Did I get a bad batch of Unique powder?

[cjwils]

I have used Unique for most of my handgun reloading in several calibers for many years. I don’t reload a whole lot, so one canister of Unique lasts me several years. A few months ago, I finished an old canister, and shot up the reloads from that. Recently I loaded some .357 cartridges using a newer canister of Unique. Even though it is newer, it sat on my shelf for several years before I opened it and started to use it. The information on the canister says CE0519 637Z040314. I have no idea what that means, but maybe someone else knows.

Anyway, the newly reloaded .357 cartridges have 130 grain jacketed bullets and 7.6 grains of Unique. The primers are Winchester small pistol. My intention was to have loads that were slightly hotter than 38+P, but well below maximum magnum. When I fired a few of these, I was shocked at the recoil. It was like a firecracker went off in my hand. The recoil was way stronger and sharper than I expected. I intended to shoot at least half a box, but I quit after just a few. Later, I pulled a bullet and checked the powder weight, which was exactly what I expected. I am baffled about what is wrong. Could I have gotten a bad batch or mis-labelled batch of powder? With the old powder, I loaded bullets of 125 to 140 grains with powder charges of 8 grains for more with no problems.

The powder looks normal to me, but I don't have any of the older power to compare it to.

 

[Charlie98]

Where is your load data from? What is your bullet seating depth?

FWIW, I think you got what you wanted... your charge weight should put you a bit under .357 max data... BUT. That is a newer can of powder, and Unique underwent a 'reformulation' some years ago... to make it 'cleaner.' I would recommend shelving those rounds and starting a new load workup with your new powder...

 

[stillquietvoice]

Are these new bullets? Maybe a tad too long.

 

[luzyfuerza]

It is a good idea to compare velocities when you switch from one batch of a particular powder to another. Particularly if one is much older than the other. If performance is markedly different, work up the load again using the new batch of powder.

I had an 8# container of Bullseye that I used for a while. It was from an older batch. About five years ago, when the old stuff was all gone, I switched to a newer container/batch, and found that the new powder produced 55 fps more for the same power charge, bullet, OAL, primer, etc. This was in 9mm.

I also checked velocities for this recipe using two different batch numbers of new Bullseye. Velocities matched within 1 fps.

 

[BBarn]

How did the fired cases extract? Fall out on their own, or extract easily? Or was extraction sticky or difficult? The load appears to be well above 38+P, more like upper midrange 357 Mag, so I would expect recoil to be a bit snappy, especially if the primers happened to be Winchester WSPM (magnum) instead of WSP.

 

[LaneP]

It's important to compare the components you used in the old loads against everything used in the new loads. This includes the bullet, the brass and the primer. Were all the components identical with the exception of a different (newer) powder lot?

Differences in bullet weight, bullet bearing length, bullet hardness, neck tension, etc all contribute to issues such as this and may require going back to a starting charge and working back up. If the powder looks and smells normal, it most likely is, outside of a possible case in which Alliant may have recalled a powder lot, unbeknownst to you.

 

[Bill M.]

deleted

 

[25-20 WCF]

Recoil is not always a valid method of comparing muzzle velocities, we can’t answer the OP’s question with any authority. As stated above, he should chonograph the new powder - and since he likely doesn’t have chrono data with the old powder, compare it with load manual velocities to see if it appears too hot. But really, if the OP doesn’t like the recoil, he should just reduce the load!



.

 

[BushMaster-15]

130 gr. bullet with 7.6 Gr. Unique ? 125's run 9.6 Gr. and 140's run 8.0 Gr. You might be light ?

 

[Shawn Dodson]

Alliant changed the formulation of Unique about 20 years ago, but it should provide the same performance. See - Alliant Unique (gunblast.com)

I used the old Unique for many, many years (5.7gr Unique with 9mm 124gr FMJ for training). I use the same charge with the new Unique and I can attest that it delivers the same performance.

Maybe you should contact Alliant and inquire about your experience?

 

[Thomasss]

I would like to know the bullet manufacturer and the seating depth of the bullet in the .38 case in order determine your problem. More information is needed to help you.

 

[GooseGestapo]

I was recently gifted some old Unique. Probably from late ‘80’s.

I had to use two powder cavities larger than what the manufacturer of the powder measure claimed was to get the weight I wanted. I worked up my loads using a chronograph to verify and matched closely with my older manuals, based on weight, not volume.

Powder smelled good... however, some IMR3031 and IMR4064 from same source was deteriorated and was fed to the azaleas...

I was also given some Green Dot and #2400 that are spot on with the earlier data, but don’t match powder cavity charts. Both smells of ether...

The newer formulations/lot#’s seem a bit faster than older samples.

 

[Bcwitt]

OP, How long of a barrel are we talking about?

 

[Nipty]

I have only loaded a few 9mm , 40s&w &.380 with Unique. Seemed pretty tamed. However, light loads. I have not checked to see of all the same batch #. I bought it 2-1/2 lbs from a fellow and all his reloading gear last year. However... I did read, in more then one major manufacturers reloading manual that when a new batch is purchased, one should kicked the load down. By at least 10% in case of minor changes. For safety purposes. Mentioned & asked this once or twice and some say yes others say no. But if you have been loading this for years. Yeah maybe contact Alliant. To be safe.

 

[FROGO207]

I always load at least 5 rounds spaced from min to my established load when changing batches of propellant. I just look for pressure signs and similar velocities/recoil. Then if all is OK load on. IMHO a full load workup is not necessary unless you find a problem. I do this when changing primers or different profile/brand bullets of the same weight as well.