Sierra 120 Tipped Gameking

[Jake TN]

For a 12.5” barrel, I think I might lean on the 129gr ABLR, one of the lighter Maker TREX bullets, or Cavity Back 105gr MKZ.

You could also try CFE223 under the 120gr TGK.

Looking at my load data for TAC under the 120gr SMK from a 16” AA/ER Shaw barrel over 10 years ago, I was getting an average of 2470fps with 28.8gr of TAC in Lapua brass with Rem 7.5 Primer.

28.3gr 2404fps
28.6gr 2456
28.8gr 2470

Running that through an internal ballistics engine calibrated for 6.5 Grendel on Shooter’s Notes website, I get the following from a 12.5” barrel:

28.3gr 2304fps
28.6gr 2326
28.8gr 2341

This is assuming the start pressure characteristics are the same between the 120gr SMK and 120gr TMK, which they likely are not due to a thinner jacket in the 120gr TMK.

With CFE223, I would work up from 29.0gr to 31.4gr. That might get you over 2350fps, which is in the weeds compared to TAC.

LRRPF52,

My original plan was to the use the 95 TREX for this build. I tested out some loads with 29.5, 30, and 30.5 gr of TAC. I have never loaded ammo that had shot so horrible before. I do have some more loaded to test with 31.6, 32, and 32.4 gr of CFE. Hopefully there are some decent groups.

I also have some 120 TGK loaded with 29.2, 29.6, and 30 gr of CFE to test. I have limited the amount of powder to what I thought would not be compressed. I use a Redding seating die, so I have not done compressed loads ( would damage the die according to Redding). Got a new forester seating die for Christmas, so that can change in the future. The 120 TGK is just so darn long.

When I talked to the sierra rep before ordering a lot of these, he said that they would expand good down to 1600 fps. So my thinking was that I could get these up to about 2200 plus fps and would hopefully get pass through on whitetail with good expansion. My friend a I have killed a lot of deer using 100 Barnes ttsx using 18 inch Grendel’s. Most of the time the bullet gets stuck in the hide on the opposite side of impact. I was thinking that even with less velocity the 120 would still get a complete pass through in a SBR vs the 100 gr.

Yes, I know, I need to get a chronograph and some magazines that allow me to seat longer than 2.26.

I appreciate you taking the time and providing sound advice. I tried accessing the shooters notes website from DuckDuckGo and it would not come up. Do you mind providing a good link or let me know if you need some type of special access?