A2520 super slow lot? UPDATE scroll down

[Tommie]

Recently got a 8 pounder of A2520. This particular powder is new to me. I put together a ladder test of loads in .2 grain increments ending at published max. Three loaded rounds for each powder charge weight. According to the load data the maximum charge should have delivered approximately 3950 FPS. All I got was 3620 FPS with the max charge and my barrel (which is new) is 2 inches longer than what was used in the published data so if anything my velocities should have bumped a little higher. The lighter loads weren't far behind. Since I only shot 1 of each 3-round load I pulled bullets on the unshot cartridges to verify charge weights were correct. They were spot on. Velocity was measured with a Garmin chrongraph which has never given me any reason to question its accuracy.

A discrepancy of over 300 FPS is massive. Unless the Garmin suddenly got constipated, all I can figure is an incredibly slow lot of A2520. Wondering if anyone else has experienced this with recent lots of A2520

SEE UPDATE BELOW

 

[SeabeeKen]

Its awesome in my 308, shooting better than TAC. IIRC its the same powder as ramshot wild boar which isnt available here in the states

 

[Tommie]

Anyone?

 

[WyleWD]

Anyone?

Do you have another powder that is similar to the 2520? My thought is to try another powder to see if it gets closer to its "published" data. I've been unfortunate enough a couple times to find out that a new barrel is the culprit. But I agree with you that 300FPS is an eye catcher. What ever you do let us know how that turns out. Thanks. WD

 

[Tommie]

Do you have another powder that is similar to the 2520? My thought is to try another powder to see if it gets closer to its "published" data. I've been unfortunate enough a couple times to find out that a new barrel is the culprit. But I agree with you that 300FPS is an eye catcher. What ever you do let us know how that turns out. Thanks. WD

I'm putting together some loads with Varget as well as re-trying the A2520 loads again. If both read low then it's gotta be the Garmin. Will post results

 

[Jager]

Some years back I had a similar experience with A4350. I had run my ladder through Quickload and it was pretty obvious the powder was not generating the chamber pressures expected. Once I adjusted QL to match the actual results I was seeing I was able to march toward the pressures/velocities expected.

Soft lot of powder, in my case.

It's very unlikely it's your Garmin.

 

[dwizum]

Do you have a known good load in another rifle you can shoot over the Garmin, just for peace of mind to rule it out?

 

[WyleWD]

Recently got a 8 pounder of A2520. This particular powder is new to me. I put together a ladder test of loads in .2 grain increments ending at published max. Three loaded rounds for each powder charge weight. According to the load data the maximum charge should have delivered approximately 3950 FPS. All I got was 3620 FPS with the max charge and my barrel (which is new) is 2 inches longer than what was used in the published data so if anything my velocities should have bumped a little higher. The lighter loads weren't far behind. Since I only shot 1 of each 3-round load I pulled bullets on the unshot cartridges to verify charge weights were correct. They were spot on. Velocity was measured with a Garmin chrongraph which has never given me any reason to question its accuracy.

A discrepancy of over 300 FPS is massive. Unless the Garmin suddenly got constipated, all I can figure is an incredibly slow lot of A2520. Wondering if anyone else has experienced this with recent lots of A2520

Also you might check the lot number of the A2520. There was a lot number on "Recall". I found this in a search. WD

[td]Accurate 2520[/td]
[td]Lot 16 only[/td]
[td]0913192116 is the only Lot Affected[/td]

EDIT: This might be a better link..... https://hodgdonpowderco.com/warnings/

Scroll down the page as it's about halfway down.

 

[mgunderson]

What cartridge are we shooting? Did I miss that. The new barrel is important here. What is the weather like and are you shooting in colder temps?

Give us a few more details to help put this in context.

 

[6.5 forever]

I'm putting together some loads with Varget as well as re-trying the A2520 loads again. If both read low then it's gotta be the Garmin. Will post results

I would probably think it's the barrel or the powder or a combination of both. The Garmin was working before? Then that's not a problem.
Most barrels will take 100 rounds to get the speed up. Good luck.
No one has mentioned brass. My experience is new brass is slow for the first two firings.

 

[SeabeeKen]

Also you might check the lot number of the A2520. There was a lot number on "Recall". I found this in a search. WD

[td]Accurate 2520[/td]
[td]Lot 16 only[/td]
[td]0913192116 is the only Lot Affected[/td]

EDIT: This might be a better link..... https://hodgdonpowderco.com/warnings/

Scroll down the page as it's about halfway down.

I had a lb of that lot. Western sent me a check for it an aske me to dump it. I never had any issues with it though

 

[Tommie]

Recently got a 8 pounder of A2520. This particular powder is new to me. I put together a ladder test of loads in .2 grain increments ending at published max. Three loaded rounds for each powder charge weight. According to the load data the maximum charge should have delivered approximately 3950 FPS. All I got was 3620 FPS with the max charge and my barrel (which is new) is 2 inches longer than what was used in the published data so if anything my velocities should have bumped a little higher. The lighter loads weren't far behind. Since I only shot 1 of each 3-round load I pulled bullets on the unshot cartridges to verify charge weights were correct. They were spot on. Velocity was measured with a Garmin chrongraph which has never given me any reason to question its accuracy.

A discrepancy of over 300 FPS is massive. Unless the Garmin suddenly got constipated, all I can figure is an incredibly slow lot of A2520. Wondering if anyone else has experienced this with recent lots of A2520

UPDATE

Firstly to answer some of the above questions, the cartridge is a 20BR using 2X fired Peterson brass. I avoided mentioning this in the original post just to keep the discussion about A2520. Sometimes threads get derailed. Load data I used is from Hodgdon's website. The 20BR data they have is really just reprinted from Ramshot's information that was compiled before Hodgdon bought them out.

I started over with A2520. Since this was more of an experiment and not a load workup, I simply put together 4 loads with A2520 starting at 30.1 grains and moving up at .2 grain increments to 30.7. Three loaded cartridges per powder weight. The max load of 30.7 is listed as 3952 FPS on Hodgdon's site. As a control group I put together 3 loads of Varget starting at 30.3, 30.5 and 30.7 grains. The idea was to isolate whether the powder has an issue or if there was some other problem (gun, chronograph etc).

Went to the local 100 yard indoor range. First was the A2520 loads. First load (starting with the lowest powder charge): high 3716, low 3563 with swipe marks on the brass head. Second: high 3669, low 3515 and more swipe marks. Third: high 3691, low 3609 more swipe marks. Fourth: high 3759, low 3572 one primer fell out. Amazingly low speeds but even more insane are the velocity spreads. And high pressure signs with velocities way below where they should have been. This is crazy erratic stuff. Next I touched off the Varget loads. No issues whatsoever. Spreads of 10-11 FPS for the three-shot groups and very linear velocity increases. First load avg 3808, second 3834 and third 3870. No pressure signs. Very straight-forward.

So as far as I can tell, the equipment is working correctly and the issue is this powder. Something’s really wrong with ES readings of 180 FPS. I'll contact Hodgdon and see what they have to say. Oh, the lot number of the A2520 is 8060225.

Edit: 01/26 I contacted Hodgdon via email yesterday. They replied this morning with questions regarding components I used, etc. I supplied the information and a few more details. Will post updates.

 

[6.5 forever]

UPDATE

Firstly to answer some of the above questions, the cartridge is a 20BR using 2X fired Peterson brass. I avoided mentioning this in the original post just to keep the discussion about A2520. Sometimes threads get derailed. Load data I used is from Hodgdon's website. The 20BR data they have is really just reprinted from Ramshot's information that was compiled before Hodgdon bought them out.

I started over with A2520. Since this was more of an experiment and not a load workup, I simply put together 4 loads with A2520 starting at 30.1 grains and moving up at .2 grain increments to 30.7. Three loaded cartridges per powder weight. The max load of 30.7 is listed as 3952 FPS on Hodgdon's site. As a control group I put together 3 loads of Varget starting at 30.3, 30.5 and 30.7 grains. The idea was to isolate whether the powder has an issue or if there was some other problem (gun, chronograph etc).

Went to the local 100 yard indoor range. First was the A2520 loads. First load (starting with the lowest powder charge): high 3716, low 3563 with swipe marks on the brass head. Second: high 3669, low 3515 and more swipe marks. Third: high 3691, low 3609 more swipe marks. Fourth: high 3759, low 3572 one primer fell out. Amazingly low speeds but even more insane are the velocity spreads. And high pressure signs with velocities way below where they should have been. This is crazy erratic stuff. Next I touched off the Varget loads. No issues whatsoever. Spreads of 10-11 FPS for the three-shot groups and very linear velocity increases. First load avg 3808, second 3834 and third 3870. No pressure signs. Very straight-forward.

So as far as I can tell, the equipment is working correctly and the issue is this powder. I'll contact Hodgdon and see what they have to say. Oh, the lot number of the A2520 is 8060225.

Good work! Looks like you isolated the powder is a problem. Make sure to let us know their response.

 

[Tommie]

Good work! Looks like you isolated the powder is a problem. Make sure to let us know their response.

Will do

 

[L.Sherm]

I've tested 2520 side by side in my 20PPCAI and RL15 they were real close.
I've had kinda the same problem in 2 rifles H4350 in my 20BRA no matter how much powder I dumped in the case it hit a wall at 3500. Same thing with RL19 in my 338WM no matter how much 2800 was it switched to IMR4350 now it shoots lights out at 2950.
Its a head scratcher when it happens.