OzFclass

In another post today, I mentioned an incident with RL-22. I started using a new container and it was much faster than it should have been - by about 140fps . RL-22 is listed in all the burn rate charts as slower than 2213SC. When I tested them together (interlaced) using the same charge weight of each powder, RL-22 was at least 140fps FASTER than 2213SC. I did the same thing between 2209 and RL-22, and they were nearly identical. A Google search revealed that others have had similar problems :

http://www.thehighroad.org/archive/index.php/t-639890.html

http://www.longrangehunting.com/forums/ ... -a-140327/

Someone stated that there has been a history of mislabelling at Alliant, so caution should be exercised.

Yes, I know, should have worked up to the load , but based on this experience, I'll be giving Alliant a miss from now on.

BTW batch number is 35069 D20314

AlanF wrote:In another post today, I mentioned an incident with RL-22. I started using a new container and it was much faster than it should have been - by about 140fps . RL-22 is listed in all the burn rate charts as slower than 2213SC. When I tested them together (interlaced) using the same charge weight of each powder, RL-22 was at least 140fps FASTER than 2213SC. I did the same thing between 2209 and RL-22, and they were nearly identical. A Google search revealed that others have had similar problems :

http://www.thehighroad.org/archive/index.php/t-639890.html

http://www.longrangehunting.com/forums/ ... -a-140327/

Someone stated that there has been a history of mislabelling at Alliant, so caution should be exercised.

Yes, I know, should have worked up to the load , but based on this experience, I'll be giving Alliant a miss from now on.

BTW batch number is 35069 D20314

So what are you going to use? I use ADI exclusively mainly because supply and stocking is consistent. We don't have many places to shop up here?

Casey,

My go to powder for the 180s has been VV N165, but its hard to get at present. I still have a little for important occasions, but am trying a few other things. I don't like using 2209 with the 180s because its harder on throats and cases, so will probably lean towards 2213SC until N165 supplies improve.

Alan

I've always been suspect of so called powder equivalent charts.

AR2213sc is a single base powder, versus Reloader 22 as a double base powder.

Interestingly I can't find any official cross-brand comparison charts from Alliant or VihtaVuori (as the other common double base powder locally available) similar to the ADI "powder equivalent chart"

Burn rates are one thing, but gas expansion rates (energy release) per unit mass is not comparable as far as I'm aware between single and double base powders let alone mil-spec triple base powders. N140 might burn at the same rate as N540, but one has more grunt than the other or VV would be listing equivalent min/max charge weights?

The double and triple base powders have a reputation of being much more easily influenced by temperature than single base powders regardless of the quality. ADI have exported their expertise in the area of single base powders to the US. I believe a lot of TR and F-Class shooters jumped on the N500 series band wagon when it first came out, but unless they kept re-tuning their loads, pressures changed with the seasons.

My best advice is to stick with OEM powder reloading guides and only use a "powder equivalent" chart as a last resort.

Good thinking Aaron.

aaronraad wrote:My best advice is to stick with OEM powder reloading guides and only use a "powder equivalent" chart as a last resort.

I tend to agree, and only used the burn rate charts to reinforce my findings. In my case I had used RL-22 from another batch quite recently, in similar temperatures I might add. With the earlier batch, it was about the same speed as 2213sc (same charge, same barrel, same time). This batch was about 140fps faster than 2213SC. Temperature sensitivity couldn't explain that sort of difference. Probably a case of mis-labelling, contamination or very poor quality control.

Allan , I've found that 2208 has gotten a little slower of late or can vary a little from batch to batch. But 140fps is a lot ! Lucky u weren't injured! G