a little help needed 120 sierra 120 hpbt and imr8208 load data

[biggdawg]

I have some 8208 and am trying to find some data with the sierra 120 hpbt bullet.

need a min and max or a place to start. is this cartridge like most others and you

can use data on similar bullet weights to get a start point?

my first time loading the grendel. i am starting out with some wolf cases and

rem 9 1/2 primers. i have lapua cases also but first time out with new gun and don't want

to run the lapua.


thanks in advance.

[Hoot]

I have some 8208 and am trying to find some data with the sierra 120 hpbt bullet.

need a min and max or a place to start. is this cartridge like most others and you

can use data on similar bullet weights to get a start point?

my first time loading the grendel. i am starting out with some wolf cases and

rem 9 1/2 primers. i have lapua cases also but first time out with new gun and don't want

to run the lapua.


thanks in advance.

I haven't loaded for the Sierra 120gr HP MK, but I plugged it into QuickLoad for you. According to QuickLoad, which errs on the side of caution, a 10% reduced starting load would be 25gr of 8208xbr, with a max of 27gr. That's assuming that your Wolf cases have an un-resized internal volume that holds 35gr of water. If they hold less, then you need to start lower. If they hold more, then you can start higher. If they are new brass, then they have already be sized and their internal volume will be different after you shoot them.

Hoot

[biggdawg]

excellent info thanks. i will measure the water capacity of the cases to verify. i have already resized the cases and they are ready to load. so i will probably just shoot the 2520 today then

measure the water capacity on the fired cases then load them for the next trip.

thanks again. i think i may have to check into getting quickload.

[biggdawg]

my firefomed cases not sized hold 36.5gn average.

so i am going to start at 25 and work up to 27 and see what i get.

just shot my first rounds of aa2520 and accuracy was so so but what can i expect for first loads out and using wolf cases.

wolf 120mpt don't shoot worth crap though. 3 inch group at 100yds. my best group was 1" or so at 100 2 touching with 1 flier.

wolf was averaging 2410fps

I haven't loaded for the Sierra 120gr HP MK, but I plugged it into QuickLoad for you. According to QuickLoad, which errs on the side of caution, a 10% reduced starting load would be 25gr of 8208xbr, with a max of 27gr. That's assuming that your Wolf cases have an un-resized internal volume that holds 35gr of water. If they hold less, then you need to start lower. If they hold more, then you can start higher. If they are new brass, then they have already be sized and their internal volume will be different after you shoot them.

Hoot

[LRRPF52]

Run a ladder test and see where your accuracy nodes are. They might be a little harder to find in the 16" button-rifled barrels.

[Deezil]

my 16" loves nosler 120gr ballistic tip boat tails with 28grains of 8208 going just under 2500fps and best group was 3/8" at 100yds

http://www.65grendel.com/forum/showthread.php?1944-16-quot-Barrel-reloads&p=24483#post24483

[LRRPF52]

QUOTE=Deezil;26971]my 16" loves nosler 120gr ballistic tip boat tails with 28grains of 8208 going just under 2500fps and best group was 3/8" at 100yds

http://www.65grendel.com/forum/showt...4483#post24483[/QUOTE]

That is a nice load for sure. At sea level, it's a great 375yd hunting load, believe it or not.

Up where I'm at, it's a 475yd effective hunting load at 6,600 ft ASL. The barometric pressure changes its effectiveness that much. Here is the ballistics at 23.5 InHg, with a 200yd zero. It still has over 900ft lbs of energy at 475yds, and only 1 Mil of drift at that range with a full value 10mph wind.

.........Range    Velocity    Energy     Trajectory         TOF          Drift
      (yards)     (fps)     (ft-lb)       (MILS)         (sec)         (MILS)
          0      2488        1649           0.00         0.0000         0.00
         50      2413        1552           0.17         0.0612        -0.09
        100      2340        1458           0.51         0.1243        -0.19
        150      2267        1370           0.33         0.1895        -0.28
        200      2196        1285           [B]0.00         [/B]0.2567        -0.38
        250      2126        1205          -0.40         0.3261        -0.48
        300      2058        1128          -0.84         0.3978        -0.59
        350      1991        1056          -1.32         0.4719        -0.70
        400      1925         987          -1.83         0.5485        -0.81
        450      1860         [B][COLOR="blue"]922[/COLOR] [/B]         -2.37         0.6277        [COLOR="blue"]-[B]0.93[/B][/COLOR]
        500      1798         861          -2.94         0.7098        -1.05
        550      1736         803          -3.55         0.7947        -1.17
        600      1676         749          -4.18         0.8826        -1.30

[LR1955]

my firefomed cases not sized hold 36.5gn average.

so i am going to start at 25 and work up to 27 and see what i get.

just shot my first rounds of aa2520 and accuracy was so so but what can i expect for first loads out and using wolf cases.

wolf 120mpt don't shoot worth crap though. 3 inch group at 100yds. my best group was 1" or so at 100 2 touching with 1 flier.

wolf was averaging 2410fps

BD:

You will end up with 28 or 28 1/2 grains of 8208 XBR with the 120's.

You will also find that with the 120 grain bullet weights and safe powders for the Grendel that all of them will end up being 28 - 29 grains.

As for your Wolf ammo. If it is the MPT, you are probably using the first lot that was imported four or five years ago. I haven't heard of anyone having problems with the lots that have come in over the last two years. Or, your barrel has problems.

You will find out if your barrel has problems when you shoot the 120 Match Kings. Providing you run a credible series of load tests, the 120 Match Kings will shoot very well with almost every load you try. Your real choice will be how much you want to push the velocity envelope in terms of pressures. If the 120 Match King doesn't shoot well out of your rifle, your barrel has problems.

LR1955

[biggdawg]

BD:

You will end up with 28 or 28 1/2 grains of 8208 XBR with the 120's.

You will also find that with the 120 grain bullet weights and safe powders for the Grendel that all of them will end up being 28 - 29 grains.

As for your Wolf ammo. If it is the MPT, you are probably using the first lot that was imported four or five years ago. I haven't heard of anyone having problems with the lots that have come in over the last two years. Or, your barrel has problems.

You will find out if your barrel has problems when you shoot the 120 Match Kings. Providing you run a credible series of load tests, the 120 Match Kings will shoot very well with almost every load you try. Your real choice will be how much you want to push the velocity envelope in terms of pressures. If the 120 Match King doesn't shoot well out of your rifle, your barrel has problems.

LR1955

thanks for the info i will start at 26 of 8208 and work up. the sierras didn't do too bad for the first work up. going to start a little lower and work up would have like to get 2500

with them though. here is my best group of the day 29.7gn aa2520

I just thought the grendel out performed my 7.62x40 more than it does. i get 2500 with 110vmax





here is one of my 223 final load eval with cfe 223 10 shot groups. my meathod does seem to work for me it might not work for the grendel we will see

[LR1955]

BD:

You will end up with 28 or 28 1/2 grains of 8208 XBR with the 120's.

You will also find that with the 120 grain bullet weights and safe powders for the Grendel that all of them will end up being 28 - 29 grains.

As for your Wolf ammo. If it is the MPT, you are probably using the first lot that was imported four or five years ago. I haven't heard of anyone having problems with the lots that have come in over the last two years. Or, your barrel has problems.

You will find out if your barrel has problems when you shoot the 120 Match Kings. Providing you run a credible series of load tests, the 120 Match Kings will shoot very well with almost every load you try. Your real choice will be how much you want to push the velocity envelope in terms of pressures. If the 120 Match King doesn't shoot well out of your rifle, your barrel has problems.

LR1955

BD:

Just like you will find out that the 28 - 29 grain load of 8208 XBR will most likely be your best load with the 120 Sierra's, you will also find out that 30 - 30.5 grains of 2520 will be your fastest and most likely most accurate load for the same bullet.

LR1955

[Bwild97]

Why only 3 shots?

[biggdawg]

Why only 3 shots?

i do 3 shot groups in my ladders to save components when i find a couple of nodes i do 2 5 round groups of each and then .2 above and below also. it worked for my 223 and 7.62x40 loads

that was just the best of the ladder. here is the other pic

[Deezil]

yep, after 3 youll know if its bad or good

[Bwild97]

3 shots just isn't enough proof for me when it come to AR's, 3 maybe from bolt guns. I like 8 shot groups, I feel better about making decisions toward my loads with good representation of the barrel/shooter combination.


2012-03-19_13-41-37_629.jpg

[Deezil]

I think it is, when you find the one that the group is tight, then you can burn more power and bullets fine tuning, look at the ladder system, thats only 1 per load