only 6.

For you statistics wonks out there the mean was equal to the median which was equal to the mode. But still, 10 shots is just the start.

I rolled enough for a range day to confirm precision.

Brass looks good. Primers are maybe a touch cratered but bolt lift was easy. Primers look proud but it’s just the angle.


27EA1E4D-29B2-4CC8-88D8-196A17EABD7F.jpeg





P


 
Last edited:

powdahound76

Old tired dad
Supporter
Full Member
Minuteman
Supporter+
Sep 7, 2011
8,447
21,101
Denver CO
Dang!!!
Thats some crazy speed!
And nice shooting!

New .223 here has an 18” barrel.
Ran into signs with 24.1 of TAC and 75 bthp in LC brass.
Wylde chamber.
 

supercorndogs

Ham Fisted Gorilla
Full Member
Minuteman
Feb 17, 2014
10,171
12,439
Colorado
So pretty crazy accuracy and numbers from mixed head stamp brass. I wouldn't expect it to do that consistently.
 

Matt_3479

Sergeant
Full Member
Minuteman
Oct 12, 2009
1,133
751
42
Back from the range day. Can confirm.



75 grain ELDM, G7 BC .235 @ 3101 fps.

Safe in my rifle only, work up to published loads. Do not exceed maximums.

That’s awesome! Makes me feel better about continuing with my load! Everyone kept telling me back off that’s way way too hot. There is 0 signs of any pressure minus the slightest little bolt click which is obviously some pressure, but the node is huge, the accuracy is even better and the speed is 3100+ fps with 75 eld.
 

Pharmseller

Sergeant of the Hide
Full Member
Minuteman
Nov 14, 2021
264
433
Oregon
So pretty crazy accuracy and numbers from mixed head stamp brass. I wouldn't expect it to do that consistently.

Wow, thanks for the sharp eyes. I’ve been using R-P for so long I stopped looking at headstamps.

I just went through 300 cases and found 5 that didn’t belong. I’ll have to be more vigilant in the future.



P
 

stello1001

Professional Newb
Full Member
Minuteman
  • Feb 20, 2017
    3,881
    2,612
    Corpus Christi TX
    Wow, thanks for the sharp eyes. I’ve been using R-P for so long I stopped looking at headstamps.

    I just went through 300 cases and found 5 that didn’t belong. I’ll have to be more vigilant in the future.



    P
    Probably just go through your entire stash and make sure. Better safe than sorry!

    😉
     

    jLorenzo

    Sergeant
    Full Member
    Minuteman
    Feb 20, 2017
    1,073
    178
    I have read that the fastest velocity achieved for an 80gr SMK was with Tac. Who knows but it seems to be a great powder. Ive been messing with 8208 XBR and the 75gr ELD. 3044 out of a 26" barrel at 35 degrees. Gonna keep working with tac too. Found some powder nodes now gonna play with seating depth. If I seat the bullet deeper the velocity and pressure should go up correct?
     

    semperfireloading

    Sergeant of the Hide
    Full Member
    Minuteman
    Apr 3, 2020
    111
    74
    I am pretty sure the fastest velocity without blowing primers in a 5.56 is using PP Varmint Powder. Its incredible. Blows away tac and very similar burn rate and consistency/metering/load data.
     

    Pharmseller

    Sergeant of the Hide
    Full Member
    Minuteman
    Nov 14, 2021
    264
    433
    Oregon
    I have read that the fastest velocity achieved for an 80gr SMK was with Tac. Who knows but it seems to be a great powder. Ive been messing with 8208 XBR and the 75gr ELD. 3044 out of a 26" barrel at 35 degrees. Gonna keep working with tac too. Found some powder nodes now gonna play with seating depth. If I seat the bullet deeper the velocity and pressure should go up correct?
    Not necessarily.

     

    Yondering

    Sergeant
    Full Member
    Minuteman
    Mar 16, 2017
    1,686
    1,138
    Skagit Valley, WA
    I am pretty sure the fastest velocity without blowing primers in a 5.56 is using PP Varmint Powder. Its incredible. Blows away tac and very similar burn rate and consistency/metering/load data.
    I have read that the fastest velocity achieved for an 80gr SMK was with Tac. Who knows but it seems to be a great powder. Ive been messing with 8208 XBR and the 75gr ELD. 3044 out of a 26" barrel at 35 degrees. Gonna keep working with tac too. Found some powder nodes now gonna play with seating depth. If I seat the bullet deeper the velocity and pressure should go up correct?
    Not quite. While both TAC and PP Varmint are capable of some great speeds, Lever is the king of speed (at least in anything commercially available) in heavy bullet (really anything over 69gr) 223 / 5.56 loads. There is no published data that I know of for it, but working up your own loads side by side with TAC will show a significant speed advantage to Lever. This has held true for me in everything from 65-85gr bullets (mostly in 223 Wylde and 5.56 chambers, so longer throats than 223 Rem) and a bunch of different barrel lengths. I have not loaded the 80 SMK, but having loaded bullet weights on either side of that, I don't see why it'd be any different.

    8208 is a great 5.56 powder and very temp stable, but it won't get you anywhere close to TAC speeds at sane pressures, much less match what Lever can do.

    Also FWIW AA2520 is capable of some really good velocity too. It and Lever are both fairly temp sensitive of course. CFE223 is no slouch either, and sometimes the data for that powder is close to (although slightly lighter) Lever loads.
     
    Last edited:

    Yondering

    Sergeant
    Full Member
    Minuteman
    Mar 16, 2017
    1,686
    1,138
    Skagit Valley, WA
    I have read that the fastest velocity achieved for an 80gr SMK was with Tac. Who knows but it seems to be a great powder. Ive been messing with 8208 XBR and the 75gr ELD. 3044 out of a 26" barrel at 35 degrees. Gonna keep working with tac too. Found some powder nodes now gonna play with seating depth. If I seat the bullet deeper the velocity and pressure should go up correct?


    On the seating depth thing - pressure generally goes up as jump to the lands decreases, meaning bullets are loaded longer.
    The "rule of thumb" about pressure increasing when bullets are seated deeper is more for straight wall pistol rounds; with the bullet being a large diameter relative to the powder space, seating just .010" deeper can have a large % effect on available powder space, and that ends up being more significant than distance to the lands.

    But in most bottleneck rifle cases, where the bullet is a small diameter relative to the case body, seating that same .010" deeper has a pretty minimal effect on the % change to available powder space. However if the bullet is anywhere close to the lands, even at .100" off, it can make a noticeable change to the bullet's starting resistance into the lands, which directly affects pressure. This is why that "rule of thumb" is usually backwards for rifle rounds, and why I mentioned to you that Gordon's tool isn't reliable because it gets this backwards as well.
     

    Scrumbag

    Sergeant of the Hide
    Full Member
    Minuteman
    Mar 4, 2020
    168
    97
    U.K.
    I like TAC with the heavier bullets (used to be great stuff with 65gr Sierra SBT) but I'm using more X-terminator now as shooting more and more 55gr bullets.