First Ladder Test - TRG 42 300WM

[oud272]

Can anyone who has previously shot a ladder test with a TRG 42 give me any feedback on this ladder. I would like to find a good grouping load that will get me to around 1500yds.

Previously when working up loads for 308 I have made a number of rounds, usually 6, at various powder charges, shot groups over the chrono, picked the load based on group size and the velocity I needed.

I have just received a TRG 42 300WM and decided to try the Ladder method. As I had no previous data on 300WM this looked attractive as it would drastically reduce the number of rounds I had to fire.

Details:
Sako TRG 42 300WM with Sako muzzle break, 1:11 twist
H1000
Wolf LR
Brass Win - new, FL re-size
208 A-max 0.020" off lands
70F Sunny

Ladder was shot at 300yds (farthest dist. available at the time). Four rounds of 73.5 (3 sighters), one each from 74 to 79 in 0.5gr.

Some thoughts:
1. The vertical displacement seems to be linear with powder increase (bad data point at 76.5gr). Although there maybe a node around 78gr??
2. Does the very heavy Sako break dampen the barrel and make it less sensitive to powder charge?
3. As the sighters were on paper I decided to shoot for group. It's only 3 shots but including the cold bore they seemed to group well (0.36moa).
4. Charges form 78gr upwards were compressed. No pressure signs.
5. The rifle did not like 190FGM, shot a couple of groups which were from 1 - 1.5moa. Velocity was 3050fps, I did not expect it to be this fast. These were jumping approx. 0.200".

I have some more primers arriving next week and will probably redo the ladder with Wolf LRmag primers starting 1gr lower.

Three sighters

 

[kyreloader]

Re: First Ladder Test - TRG 42 300WM

77.5-79g looks pretty good to me.

In my experience with H1000 in other calibers, the Wolf LRM primers worked better for me than the Wolf LR primers. Wolf primers are known for being a little less hot than comparable primers, so you may get better ES/SD with a litte warmer primer.

 

[Casey Simpson]

Re: First Ladder Test - TRG 42 300WM

Magnum primers work better for me too in this caliber

 

[jsthntn247]

Re: First Ladder Test - TRG 42 300WM

I would try 5 shot groups at 77.5, 78, and 78.5. Stick with the one that has the least E.S.

 

[oud272]

Re: First Ladder Test - TRG 42 300WM

Thanks for the info.

I will try a ladder with the Wolf LRM primers first and see if that shows an accuracy node. If not, then it's back to my old method of loading 5 rounds of each charge and shooting groups over the chrony.