Crazy results w/ Unique ?

[Dubious_Beans]

Well, I've been experimenting with different powders. Had pretty good luck with Titegroup, Bullseye, and Blue Dot.
Now I've got a jug of Unique to play with , and WOW! what weird results I get...
I've tried several different recipes with several different bullets. No matter what I do, my Unique loads are quit a lot hotter than what I expect.

For instance...
124g Hornady XTP bullets over 4.2g Unique gives me an average speed of 1026FPS.
124g Hornady XTP bullets over 4.4g Unique gives an average speed of 1074FPS AND is starting to show signs of flattened primers. (Danger!)

According to the manuals I have, I should be able to get to about 1100FPS safely with Unique and it should take around 5g or better to get there:

Hornady: 4.0g (900FPS) - 5.0g (1100FPS)
Lyman: 4.5g (997FPS) - 5.0g (1078FPS)
Speer: 5.2g (1080FPS) - 5.8g (1180FPS !!)
Sierra: 4.1g (900FPS) - 5.6g (1150FPS)

So why do I seem to be in the "Danger" zone already with only 4.4g?

I get similar results with 115g bullets. I get a LOT more speed than I expect even at the low end of the charging scale.

I'm sure I've measured the powder accurately and that the scale (RCBS 5-0-5) is working.
I'm also sure that the chronograph is working right. It measures exactly what I would expect with other known loads.
Bullet seating depths are within spec, and have given predictable results with *other* powders.

It only seems to be Unique that's acting strange for me.

Any suggestions? Is Unique just not very suitable for 9mm, or am I just going crazy...

[J-cat]

Flattened primers are not necessarily a sign of danger.

[f4tweet]

OAL? Check several manuals.

[bohoki]

mixed brass whats your spread? whats your primer?

[Dubious_Beans]

Flattened primers are not necessarily a sign of danger.

Mmm. Perhaps not, but the flattened primers along with the much higher than expected velocities makes me nervous. I've never seen flattened primers with any of my other loads, and I've pushed some of them to the maximum recommended dosage.

[Dubious_Beans]

OAL? Check several manuals.

With the Hornady XTP's I'm using 1.075". The Hornady book recommends 1.060" for those bullets, but I'm seating them a bit longer.
I've used those same bullets and OAL with Blue Dot and got the expected velocities listed in the Hornady book.

[Dubious_Beans]

mixed brass whats your spread? whats your primer?

Yes, mixed brass. Mostly REM, WIN, PMC, and RWS.

The spread is pretty wide.
With 4.4g of Unique, I got a high of 1096, a low of 1057, and an average of 1074

With 4.2g Unique, I got a high of 1084, a low of 1050, and average is 1026.

Primers are Federal #100.

[CSACANNONEER]

Even with canister grade powders, burn rates will vary from lot to lot. Also, you may just have a barreland or chamber which is on the small side which can increase pressures.

[J-cat]

I've never seen flattened primers with any of my other loads, and I've pushed some of them to the maximum recommended dosage.

And this was with FC-100 primers as well? Do you know that FC primers are the softest primers on the market and will flatten out at pressures as low as 20,000 PSI? At 40,000 PSI they look like they have melted into the primer pocket. In contrast, CCI primers will maintain their round profile well into the 40,000 PSI range due to the harder primer cup.

Loads using fast burning powders will tend to flatten out primers moreso than loads using slow burning powders.

Powder position affects pressure. Point the muzzle down before firing, and the powder will lay against the base of the bullet. The velocity and pressure will be low. The primer will remain round. Point the muzzle up, and the powder will lay against the primer. The velocity and pressure will be higher. The primer will flatten more.

[fsx]

I am getting a very mild load for my G19 at 5.1gr unique. 115fmj with WIN or F.C brass. What's your OAL?

[ireload]

Dubious as Jcat indicated regarding primer, do you have another brand to try for the same load recipe? Unique from my experience likes to be loaded mid to max level.

I use 115 gr. and have not tried 124 gr. yet. I may try it in the near future. For my loads I use Win (currently) primers. But in the past have also used CCI and Fiocchi. All three brand primers has not given me any "flattening" till I've loaded it past the max level (Speer #13 load manual).

[bohoki]

Yes, mixed brass. Mostly REM, WIN, PMC, and RWS.

The spread is pretty wide.
With 4.4g of Unique, I got a high of 1096, a low of 1057, and an average of 1074

With 4.2g Unique, I got a high of 1084, a low of 1050, and average is 1026.

Primers are Federal #100.

as strange as this will sound i loose about 30 feet per second same load between win and rem cases


try a batch all with the same case you will probably notice the remington brass ammo goes slower with all variables identical

[bjl333]

Use Unique for 30 years. There are other variance as well. your chamber could be different the the test chamber in the book. The primer you use, are they the same one as the recipe? The brass you use, are they the same as teh recipe. The cycling of your auto has something to do with it also. That is why they suggest starting low and work up, because of the various different componant.

Are the loads cycling your 9mm ?? If they are then you don't need to go to a higher load. If not then switch powders to one of your others you've listed and save the unique for other caliber.

[J-cat]

as strange as this will sound i loose about 30 feet per second same load between win and rem cases

R-P cases have less capacity than WIN.

[bjl333]

R-P cases have less capacity than WIN.

But if he needs the increase capacity of the Win case using Unique then he might not have a gun left !!!