Blue Dot..enlighten me please.

[cephas]

Didn't want to step on Bricks 357 mag thread, but the mention of Blue Dot powder rubbed a couple neurons together in my head and recalled some warning about it. Looked around and found this from Alliant:
"Blue Dot® should NOT be used in the 357 Magnum load using the 125 grain projectile (Blue Dot® recipes with heavier bullet weights as specified in Alliant Powders Reloading Guide are acceptable for use).
Blue Dot® should NOT be used in the 41 Magnum cartridge (all bullet weights)."
http://www.alliantpowder.com/getting...y_notices.aspx
So what's the deal with Blue Dot and why is the 41 mag specifically verboten?

[abner13]

Glad you asked. I emailed back & forth with Alliant several times back when these notices came out as I've been using Blue Dot in .41 and other magnum revolver cartridges for a long time.

Blue Dot , unlike H-110 , W-296 , 2400 , does not like to be compressed. Seems that a lot of people were using data from the Lyman book for the 220gr 410459 Keith-style SWC with the more commonly available 215gr BB-SWC. These Lyman bullets are designed with much less 'shank' and don't compress powder charges as much as the other styles commonly available. Some reloaders think ya can go only by weight. And the max load data for the Lyman bullets is usually much heavier than for bullets of different design , of even lower weight.


bullet shank.jpg


As you can see , the 220gr Lyman 410459 Keith-style SWC (2nd from left) has the shorter 'shank' and does not compress a charge as much as the 215gr Saaco SWC-BB (3rd from left). Elmer Keith designed these bullets to get as much powder in the case as possible. But the long nose can cause problems in some revolvers. Max. load for the Lyman/Keith-style bullet is a few grains higher than equal weight bullets or different designs that seat deeper and compress the powder charge more.

And if you use the max load listed for that 220gr Lyman SWC with a 215gr BB-SWC or 210-220g JHP or JSP , you will notice HIGH PRESSURE signs.

Lyman has a 215gr SWC-GC with a base similar in seating depth to that 215 BB , and it's max load of Blue Dot is several grains lower. (Lyman Cast Bullet Handbook)

[raxar]

I never got into blue dot for the simple reason that you have to use so much more of it compared to other powders.

[abner13]

I never got into blue dot for the simple reason that you have to use so much more of it compared to other powders.

Compared to what other powders?

When going for top velocity in magnum sixgun rounds , you actually use less Blue Dot than H-110/W-296 , AA#9 , 2400 , to achieve the same or higher velocities with a given bullet.

[raxar]

Compared to what other powders?

When going for top velocity in magnum sixgun rounds , you actually use less Blue Dot than H-110/W-296 , AA#9 , 2400 , to achieve the same or higher velocities with a given bullet.

Red dot, green dot, unique, titegroup (but that is the point of titegroup). I'm not loading magnum stuff though, might be the difference.

[Brick]

Very interesting! The Sierra Manual Edition 5 shows load data for the 2, 125 gr bullets using Blue Dot and both of their bullets for 41 Magnum!

[pennlineman]

I've used blue dot in a pinch during powder shortages. I don't care for it, seems to have more unburnt powder than others. I much prefer H-110, 296 or 2400.

[abner13]

Very interesting! The Sierra Manual Edition 5 shows load data for the 2, 125 gr bullets using Blue Dot and both of their bullets for 41 Magnum!

Seems that most trouble comes when people use generic data that list bullets only by weight , not by brand or design. Design and material has just as much effect. Some reloaders just look for the max load listed for a particular bullet weight and think it's safe.

[cephas]

Thanks for the info abner13, couldn't send rep.
Your Lyman cast looks exactly like my 429421 for my 44. Never notice the shank. Even with its long nose feeds through a lever action I have.
Came from an era where data wasn't specified for specific bullets. Better pay more attention.
Too bad Alliant never came back with a more public detailed explanation after all these years.
Don't use BD but this stuff interests me.

[abner13]

Thanks for the info abner13, couldn't send rep.
Your Lyman cast looks exactly like my 429421 for my 44. Never notice the shank. Even with its long nose feeds through a lever action I have.
Came from an era where data wasn't specified for specific bullets. Better pay more attention.
Too bad Alliant never came back with a more public detailed explanation after all these years.
Don't use BD but this stuff interests me.

Used to shoot metallic silhouette with my .41 Redhawk and that bullet. Used to use H110/W296 and 2400. Got much better results with B-D. Better accuracy and judging from how the steels went down , more power. Cleaner too.