Interpreting Data - Help

[rem243]

Alright guys, I recently decided to start running a lighter bullet in my .280 Remington, the 140 Hunting VLD. I did a ladder test up to .3grs from max (as per Bergers handbook) in .3gr increments.

i have limited powder/primer/bullet availability so want to maximize my data interpretation so I dont waste many resources.

gun: R700LA, Bartlein 2b 1:9tw 23" plus muzzle break, mcm ks stock pillar bedded. 40x trigger

Ammo: new Peterson brass, cci250 primer, imr 4350, berger 140 hvld, coal 3.330 (as per Berger handbook, as per my comparator theres a very slight variance but overall cbto is consistent with a 3.330" coal)

see target and charge/velocities. Range 200yds 58 degrees and 8-10mph head wind. 3-5 minutes between shots

which charge would you hone in on? Why?

 

[LaHunter]

shots 4,5, & 7 have very little vertical, which is what you are looking for. However, shot 6 has a good bit of vertical compared to the other 3.
Setting your targets out at 400+ yards will tell you much more, assuming you have a place to shoot that allows for that. At 200 it's hard to draw firm conclusions.
Do a search and look for the a thread that Alex Wheeler has regarding ladder testing. It is really informative.

 

[ShtrRdy]

I'm afraid I couldn't trust the velocity data. Those are some big swings from 26xx into 27xx and then back to 27xx. What kind of chrono are you using?

I usually go in 0.2 grain steps when doing this sort of test. But that's not going to help what you're measuring.

 

[Deputy819]

Did you take the rifle to pressure to see where your ceiling is? Your velocities seem a bit low for a .280 Rem with a 140 gr bullet.

 

[rem243]

Using a Magneto and made sure it was same distance from muzzle and kept it as consistent as possible.

i did not see any pressure signs on my highest charge.

i agree my speeds are very low compared to what the berger manual states as far as their tests went. Understand my barrel is shorter but wasnt expecting not touching 28xx at my highest charge.

 

[308win]

I'm with ShtrRdy, your velocities are all over the place. I like the idea of the OCW test, but your reloading practices have to be spot on before you can make it work. I'm thinking you might have a neck tension problem?

With the info given I would concentrate on shots 1, 2 and 3 as they have the least amount of vertical between them. Within the 8 shots your still just slightly above 1 MOA, not great, but not that bad either for the difference in powder charges.

I would continue to increase the charge as it looked like 7 and 8 were coming together and see if the next 2 or 3 charges would start bringing you up to 280 velocities and possibly a good node? Proceed with caution, but I think you have room to go?

 

[Ckleeves]

I personally wouldn't chase any of those loads. The target isn't really telling you anything useful at all at least IMO.
4,5 and 8 look like there might be something in the 2700-2750 range, but I don't know how you stay in that node. My guess is if you loaded 5 between 51.5 and 51.8 the ES is gonna be wild just looking at the loads above and below it.

I think I would try a different powder, or if that's all I had proceed up in charge (at your own risk) and see if there is a spot with linear gains.

 

[Deputy819]

Using a Magneto and made sure it was same distance from muzzle and kept it as consistent as possible.

If you shot that 200 yard target/ladder with the Magnetospeed attached to your barrel then I wouldn't have any confidence in the points of impact...the bayonet will most certainly affect that.

Understand my barrel is shorter but wasnt expecting not touching 28xx at my highest charge.

You've got room to explore a little more, but I totally understand your concern for 'limited component availability'.
Even with a 23" barrel I'd think you should be scaring 2900 fps to death... Do you have any/can you get your hands on some H4831?

I would continue to increase the charge as it looked like 7 and 8 were coming together and see if the next 2 or 3 charges would start bringing you up to 280 velocities and possibly a good node? Proceed with caution, but I think you have room to go?

^^^^THIS^^^^

 

[Tiny Tim]

Your numbers are all over the place. I would be suspect of some of your data/loads. 117 FPS difference between shots 3 & 4 (.3 gr apart at a low lowish level). Also agree bayonet adversely affects group data. I'd check your chronograph set up to be sure its not coming loose or otherwise affected by something. I've struggled with many of these same issues at times.

 

[skipglo]

shots 4,5, & 7 have very little vertical, which is what you are looking for. However, shot 6 has a good bit of vertical compared to the other 3.
Setting your targets out at 400+ yards will tell you much more, assuming you have a place to shoot that allows for that. At 200 it's hard to draw firm conclusions.
Do a search and look for the a thread that Alex Wheeler has regarding ladder testing. It is really informative.

Totally agree and I'd discount 6 as a flier!

 

[rem243]

Alright guys, i went out and loaded a few more up to 55grs in .3gr increments. I went online and found some Quickload data and figured 55grs would put me into some pressure signs (but didnt) however, its been cool today and yesterday and have concerns about settling on a load and then warmer temps messing that up.

i do have, and tested IMR4831 but was barely able to break 27xx so i figured id focus my efforts on imr4350 (which i have more of anyway)

here are todays results:

 

[JMW67]

.

 

[Deputy819]

With your stated concern(s) in mind I'd probably explore in between #4 & #5. There's only a 13 fps difference between the two. Couple questions though....Have you tested seating depth yet? Were these shot at your 'target dot' with the bayonet hanging off the end of the rifle?

 

[rem243]

With your stated concern(s) in mind I'd probably explore in between #4 & #5. There's only a 13 fps difference between the two. Couple questions though....Have you tested seating depth yet? Were these shot at your 'target dot' with the bayonet hanging off the end of the rifle?

Yes the string was shot at same target square with bayonet off the end of barrel.