Blue Dot: To mag primer or not

[bmcush]

First off I want to say thanks for helping a reloader get back into his hobby of passion after a nearly ten-year absence.

My question, I'm loading some 158-grain "lead safe" soft copper bullets for my model 28-2 (Love this gun). My older manuals (1991 and older, Horn, Sierra, etc) aren’t really together conclusive on which primer to use. What do you folks think?

Thanks for your time!

Bill

USAF Retired

 

[Mr.Revolverguy]

I have used standard pistol primers with bluedot and 357 loads. I did use mag primers but found bluedot depending on the environment can spike even when using a mild load. If you use magnum primers make sure you start exactly at the recommended starting load and work your way up from there.

 

[rcmodel]

Use Standard primers only with Alliant pistol powders.

All of the Alliant "Dot" powders, as well as Unique, Herco, Power Pistol, and 2400 are double-base flake type powder, and are easily ignited with standard primers.

Using Magnum primers with these powders may give unexpected pressure spikes.

As long as your loads develop sufficient pressure for the power being used, they will burn just fine.

rcmodel

 

[bmcush]

Thanks for the input guys, yeah its starting to come back. I've never did BD before, usually 296 or H110 when loading 357/44, but though I'd give this a try since the barrel length is only 4 1/2 in this old service revolver.


Thanks again

Bill

 

[zxcvbob]

Use standard primers. I loaded some .38/44's with Blue Dot a few weeks ago and I used small rifle primers (about the same as a magnum pistol primer) and I got case head separations on about half of 'em (not when I fired them, but when I was resizing) These were pretty hot loads but not ridiculous; it must have been a terrific pressure spike to ruin the brass like that.

 

[rg1]

I use standard primers for 125gr Blue Dot loads. I chronographed several different loads of Blue Dot and standard primers were the most consistant with the lowest extreme spread. Magnum primers gave me spreads as much as 100-150fps.

 

[Jim Watson]

I loaded Blue Dot for .357 because it was the slowest powder that did NOT call for a magnum primer. Ammo was for use in a softly sprung Python that pretty much demands Federal Standard primers.

 

[tlen]

Alliant's online Reloader's Guide calls out magmun primers for the .357. I only use magnum primers in my .357 loads and have never had a problem,

 

[joneb]

When I first loaded for .357 mag. with Blue Dot I used magnum primers, accuracy was just ok someone here or the TFL suggested standard primers the accuracy noticeably improved
Blue Dot is a bit temperature sensitive and just plain unpredictable, I switched to AA#9 using small pistol primers for my 2.75" and 4" guns and I'm much happier now

 

[38 Super Auto]

One thing I have found with Blue Dot is the ES is larger than some other powders. I chrono'ed 38 Super and .357 Mag with WAP, AA#7, Blue Dot and others, and got more uniform velocities with finer grain powders like AA#7, WAP, etc. I think its because the larger flakes don't get metered as accurately in my measure. I think you'd have to measure more accurately than my present capability to verify that, but it's a hunch.

I know velocity and variation in velocity isn't always the most important factor in accuracy, but all the rounds were loaded with the same case, primer, bullet, OAL, etc - the only factor I varied was the powder type and weight.

 

[wally]

When I first started reloading I used magnum primers for the magnums, but when I ran out and used some standards instead, and noticed little difference, I quit buying magnums and now have a much more manageable inventory.

--wally.

 

[zxcvbob]

When I first loaded for .357 mag. with Blue Dot I used magnum primers, accuracy was just ok someone here or the TFL suggested standard primers the accuracy noticeably improved
Blue Dot is a bit temperature sensitive and just plain unpredictable, I switched to AA#9 using small pistol primers for my 2.75" and 4" guns and I'm much happier now

I'm planning to use up all my Blue Dot this summer, then switch to AA-7. I've heard too many stories about Blue Dot in cold weather (it gets stronger, just the opposite of most powders.) Also I wasn't impressed with it with moderate loads, and it goes from moderate to too-much really quickly.

I have a half a pound left. That won't last very long loading .357's, .30 Carbines, and .45 Colt +P's. They all use a lot of powder (especially the .45)

 

[Walkalong]

Standard primers. I am like many. I have relegated Blue Dot to a couple of specific uses, but have mostly gotten away from it.

 

[PC40]

Good luck with the BD. It's been said that it requires heavier bullets at max loads with strong crimps to burn it all, I couldn't figure it out except for one 9mm load with a 124 gr bullet. Unburnt flakes everywhere especially in 45 ACP. Just a few of those unburnt flakes in the chamber of an autoloader can choke it up. At a summertime pin match I noticed I had powder all over my arm, I said it was Blue Dot, my buddy asked how I knew - Duh! it has blue flakes in it!

Maybe it was just a lousy batch but I won't buy it again. I hope that you have better luck, some people swear by the stuff. Keep an eye out for incomplete burns.

 

[XD-40 Shooter]

I load 10 grains of Blue Dot behind a 158 grain Nosler JHP, its a good load. It gives ~1150 fps from a 4 inch barrel and its accurate. Also, the recoil is noticeably lighter, compared to my 296 loads, which are boomers. I use standard primers by the way.

 

[Slamfire]

I conducted load testing in a 357 with Blue Dot. While it shot well with jacketed bullets, it created a high amount of leading with commerical cast bullets.

I also tested 2400 and AA#9 in the 357 with the same bullets, same day. Those powders created zero leading at the same or higher velocity.

I don't recommend Blue Dot for any application. I have tried it in 9mm, 38 Spl, 44 SPL, 45LC, and 44 Mag. It works best in the magnum applications with jacketed bullets.

I did not use magnum primers, though WSP primers tend to be very hot.

I am sticking to 2400. Works well with cast or jacketed.

M27 S&W6.5”
 5-Aug-06 
T = 102 °F	
						
357 Mag				
Load	158 JHP (W/W) 	158 LRN Lead	     158 LRN Lead
	13.5 grains 2400	9.0 grains Blue Dot       10.0 grains Blue Dot
	R-P cases WSP 	Midway cases CCI 500     Midway cases CCI 500
				
	
	
Ave Vel	1222		1203	                      1290
Std Dev	26.45		29.22	                        24.91		
Ex Spread 72.12		120.8	                        88.15	
High	1262		1261	                        1324	
Low	1190		1141	                        1235	
N =	5		22	                         20	
		
	Great load	         Difficult extraction       Accurate Difficult 
		              Leading		          extraction
				                     heavy leading

 

[Walkalong]

it created a high amount of leading with commerical cast bullets.

Agreed, but I fixed that with Super Grex. I used it for medium plus .44 mag loads and lead bullets in my Winchester. Without the filler it would lead the entire bore.

 

[zxcvbob]

conducted load testing in a 357 with Blue Dot. While it shot well with jacketed bullets, it created a high amount of leading with commerical cast bullets. I also tested 2400 and AA#9 in the 357 with the same bullets, same day. Those powders created zero leading at the same or higher velocity.

Maybe that's why I don't like Blue Dot. All I shoot is cast bullets, and the leading is always bad.

(I've loaded a handful of very hot .38 Special loads, almost .357 Magnums, with hominy grits compressed between the Blue Dot and the bullet to see how that works. Haven't had a chance to shoot them yet)

Herco is a good powder for hot loads using heavy cast bullets -- but not as hot as you can get with 2400 or 296. I thought Blue Dot was gonna be the best of both.

 

[jodyb]

I've been trying 13gr of Blue Dot, CCI 550, and 140gr Hornady XTP HPs. My new Speer manual shows that's a max load but my old Speer manual shows that as being low. Alliant's site shows that as a starting load with magnum primers. Feels pretty stout in my 4" 686, though, so I'd tend to agree with the new Speer manual.

Strange info about Blue Dot... load data is all over the place. So far I'd only rate performance as mediocre. I just loaded up some tests using 2400 (with standard primers) and results so far suggest that's a better road to go down.

 

[454PB]

I use Bluedot in all my magnum handgun loads, and for me it's the most versatile of the medium burn rate powders. I've been hearing the temperature sensitivity story for many years, yet I've never seen it happen. Maybe it's because I don't do a lot of shooting at -20 degrees. With the .357, .44 magnum, and .454 Casull, it will achieve 80% to 90% of the velocity available from slower burning powders, and with far less powder weight. Yes, it can be "peaky" since it is a medium burn rate powder, so loads must be worked up carefully.

95% of my pistol shooting utilizes home cast bullets, and I see zero leading with Bluedot or any other powder as long as the cast bullet fits the gun. The idea that powder type or burn rate affects leading escapes me. The old idea that some powders burn "hotter" and melt the base of a cast bullet is an old wives tale. Propellant gas may leak past the bullet base causing gas cutting, but that is a function of pressure, alloy, and proper bullet fit in the cylinder throat, forcing cone, and barrel.

I also use Bluedot for reduced cast bullet rifle loads, and have had excellent results.

In general, standard primers work well for all my Bluedot applications. I have experimented with magnum primers and never found a need for them with this powder.

 

[Clark]

1) The 25acp does not like the magnum small pistol primer.
2) The 6mmBR really does like the small magnum.
3) Belted magnums filled with ball powder like magnum rifle primers.

Based on my experiments with the 25acp and 9mm with very hot loads and switching between magnum are regular primers:

The reasons for using a magnum primer:
1) It is thicker, and so will take higher pressure before piercing
2) It ignites better

The reasons for not using a magnum primer
1) It gives more pressure increase than velocity increase

It does not matter much if you use a magnum primer or not in 357 mag, but it definitely not needed with Blue Dot. You will find it very hard to detect the tiny extra bit of detrimental pressure in the 357.

What does it all mean?
I would not use the magnum primer with Blue Dot in the 357.

 

[grenadier]

First, and foremost, get a more modern reloading manual. Manufacturers can, and do, change their recommendations on a regular basis.
If the manual says to use standard primers, then use standard primers.

Only use magnum primers when the recipe calls for it.

 

[Crazy4nitro]

454PB I agree,
I have pushed Lead pretty hard without leading. Proper Bullet fit in the barrel has "in my opinion" the most impact on reducing leading,even more so then todays Magic lubes.

'Nitro