Powder Comparison: 38 Special

[Radny97]

So I’ve spent a couple years off and on looking for the most accurate powder and bullet combination in 38 Special that would also make a power factor of 125. We’ve all heard that the HBWC with 2.7 gr of Bullseye was the old accuracy load. But it is really low powered.
So I set out looking at different bullet profiles and powder combinations to see what was most accurate.

I used two different revolvers for the test. A S&W model 14 and a Dan Wesson 715. Both exceptionally accurate firearms.

One thing I discovered was that the large space inside the 38 Special cartridge made for inconsistent burn rates due to the powder being in the front or back of the case. Some powders were more or less position sensitive, but they all are to some extent or other. Thus the most accurate bullet profiles ended up being those that eliminated the position sensitivity issues and take up the most space in the case. Thus either the double ended wad cutter or the button nose wad cutter were the best bullet profiles for consistent repeatable accuracy.

As to powders, I tried many. Here’s a list:
VV320, Sport Pistol, W231, Bullseye, American Select, WSF, WST, Titegroup, 700x, 800x, HS-6, Clays, Unique, Red Dot, and Ramshot Competition, None were bad, but two stood out as exceptional.

I measured accuracy with at least three separate groups of 20 at 25 yards from a bench rest. Obviously this project took hundreds and hundreds of rounds.

Ultimately the most accurate powder was Ramshot Competition, followed closely by Clays. All the other powders would have flyers, or just couldn’t group the same.

Thought you guys would find this interesting.


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[dahermit]

Did you begin with the suggested starting load and work your way up in 1/2 grain increments to maximum in a load manual for each powder? I assume you only changed the powder variable... used the same bullet, case, and primer for each load.
Edit:
"...make a power factor of 125." Whoops! missed that part.

[AzShooter]

Why are you trying to make 125 power factor? If you are looking for a bullet for competitions requiring 125 you should start out with a RNL instead of a wadcutter just for the reliability in reloading.

There are a lot more variables to consider. OAL is one. I've found that seating the bullet out farther is more accurate in my guns. Yours may be different. VVN320 worked real well for me but Unique came in with some fantastic groups as I added more powder.

I'd like to read more of your experiment.

[jetinteriorguy]

Clays is one of my favorite powders for both .38sp and 9mm, but the one I use most in these two calibers is 700-X. I do two different loads for Wadcutters though using Be. One is 2.8gr and the other is 3.1gr. The 2.8gr is used for HBWC and the 3.1 for solid cast WC’s.

[74A95]

It's hard for us to evaluate your claim unless you post ALL your data, such as charge weights and ALL of your group sizes.

[Radny97]

Originally Posted by AzShooter

Why are you trying to make 125 power factor? If you are looking for a bullet for competitions requiring 125 you should start out with a RNL instead of a wadcutter just for the reliability in reloading.

There are a lot more variables to consider. OAL is one. I've found that seating the bullet out farther is more accurate in my guns. Yours may be different. VVN320 worked real well for me but Unique came in with some fantastic groups as I added more powder.

I'd like to read more of your experiment.

Bianchi Cup. No reloads in that one.

I shoot ICORE as well, but my load in that one is using 38 short Colt brass, 160 gr bayou bullet and Sport pistol powder. I agree that in that case OAL (and the amount of bullet engaging the rifling) has a great effect on accuracy.

I did several experiments with OAL as well on this project. What ever accuracy might have been achieved with length was negated by creating space in the case, resulting in inconsistent ignition issues.


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[Radny97]

Originally Posted by 74A95

It's hard for us to evaluate your claim unless you post ALL your data, such as charge weights and ALL of your group sizes.

I can snap pics of my load data book. I’ve got pages and pages. Also I’m not here to prove anything. Just share what some may find useful. If you doubt my findings, you can reinvent the wheel if you like.


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[Radny97]

Originally Posted by dahermit

Did you begin with the suggested starting load and work your way up in 1/2 grain increments to maximum in a load manual for each powder? I assume you only changed the powder variable... used the same bullet, case, and primer for each load.
Edit:
"...make a power factor of 125." Whoops! missed that part.

Yes, started usually middle of the load data and worked up. Tried about 15 or 20 bullet profiles at first with about 4 of the most popular powders. (Bullseye, W231, VV320 and Sport Pistol). Once I found a bullet profile that was consistently more accurate across all types of powder, I started experimenting with powders. Usually moved in .3 grain increments.
Used starline brass and federal small pistol magnum match primers for all loads.

148 gr BNWC over 3.2 grains of Ramshot Competition yielded an ES of 14 fps, averaged 865 fps, and produced a 20 shot group of 1.2 inches at 25 yards.

All other things equal, 3.1 of Clays produced a group of 1.5 inches, 20 shot group.

No other powder could get a 20 shot group under 2 inches at 25 yards.

The 20 shot group was important to me, as I wanted to reduce the statistical possibility of getting an unusually tight 5 shot group from a fluke. So I used large group numbers to measure consistency.

[Radny97]

BTW I’ve done a similar but less rigorous test with 357 mag and the most accurate loads are with high quality jacketed bullets and powders that almost completely full the case. Thus, I’m not suggesting that wadcutters are inherently more accurate.
But I am suggesting that accurate loads come from the powder filling most of the empty case space and at the low pressures involved in 38 Special you can’t find a powder to fill the case unless you also deep seat a wadcutter style bullet.

As a side note (and outlier) I’ll say that I forgot to mention that I tried Trail Boss and even though it fills up the case nicely, it couldn’t make power factor and wasn’t particularly accurate regardless.


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[Unclenick]

Radny97,

Important to note from the wadcutters is how little space they leave in the case when seated flush with the case mouth. If I use Quickload to put a 148-grain wadcutter flush with the case mouth with 2.7 grains of Bullseye, I get 2.15 times more pressure and 1.2 times higher velocity in a 6" revolver than with a same-weight round nose seated to 1.55".

You may find this article on evaluating group size interesting. If you are just measuring group diameter by the two most distant holes, as the groups get bigger you have more chance of an outlier skewing your result. As a result, you would be better off averaging the diameters of four groups of five, than taking the diameter of a single group of twenty. On the other hand, if you track the location of every single hole and use those twenty locations to find the center and the standard deviation of the distance of all the holes from that center (the radial standard deviation) that's actually the most meaningful result and will tend to mitigate the influence of outliers.

[10-96]

I never thought of it before, but the question came to me- Is there any reason not to experiment with dacron filler in a .38 or .357 case?

[Radny97]

Originally Posted by Unclenick

Radny97,

Important to note from the wadcutters is how little space they leave in the case when seated flush with the case mouth. If I use Quickload to put a 148-grain wadcutter flush with the case mouth with 2.7 grains of Bullseye, I get 2.15 times more pressure and 1.2 times higher velocity in a 6" revolver than with a same-weight round nose seated to 1.55".

You may find this article on evaluating group size interesting. If you are just measuring group diameter by the two most distant holes, as the groups get bigger you have more chance of an outlier skewing your result. As a result, you would be better off averaging the diameters of four groups of five, than taking the diameter of a single group of twenty. On the other hand, if you track the location of every single hole and use those twenty locations to find the center and the standard deviation of the distance of all the holes from that center (the radial standard deviation) that's actually the most meaningful result and will tend to mitigate the influence of outliers.

Thank you!


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[dahermit]

Originally Posted by 10-96

I never thought of it before, but the question came to me- Is there any reason not to experiment with dacron filler in a .38 or .357 case?

I used Dacron filler in .444 Marline cast bullet loads. Found some rust in the barrel... was told by people knowledgeable in the field of chemistry that water is a by-product of Dacron combustion.

[Unclenick]

True, but it's also one of the smokeless powder combustion products. The hydrogen in the nitrocellulose (C₆H₇(NO₂)₃O₅) molecules oxidizes readily.

One of the reasons I gave up on petroleum-based bore cleaners is the water-based ones (Bore Tech, KG, Hoppe's Elite) have corrosion inhibitors in them that are so good, you can let the water in these products dry out in your bore without rust being able to start. I always have one in a pump-spray bottle with me at the range. At the end of a session, I squirt a couple or three pumps down the bore from the breech end (and in all chambers of a revolver) and plug the openings with stoppers and pack up and go home. Not only is the gun clean, except for patching out the loosened crud, when I arrive, if I have accidentally used corrosive primers or had nitric acid from powder that was starting to turn (did that once) the otherwise corrosive effects are effectively blocked by those inhibitors.