So, out of boredom I decided to play with this (or I should say "that" because PSA is being awful slow to ship) new upper. A little reading lead me to choose the 120 SST which I plan to lob at hogs.

Powders I have on hand to try: LT-32, TAC, Benchmark, AA2200 (this one sems to be the most popular choice but I'm a bit of a maverick by nature), X-Terminator, and maybe AR-Comp if I find I can get enough of it under a bullet. I'd appreciate any advice based on real world experience with this bullet with any of the listed powders..

I'd also like to hear about any differences in results using cases with LRPs and SRPs. I bought a couple hundred LRP cases because that was all I could find when I took the first steps down this path. I think I'd much rather use CCI 41s, though, in part because I am well stocked with them. This morning I was able to snag 500 new SRP cases, which suits me fine...so, whatcha got for me?

TIA.

I can't offer much info about reloading the 120 SST because I handload Barnes TSX in my 6.8 using H4198 (not the best, but works well enough). However, I have shot many critters with the factory 120 SST loads and nothing has lived to tell the tale. They work very well on deer sized game and they do the job on hogs. I would advise you to wait for an ear shot when shooting large hogs because you more than likely will NOT get an exit if you shoot one in the shoulder with an SST and you will not get a blood trail. I use all Hornady SRP brass so I cannot help with the LRP vs SRP debate.

Load the powders you have and have fun finding what your rifle likes, isn't that why we handload after all?

I run mine with X-Terminator. Currently using Remington brass (LRP) until they crack or I loose them. After that I'll switch to Hornady brass with SRP. I'm not really concerned with the brass as this is a hog killing rifle and I do that 70 yards from the back door. Precision is not key for me. Off the top of my head, I think I'm using 30gr powder under the 120SST. This bullet kills hogs deader.

I got nothing on those powders.

But small rifle primer would be the way that I would go. Small rifle primers have been more available. And, if you run a brass catcher (hopefully you are) you can get more firings out of the brass, with annealing that I know you do.

I mainly used SRP but it’s nice to have supply of both that way if things get tighter you can go with what you have the most of.
I personally would look first at the powder that I had most of or could easily replace.

IMR 8208 is another powder to consider. I've loaded the 120SST, 115 AB and 110 AB and went with the 110 AB for the increased speed. I have not shot anything with the 110 AB but the accuracy was impressive. I have taken a large 200+ lb boar with the SST and it was DRT with a heart shot. I prefer the small primer CCI450 but did not notice any difference in accuracy compared to LRP.

I am using Hornady (old S&B manufacture) with 120 SST, CCI450's, 26.6 A2200. Many report they are using 27.5 A2200 but I can't get over the 26.6 without brass damage. It kills hogs fine for my shots. Is your barrel SPCII of just SPC chambered? I am using a 16" ARP barrel, mid length gas, AGB. Working on finishing a 12.5" for easier carry.

Check you mags, PRI mags will let you load a little longer. Forget the length.

The 68 forum has a lot of posted load data. You can find info on some of the powders you listed. It may save you wasting some components.

https://www.68forums.com/forums/6-8-spc-ammunition-reloading.56/

I'm loading 120 SST in Win brass, CCI 400, A2200. I'm averaging 2530 fps out of a 16" WC barrel. I can't recall the exact load but I think it was 26.5 grains. Works great on hogs and the one deer I shot.

I handloaded all types off bullets in the 6.8 for like 7-8 years, I liked the Barnes 95TTSX the best and was sent a bunch to test and provide feedback on.
I ultimately switched to factory Hornady 120SST ammo and can definitely say it works exceptionally well on deer and hogs.
The 95g TTSX I was running as hot as I could out of SSA brass and getting like 2850 from a WC 16" barrel.
The 120 doesn't shoot as flat but 90% of my shots on pigs are close range, under 200 and often 25 yards at night with thermal.

Never developed any load data for the 120s but they definitely work.

Good stuff, fella...thank you.

I think I've only found one negative comment on the 120-grain SST and many positive comments. I've been all over the 68forums digging up whatever I could on loading this bullet and that's how I selected candidates from the powders I have on hand. I didn't have AA 2200 already, so I snagged 7 pounds of it...if I find one of the others works better for me I'll still have ways of making use of it. The one powder that I found next to NO info on was AR-Comp, but I'm not averse to experimenting. When I played with 6.5 Grendel several years ago no one seemed to think it would work, but I found that it was perfect with a 129-grain LR Accubond...I may just find the same to be true with the 6.8 and 120 SST. Or maybe not.

Brass catcher--yup. If you ever see someone on the firing line who seems to spend more time walking around looking for brass than shooting, that may be me on a day when I forgot my brass catcher. I try not to leave home without it.

No 8208 on the shelf, or I would try it. Fact is, I used the last bit of room I have to keep powder and adding yet another few pounds might require an extensive remodel. I'm pretty confident that something on my list is going to work out. Sirrah's 2500+ fps out of a 16-inch barrel and loaded to a grain under max is pretty encouraging. That has me thinking I might break 2600 easily with 2200, but I'm not holding my breath. I'm really kind of obsessed with the AR-Comp idea, but I won't know a damned thing until I know.

The upper I purchased has finally been shipped--after eight days. PSA is never fast and I did not expect it to be here in two days...but I did begin to wonder. Anywho, it is indeed set up with the SPC II chamber.

I really wish I had about a thousand of the 100-grain Accubonds on hand. Accubonds have always worked very well for me, save one time that I think I didn't poke the bullet in the right place on a big boar's carcass. He went down on the first shot and started the death kick and I was totally unprepared and pretty damned surprised when he got to his feet and started for the fenceline. I know I killed him, but we never recovered him because he managed to get under the fence onto neigboring property before he expired. I know I hit him twice because we found chips of bone in pools of blood where the second shot hit him. That was a 90-grain AB (out of a 6mm AR), which has otherwise worked like a charm so I have to assume I didn't hit him where I intended to...anyway, I could drive the 100-grain AB pretty fast if I could get my hands on some. But, bullets come and bullets go.

Ccoker, 2850 with a 95 sounds awesome. In an 18-inch I bet it might break 2900. Pure poison.

Now that I think about it, having both LRP and SRP brass on hand could be right handy.

Thanks for all the insights, gentlemen.

I'd stick with the tried-and-true SRP brass and AA2200 powder. 26.5 to 27.5 seems to be the sweet spot with this powder. I 've had the best luck with CCI 41's and CCI 450's with 26.9-27.2 depending on which one of my 6.8's I'm loading for. Although it's been a while since I loaded 120SST's as I was able to buy 8k of the Speer 90gr Gold Dots.

Just remember AA2200 is temp sensitive so if you develop a max load in the winter, it will most likely be over pressure in the warmer months. H322 has proven to be very accurate, but will not generate the same speed as AA2200 and is much more temp stable. Reloader 10x works well with 110 grains bullets, but I have not tried it with the 120's.

Yeah, I've been thinking about the temperature sensitivity aspect of it. I normally choose temperature tolerant powders AND do load development in the summer, but that is out the window for the moment. I'll probably just develop my load and load up 50 or so for hog hunting through next spring, and then revisit the whole thing next July or so. I hear we're going to be in for a little hot weather. I used to use some H322 for .222 Rem, but that got replaced several times over. I kinda would like to see Benchmark take the title, then I wouldn't have to worry about it much...but I don't expect Benchmark to be The One. But who knows?

My 26.6gr load is fine winter or summer. I went for accuracy over speed.

If you forget your brass catcher use a towel draped over your scope down to the bench. Or use a hat with the adjustment strap hooked over the scope elevation turrent. May blow the towel off a few times but beats looking for 6.8 brass.

RiverRider, check your inbox.

Thanks Gary. Maybe I'll be hitting you up one of these days.

As far as temp sensitive powders go, I have always thought that if you get seasonal velocity variation, then you would probably se corresponding accuracy variations but I've never tested that theory. I've most definitely seen evidence of pressure variations, though.

H322, 8208, or Xterminator/2230 are my picks. Oddly, my Hornady manual has different max loads for Xterm/2230 even though they’re the same powder.

They're very close but not exactly the same. TAC and 2460 (IIRC) are very similar too...but not the same.

Accurate's powders are made in the USA and Canada by St. Marks (General Dynamics) and Ramshot's TAC and X-Terminator powders are made in Belgium. The sourcing may have changed over the years and maybe they were the same powders at one time, but not these days.

I have not observed accuracy variation, but that doesn't mean it can't happen. I also like to test unknowns in hot weather, even while using temp stable powders. They are not completely immune.

I do see zero shift with temperature changes. And of course, shooting distance, elevation corrections are more in the winter and less in the summer due to air density.

I don't want to veer off too far into the weeds here, but how have you determined that air density accounts for the change in trajectory in lower temps? Does it match up with the charts and such?

Another question...I'd bet a dollar to a donut you're sticking mainly with "temperature-tolerant" powders in the first place but have you chronographed at high and low temps to see what happens?

All powders will increase pressures and velocity once you get to the summertime temps we see in this part of the world. As you stated, none are immune---but some tolerate the heat better than others. The same goes for low temperatures.

To not veer too far off into the weeds. There are apps that will ping the nearest NOAA weather station, and populate temp and Density Altitude. And the better option (which I have) is a Kestrel 5700 with Elite ballistics. It is a stand alone weather station, as well as a ballistics calculator. It adjusts elevation corrections based on weather changes. Put good data in (MV, BC, weight, caliber, sight height, zero distance) and you'll get good data out. "Truing the calculator" is an adjustment of the MV. Chronographs give important information, however the chronograph data doesn't always jive perfect inside wach calculator the same.

But you can have great results out to 500 yards, and not have perfect MV plugged in. 600 to 800 yards is where I really true up the MV. I did one this way in the spring, last year. 16" 7mm-08 and a 168 Berger. I told him 2550 fps (if memory serves) four days later a Lab Radar measured it at 2560 fps. I said "six hundred to eight hundred yards doesn't lie".

I have chronographed some powder charges on the known tolerant powders. But there are also places to dig in the internet where there have been fps changes based on ambient temperature increases, put on a chart. H-1000 is one of the most stable powders made. If memory serves its something like .2 fps change per degree ambient increase. On the other side, there are rifle powders out there that at 2.5 fps increase per ambient temperature increase. Get that autumn 35° morning and a 75° afternoon and your MV has increased 100 fps, in the same day!

Think it was last year, Judd and Russ asked me about R-33 as an H-Retumbo substitute. I told them I had dug around on lots of forums and half the people were saying temp sensitive and half were saying temp stable. So it was a no go for me. Their first trip to my range using R-33 in a 28 Nosler, they narrowed down their charge ranges. The next time out I think it was 20° warmer outside, and the loads were blowing primers.

If you look at Accurate's own load data, it's exactly the same. TAC and 2460 have never been considered to be the same.

Is that data for 2230 and X-Terminator the same for all cartridges? I honestly don't know, never looked into it that deeply. But, tjey are not the same powder. The two are made in different places.

Yes.

I recently started playing around with the 120 SST's and A2200 this summer. Accuracy settled in for me at 27.1gr with my 18" 3R rifled barrel. Haven't used on any critters yet.

I have had the best overall performance (on animals) out of the Nosler AB 100gr bullets, but finding any lately is like unicorn hunting.

Doesn't make me sad that the SST's are half the price either, provided they perform as well on animals.