123 A-Max and 8208 XBR Load Dev

[Eg3]

First post on this site. I figured this was the best place to get some advice on where to go next with my load development. I also have access to CFE 223 but I read that 8208 and 28.5gr was a good load.

Working up a load for my 20" Satern Barrel 1-8.75 twist, 8208XBR, 123gr Amax, Hornady Once Reloaded Brass, CCI 400 Primers, 2.260" COAL, and 1.680" Ogive.

Factory 123 Amax is right at 2600 ft/s and is what i used to zero my scope. I loaded up 10 rounds to see what the best charge to use for the most consistent vertical spread at 200yards. Based on the results I would think #7 would be the best bet and give me some cushion if I load slightly under or over 27.9gr.

My questions is: My shots did not not pick up to the factory ammo point of impact till shots 9 and 10. Do I need a velocity closer to 2600ft/s such as the factory loads for longer range shots? Is 2520 ft/s fast enough? I plan to eventually shoot at 600yards and do not want to be let down by 2520ft/s, should I switch to CFE 223 since it is a bit slower burning?

My next test would be 27.9gr of 8208XBR with a little bit longer and shorter COAL's, even though i cant go much longer if you all think 27.9gr|2520ft/s is good enough.
1: 26.2gr|no reading
2: 26.5gr|2372ft/s
3: 26.8gr|2422ft/s
4: 27.1gr|2438ft/s
5: 27.4gr|2433ft/s
6: 27.7gr|2496ft/s
7: 27.9gr|2520ft/s
8: 28.2gr|2540ft/s
9: 28.5gr|2569ft/s
10 28.8gr|2583ft/s
123LoadDev.JPG
Thanks for taking a look

[ricsmall]

2520 fps will get you to 600 yards easily. Just load one step under and one step above your node and test for accuracy over say 3, 5 shot groups of each load. If possible test these at 300 yards to see how they do at distance.

Richard

[majohnson]

Load Development

While I am shooting a 23" Lilja, I had no issues with being able to reach out to 600 and 1030 with Hornady factory ammo. Part of what you are asking is dependent on what your glass is and how much adjustment is available. I have a Nightforce SHV 4-14 F1 on a Babro 20moa mount. It leaves me with enough adjustment that I do not need to hold over. If you have a ballistic program, put in your environmental conditions along with your load data and see how that compares to how much adjustment you have.

[Heinz57grendel]

I have they same barrel and twist rate you have. mine is a 24 instead of a 20 inch barrel but mv will be close. I could never get the 123 amax to shoot good. I went to the 107 gr sierra matchking with 8208xbr cci450 primers and finally got accuracy that's worth bragging about. Not all barrels are the same but its food for thought. 107gr muzzle velocity is 2730fps and still has the characteristics of the 123 gr.

[majohnson]

You need put all your data including environmental conditions in a ballistic program? That will give you the amount of bullet drop.

[Eg3]

Thanks for all the input. I will continue fine tunning my load and pick up some107gr bullets to see what they do. I will also see what a ballistic program has to say.

[LRRPF52]

600yds is boring for 6.5 Grendel unless you shoot really small plates/targets. 2200fps is child's play at 600yds with the 123gr AMAX.

I shoot the 123gr AMAX in the 2435-2480fps range from short barrels out to 1200yds.

At 1000yds, I shot a sub-MOA 6rd group rapid-fire with my 18" Lilja with 123gr AMAX. You don't need a lot of speed. These things don't like to slow down much at all.

[Heinz57grendel]

Thanks for all the input. I will continue fine tunning my load and pick up some107gr bullets to see what they do. I will also see what a ballistic program has to say.

I'm using 29.3 gr of 8208xbr, cci450 srm primers, lapua brass, and the 107gr smk. Again, This is what worked for me. I believe I'm loading these at a 2.265 col., which is my mag length. I love the 107smk and cant find a reason to change. Always work your load up from minimum to maximum, This cannot be stressed enough, because bullets, primers, and powder are cheap, Faces and barrels are not.