RCBS 38-150-SWC Load Data: 38 Special

[LET-CA]

I recently acquired the subject RCBS mould and am looking for some good load data for use in a 38 Special. My preferred powder is Unique. Does anyone here have experience with this bullet? Thanks in advance. :Fire:

[Leftoverdj]

It's an excellent bullet, very easy to get results with. No need of any special data, 158 grain loads work fine. Current book max is 4.5 grains of Unique. Older sources used heavier charges, but I don't see the point. Once you get up around 1000 fps in the .38 Special, there's little more gain to be had.

[xtimberman]

Leftoverdj's load recommendation in an excellent one that is hard to beat.

I agree that there's no need to push .38 Special up to Magnum levels, but I'm concerned that many of the recent across-the-board charge reductions are lawyered-up hooey.

With the 158gr. bullet, I've shot a lot of the 4.5gr Unique, thousands with 5.0gr. Unique, and some with even more Unique than that. I chronographed the 5.0gr load just a few weeks ago on a day when it was ~55 deg. F, and it measured 864 fps ave. velocity in a 4" S&W M-15. That velocity is far below the 4.5gr. Unique/950fps velocity published by Alliant. I've tried the load in other revolvers/bbl. lengths with prop. similar results. Other shooters with other brands of chronographs have told me similar stories.

I've run into this discrepancy between my experience and the newly published data with other calibers, too - 9mm Luger in particular.

xtm

[Dale53]

Quite often the velocities are taken with a longer (and tighter) pressure barrel than our test revolvers. Most of the discrepancies lie there.

I suspect that most of the lower powder charges that you see today is NOT because of "lawyering" but by the wider use of pressure test equipment these days.

Different bullet designs will cause serious pressure swings with the same weight bullets. If your "recipe" is not EXACTLY like the test loads (exact same bullet, same lot and brand of primers, same lot and brand of powder, same exact bullet seating depth, etc) then add gun differences (our guns are not all the same, by a LONG shot) and you will see significant different results.

Dale53

[xtimberman]

Thanks Dale, good points. Good reasons to work up all loads - no matter where you get the data.

xtm

[mtgrs737]

I have shot a lot of 5 grs. of Unique loads with that boolit with no problems. I like the single lube groove that boolit has over the other multiple groove designs, it makes it a little easier to cast. I have a four cavity mould in that design on backorder now from Midsouth, all the suppliers are out of stock on that design.

[Larry Gibson]

The factory .38 special duplication load with 150 SWCs is in fact 5 gr of Unique and it is a darn good load. Always runs between 840 and 860 fps out of 4" revolvers. Factory 150-158 lead bullets run 820-880 fps (Oehler m35P) out of my 4" M15, a tudge more out of my 5" M15 and a tudge more out of my 6" Ruger SS. Winchester 150 LWCHP+P runs 920-950 fps out of 4" revolvers. Most of those were taken on 60-75 degree days.

Larry Gibson

[xtimberman]

Ok, Larry. Thanks for posting those chrono readings. You have a different brand of chronograph than I do, yet came up with closely comparable results.

Factory duplication load. Putting it like that, I don't feel so much like I'm treading on dangerous ground with my 5.0gr. Unique standard and the 150-158gr. bullet. I have actually been accused of firing "Proof" loads with that particular combination.

Our velocity data surely indicates that we're in Factory-Load territory. As Dale stated, I realize that Alliant is likely publishing velocity data from test guns and pressure barrels - but I still wonder why they are publishing data that doesn't fit real-world firearms. Most handloaders look at their velocity and pressure data and expect similar results from their own equipment.

xtm

[LET-CA]

I really appreciate the inputs here. I'm shooting these in a S&W 357 Magnum - 627 so it's capable of handling anything that a 38 case can hold but I'm looking for just plinking loads at the range. I've shot as little as 3.3 grains of Unique with a 158 grain bullet (felt like a 22 and was wonderfully accurate). I'll load a few hundred this weekend with a little more.

[Larry Gibson]

xtimberman

Different chronographs, different weather, different revolvers, different lots of componants, different moulds and different alloys yet as you say we are in factory-load territory. I agree; Most handloaders look at their velocity and pressure data and expect similar results from their own equipment." Most handloaders look at published figures and really do not understand what they are reading. Most pressure figures published are either maximum average peak pressures or maximum allowable peak preasure. Those are two different pressures. Also handloaders assume that with the given load they WILL get that published pressure. That isn't so.

The pressure figures are most often the maximum allowable pressure (either type) that any "lot" of that powder can give with that charge in a test barrel. It doesn't mean that the "lot" of powder you have is giving that pressure in a test barrel. Most likely your lot is giving less pressure. I'm not suggesting that is license to "load 'em up" past what is recommended but there are many instances where factory recommended loads can be exceded safely and stay within the pressure limits of your cases and your firearm.

We must also take into consideration the difference of pressure measuring systems. We've still lots of loading data with pressure figures published in LUP, PCUP, CIP, British lbs/pressure, psi(conformal transducers), psi(gas flow transducers) and strain guages. Are they all correct? Dr. Oehler rightly states they are all "estimates" of pressure. Do they correlate to each other? Some do (the transducers and strain guages) but the rest don't. So when we see a pressure figure listed in psi we have to ask; what does it mean? What type of system was used to take the measurement, was the test barrel/chamber to SAAMI standards or, British standards or european standards (they are all different you know)? Is the psi listed an average peak pressure (if it is then what are the +/- allowable limits?), is it a maximum peak pressure (based on who's test and what conditions), does the chart say that a specific load in a commercial firearm will give you that pressure? I guess what I'm saying here is the published figures are guidlines.

However, most American sources derive thier data these days either from the older copper crusher method which list the pressure in CUP (LUP for low pressure cartridges) or from piezoelectric conforming transducers which now list the pressure in psi. Problem is the older data from the CUP method was "converted" to psi and published as such. There is little correlation between the converted CUP/psi and the psi of confroming transducers or strain guages. In other words the two psi's are different and not comparable. So which psi was used on the chart we're looking at?

I have found it quite interesting conducting tests the last week with two .308 winchester rifles and two 30-06 rifles using an Oehler M43 Personal Ballistics Laboritory. This system uses strain guages on the barrels directly over the chambers. I have been testing various military loadings and factory loadings along with a couple handloads for each caliber. The pressures and velocities are pretty close between the rifles of each cartridge. However it is interesting to note that the pressures of neither military or factory .308/7.62 NATO are as high as many claim. It is also interesting to note that factory 30-06 cartridges are of generally higher pressure than the .308 Winchester factory cartridges. Probably why equal weights of bullets of the same manufacture were 100+ fps higher in the 30-06 even though the '06 barrels were 2"+ shorter than the .308 barrels. I know this seems ass backwords but I ran the tests on the same day alternating between rifles. Just in case there is some anomoly I've created in mounting the guages on the .308s (two different rifles so it doesn't seem I would screw them up equally the same) I've a new barrel in .308 coming with a 10" twist that I will also test. If the velocities and pressures fall in line (I will make the comparison using a specific lot of .308 "reference ammunition" I have) with the other two rifles then it is what it is. Of course we also realise it is expected that actual pressures in commercial firearms will be less than that in SAAMI test barrels given most similar test conditions. It is interesting anyway.

When I get around to it, one of these days I will put a strain guage on my Ruger Security Six (6" barrel) .357 and begin testing with the M43 PBL. I will then know what my .38/.357 handloads actually are doing in a revolver.

Larry Gibson

[xtimberman]

Interesting stuff, Larry. Thanks for taking time to post all that information.

I'm gonna have to ponder that .308-.30'06 anomaly. :???:

With most cartridges I reload, it does seem like Alliant's and others' load data is in line with what can be expected with standard firearms that most people would own. The .38 Special thing has been bugging me for awhile. :)

xtm

[Dale53]

Larry;
Interesting thread. One thing that I seldom see mentioned regarding this subject:

People continually talk about "working a load up" with respect to ALL revolvers whether magnum or NON-magnums. You can easily load a revolver up far above reasonable pressures for the round (think .38 Special) without one single bit of "warning". I believe that light frame .38 Specials should be held to SAAMI or SAAMI +"P" levels without exception. There is little gained here and much to lose (generally a fine revolver is shot loose).

In most cases, revolver cases will not show "pressure signs" until the 40,000 lb level. That is way, WAY too high for even "K" frames much less the "J" frames.

The rational thing to do if you need more power is to just get a bigger gun:mrgreen:.

Just a thought...

Dale53

[Larry Gibson]

Dale53

Excellent observations, particulary when loading for revolvers, with which I totally agree. With some .38s one can go to +P levels but unless you can accurately measure them you'd better stick with published data.

I do like your "rational". If the .38 is enough I go to the .357. If that's not enough I go to the .44 Magnum and if that's not enough I go right from a handgun to a rifle...usually one of sufficient cartridge like 7.62 NATO or 30-06. And when that's not enough I jump right to the three six bits or my 450-400-70. Now there have been times in the past when even that wasn't enough...I then reached for the most effective weapon on the battlefield....a PRC75...."Maverick 41 this Red Dog 6, what have you got stacked up there for me, over.......

Larry Gibson

[jleneave]

I recently acquired the subject RCBS mould and am looking for some good load data for use in a 38 Special. My preferred powder is Unique. Does anyone here have experience with this bullet? Thanks in advance. :Fire:


You didn't by chance win it on Ebay a couple days ago did you?? The reason I ask is that I was bidding on the same model mold the other day on Ebay and got beat at the last second.

Jody

[Bret4207]

Leftoverdj's load recommendation in an excellent one that is hard to beat.

I agree that there's no need to push .38 Special up to Magnum levels, but I'm concerned that many of the recent across-the-board charge reductions are lawyered-up hooey.

With the 158gr. bullet, I've shot a lot of the 4.5gr Unique, thousands with 5.0gr. Unique, and some with even more Unique than that. I chronographed the 5.0gr load just a few weeks ago on a day when it was ~55 deg. F, and it measured 864 fps ave. velocity in a 4" S&W M-15. That velocity is far below the 4.5gr. Unique/950fps velocity published by Alliant. I've tried the load in other revolvers/bbl. lengths with prop. similar results. Other shooters with other brands of chronographs have told me similar stories.

I've run into this discrepancy between my experience and the newly published data with other calibers, too - 9mm Luger in particular.

xtm

I found this out years ago when a friend got a chronograph and we ran some 9MM across it. The "superwhizbangtacticalelite" 1350fps loads were loafing along about 1100-1150fps! Not surprising at all.

5.0-5.3 Unique sounds like what I was loading. I don't have the books here, but if you search abck a little in Wheelguns there is a thread on this very subject.

Larry- Interesting work you're doing. Hope you post results when you finish.

[xtimberman]

Larry's comment mentioning "Factory Duplication Load" struck a nerve.

In general, that's what I'm looking for. Most of my loads are for informal target shooting, plinking, and knocking around in the woods - occasions when I might shoot a mag. or cylinderful, or maybe 300 rounds in a fun activity. Many of my revolvers and autopistols have fixed sights - and in most cases, a Factory Duplication Load will put that bullet right at my P.O.A.

I can't tell you how often I've tried to do this when working up new loads using certain sets of recent loading data and undershot my velocity goal by ~200fps.

xtm