load testing help needed

[Hengehold]

I need some opinions on interpreting chrono data. I was testing some loads in a new palma barrel this weekend at 500yds and had some scope malfunctions. Consequently, ALL of the groups looked like garbage. Replicating this load testing process again this summer will be difficult to do so I will probably need to use the chrono data to decide which load to go with. I usually choose the smallest group as long as it is round and look for an ES less than 10. Without groups to compare I am having a hard time making a decision on which load to use in this gun. Below I have listed the chrono results for reference.

Based on the Avg velocities, it appears that there is a node around 46.4 & 46.6 because the avg velocity essentially stayed the same between these two powder charges. The avg velocity difference becomes greater as I increased the powder charge. My conclusion based on the avg velocity is go with 46.4gr.

The SD and ES are best for the 46.8gr charge but this does not appear to be in a node because of the amount of increase in avg velocity from 46.6 to 46.8. My conclusion based on the SD & ES numbers is to go with 46.8gr charge.

Question 1: What are your conclusions given this chrono data?

Qustion 2: Would you place more value on the changes in avg velocity which I understand to indicate a node or the ES/SD values?

Powder: Varget
Bullet: Sierra 155gr (2156)
Primer: Fed 210M
Brass: Lapua
# of shots fired per powder charge: 6 rds

46.4gr
Avg velocity – 2995 fps
Hi - 3009
Lo - 2970
SD - 14
ES - 39

46.6gr
Avg - 2999
Hi - 3014
Lo - 2988
SD - 11
ES - 26

46.8gr
Avg – 3012
Hi - 3021
Lo - 2998
SD - 8
ES - 23

47.0gr
Avg-3035
Hi- 3053
Lo - 3013
SD - 13
ES - 40

Thanks for your opinions,

-Trevor

 

[Ned Ludd]

FWIW - you have the the ES and SD values switched. Regardless, I would probably load more at 46.6, 46.7, and 46.8 and redo the MV and groups. Based on the average velocity and ES minima, 46.6-46.8 may well be the window. It'd be good to repeat it and see if the velocity holds up and how it groups in that window. The downside is that ES close to 25 fps is not so great. You might want to try different primers and see if you can get that down to a more reasonable level. After that, seating depth test will likely get your groupings where you want them.

 

[Zero333]

Just wondering the barrel length and what COAL where you using ?

 

[Hengehold]

Just wondering the barrel length and what COAL where you using ?

30" barrel 1-13 twist
Palma 2011 chamber loaded for .020 jump.

COAL= 2.870in.

 

[Zero333]

I would work around the 46.6gr load.

 

[mgdietrich]

Trev:

I think you are on the Hot side for LP brass. 46.5 has been standard for quite a while in that case. I think you are using a Barnard, which can take the pressure. SP brass many people are in the 47 gr range, 47.2 has been a buddies load for 3 barrels with same setup as yours. Usually LP has to be about 0.5 gr less than SP Palma brass.

I would do 46.5 and change lots or even type or LR primer (Try fed 210 not M and CCI BR2 or Reg as examples) and see if you can get some better numbers. Also, many people are finding MORE jump is better with 2156. 0.045-0.055 for many.

Sucks to have a scope issue when you are testing. I had a T-16 that died on my a few years ago, that scope cost me several matches until I figured out it was the culprit.

Morgen

 

[Hengehold]

Trev:

I think you are on the Hot side for LP brass. 46.5 has been standard for quite a while in that case. I think you are using a Barnard, which can take the pressure. SP brass many people are in the 47 gr range, 47.2 has been a buddies load for 3 barrels with same setup as yours. Usually LP has to be about 0.5 gr less than SP Palma brass.

I would do 46.5 and change lots or even type or LR primer (Try fed 210 not M and CCI BR2 or Reg as examples) and see if you can get some better numbers. Also, many people are finding MORE jump is better with 2156. 0.045-0.055 for many.

Sucks to have a scope issue when you are testing. I had a T-16 that died on my a few years ago, that scope cost me several matches until I figured out it was the culprit.

Morgen

Thanks for the feedback. I have used Fed 210M and Varget a lot in Palma rifles and it has always been a consistent performer for me. So far the consensus is that I should change primers so I will give that a try.

I have some BR-2 and Wolf primers I could try. I have not used the Wolf in a 308 yet, do you have any experience that would suggest Wolf and Varget would be a consistent performer?

Thanks,
-T

 

[mgdietrich]

Thanks for the feedback. I have used Fed 210M and Varget a lot in Palma rifles and it has always been a consistent performer for me. So far the consensus is that I should change primers so I will give that a try.

I have some BR-2 and Wolf primers I could try. I have not used the Wolf in a 308 yet, do you have any experience that would suggest Wolf and Varget would be a consistent performer?

Thanks,
-T

I used plenty of BR2's in mine, have just switched over to wolfs in the 243. I am sure your 210m's are fine, but it seems even lots of the same can help tweak the loads. Try what else you have on hand to se if there is an improvement.

 

[watercam]

Wolf's have been stellar for me with Lapua cases/Varget. SDs were a digit or two higher than Palma brass but they shot well.