45 ACP, Unique, different powder lots - a test

[Nick_C_S]

As I was nearing an end to a # of Unique I first opened on 1/21/16, It dawned on me to try something I’ve always wanted to do: Test different lots of a propellant, straight across, by volume. All summer, I’ve been extensively testing 45 ACP, 230gn bullets, using intermediate burn rate propellants. So this test would logically be an extension of that testing.

For the test, the bullet used is X-treme’s 230 PHP (plated hollow point); since I just purchased 2000 of them (came in a bucket and weighed almost 70 Lbs.), it seemed the logical choice. Charge weight was 5.5 grains. OAL 1.203” – I aimed for 1.200, so close enough.

My hopper is an RCBS Uniflow; I loaded 50 rounds at 5.5 grains. This took me near the end of the #; at which point, I emptied the hopper – not touching the 5.5 grain setting. This residual powder became lawn fertilizer. I then filled the hopper with the new lot of a previously unopened # of Unique. I weighed ten throws and got 55.8 grains. So the average throw weighed .08 grains more with the same volume. This surprised me because in times past, I’ve noticed even more of a difference between old and new #’s of powder – even with the same lot. Anyway, it is what it is. For the sake of records, I considered the new lot to have a charge weight of 5.6 grains. I loaded 50 rounds of these.

All of the above-mentioned ammo was loaded with once-fired (by me) brass from factory Winchester White Box ammo (230 ball ammo). This was done to deliver maximum consistency for the test. However, I also recently purchased 1K pcs of Starline 45 ACP+P brass. Starline says that they are built stronger for “unsupported chambers” – i.e. Glocks – and have 2 grains (H2O) less internal volume than their non+P offering. So I figured this would be a good time to test this brass against the WWB.

So, using the same hopper setting, I loaded another 40 rounds, using the Starline +P brass.

Unique, 5.5 & 5.6 grains; CCI 300 primers; X-treme 230 PHP; WWB & *-*+P brass; shot through a Kimber full-size 1911. All data is from 20 round samples. Chronograph (Chrony Beta – or whatever it’s called) set at four yards, with diffusers, bathing in direct sunlight. 71 degrees Fahrenheit, slight south breeze coming from about the 5 o’clock position. I didn’t have the barometric pressure or humidity .

Old lot of Unique, WWB brass – 5.5 grains: 833.6 f/s; 20.81 SD
New lot of Unique, WWB brass – 5.6 grains: 825.2 f/s; 28.37 SD
New lot of Unique, *-*+P brass – 5.6 grains: 875.5 f/s; 23.88 SD

Remember, all three of these loadings are with the same hopper setting (volume). The difference with the Starline brass was a real eye opener. It is also interesting how the new lot of Unique has a higher density, yet seems to deliver less energy – or at least, a lower average pressure. Getting back to the brass, WWB brass, by casual observation, appears more cavernous than most. Looking down to the floor (where the flash hole is), they are very flat on the bottom and have a very sharp turn going up to the wall. By comparison, most other brands of brass are more “coved” on the bottom and leading up the wall – as is the Starline +P brass. So I believe my brass test here is likely a case of extremes. An eye-opener, none the less.

Another observation, the loaded rounds of the Starline brass show more distortion on the outside from the bullet insertion. They do indeed seem to be thicker brass.

To summarize, different powder lots do indeed make a difference. And in this case, the difference would have shown to be even greater had I conducted the test by weight – rather than volume. And yes, internal case volume can make a profound difference on burn rate, pressure, and performance. This is why using different bullets – even of the same weight – is not always an apples-to-apples comparison when looking at load data. Novice loaders, take particular notice here.

Since this range trip started with a clean gun (as always – I have never taken a dirty gun to the range) and I fired all 140 rounds – and only the 140 rounds – it made for an excellent opportunity to test how clean – or dirty – Unique runs. Pressure-wise, these rounds were fairly stout. So Unique should have been running pretty much right in its wheelhouse. Result: the gun was no more dirty or sooty than from any other range trip shooting a similar number of rounds. The moral of the story here is that any propellant will run clean if it’s being used properly. I did however observe a slightly tinged hue of orange throughout the barrel. This is a sign of copper plating breakdown. So I do believe I was over-driving the X-treme plated bullet. Further loadings with this bullet will be in the order of 5.2 grains or so – something in that neighborhood. They should make great range shooters at that level.

[reddog81]

825 vs 875 with a SD of about 25 is quite a big difference. Ive always treated .45 ACP brass as interchangeable. I do sort 9mm and load by headstamp figuring the small capacities could make a difference there but wouldn't have guessed that in 45 ACP.

What's the weight of the WWB brass versus the Starline?

[buck460XVR]

Nice test, and nice summary of your results. I'm glad you did the test using similar volume as I feel that is how Unique should be loaded. I see so many folks concerned over it's inconsistent metering by weight, when those folks that use dippers have no issue when their charges vary by +/- .1 a gr or so. I was not surprised that by volume the difference in velocity was so close. The big jump in SD tho was a surprise. How was accuracy or did you not check?

As for the Starline brass, I have always thought their standard .45 ACP brass was thicker than Winchester since I too have noticed more deformation from bullet seating when using it. Neck pressure to me in taper crimp ammo is a good thing and I prefer to see that "waist". This would tend to tell me that even their standard .45 brass has less case capacity than Winchester. Iffin their +p brass was claimed to have that much difference in case volume over their standard brass, I'm surprised there was only that much difference in velocity, since I've seen very small increases in seating depth(i.e., less case capacity) make huge differences in velocity when it comes to .45ACP.

Do you think that the copper fouling may have had any influence on the test?

[std7mag]

I'm no mathamatician by any means, but by volume you started with 5.5gr.
Switched to new powder and by volume got 55.8gr.
How did you arrive at a 0.08gr difference?
To me would be 0.3gr.

Which in a 45ACP pushing a 230gr bullet would definitely give you your velocity and pressure difference.

[Nick_C_S]

What's the weight of the WWB brass versus the Starline?

I should have known somebody was going to ask me that . So I just now weighed 20 of each:

107 graMs for the WWB
115 graMs for the *-*+P

How was accuracy or did you not check?

Not formally. I was only shooting at 10 yards and knocking out the black. Plus, the first 60 rounds were over a chronograph, so I wasn't truly zeroing in. They all seemed to go pretty straight, I suppose. My Kimber is an accurate gun and I have lots of experience with this bullet (wouldn't have just bought 2K of them if I wasn't very pleased with their performance) and they seem to pretty much shoot straight at my shooting distances.

As for the Starline brass, I have always thought their standard .45 ACP brass was thicker than Winchester

I have a couple pieces of Starline sandard 45 ACP brass (range pick-up); and they appear identical to the +P in terms of casual visual observation of construction (I don't have enough samples to weigh; plus, they are part of my mixed brass stock, so it would be a needle in a haystack to find them at this point). So yes, I agree, I believe their standard is thicker than WWB brass.

Neck pressure to me in taper crimp ammo is a good thing and I prefer to see that "waist."

Yep. Me too. And the *-*+P brass is very "waisty"

Do you think that the copper fouling may have had any influence on the test?

Probably not. Because my chronographing was at the beginning of the shoot - it was the first 60 rounds. And . . . I rotated in groups of 10. i.e. 10 of one loading, 10 of the next, 10 of the next, repeat.

I'm no mathamatician by any means, but by volume you started with 5.5gr.
Switched to new powder and by volume got 55.8gr.
How did you arrive at a 0.08gr difference?
To me would be 0.3gr.

I explained too briefly as to what I actually did. Here's more detail:

I set the hopper at 5.5 grains, and did a final test by weighing 10 throws. Those 10 throws yielded 55.0 grains. With the new lot of Unique, that same hopper setting yielded 55.8 grains from 10 throws. That divides down to 5.58 grains per throw - i.e 0.08 grains more per throw. To me, that was close enough to consider it 5.6 grains - so that's how I entered it in my loading log book (along with a notation).

[std7mag]

Ahhh, gotcha..
Thanks!!

[Unclenick]

Buck460XVR,

From the slightly larger average charge weight of new powder producing slightly lower velocity than the original lot, we can assume that with identical charge weight to that of the old lot, we would have seen it lose another 10 fps or so. As part of being slower, the pressure peaks would be a little lower, which can affect pressure uniformity and ignition adversely. It allows more time for primer pressure to start moving the bullet, which also increases velocity variation. But another possibility is that having come from a new bottle, it has a different moisture content, so it might simply not have metered quite as uniformly and it may have had a slower burn rate that will catch up after the moisture content has time to equilibrate.

There is seemingly no end to what you can measure to try to understand this stuff.

Incidentally, if the -2 grain water capacity difference in the Starline +P brass were due entirely to brass added above identically dimensioned heads, you would expect about 17 grains difference in case weight. Since the difference was smaller, you can expect the head dimensions are not a match or that Starline standard brass is lighter than Winchester (which I do not recall being the case, but it has been some time since I measured it).

Nice job Nick!

[74A95]

With respect to the Starline +P brass: https://americanhandgunner.com/exclu...ading-p-brass/

[Nick_C_S]

Nice job Nick!

Thanks Unclenick. That means a lot. I try to contribute in a positive way.

[CommandoX]

Yet again I find myself sitting here saying, "Thank you for your effort sir." Great and interesting post Nick C S.

I learn so much when I come here. I really love this place because it is a constant reminder to me that I don't know near as much as I'd like to.

[buck460XVR]

Originally Posted by Unclenick

Buck460XVR,

From the slightly larger average charge weight of new powder producing slightly lower velocity than the original lot, we can assume that with identical charge weight to that of the old lot, we would have seen it lose another 10 fps or so. As part of being slower, the pressure peaks would be a little lower, which can affect pressure uniformity and ignition adversely. It allows more time for primer pressure to start moving the bullet, which also increases velocity variation. But another possibility is that having come from a new bottle, it has a different moisture content, so it might simply not have metered quite as uniformly and it may have had a slower burn rate that will catch up after the moisture content has time to equilibrate.

There is seemingly no end to what you can measure to try to understand this stuff.

I agree. I have noticed in the past, that I get slightly different performance from the tail end of a jug than I do from the jug when first opened. I often wonder if it is from chemical breakdown of the components in the powder after exposure to the air/environment, if it's from physical breakdown form filling and emptying the hopper(i.e. breaking the powder into smaller pieces or from rubbing the surface components off, like the graphite lube and burn deterrents.) Could it be, like chips and cereal, that the stuff on the bottom has more smaller pieces because of settling? We know many powders are shaped or sized to affect their burn.

While Nick's test was very informative and interesting, there was very little that surprised me, especially when it comes to how very little of a difference in case volume can impact velocity/pressure. Small capacity cases like many handgun cartridges are most severely affected. So many folks do not consider this when developing loads, most of the time it has to do with OAL and seating depth with non-cannelured bullets used in auto-feeders, than difference in the volume of the case itself. The link provided by 74A95 does a nice job of verifying Nick_C_S's test and shows us that in the end, the is considerable difference in the overall case capacity between the two Starline .45 ACP cases. While none of this would negatively affect most of us loading for .45 ACP, for those that are on cusp of max for their gun already, it may. What it showed me was, the difference in components probably has more of an effect from batches of loads than from lots of modern powder. Could be I'm wrong.

[Charlie98]

I do sort 9mm and load by headstamp figuring the small capacities could make a difference there but wouldn't have guessed that in 45 ACP.

When I first started loading 9mm I just used what cases I found lying around at the range... bad move. My handloads would go from short cycling my BHP to primer flow in one magazine... it was crazy. Not only did I cull out my 9mm brass to 2 or 3 headstamps, I actually pretty much quit loading 9mm.

I'm glad to see someone is actually reporting Unique as fairly clean burning... you would think you would need a shovel to get rid of all the soot the way some talk.

It would have been interesting to run the same test with charges measured by weight, not volume.

I did however observe a slightly tinged hue of orange throughout the barrel. This is a sign of copper plating breakdown.

The copper was breaking down... at sub-900fps velocity? That's sort of... extreme, isn't it?

[Metal god]

825 vs 875 with a SD of about 25 is quite a big difference. Ive always treated .45 ACP brass as interchangeable.

I have yet to figure out how some think mixed brass is really no different then all the same headstamp or a charge in one headstamp will be the same in another . I have to assume when someone says that what they really mean is they don't care about consistency because of the type of shooting they're doing or there abilities make it hard to tell the difference . That's not the same as mixed brass is the same . I try not to load mixed brass but do for most cartridges I load for and I can say with 100% certainty that mixed brass regardless of cartridge will result in a less consistent load or changing headstamps will likely change your over all result of that load .

When I'm sizing mixed 9mm or 45acp brass I can almost tell what headstamp I'm sizing just by the feel of the single stage press . Don't even get me started on thin walled and thicker walled cases . If I have my 9mm or 45acp crimp die set for thicker walled cases it almost does not give the thin walled cases a crimp .

That's just handgun brass , switch to rifle brass and there can be HUGE differences from manufacturer to manufacturer . Like I said , I load mixed brass with good results but disagree completely that some brass in a specific cartridge is interchangeable . Maybe the word "interchangeable" needs to be better defined for the topic . If we are talking just the ability to safely use the same components including charge in multiple head stamp cases . I'd say yes many cartridge cases are interchangeable but that's not the same as saying you will have the same consistency from headstamp to headstamp .

[45long]

I think this was a wonderful test, as I was wanting to do this one myself... Always wanted to know the difference between the old formula and the new "cleaner" formula of Unique and plan a few tests of my own on this powder..

One thing I've noticed with my testing, when checking velocities over the several chronographs I have, If I set up a target and and aim at the same spot (with POA different from POI) My readings lend themselves tighter.. Whereas just shooting randomly through the skyscreens can give a more erratic reading on both ave vel and extreme spread...

And I'm not talking just a little.. Sometimes it can add up to a lot more than I'm comfortable recording. Especially if I'm trying hard to drop my ES on a precision load I'm working up..

I figure if I'm going to spend a lot of time using and weighing brass from the same lot, miking it, inspecting every bullet, weighing it,miking AOL, using fresh uptodate primers seated evenly, I'm then going to go the extra time needed to set up the target and chrono...

It actually helps me save a little time checking groups too because once it's setup for a specific yardage I can go to my ballistics calculator and dial up my elevation because I've already gotten the group.

[DMY]

Thank you and curse you Nick. Your tests and the results which you kindly shared were very interesting and now you have many of us curious about other variables. I follow your posts as carefully as any because they provide very detailed information in a relatively succient manner. I particular benefit because i am primarily a wheelgun person as well. Your posts probably subconsciously influenced me to buy my own 686+, although I just sent it back to repair a canted barrel.
Kudos and thanks for making me take forever to load a few string of different loads with minor tweaking, shooting real slow, logging each round and analyzing the results. Shooting just got cheaper when you only shoot 30 rounds per hour.

[Unclenick]

Buck460XVR,

If you look in the current Norma manual, you will learn powder burn rate can vary up to about 12% depending on the relative humidity it is stored in, being 12% faster at near 0% RH than it is when stored in about 80% RH. They say they keep their powder in 40%-60% RH before shipping, if I recall correctly (my copy of the manual is out on loan at the moment, so I can't check), and if you don't have that 50% average RH where you keep your powder, then it will change over time, even through a closed lid. In fact, they point out it even changes in loaded cartridges (without). It takes about a year, but it happens.


Charlie 98,

Old information never dies in the reloading world. Unique was reformulated seventeen years ago to be less dirty. It changed the grain appearance a little, too. But before then, it was frequently used by target shooters running 45 ACP with 185 and 200-grain bullets in the 700-750 fps range, so it was very low pressure, which doesn't burn powder as thoroughly as higher temperature and pressure do. As a result, it was extras dirty in those loads both from the standpoint of carbon and unburned grains left in the bore and it also pushed graphite into every crack and crevice of your Goldcup. This is what the collective memory is referring to and won't let go of. It is better now. Here's a side-by-side comparison of the old and new Unique.


DMY,

If you don't have one, you might be a candidate for owning the Labradar instrument. The latest firmware lets it talk to your Android device so you can control it from your phone or tablet without having to reach all the way to the gun's muzzle and possibly disturbing its position on the bench by pushing its buttons. It is way quicker to set up than optical chronographs because it sits next to the gun muzzle on the bench, getting you out of having to get the optical chronograph's bullet aperture in the gun's sightline with the target. That's the part of optical chronograph setup that takes me the most time, though I shortened it with a laser bore sighter. Still, the Labradar is less bother.

[Charlie98]

Charlie 98,

Old information never dies in the reloading world. Unique was reformulated seventeen years ago to be less dirty. It changed the grain appearance a little, too. But before then, it was frequently used by target shooters running 45 ACP with 185 and 200-grain bullets in the 700-750 fps range, so it was very low pressure, which doesn't burn powder as thoroughly as higher temperature and pressure do. As a result, it was extras dirty in those loads both from the standpoint of carbon and unburned grains left in the bore and it also pushed graphite into every crack and crevice of your Goldcup. This is what the collective memory is referring to and won't let go of. It is better now.

My original swing at reloading was the .45ACP and Unique, back in the late '80's so, yes, I know what you are talking about. I never really loaded target level loads, I loaded what I considered factory 230grn ball ammo (6.5grn Unique, 230grn FMJ... back when FMJ was really FMJ...) and I never really had problems with it. The only place I saw any 'dirtiness' was with the light .38SPC loads and such. I've always considered it a non-issue.

[zeke]

Back when loading up plus p velocity 45 acp, used Starlines 45 super brass instead of their 45 plus p brass. If memory holds, negligible volume difference from normal brass and not as soft.

Am using mostly unique for 230 gn 45 acp. 6.2 - 6.4 grains for jrn, and 5.5 grains for lrn. The use of unique for people interested in 4 decimal place ES of charge weight may distress them, but how it actually functions for me matters more.

Those were interesting test results, and testing on slightly differing COL's/ bullet dia's may also be enlightening.

[RickB]

When I started down the .45 Super road, I weighed a number of different cases, and measured the water capacity, to try to determine how the .45 Super brass, presumably stronger than .45 ACP, gets its strength.

It appeared to not be from thicker case walls, as the Starline Super cases did not have the smallest internal volume from among commercial .45 ACP, military .45 ACP, commercial .45 +P, and Super.

I keep reading that Super is thicker, and maybe it is thicker than Starline's .45 ACP brass, but it's not necessarily thicker than a random selection of other .45 cases.