POSITION SENSITIVE POWDERS for pistols.

[mozeppa]

wife and i shoot ...
.380
9mm
.38
.357
.40
.44 mag.
.45 acp
.45 colt

we have 28 examples of powders to choose from.

in the range of nitro 100nf to 2400
(about 110 pounds of the stuff.)

does any one keep track of which powders are more prone to being "position sensitive" in the cases?

might not be too critical in the .380 -or 9mm

but the longer cases might be a trick.

any listers of odd data out here?

[williamwaco]

It is my personal opinion that neither Bulls Eye or Unique are even slghtly position sensitive..

I have actually only tested Unique. 9 grains in the .38-55 cases.

Three shot strings with the powder shaken forward, shaken along the bottom, and shaken to the rear.

The difference in average velocity from one string to the other was less than half the difference from max to min in a single string.

( I know there are others who will not agree with this assessment but that is the result I got. )

[mozeppa]

nobody knows of any pistol powders that are "position sensitive" in 38 - 357 - 40 - 44 - 45 acp or 45 colt?

[Alablam]

I think "position sensitivity" sometimes is more a case of load density and skimping on crimp. When loading CAS level .44 mag cased loads with 200gr. RNFP boolits, even fast burning W231 was giving shotgun patterns below 7.0 gr. with a light crimp. Just a tenth or two grains more with a moderate crimp got pressures into W231's happy place and half a grain more gives a tiny group.

[Char-Gar]

I have been at this a while and have used Bulleye, 231, Herco, AA 5 and 9, Unique, 2400, 296 and a bunch more, and I have never noticed any being position sensitive.

[35remington]

William, you need to do a lot more shooting with a lot more cartridges. I've noted considerable position sensitivity with Unique and Universal in the 38 Special case, just to mention one.

A wider range of experience would do you considerable good. Make this the coming spring's project and get back to me.

I cannot bless most pistol powders as being position insensitive. I know better than that, mostly because in load development I test specifically for it.

If there's considerable room for the powder to move, it will show up on the chronograph. Velocity with powder rearward is alway, always higher on average, and often very noticeably so, than powder forward. Even in short cases. It's much more noticeable in long ones.

[MattOrgan]

35 Remington can you give some specifics of your testing? I load, fire, and chronograph a lot of rifle and handgun cartridges loaded with pistol and shotgun powders and have only noted that certain powders operate best at higher pressures and require tighter neck tension and crimps.

[35remington]

Low pressure, long straightwall cartridges are the worst. In the 38, the upper end standard charge of 4.7-4.8 grains Unique under a 158 gave up to 80-90 plus fps variations with extremes in positioning. Universal is worse than that. What bothers the .38 barely affects the teeny tiny case of the 9mm with its tiny powder volume and much higher pressures. Acceptable in the short cases like 45 ACP is in the 50 fps range, yet Universal will give over 100 fps variation with loads neither mild nor maximum with 200 LSWC HG 68's. That's how to weed out bad selections in powder........results below the normal.

Don't pursue unattainable goals in powder position sensitivity. Rather, know what is acceptable and attainable and go with that as you will not find perfection in this area. Chemistry and physics tends to deny it.

Those that postulate "no position sensitivity" for this or that powder haven't done much testing. Titegroup is often feted as being beyond compare, but I can produce variations with it too, most recently in the small powder space of the 32 Long using none other than deeply seated RCBS 98 WC's. Consistent as the rising sun as to velocity with powder position variation? Don't bet on it.

I ask no one to take my word for it.....rather, do what I do and test for it in a variety of cartridges. Know it occurs, and if you know the relative severity of the problem you can avoid it by judicious handling of the gun or a better powder selection. For example, anyone that deliberately chooses Universal for standard velocity 38 loads and is complacent about the true potential for variation has a big shock coming when position variation is deliberately modeled. After so doing, you'll never use Universal for such employment ever again.

But first, you gotta know it's happening.

[fecmech]

I hear of the position sensitivity thing often but can't say that I have ever seen it in my chronographing or shooting. My normal pistol shooting involves loading the handgun barrel down then raising it to a somewhat level position and firing it at the intended target. I chrono the same way, loading barrel down and firing in a somewhat level positon. My good loads with Bullseye, Unique,231 etc all have single digit or low "teens" for SD's and extreme spreads of less than 50 FPS. Maybe if I were to carefully and slowly raise the gun to fire it without disturbing the powder I might see something or do the same with the barrel raised to the sky and slowly lower to fire I might see something, but that's not the way I handle my firearms. So while theoretically powder may be position sensitive (if you work at it) from a practical standpoint it's not, at least that's my take on it.

[35remington]

From a practical standpoint it does matter, because pistols are handled and tipped just like any other firearm and sometimes not precisely the same way. Witness how a pistol is handled....I have occasion to do so when teaching others how to shoot firearms. It is entirely possible to handle or shoot a pistol that powder may be in extreme positions in the case. This happens more often than one realizes....for example, tipping a revolver to thumb cock it as opposed to DA fire.....I watch my students tip the pistol notably. ONLY if one is aware of variations can one select powders that exhibit less of it.

Worse case testing is SOP for any powder selection I make.....because some conditions can make it happen. Only if you know about it can you address it. Ignorance in this area is not something I strive for........I actively seek to eliminate uncertainty.

The only way to see how position sensitive a powder is.....is to position the powder. Then the claims of "insensitivity" go away, because you're truly modeling the extremes.

How can one claim "position insensitivity" to powder positioning in a practical sense....if one does not model potential variation? Sorta like assuming your drum brakes will not fade when they get hot because they always work when they're not overheated. How do you know what works and what does not under extremes unless said conditions are tested for?

The very idea of tipping a pistol up or down a bit before firing the shot or having the potential for the powder to move in quite normal handling is hardly "extreme." Actually, it is more the norm. Depending upon how quickly said pistol is handled or "thrust" at the target when practicing defensive employment or a quick shot the powder may get thrown forward or backward in the case.

[sargenv]

Well, it must be an issue since Titegroup was designed specifically to NOT be position sensitive. I've been doing a lot of work with 41 mag light target loads, 38 super target loads, and 40 S&W target loads and have some specific powders that are sensitive to case volume and position sensitivity. I'd have to look at my data but except for a few fast burners or a few that fill the case up to 90%, I've found most powders to be position sensitive once the size of the case increases as a percentage.

[leadman]

I have seen more velocity variation from different crimps, hardness of brass, and especially how the gun is held and with how much pressure when fired. I have purposely held the gun tighter and looser and changed the average velocity up to 100 fps.
As far as position sensitivity of the powder I have not seen that being and issue. I have chronograph data going back about 15 years.

[35remington]

Given that relatively few have tested specifically for powder forward/rearward velocity sensitivity, keep any comments in perspective unless respondents have stated they have done so, since this was the question posed by the OP.

I do not think of myself as some exception to the rule......just that it's hard to believe opinions can vary to this degree unless they've done exactly as I have. If they have not, then it's quite understandable.

[geargnasher]

There is no such thing as a "position insensitive" powder. It is a matter of degrees and instances.

Gear

[shooting on a shoestring]

Most of my testing for position sensitivity of powders has been in 38 Spl. My testing with an Oehler 35P is to fire a string of 5 shots rested over bags with no special handling, then fire a string of 5 shots pointing the barrel down before each shot, then a 5 shot string pointing the barrel up before each shot.

My results have always shown higher velocities with the powder positioned at the primer. Even Bullseye and 700X have measurable differences. Bullseye and 700X gave me the least difference. HS 6 gave me the most. I've seen close to 150 fps differences in the averages of the powder rear vs powder forward with HS 6 in 38 Spl with 358477.

Often i I see very good SDEVs and fairly low extreme spreads when firing a 38 Spl without intentionally positioning the powder before shooting. It seems the normal recoil tends to repeatably get the powder in relatively the same position when target shooting.

I've seen similar results in 45 Colt and 357.

If if there is space in the case for the powder to move, and if you intentionally position the powder, there will be measurable position sensitivity. Compressed loads are exempt. The easily ignited fast powders show some PS. The harder to ignite mid speed ball powders like HS 6 and AA 5 show the most PS.

I do use lots of AA 5, but not when I load for tiny groups. But then when I want tiny groups I use a rifle.

[prs]

I have not tested for position sensitivity. I believe 35 Remington, no reason not to; he has been there and seen the elephant. His insights about how it can matter suggests me there is not much of practical matter that I can do about it since I shoot off hand and moving and at varying targets. Well, I guess I could do as the OP seems to yearn to do; I could try to identify and use less position prone propellants such as Tight Group claims to be, or maybe use powders of lower density such as TrailBoss, or I could forsake my semi-autos and feed my single action "revolters" a diet of real gunpowder such as Swiss FFg. But, I tend to feel it best to stow away the information given for now and not worry so much UNLESS I need to do some serious bench or Bullseye shoot'n; I need I have yet to realize.

However, on a tangent thought, I have noticed obvious subjective evidence that ambient temperatures make a difference in powder "vitality". Some powders, such as 800X, are prone to anemic performance in very cold temps, such as near or below 0 F; where as other powders, such as 700X, are prone to robust excitement during summer swelter. You don't have to be looking for this to notice, but you might have to get a bit chilly and/or hot under the collar.

prs

[35remington]

Inherent in all of this is finding out just how much it matters. Once you've quantified that, you can file it away and not worry about it.

In a lot of cases, it doesn't matter, but with a few powder combinations as were mentioned previously, it can. Once you've found those out and avoided them the rest can go in the roundfile in a practical sense. When it does matter with a position sensitive powder, unless you're shooting for your life or with some shooting games it's a simple matter to position the powder first.

Fortunately, for most things it does matter up to the point when correct powder choices are made. And THEN it doesn't matter!

[williamwaco]

William, you need to do a lot more shooting with a lot more cartridges. I've noted considerable position sensitivity with Unique and Universal in the 38 Special case, just to mention one.

A wider range of experience would do you considerable good. Make this the coming spring's project and get back to me.

I cannot bless most pistol powders as being position insensitive. I know better than that, mostly because in load development I test specifically for it.

If there's considerable room for the powder to move, it will show up on the chronograph. Velocity with powder rearward is alway, always higher on average, and often very noticeably so, than powder forward. Even in short cases. It's much more noticeable in long ones.

That is precisely why I tested it in the .38-55 instead of the .38 Special.
.

[dnotarianni]

Don't know about position but 296, LilGun and H-110 you can't do light charges as it either fizzles or detonates, I would assume from it not filling the case and lighting off along the length of the charge in the case. I do do light charges but use a buffer to keep the powder packed against the primer hole and no problems with my loads. Position is not a issue if there is no air space in the case and you use a filler to obtain 95-100% fill

[sargenv]

I've done what some described here when working up loads for my 41 magnum when trying to find which powder was most consistent with powder randomly distributed, powder away from the primer and powder right up against the primer (held naturally, muzzle down before ignition, and muzzle up before ignition). I have chrono data for each instance for several modern powders. I think I was pleasantly surprised at some of the combinations. I'll see if I can compile what I have. I don't insert wadding material since at the time I was reloading on a progressive press.. and since I'm loading for use in an action game, I'm looking for something that can be loaded in volume, so adding a filler would certainly be a detriment to production.