Hornady 129 SST & 8208

[Whelenon]

I was pleased with the 129 SST, shot Sub-MOA with 26g of 8208. If I discard the largest group and I don't know what happened there, most likely operator error but otherwise I averaged 1.108.

Bullet - Hornady 129 SST
Powder - 8208
Charge Weight - 25.4, 25.7, 26, 26.3, 26.6

Case - AA(Lapua)
Primer - CCI 450
COL - 2.255

Barrel
Chamber - Grendel
Make - Liberty/Satrun
Length - 18"
Twist - 1-8

Average Group Size in MOA
Distance - 100yds
Largest Group Size - 3.269
Smallest Group Size - .944
Number of shots per group - 5

Temperature - 65 degrees
Humidity - 80%
Wind - 5-10mph @ 7 o-clock

[sneaky one]

Maybe try a bit warmer-I remember rj stokes using 28.5 of 8208 w/ the new 123sst-he had great groups w/ it. Try to up it slowly to 27.9, or so. Be very careful dude.
Also try loads at 2.275 col., if the mag can flow them thru. If not, I'll make you a mag. like mine=I can run 2.33 thru it. Or you can polish the tip down a bit-to fit the mag.
Hornady's old school approach to ogives is -well-not perfect for the Grrr. I sold my 123 sst's. Was not happy happy w/ them either.= tooo short.

Keep on it-the 129 is a fine bullet construction--check backward a few months, Von & Drifter & I did some work w/ conan -lead hardness testing-& such. Remember? The 129 is in there -halved like the rest-

The 129sst was a beauty on the internal curl back area, =one tuff bugger.
I used Tac w/ 27.? w/ them 3 yrs. ago=1" groups all day in some wind @ 100yd.

I use cfe-223 mostly now, it gives a tic more speed. Accuracy is always equal to the previous powder darlings, plus it keeps the bbl. cleaner.

[Whelenon]

More good results with the 129 SST & 8208 which duplicates my last time out. 25.9g of 8208 gave me a .565 group. First time out 26g gave me a .947 group.

Bullet - Hornady 129 SST
Powder - 8208
Charge Weight - 25.5, 25.7, 25.9, 26.1, 26.3

Case - AA(Lapua)
Primer - CCI 450
COL - 2.260

Barrel
Chamber - Grendel
Make - Liberty/Saturn
Length - 18"
Twist - 1-8

Average Group Size in MOA
Distance - 100yds
Largest Group Size - 1.660
Smallest Group Size - .565
Number of shots per group - 5

Temperature - 70 degrees
Humidity - 75%
Wind - calm - 5mph @ 1 o'clock

[XcountryRider]

Do you know barrel velocity?

[Whelenon]

No, I don't have a chrony.

[Whelenon]

I'm sold. 25.9 of XBR 8208 and the Hornady 129 SST.

Bullet - Hornady 129 SST
Powder - 8208
Charge Weight - 25.9

Case - AA(Lapua)
Primer - CCI 450
COL - 2.260
Jump .020

Barrel
Chamber - Grendel
Make - Liberty/Satrun
Length - 18"
Twist - 1-8

Average Group Size in MOA
Distance - 100yds
Largest Group Size - 1.169
Smallest Group Size - .564
Average = .885
Number of shots per group - 3

Temperature - 80 degrees
Humidity - 60%
Wind - calm

I normally shoot at 100yds but it was shooting so well I took it out to 200yds, shot a five-shot group for 1.939". Good day for me.

[Sputnik]

...I use cfe-223 mostly now, it gives a tic more speed. Accuracy is always equal to the previous powder darlings, plus it keeps the bbl. cleaner.

Drifter recommended CFE 223. What amount works well with 123 SST? He also likes 8208 , H4895 but really prefers ARComp. He says 27.7 gr has shown promise. I think that amount was just for the AR Comp. He posted some groups with that charge a while back.

[Whelenon]

I tried CFE 223 with the the 123 SST with disappointing result. That not to say don't try it, it just didn't shoot well for my Grendel.

I tried:

1640/2.215 COL
30.4 1.313"
30.5 1.313"
30.6 1.79"
30.7 2.07"
30.8 2.068"

COL 2.230
30.6 1.11"
30.9 1.756"
31.2 2.701"
31.5 1.744"


these were 5-shot groups at 100yds,

[KentuckyBuddha]

What barrel was that Whelenon?

[Whelenon]

18" Liberty/Saturn 1:8

[KentuckyBuddha]

Thanks! I have a few, but none are Saturn.

[Sputnik]

Wow! Nice shooting! Let us know if these results are repeatable and if you intend to tweak it further..."More good results with the 129 SST & 8208 which duplicates my last time out. 25.9g of 8208 gave me a .565 group. First time out 26g gave me a .947 group."

That 25.9 gr load of 8208 looks very promising! I won't even have my upper for a few more months, but I will sure remember that recipe.

[Whelenon]

Wow! Nice shooting! Let us know if these results are repeatable and if you intend to tweak it further...

That 25.9 gr load of 8208 looks very promising! I won't even have my upper for a few more months, but I will sure remember that recipe.

The last time out proved the load out. Four 3-shot groups @ 100yds averaging .885, two of those groups sub-moa and a 5-shot group at 200yds also sub-moa.

I will be loading up some more 129s once i find another box of them. Will continue to shoot some more groups with this load and make any changes if required.

[Sputnik]

Thanks, this helps me with a building block approach; when I get my Grendel. I Have 120 rounds of 123 Factory Amax and 120 rounds of factory 123 SST to break it in. If they shoot well, I will experiment with 123 SST reloads using some posted recipes, and if I want to go heavier, work on the 129 SST with your results in mind. I will now actively seek out the 8208 powder, but would like to make a few batches with CFE 223, AR Comp and maybe H4895. Local availabilty will be the short term problem. Many powders are scarce around here; but getting better at the gunshows. Too bad nobody sells build-your-own sample packages of powders. Seven 1000 grain samples is about a pound.