Howdy Guys,

My apologies, this happened a week and a half ago and even though I had the best intentions of putting it up here work and life have gotten rather busy so I kept putting it off. However, since there are a couple of posts regarding Blue Dot and pressures now is an appropriate time to post it up.

I was working up a load for my 20 tactical. I wanted something somewhat fast but easy on the ears. I was using the Hornady 32 grain Vmax, and had set an arbitrary velocity of 3800 fps to strive for. Here is my load data:

14 gr Blue Dot- 3440 fps
14.5 Blue Dot- 3518 fps
15.2 Blue Dot- 3658 fps
15.8 Blue Dot- 3723 fps
16.2 Blue Dot- 3 shot string 3745,3742,3749 fps

Actually they were all strings but those are the average velocities.

At any rate, even though the velocity was less than some random number I thought up, I was impressed with the uniformity of the velocities at 16.2 grains so I went and loaded up 12 rounds. I used a RCBS uniflow powder measure, and a lyman 1000 digital powder scale. My measure also has the 17 caliber adapter on it.

I also had mounted a different scope so I was shooting these rounds at 150 yards and getting the scope dialed in too. Not that it makes a difference but just so you know that my attention was also being spent on other things as well. At any rate, fired the first 6 shots fine, round #7 sounded the same but there was a little smoke around the bolt, and then I noticed the bolt was stuck. After some whacking with my palm and a hard yank it came up, and the brass was quite bulged. I distorted the cartridge a bit getting it out of the bolt, then found that not only was the base bulged but the primer was blown. Left me scratching my head, but an inspection of the gun showed nothing wrong with it, so I made a mental note to maybe use the scale to double check the loads in case I had a powder bridge or something. At any rate, I chambered #8 and pulled the trigger. This one even sounded a little different, and no amount of gentle whacking could get the bolt to move at all! I figured that I was done shooting for the day and took the gun into the shop, a combination of a hard plastic mallet and other methods of persuasion finally got the bolt open. Not only that, but this one was REALLY stuck in the bolt, bent the brass up a bit getting it out of the bolt. Needless to say, I pulled the remaining loads and weighed them all. None were over 16.2, I had one that was 16.0 but I think what happened with that one was I poured the bullet and powder into the pan and fished the bullet out with my fingers and some powder stuck to my fingers.

So what happened? I do not know. The main reason I haven't posted this yet is that I have been meaning to take pictures and post them. The initial 6 loads, and the 3 test loads, show NO signs of excessive pressure at all. Bore is unobstructed, in fact I watched both of the over pressure bullets hit when I fired them. It could be fouled somehow, but it had been cleaned maybe 30-40 rounds earlier. Truly a mystery to me, and if anyone has any ideas I'd sure be glad to hear them! Probably be a while before I work up the nerve to shoot Blue Dot in this gun again, but sometime I'll go down a few grains and explore that area again. I do know that I will never go over 15 grains BD in a 20 tactical again.

My gun (rem 700 short action) survived OK, but did not get off scot free- the second round blew the extractor off (actually I think it stuck to the rim when the case head expanded and broke while I was getting the case out), and also there is a slight pit in the bolt face, but lugs seems to be OK. If anyone has an extra new style extractor send me a PM letting me know how much you want for it, I need one....

However, I would have no safety issues shooting this gun with 10 grains of Blue Dot. I do not see how that could be harmful, but I do know that I could fit 20 grains in one of my cases, so a double charge could be possible. The main issue that I do have is I had quite a bit of variation in the bullet velocities at lower loadings. Don't have those notes here but it was as much as 450 fps, and at least 200 fps deviation until I got the velocity up into the forbidden zone.

If anyone knows Randy, who posted on Predatormasters, please give him my best wishes and let him know that I'll include him in my prayers tonight that his eye gets better.

I'll make it a point to take some pictures tomorrow, both of the 6 normal looking empties and the 2 with blown primers.

At any rate, since Blue Dot is up for discussion right now I thought it appropriate to post, and if anyone has some ideas or insight I'd appreciate hearing any theories out there.

Mark

I am not sure about the caliber used here but would be happy to run it through QuickLoad. Please indicate the cartridge length as well.

BlueDot is not meant to reach high speeds with little powder. This could be dangerous and there are other, better suited powders if one wants to go full speed. Reason is that already lower velocities go with pressures close to the maximum. The spike is just shorter than the one of a regular rifle powder.

Blue Dot is not a rifle powder. People have been seriously injured using Blue Dot for reduced loads.

I have no idea why someone would take that chance when more suitable powders will work.

Chris

that is interesting. i have shot hundreds of rounds of 13.5gr of blue dot with a 40gr nosler bt with good success outta my 14" .223 contender.
this past summer i mysteriously had one round blow a primer only thing i could figure was that one round may have been too close to the lands causing pressure to go too high.
all loads previous to that ONE were just fine. i adjusted my seating depth, and will continue using them to see how they do.

I thought the practical limit for a 223 type case 14 - 14.5 grains I would think with the smaller bore that might be a touch less. One thing even though the blue dot loads don't heat up the gun quite like regular loads I bet it heated up enough to push the pressures over the top.

Seem that with seafire's reasearch showed is that the line between good and grenade is very narrow with blue dot loads. Count yourself lucky and back off sum next time.

Interesting comment about the heat, but in this instance I do not think that caused anything. I was chambering rounds individually and the shot would be fired immediately after chambering, so there was not much chance for the heat to soak into the brass.

I am not sure of the dimensions of the 20 Tactial, or the case size.

What I can tell you is that 14.5 grains is about as safe as you want to go in a 223 case. And that is with bullets under 45/46 grains.

With a 50 grain bullet, I back that off to 14 grains, and 13.5 with a 55 grain bullet.

I am sure that even tho the first rounds did not pop a primer, I am sure that when you reload them you will find ALL have a loose primer.

I apologize that I do not have, or have access to a 20 Tactical. However, I would have started my reloading at lower than the 14 grain area. Because of a narrower neck diameter, you have less outlet for the case so pressure will be higher for a 40 grain 20 caliber bullet than a 40 grain 22 caliber bullet with the same powder charge.

Blue Dot is a very balanced powder and not subjective to quick pressure spikes like Red Dot and Green Dot are. However also remember the faster the powder is, the closer your parameters are between safe and popped primers.

If it was new brass and you popped a primer, then I would have stopped and checked the primer pockets in the other rounds that had been fired, before shooting the others.

Case capacity could also vary it if it was out of specs. Just last night I was loading some Federal 223 brass with a load of W 748. With about 250 of them taking 28 grains just fine, I had one that was overflowing all over the place.

I thought the scale might have been off, and checking it, it was not. Then I poured in another load of 28 grains and same thing, an overflow.

Then I put 28 grains in the next case and no problem. Then poured the powder from that case into the other case, and once again overflowed.

So I deprimed it, and was looking to see if maybe some walnut cleaning media was still in there. Not at all.

Then I weighed a case that was fine, and then weighed the overflowing case. It was much heavier and therefore had much thicker walls. Yet it was from the same brass lot of Federal brass as the rest of the cases were.

Screw ups can happen with any powder. I do suggest the gentleman who started the post probably should have started at a lower point.
14,5 grains is what I have listed as max, with the lightest bullets. My apologies to him for his misfortune. I am glad neither he or his rifle were hurt.

But a lot of other people have used Blue Dot loads with good results in both accuracy and intended goals, without problems.

That is also why I posted my data, with ranges of 4 grains to 14 grains in my blue dot load data with the 223 and a 40 grain, 45 and 46 grain bullet.

We all need to work up when developing loads.

cheers
seafire

quote:

Originally posted by P47D:

Blue Dot is a very balanced powder and not subjective to quick pressure spikes like Red Dot and Green Dot are. However also remember the faster the powder is, the closer your parameters are between safe and popped primers.


cheers
seafire

Excuse me for chiming in fellas, but the first quoted sentence above is balogna! It may be true for magnum shotshells and also for certain pistol cartridges, even reduced loads in some applications, but NOT FOR A HIGH INTENSITY BOTTLE NECK CARTRIDGE AT NORMAL FULL PRESSURE!!

We should HEED the second sentence however, as it is a true statement.

You guys are walking down a road that is a mine field. The very reason they developed progressive burning powders a hundred years ago are the pressure spikes you are seeing in this application.

I don't understand the logic going on to use a WAY TOO FAST powder here. Less noise??? Economy??? Has anyone thought what this hot high nitroglycerin content (probably 20% or more) powder is doing to the throat of your barrel working at these FAST time pressure curves?

In this Blue Dot .20 Tactical (or .223)situation pressure goes up quick! The time pressure curve is probably vertical! My guess as to what is happening with the air space left in the shell with this load is that something as simple as elevating the muzzle (and putting the powder back against the primer) can spike these loads into orbit 30,000psi or more and give the shooter the blown primers they are experiencing. After blown primers things get worse I can tell you!

.20 Tactical? I would start with something like Varget for a burning rate. The .223 does great with H-4895 EVEN IN 14" CONTENDER BARRELS!

Please be careful guys and leave Blue Dot to the goose hunters like it was designed for!

BigRx

Since there is no data on the .20 Tactical in QuickLoad, I used a cartridge called .20 TNT or .20/17 Rem. The 32 grain bullet and 16.2 grain gave 4161 bar, that is the maximum pressure allowed, no room for deviations any longer! The velocity was 3697 fps, less that what was originally posted so I guess that in the accident the pressure must habe been much higher.

Thanks DUK.

I haven't filled a case with water yet, but out of curiosity I filled a shell to the base of the neck with B Dot and it weighed out to 22 grains. If there is any other data you need that I can measure for you I'd be glad to do it, I'm learning something here!

We have visitors tonight but I am going to try and post pics tomorrow.

Also to Seafire, I started at 7 grains initially, sorry I didn't post that data but it is rather tedious going typing in the 7-14 grain velocities at .5-.6 steps and didn't think it that relevant for the issue at hand.

The 22 gr. blue dot case capacity seems too high, and is not a reliable way to measure because the powder is compressible, but never mind that for the moment. Quickload says you'll need about 64,000 - 66,000 psi to get 3745 fps with blue dot in the 20 TNT, and that will be true regardless of small differences in case capacity. You were pushing it, bud. Add variables like barrel fouling and temperature (sitting in a hot chamber for a couple of minutes can increase the powder temperature significantly), and that 65,000 figure could climb higher.

In my young and foolish days I worked up a max load for a 7 TCU in the winter. It was right on the edge, but safe at the time. Fast forward to a 40 round match on hot July day ... at first the extraction was stiff and primers were flat, and as the gun got hotter, primers were falling out and cases were seperating. There's a reason you don't want to load on the ragged edge of safety.

quote:

Originally posted by popenmann:
The 22 gr. blue dot case capacity seems too high, and is not a reliable way to measure because the powder is compressible, but never mind that for the moment. Quickload says you'll need about 64,000 - 66,000 psi to get 3745 fps with blue dot in the 20 TNT, and that will be true regardless of small differences in case capacity. You were pushing it, bud. Add variables like barrel fouling and temperature (sitting in a hot chamber for a couple of minutes can increase the powder temperature significantly), and that 65,000 figure could climb higher.

In my young and foolish days I worked up a max load for a 7 TCU in the winter. It was right on the edge, but safe at the time. Fast forward to a 40 round match on hot July day ... at first the extraction was stiff and primers were flat, and as the gun got hotter, primers were falling out and cases were seperating. There's a reason you don't want to load on the ragged edge of safety.

Nice tag pman

On the pressure spiking as the powder is rearranged in the case :

I tried exactly that in 300WSM ( tilting the barrel up before shots, and tilting down before shots ) and the chrono did not show any significant differences that would cause pressure excursions into unsafe territory from where I had determined the maximum safe load was.

YMMV on any load at any time , but I was really quite impressed with Blue Dot as a powder for reduced velocity standard pressure loads in 300WSM. I made a post a while back when I range tested this stuff with the pertinent data.

Read what Seafire has said about his experiences with this powder, and heed the warnings to not make this something it is not. Full pressure with reduced velocity and reduced noise and barrel heat is the goal. If you try to load Blue dot to the same velocity as a standard rifle powder you will be in VERY unsafe territory.


Travis F.