Home Forums Hunting & Shooting Elk Hunting Ramshot TAC temperature sensitivity?

Does anyone have any real-world experience with the temperature sensitivity of TAC in .223 with heavy bullets (77-80 grains).

Not with bullets that heavy, but with 50's the velocities are very close from zero to 90 degrees.

I don't know how I ended up posting this under the Elk Hunting forum. I'll see if I can move it.

Thanks, Mule Deer.

Interesting, I've heard that Tac is temperature sensitive, but 0 - 90 covers about all the temps I shoot something like an AR in. I just bought a pound of Tac with the intent of trying it in bulk 55gr and 68gr 5.56 loading on my progressive. Love Varget and IMR4064, but they don't meter all that well.

Varget is easier than imr4064 for metering, no?

Most powders are easier-metering than IMR4064. Varget is just one among dozens....

In testing many years ago with 77s, it was stable enough for 600 yard NTIT shooting groups for us, holding solidly MOA and just under in various uppers/barrel brands for team members.

Tested from around 40 degrees to what was likely 125 or so in direct sun and even leaving rounds chambered in a hot chamber up to about a minute or so IIRC.

We hardly ever see much less than 40 unfortunately so I can't comment on the low side. But it was very similar to Varget IMHO, though I've not seen anything exactly as stable as Varget. And varget meters just fine for me.

YMMV

When Western Powders first introduced TAC around 2000 or 2001 (I'd have to look it up in my loading notes) they claimed it was very temp-resistant (have heard they don't anymore). I'd been running cold tests with various powders for close to a decade by then, because I'd had some really wonky stuff happen when hunting here in Montana down around zero.

That winter I ran some more tests at just about zero, including TAC with a load with 50-grain Ballistic Tips I'd used during summer on prairie dogs. It averaged EXACTLY the same velocity as it had at 70 degrees, which is the one and only time that's happened in all the cold-weather testing I've done--which had to be pure chance, because even when two strings of any load are chronographed during the same range session, one always averages a little different.

Ran several cold-tests this past summer and winter, and partly to check my results from 2001 tried several of the same basic loads I'd tried back then, to see if there was much difference in the results. There wasn't, though the .223/50 load didn't average exactly the same at zero as at 70. This was with entirely different chronographs than used back then, but the results were consistent.

A few years ago, I worked up some loads for a prairie dog trip to Montana. I settled on 28.3 grs of TAC with the 40 gr Varmageddon in a Remington 700 223. Everything looked great. This was in March.

Fast forward to mid June in Montana -- it was hot and I kept the barrel hot. I had some serious bolt lift issues.

I've since backed the charge down to 28 grs. Just as accurate and almost as fast. I doubt my experience was due to temperature sensitivity. I'd say it was more pressure related😀 Not 100% sure, but???

That's the only issue I've ever witnessed with TAC.

Any powder tends to develop more pressure at temperatures much over 70, but the less temp-sensitive powders develop less. And hot barrels change things too!

That said, I've had far fewer problems with TAC when prairie dog shooting than some "traditional" spherical powders.

I have burned through a LOT of TAC since it came on the market. I use it with 40 and 50 grain bullets in 22-250 and in my 222. I have not found much of a difference in velocity between 35 and 110 degrees. I doubt I have ever fired a round in temperatures below 15 degrees that weren't 50 yard or closer shots (elk in timber) so no experience with cold weather testing. It's good to go in the two aforementioned calibers at above freezing temperatures.

Jeff (? I think), that is what I was hoping to hear as I plan to use it this year for XTC Service Rifle comps. I'm still in the hunt for DR points and hope to knock it out this year.

I simply got tired of having to search for Re-15 and Varget when every shop I went into had plenty of TAC on the shelf. If it's no more temp. sensitive than Re-15 I'll be satisfied. I don't own a chrono, so even with my notes on temp. using other powders, I could not really tell if my loads exhibited temp. sensitivity or it was just day-to-day differences in my position.

Thanks to everyone for your discussion on the topic.

I don't think its as sensitive as RL15 IMHO.

Granted something may have changed since I haven't shot it since 2004 basically.

Good luck on the points! It'll happen. Just shoot. Don't worry about points. Shoot it as 50 one shot matches. Best on every shot, don't worry about score. It works itself out.

Good luck!

Jeff

BTDT with N540 when on the ragged edge... Had to keep that bunch of loaded ammo in a cooler prior to use in the matches.

IIRC either .2 or .4 reduction kept everything fine too.

I understand that it will come, but 5 first-leathers in the past two seasons is getting old!
And now that many (most) folks have switched to optics, myself included, it's upped the ante a bit.

That's good to hear about TAC compared to Re15. I've always thought it to be more temperature sensitive than some folks would admit, including the mfr..

Yes, 4064 meters like little Lincoln Logs. Varget does ok in my 3BR, but still has more variance than say Ar-Comp. I do all pistol on my progressive, but am going to start doing 5.56 as well, and thought I'd try a spherical powder since I know my Hornady meter does well with a few different sphericals. Tac gets good reviews for 5.56, and my only concern was temp sensitivity. From the experiences in this thread, it seems my concerns were probably overblown.

I"m sure I"ve had as many leathers... LOL.

The optics have not upped the ante, they have actually lowered it some if you think about it. Surely some are still shooting irons.. those are out instantly when you think about it.

And the ability of the shooters is going to be the same as it always was. Just that the end scores will be higher. Its effectively the same.

Yes this was a mental game lecture.

If I can manage a 495 in a leg, anyone then as the ability to, as my shooting ability is far from teh top and its dang sure not natural ability...

Jeff