300 win - help - next step

[MN Hunter]

Went to the range today - 100 yds
Remington Sendero 300 win mag
H1000 powder - Rem brass. - CCI 250 mag primer - Barnes 180 ttsx .05 off lands
Barnes book list max load 77 grains H1000 - Hodgdon web site lists 81 as max.
Started with 74 grains - 3 shots - .75 moa
75 grains - 3 shots -1moa
76 grains - 3 shots- 1moa
Following were just one shot in relationship to each other.
77 and 77.5 - 1 moa off bullseye - aprox .5 moa apart
78 and 78.5 touch each other 79 was .25 moa off of them - all three shots were 1moa away from 77 and 77.5
79.5, 80, 80.5 and 81 shot 1moa with 80 and 80.5 .25 moa.
No pressure signs.
Someday I will learn to post pictures. Also need to buy a chrony.
My thought is to leave the bullet seated where it is. Then load up 9 rounds at 78.5 and 9 at 80.
Is my thinking correct?

Thanks

 

[johnnyk]

MN Hunter,
Kinda confusing the way you have it written, but it looks to me like 80.5gn is a .25" group? If that being the case I would try at least five of those again. I like 'em fast and accuracte. If I can have both I'll settle for accurate. JohnnyK.

 

[Moman]

I'm with JohnnyK on that one. It sounds like you might have a promising load in there somewhere but you should probably try 3 to 5 of each loading and go for group.

 

[Stratmeister]

Yeah, I'm with the other guys on understanding your meaning there. But that said, don't try to relate where a group of one load lands on the paper compared to another load. The POI can move and you only want to compare shots of the same load. I did this with my new .300 Win Mag this week and my starting load was 2" lower POI than my ending load. But the shots of the lower load were closest together.

So shoot 3 rounds of 'load 1' at a target spot, shoot 3 rounds of 'load 2' at a different spot, and so forth until you find the grouping(s) that appear to be the closest to each other within the same load.

Then load up some of those and maybe some on either side by .5 grain or so and pick the one with the closest grouping (in relation to itself).

Use different target spots for each load so you don't get confused and mix loads together.

 

[trebark]

Yeah, I'm with the other guys on understanding your meaning there. But that said, don't try to relate where a group of one load lands on the paper compared to another load. The POI can move and you only want to compare shots of the same load. I did this with my new .300 Win Mag this week and my starting load was 2" lower POI than my ending load. But the shots of the lower load were closest together.

So shoot 3 rounds of 'load 1' at a target spot, shoot 3 rounds of 'load 2' at a different spot, and so forth until you find the grouping(s) that appear to be the closest to each other within the same load.

Then load up some of those and maybe some on either side by .5 grain or so and pick the one with the closest grouping (in relation to itself).

Use different target spots for each load so you don't get confused and mix loads together.

+1.....

Also, according to a reliable source, I found a max of 83 grains of H1000 for the 300win

308_7_180

 

[MN Hunter]

Sorry for the confusion. The intent of todays trip was to determine max load. Looks like I will try working up just a little higher.
Just found it interesting that 78, 78.5 and 79 shot so close together and that 80, 80.5 were so tight. Just thought that might be telling me something.

Where did you see 83 gr of H1000
Would like to verify and work my way up.

Good idea to try 3 at 78.5 and 3 at 80.5 gr?

 

[johnnyk]

MN Hunter,
Try that link he posted in his last "308_7_180". That will take you to a webiste with that info.

280 Fan,
Thanks for that website/link. I read stevespages years ago, when I first started reloading, and got so much info from there. I had forgotten all about it. There is some good info there. Some of it is funny. JohnnyK.

 

[MN Hunter]

Missed the link I will check it out.

Thanks

 

[WRG]

Yeah, I'm with the other guys on understanding your meaning there. But that said, don't try to relate where a group of one load lands on the paper compared to another load. The POI can move and you only want to compare shots of the same load. I did this with my new .300 Win Mag this week and my starting load was 2" lower POI than my ending load. But the shots of the lower load were closest together.

So shoot 3 rounds of 'load 1' at a target spot, shoot 3 rounds of 'load 2' at a different spot, and so forth until you find the grouping(s) that appear to be the closest to each other within the same load.

Then load up some of those and maybe some on either side by .5 grain or so and pick the one with the closest grouping (in relation to itself).

Use different target spots for each load so you don't get confused and mix loads together.

I agree, as you increase or decrease the charge that POI changes because so does the velocity. It may be as little as 10 -20 fps to as much as 50-60 fps per half grain increments depending on the powder your using. To me, it sounds as though the rifle so far likes the combination of components you are testing and the seating depth of the bullet.

Once you do get the chronograph I would bump up the test strings to five per charge weight. Shooting five will tell you just how repeatable the round really is. Using a chronograph will also tell you a lot of things you can't possibly know with out one. For one, how consistant or repeatable the velocity is for any given combination of components i.e ES and two, when you see that the velocity starts to level out you know your at or near your max with that powder charge. Just because you may not see visual signs of high pressure does not mean you are not at or nearing the max! Then once you find a charge weight that is giving you the best group & consistant velocity you can fine tune it by moving the charge weight by 2/10 of a grain in either direction until you find the optimum charge. You can then move the bullet seating depth around to see if you can improve on that any more. I look for max accuracy not max velocity and more often than not they do not coincide with each other and then there are times that they do. Without a chronograph you will never really know for sure. My feeling is you really can't do accurate testing without one!

WRG