#69436
Larry Gibson
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All my pressure testing of 32 S%W, 32 S&WL and 32 H&R Magnum are done with .312 sized bullets in a 10″ Contender barrel.  It is a .308 groove diameter barrel.

 

Still putting together all the 32 load data from my tests.  It’s been strung out in multiple tests.  And other testing projects have interceded…..  Here’s one article on the 32 S&WL though….

 

32 S&WL; 311008 115 gr SWC; Bullseye & Unique PSI Test

A fellow CBF member, JoeJames, who is an aficionado of the 32 S&WL offered up a sufficient quantity of 311008 bullets for a comprehensive test of Alliant’s Bullseye and Unique powders. The nominal weight is 115 gr but Joes’, cast of COWW + 2% tin, weighed in at 116 gr fully dressed…..close enough for government work…… His bullets were sized at .312 and lubed with 50/50 lube.

I used my 10” barreled TC Contender barrel for the pressure and velocity testing. I lose about 200 fps when the same loads are fired in my 3” M30 S&WL and a bit over 100 fps when they are fired in my 6 ½” Ruger SS 32 H&R. The Oehler M43 PBL was set up at the local range. Bench position used with sandbag rests. The Contender barrel has an old TC 2.5X scope on it, not the best but sufficient for testing purposes.

The temperature during the test ran from 77 to 82 degrees. Humidity was26% and the barometric pressure was 29.82. Target is at 50 yards.

There is little current data available using 115 gr cast bullets in the 32 S&WL. The last really relevant data was found in the Lyman #3 CBH. As you can see from the pressure measurement data of this test it appears the Lyman data for their listed max load of Bullseye is somewhat mild while their max load listed for Unique is a bit heavy, especially for use in older weaker break top revolvers and those having “pot metal” solid frames.

Thus, JoeJames and I had settled incremental testing of both Bullseye (2.3, 2.5, 2.8 and 3.0 gr) and Unique (2.5, 2.8, 3.0, 3.3, 3.5 and 3.8 gr). Both powders are of Alliant manufacture. I used a Lee powder thrower as it throws both powders evenly. Thrown powder charges were set using an Ohaus 10-0-5 scale. Ten rounds of each increment was loaded for testing.

Cases were R-P 32 S&WLs loaded on Hornady dies. Primers were Winchester WSPs for all charges. A mid range charge was selected for each powder and was also tested using CCI 500 primers. The 311008s were seated to an OAL of 1.257 and a slight roll crimp was applied just under the front drive band.

Accuracy of all the loads except the 3.8 gr load of Unique was 2” or less at 50 yards. That’s about the best I can do these days off sand bags. The 3.8 gr Unique load with its high psi obviously obturated the bullet more in the longer 32 H&R chamber giving some leading in the throat and first couple inches of barrel. May have been some gas cutting going on also. The 50 yard group opened up to about 5”.

Here is the test data for each powder:

Bullseye Powder
Increment…..Vel……SD……….ES……psi(M43)….SD………ES
2.3 gr……….863 fps…7 fps…..20 fps….14,900……600………1,800
2.5 gr……….908 fps…14 fps….36 fps….15,900……1,500……4,400
2.5 gr……….902 fps…10 fps…35 fps….15,300……500……..1,800…..CCI 500 primers
2.8 gr……….977 fps…..7 fps….22 fps….17,800……400…….1,200
3.0 gr……….1028 fps…12 fps…43 fps….20,300……700…….1,900

Unique Powder
Increment…..Vel……SD……….ES……psi(M43)….SD………ES
2.5 gr………849 fps…21 fps…..69 fps….13,600……600……..1,900
2.8 gr………886 fps…19 fps…..54 fps….14,100……500…….1,400
2.8 gr………886 fps…22 fps…..61 fps….14,500……900…….2,500….CCI 500 primers
3.0 gr………951 fps…18 fps…..55 fps….16,300……800…….2,400
3.3 gr………1010 fps…15 fps….41 fps….18,000……1,100……3,400
3.5 gr………1062 fps…15 fps….47 fps….21,400……1,500……4,200….max Lyman CBH #3
3.8 gr………1134 fps…10 fps….30 fps….24,700……1,100…..3,900

Now, please, before complaining about “hot rodding” or “over loading” the 32 S&WL cartridge understand that I am not recommending anyone load any of these charges. Given the wide discrepancy in quality and strength available in 32 S&WL revolvers each must make up their own mind what they deem “safe” in the revolver they have. The choice is theirs if they have 115 +/- cast bullets and wish to load Bullseye or Unique. For my own M30 S&W (pictured) I have loaded 12 rounds each using the remaining 311008s of Bullseye (2.8 gr) and Unique (3.3 gr) to chronograph and test for accuracy and POI at 25 yards. I deem those loads as entirely safe in my M30 as previously test 32 S&W (which is proclaimed to be safe in all 32 S&WLs) because they do not exceed the highest 32 S&W psi measured [18,900 psi] in the same test gun. I will edit this post and post the chronographed velocities when I get them.

Larry Gibson

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