Blue Dot Info needed

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cdoc42

New member
I no longer shoot shotguns frequently and I have 2-lb of Blue Dot I want to use up in my 9mm loads. I found a recipe some time ago but I cannot locate the source. All I have listed is

6.8gr – 1110fps – 27,300 CUP
7.6gr © -1189fps – 32,300 CUP (compressed load)

I loaded and fired 10 rounds with 6.8gr with CCI 400 small rifle primers,
X-treme 115gr RN bullets at 1.060” and I had no problems. I researched other sources because I noted that even 6.8gr produced a compressed load so I wanted to review the original data. Alliant, Hodgdon, and Hornady do not list Blue Dot at all with a 115gr bullet.

What I found makes me more uncertain because the recipes are much different.

Sierra 4th Ed. (1995)
With either their 115gr JHP @ 1.015” or FMJ @ 1.090” they list 6.0gr (1100fps) and 7.4gr (1400fps)

Speer #12 (1994)
With either their 115gr JHP @ 1.125” or TMJ @ 1.135” they list 7.7gr (1161fps) and 8.5gr (1258fps).

Even though the 6.8gr I used appears to be safe in either case as far as weight goes, my deeper seat may give much more pressure and velocity (but I have not graphed it). But there is no sign of primer deformation.

I would appreciate any thoughts and suggestions.
 
R

Recycled bullet

New member
I have used eight grains of blue dot compressed under an one hundred and fifteen grain full metal jacket at a cartridge overall length of 1.1" and the results were marvelous on target and the fire ball was profound.

I quit it when the pound of powder was used up and the gun is no worse for wear the best I can tell, because of it. It recoiled more than just about any other 9mm hand load I have tried. Felt like 357 lite.
 
4

44 AMP

Staff
Speer #11 (1987) lists Blue Dot loads for 9mm Jacketed bullets from 88 to 125gr.

Blue Dot is either the slowest or 2nd slowest powder they show in 9mm.

Many manuals do not list Blue Dot for anything in 9mm, considering it to be too slow to be suitable.

You can use it, but it will be compressed, and max loads show velocity in the 1200fps range with 115/125gr bullets (from a Beretta with a 4.9" barrel).

its not the most suitable powder for the small 9mm Luger case. if you've got a couple of pounds of it, that's enough powder for close to a couple thousand rounds of 9mm with it.

If the only thing you have to use Blue Dot in is 9mm Luger, you can, but I'd look into trading it to someone for a faster more 9mm suitable powder.
 
A

AL45

New member
I used Blue Dot in .380 auto rounds a few years ago and it was filthy. Worked a lot better in some .45 Colt loads.
 
C

cdoc42

New member
Well, so far, I've not been impressed with how well it drops through the measure. I have a Bruno, Redding, and RCBS measure. Bruno is fine for rifle, and although it appears to be a fine piece of equipment when it comes to small charges I don't find it dependable. The RCBS is really good but I don't have an acceptable drop tube for small cases like 9mm and .380 Auto, so a lot spills out. The Redding measure is fine in that regard but with Blue Dot, no matter how much attention I pay to technique, if my goal is 6.8gr, I can drop 6.5 to 7.2. That's enough frustration to make me change my mind about using Blue Dot just to get rid of it. CFE at 5.7gr is much more dependable.

AL45, I think I'll look into using it for .45 Colt!
 
4

44 AMP

Staff
Unless you're looking to load .45 Colt to Ruger or T/C Contender only level loads there are better powders than Blue Dot. IF you are looking for heavy loads there are better powders than Blue Dot.

However, if you're looking for heavier loads less than highest possible, Blue Dot will serve pretty well.
 
C

cdoc42

New member
Thanks to all, and a repeat to Marco for the 2017 Speer data on 115gr. that matches my Speer #12, 1994 manual.

It looks like my 6.8gr is an "underdose" but I'm now seating at a deeper 1.098." I wonder how the pressure looks with 7.7gr and seated 1.135."

I'll try Recycled Bullet's recipe just to see what 8.0 gr looks like with a 115gr RN seated at 1.1" - !!
 
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Marco Califo

New member
I used Blue Dot in .380 auto rounds a few years ago and it was filthy.
Click to expand...
Powder cleanness is driven by how far up you are in its pressure curve. Anything lower than max load will be dirtier as powder charge goes down. Blue Dot was designed for very heavy shotgun loads. It needs substantial pressure to burn completely, let alone cleanly. It will work in pistol calibers, but, it is not a pistol performance powder. BE-86 fits that bill better (and is flash suppressed) but max load is a little slower.
Metering Blue Dot can be tough due to its flat disk shape. I have found the Lyman #55 powder measure CAN be used effectively, IF you know how to adjust the 3 different cavity slides for the powder shape you are using.
I now have an RCBS Chargemaster, but have not tried using it with flake powders.
 
C

cdoc42

New member
"I'll try Recycled Bullet's recipe just to see what 8.0 gr looks like with a 115gr RN seated at 1.1" - !!"

I went right to my reloading room and did it. It was no different than loading 6.8gr at 1.097." But first chance that I get, I'll fire one off to see.
 
4

44 AMP

Staff
My guess would be that 8gr of Blue Dot under a 115gr 9mm will get you into the high 1100fps range from a 4" tube and a bit over 1200 from a 5".

I've used Blue Dot as a "midrange" load in the .44AMP. "Midrange" in that gun meant 1300fps range :D

16.5gr cycled the action for a full 50 rnd box and had less felt recoil than full power loads with W296. Interestingly 13gr Unique only worked for about half a box then the action was too dirty for that level load to work it reliably.

Blue Dot, being a flake powder doesn't meter like water, the way some ball powders do. But it is a lot smoother running through a measure than any IMR stick powder.

I'm not overly concerned about small variations in measure throw weights, as I charge from the measure until the loading block is full, then weigh each charge on my scale (trickling as needed) to get the precise weight I want.
 
U

Unclenick

Staff
cdoc42 said:
Speer #12 (1994)
With either their 115gr JHP @ 1.125” or TMJ @ 1.135” they list 7.7gr (1161fps) and 8.5gr (1258fps).
Click to expand...

Note that this is the same load listed on Alliant's site for the Gold Dot bullet seated to 1.125" COL (having the same corporate owner, Alliant does Speer's pressure testing, hence the crossover). This bullet is 0.55" long, so we are looking at a seating depth of 0.163" to 0.173" going from case minimum to case maximum, for an average of 0.168". The Gold Dot has a plated jacket, which is softer than the usual cup-and-core bullet, so this data would be applicable to a Berry's or an X-treme plated bullet at the same seating depth but would be warm for a conventional cup-and-core jacketed bullet.

I don't know the length of the X-treme bullet, but you have your own calipers, so you can measure that length and plug it into the formula below to have the same seating depth as the Alliant/Speer data shows.

COL = 0.575" + bullet length
 
4

44 AMP

Staff
Speer #12 (1994)
With either their 115gr JHP @ 1.125” or TMJ @ 1.135” they list 7.7gr (1161fps) and 8.5gr (1258fps).
Click to expand...

Just for comparison, the Speer #11 lists max of 8.9gr with their 115gr HP or TMJ bullets. COAL is not given. Velocity given is 1249fps,
Test gun was a Beretta 92SB, 4.9" barrel.

My point here is not to expect your results to exactly duplicate ANY of the published data exactly. Something in the vicinity, something close is expected, but an exact repeat of their results is serendipity, not something possible to intentionally achieve.

Your gun is not their gun, your components are not the same lot# they used. Close is reasonable, don't get hung up expecting to get exactly what they got.
 
H

HiBC

New member
Uncle Nick alluded to this thought above,but I'll restate it.

There are a number of reasons to be concerned about seating depth.

The accuracy folks look for improvement there.

Cartridge length may be critical to magazine feeding.

These are good and valid reasons. Measuring cartridge length overall is one approach. But bullet designs within a weight vary. Round nose,flat point,hollow point , cast vs jacketed,etc vary the bullet length. Measuring cartridge overall length based on the bullet tip results in variation of where the bullet base is located within the loaded cartridge.
This results in variation of pressure. Sometimes increase in pressure.

We can't directly measure case head to bullet base of a loaded round.

But we can start with a recommended cartridge length for a known bullet. If we know the length of that bullet, we can do a little simple math to calculate a new cartridge overall length that will position the bullet base correctly to provide similar combustion chamber volume .

Regarding pressure,its the bullet base that matters,not the measurement over the bullet tip. Keep in mind,its ALL about approximation and estimation with variable results.

To proclaim "Therefore....." and jump to a conclusion may provide alarming results.

There are ALWAYS gremlin variables.
 
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44 AMP

Staff
Measure the length of the bullet, base to tip, (before you load it), measure the length of the case, and compare those numbers against the loaded cartridge length to determine how much of the bullet is inside the case.

Keep in mind that tiny differences in the depth of the bullet base, taken as a percentage change of the powder space may have a measurable effect but not a significant effect. And that what might be insignificant in one cartridge could be quite significant in a different one.

For example, a couple thousands difference in seating depth might be of no concern in a .45-70 but very important in a 9mm Luger, and many other factors also apply.

Also consider that sometimes the COAL given for a particular load combination is not what you have to load it to, its just what they happened to get. And that the max COAL industry numbers are not what you have to load to, but a limit one should not exceed without valid reason.

Sometimes the reason is simple, and the firearm allows it. Other times, not so much.

A lot of what I load is bullets with cannelures or crimp grooves and those are where I seat them. As long as the COAL comes out at or below listed max length, I'm good.
 
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Unclenick

Staff
HiBC said:
We can't directly measure case head to bullet base of a loaded round.
Click to expand...

No, but if we know the bullet length, we can get the seating depth.

Seating Depth = Case Length + Bullet Length - COL

If you have measured the case water overflow capacity of one of the empty cases, you can use that together with the seating depth and bullet diameter, both in inches, to get case water capacity under the bullet in grains of water as:

Case Capacity = Case Water Overflow Capacity - ((1/2 Bullet Diameter)² × pi × Seating Depth × 252.89)

252.89 in is the number of grains of water in a cubic inch at 4°C (39.2°F), which is the temperature at which water volume is referenced. However, if you measured case water overflow capacity at the standard temperature of 25°C (77.0°F), then divide your result by 0.997 to allow for the expansion of water at that temperature.
 
S

Scorch

New member
Many manuals do not list Blue Dot for anything in 9mm
Click to expand...
There were a number of "pressure excursions" reported with Blue Dot when used with lightweight bullets back in the 1990s. Not sure if they got that all figured out or not. I only use Blue Dot for 44 Mag loads anymore.
 
4

44 AMP

Staff
Many manuals do not list Blue Dot for anything in 9mm
Click to expand...

Many manuals don't list a lot of things. Sometimes its because their results were not suitable, or consistent. Sometimes because a given load is not what the majority of the public is looking for. Sometimes something doesn't get listed simply because there was none on hand to test when they did the testing.
 
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