120 MKZ load recommendations

68lobo!, if you have a favorite load with the SST, you might start a 0.5 grain less and work up from there. Most reloaders are reporting pressure signs when they go past 28.0 grains of AA2200 at mag-length COALs. I use S&B once-fired brass AA2200 with CCI450 primers with the shoulder bumped back 0.003" to 0.004". I have found these bullets benefit from loading longer than mag length so I run mine 0.010" off the lands and get to put a bit more powder in to achieve s few fps more muzzle velocity. I found my accuracy node before I got to high chamber pressures.

That's good to hear that i can use cci450 primers, i had bought some awhile back to try my hand at yam's 130gr berger classic hunter. I have to be honest though, i am still relatively new to reloading and reloading the 6.8 in particular. I've never loaded Hornady sst before, so i dont have a starting load for this current endeavor. I do however have a bunch of cci 450 primers and s&b brass, so it sounds like all i will need is the projectiles and some aa2200...and a starting load for the powder.


Also, i should add in that these will be ran out of a 16in arp 5r melonite barrel, if that makes any difference.

Thanks again in helping me to get started!

Xman is spot on.
Any load used with the 120 SST is good to go with the 120 MKZ from all reports.
Work up to find your barrel/chamber sweet spot.
Please use safe reloading practices.

68lobo!, S&B brass can take a higher starting load than others with smaller capacity like Hornady. I would suggest starting at 26.5 grains of AA2200. I would start out loading one round per charge in 0.5 grain increments up to 28.0 (COAL 2.295") and fire them in sequence to define your performance boundaries. If you mark you impacts, you may find 3 in a row that group under an inch. If you do, that is where I would start with a 3-shot group to see if that is your accuracy node.

Thank you so much for this information! I am definitely excited to get this project under way. I think I'm also going to order one of Yam's windowed pri mags as well, but i will wait to attempt to load longer than mag length until im more comfortable with reloading in general. Once again, thank you xman and yamaraja!

Im not saying this is the gospel, but it's what I got for results

http://68forums.com/forums/showthread.php?71290-Cavity-Back-Bullets-Thread/page8

Firearrow said:

Im not saying this is the gospel, but it's what I got for results

http://68forums.com/forums/showthread.php?71290-Cavity-Back-Bullets-Thread/page8

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Looks like 27.7 at 2.295 is a good load for you.
Especially since you said you pulled one of the 3.
You were able to find a sub MOA load at all 3 OAL's

As you know some barrels are faster and some are slower.
Its good to see a slow barrel still runs 27.7 grains of 2200 with a 120 grain solid copper at 2.295 OAL at sub MOA measured to the outer edges.

Yamaraja said:

Looks like 27.7 at 2.295 is a good load for you.
Especially since you said you pulled one of the 3.
You were able to find a sub MOA load at all 3 OAL's

As you know some barrels are faster and some are slower.
Its good to see a slow barrel still runs 27.7 grains of 2200 with a 120 grain solid copper at 2.295 OAL at sub MOA measured to the outer edges.

Click to expand...

This is a WC 16" barrel and it has been about 30-50 fps slower on all of my loads compared to other WC barrels of the same length. Accuracy is good so I don't care about 30 fps.

I shot the loads again to validate what I shot the first time and was able to get the same results.

I'm using an a Syrac adjustable gasblock and never got flat primers. Just started to see my Vel drop of then had no gains at 28.0gr of AA2200 with swipes. Only reasion I say this is because I don't want guys over doing it from the start. Load'em up at 27.0gr and go from there safely.

O and by the way I have shot these bullets out to 546 yards (500 meters) on steel targets and was able to to keep my shots on what I estimate a 5" (1 MOA) head. Great bullet. I'm looking forward to trying these bullets on some hogs at 300ish yards.

Firearrow said:

This is a WC 16" barrel and it has been about 30-50 fps slower on all of my loads compared to other WC barrels of the same length. Accuracy is good so I don't care about 30 fps.

I shot the loads again to validate what I shot the first time and was able to get the same results.

I'm using an a Syrac adjustable gasblock and never got flat primers. Just started to see my Vel drop of then had no gains at 28.0gr of AA2200 with swipes. Only reasion I say this is because I don't want guys over doing it from the start. Load'em up at 27.0gr and go from there safely.

O and by the way I have shot these bullets out to 546 yards (500 meters) on steel targets and was able to to keep my shots on what I estimate a 5" (1 MOA) head. Great bullet. I'm looking forward to trying these bullets on some hogs at 300ish yards.

Click to expand...

Excellent results, thank you!!!
As you have probably seen a guy took our 118 grain 6.5 MKZ out to 1000 yards. His load was sub .7 MOA at 100 and sub .7 MOA at 1000.
It looks like your holding MOA out past 500+.
Well beyond the effective energy range on game.

Everyone should always work their own loads up load.
The good thing is we are establishing that folks can start at 26 to 26.5 grains of 2200 and do a 1 or 2 bullet work up up to 28 or 28.5 grains in half grain intervals, stopping where they find pressure.
Then once they have their rifles pressure limit dial in their accuracy node and best OAL.
I will say we are seeing nodes in most barrels between 27.4 and 28 grains. With another near 28.5 a particular combination allows it.
Fully resized brass will not hit the upper limits, only brass sized with a .03 shoulder bump get me there.

Once the snow melts and I can get to my longesnge spot I will take some videos of these bullets at 800-1000 yards and try to post them. If guys have had good results then I won't be posting any ground breaking news, but videos at longer distances shooting rocks and steel can make your day go from bad to good.