BLUE DOT questions...

[CWLONGSHOT]

OK guys question...

I like Blue Dot. Its worked really well for me. I started using it for 12g Heavy Duck loads. I then started uing it for my 357 Mag cast loads. Then in the late 80's it was found to be great in the 10MM.

I have been working allot with 350 Legend and with the help
Of quick loads discovered it might be a good candidate for the Legend! Using the new 195g cast bullet. Figuring OAL, Seat Depth, diameter, exact weight I ran tbru some powder charges and found that 18.7g was 56K. I backed that to 18.5 and called that max. Dropped 2.5g and used 15.5 as a starting load.

This is a bolt gun so stronger than a MSR. I loaded and first a 15.5g load with a 197g bullet. Bolt was stiff to lift and case would not extract... Been here a couple times. OK OVER LOAD. I REMOVED THE BOLT AS THE CASE HAD EXPANDED to wedge fit inside the bolt recess. It came out along with the primer. Case head had a pronounced ring. WOW. I was lucky!!

Now there is a chance something I did wrong on that one cartridge. But I pulled all the remaining and every one was so on. So Im doubting it was my mistake.
I double and tripple checked everything in hand and then again on QL.

I was talking to a friend who reminded me Alliant had a warning about NOT USING BlueDot in the 41 mag or for light 357 Mag loads.

QL says I should be 100% fine to 18.7g with this bullet. While in reality in my gun... 15.5 was probably 80K +!!!

What do you guys say here? Is there some unknown Anomaly with BD in some magnum cases???

Im fine gun is 100% fine. I shot some 100 shots after this.

Had a BALL WITH SUBS!!

CW

 

[RicinYakima]

IMHO, never trust a computer program. Start at least 10% less that what it says. Blue Dot has had a reputation for doing freaky things for over 30 years, just like SR4756. FWIW

 

[CWLONGSHOT]

Thats why I started at 15g!!!

CW

 

[Missionary]

When ever I tread into the unknown I give the power people a phone call.
I did so when we started shooting a 50-95 Repro. Had some good established accurate 3F loads as our base velocity.
Accurate techs spent a good while to give me their estimate what would be near the same FPS safe loads with 5477. They were within 2 grains .

 

[RBHarter]

I loaded 140 XTP with BD from the #12 Speer book and had jam fit cases with the book start load in 357 mag . About 6 weeks later I saw the don't use it light warning I never thought that light would be a 140 looking for 1200 fps .

I just stayed away after that although in hindsight it may have been as much on the gun as the powder . 7.0 Unique under a 95 gr Gold Dot was the only thing that shot really well past 38+P .

 

[Ian]

Had the same thing happen with Longshot and the .458 Socom. Predictions with velocity were bang-on with Herco, HS-6, True Blue, and 2400. Longshot was what was needed, modeled it and started at minus 10% of 35K psi max. First shot pushed brass into the ejector and extractor recesses, and by velocity I estimated 42K psi, which is well over proof load pressure for an AR-15 with a .473" bolt face and who knows how close to the hoop strength of the barrel around the enormous chamber. You never know.

I ended up reducing the load something like 30% of the model and it worked perfectly after that, being exactly the pressure curve and gas volume I needed to make the system cycle at the velocity and bullet weight I needed. So far that is the only "holy sheep!" moment I've had with QL, but also one of the very few instances where I did not have any load data to go on whatsoever to sanity check the prediction. Longshot isn't listed much for metallic cartridges, but does well in them if you get the load right.

The takeaway is don't get over-confident in QL, it is only a thermodynamic model, and while an excellent one, some powders don't play well in certain circumstances, something which the model cannot possibly predict. Modeling and testing a whole string of powders and having very consistent, predictable results let me get too comfortable and trusting of a system that cannot have the ability to give ANY guaranteed safe or exact load predictions, and it almost bit me too.

 

[RBHarter]

Ranch Dog ran some QL numbers for me once on a .007 neck up mild cat and I 4350 showed 105% density in the table but the actual case fill to the bottom of the neck was about 145% of that number .

I was surprised to learn that Unique develops just 22kpsi under a 350 gr bullet @10 gr in a 45 Colts @1.610 OAL . .........I don't believe I'll go there that's well into Ruger data with a 255 and about 20k at that . Might be ok .

 

[CWLONGSHOT]

THANK YOU!

Herco is doing great thinks for me in sub sonic velocities. Ill research how far that goes and maybe try that powder.

I dont have a velocity need here. But targeting 1800. Dependent upon accuracy attainable.

I have a ladder started with the 358315 and 296. Thats a GC bullet.

CW

 

[fiver]

blue-dot wasn't ''invented'' by the guy that invented red-dot bulls-eye and Unique.
the first one is the one I'd like to talk to, the blue-dot guy?,,, not so much.

anyhow, there have been lot's of other powders over the years that really should have been the schziznit and a perennial leader in powder sales for years and years to come.
most of them failed or had bigger problems when it come right down to actually doing what they should have done.
H-450, lightning no-2 come to mind right off.
remember when rl-17 was gonna set the world on fire? progressive burn rate, temp insensitive, good metering,,, who uses it?
where did 230 and 230-P go?

 

[Ian]

Reloder 17 has the same problems that Superformance and Leverevolution do, erratic as heck and extremely limited applications where they do well. I gave away the remains of my pound of 17, still have the other two, not sure why.

 

[Tomme boy]

BD is the only powder I ever ringed a chamber with. I was following another guy that was using it for reduced loads. I loaded up a bunch of the Turk 8mm bullets in commercial brass. Shot them off and went home to clean my gun. A M24/47 8mm. I then noticed there was a ring on 2 pieces of brass. I looked in the chamber and it also had a ring. If I remember right it was 17grs. I have never gone back to that powder since.

 

[CWLONGSHOT]

Wonder what the phenomena is that causes that. pressure spike for sure.. But why and what causes that.
Ill be using it for what I know. But I agree I wont be testing with it!!

CW

 

[CWLONGSHOT]

Reloder 17 has the same problems that Superformance and Leverevolution do, erratic as heck and extremely limited applications where they do well. I gave away the remains of my pound of 17, still have the other two, not sure why.

. I just couple
Months ago bought my first pound of leverevo. Never used any of them yet!!

CW.

 

[RBHarter]

I will venture that Blue Dot was purpose designed for a specific window of use with a stack to dia ratio window upper and lower pressure limits and nil airspace .

I suspect a low grade SEE like event where both ends of the charge are ignited and the fronts collide in a 40kpsi event over a 20kpsi peak ...,.... mechanics terms physics is above my pay grade .
In the confined column you get more of + shape effect .

97% speculation with only design and failure results to refer to .

 

[Bill]

I have been using blue dot for years in my plain based loads for mil surp matches, around nine grains is perfect for most of them, a little less for the 303, the best score so far was a 292 with an old Turk 8 mm

Bill

 

[CZ93X62]

Blue Dot does weird stuff--just not in my experience. I use it in 10mm, and that's it. Once it is used up, it won't get replaced. Too much weirdness reported by people whose judgements I respect.