unwinner and Wayne Dobbs-belated 38 SPL pressure tests

[FergusonTO35]

The 3.5 grains Bullseye loads show just how much pressure can jump up with the lower useable volume of a wadcutter boolit. I find 3.1 grains is a sweet shooter with my Lyman slugs.

[Mk42gunner]

Interesting test, as Lyman Cast Bullet Handbook, 4th Edition, 2010 on page 255 lists Saeco #052 at 1.265" OAL with 3.5'grains of Bullseye as 905 fps and 17,000 psi from 4" test barrel in Universal Receiver.

NOT disputing your results at all, but is possible that a soft DEWC in .38 Special brass, when fired in the longer .357 chamber might upset the base into the unsupported portion of the longer .357 chamber, so that it must squeeze down to enter the ball seat? Also have no idea on possible effect of powder coating vs. conventional lube on shot start. pressure or bore drag.
...

My expectation was somewhere in the 16-18000 PSI range for the 3.5 Bullseye load, As verified by Outpost75 and a look in my own copy of the quoted book.

A suggestion that may or may not make sense, but will save the cost of a new barrel. What about deep seating the WC to the same length in .357 Magnum brass? This assumes (really don't like doing that) that this is possible without case thickening getting in the way.

Robert

[ddixie884]

First of all, my sincerest apologies for the lateness of these tests. between a very ot summer here, high winds and illness in the family having me gone from home I wasn't able to get the testing done in a timely manner. However, I did manage to conduct the tests yesterday as i was home, the weather was nice with 75 +/- degrees and minimal wind.

Thesting was conducted using a 7.94" Contender barrel. The Oehler M43 PBL was attached to the Contender via a strain gauge. The test barrel is a 357 magnum barrel and using 357 reference factory ammunition test out compatible with the psi for that lot of factory ammunition. I first ran a test of my reference Speer 158 LSWC 38 SPL ammunition which consistently tests at 15,500 psi +/-. A test of that reference ammunition resulted in a 15,400 psi average. Thus all was well with the test system.

Wayne had sent some 147 gr WCs he had PC with a red PC. I loaded them in W-W 38 SPL cases over his requested 3.5 gr Alliant Bullseye load. I tested them with 3 different primers. OAL was 1.257". Test results;

Note; these psi's seem abnormally high for the load used. I am working on doing a retest so take these with a grain of salt.

With WSP primers the psi was 26,100
With CCI 500 primers the psi was 28,600
with Federal 100 primers the psi was 24,500

Wayne also sent along some Buffalo Bore Hard Cast WC (item 20D/20) non +Ps. The SAAMI MAP for standard 38 SPL is 17,000 psi and the MAP for +P is 20,000 psi.

The Buffalo Bore pressure tested at 20,100 psi.

unwinner sent some 358429s cast of 50/50 COWW/lead with just a "skosh of tin. They weighed out at 167.5 gr. I sized them at .359 and lubed them with 2500+. They were loaded in W-W 38 SPL cases, WSP primers with an OAL of 1.480". He had requested a test with 3.7 gr Alliant Red Dot. I loaded tests with 2.8, 3.1, 3.3, 3.7 and 4 gr of Alliant Red Dot. The pressure test results;

With 2.8 gr the psi was 16,800
With 3.1 gr the psi was 16,900
With 3.3 gr the psi was 20,000
With 3.7 gr the psi was 22,400
With 4.0 gr the psi was 25,700

Sometime, on a past thread or PM, someone had asked me if i had ever tested 5.0 gr of Red Dot under a 158 hard commercial cast bullet in a 38 SPL case. I had some so I loaded a test string in Speer cases with Remington 1 1/2 primers. The OAL was 1.50". The test results

With the requested 5.0 gr Red Dot the psi was 24,500

Good deal..

[Silvercreek Farmer]

Larry, have you been able to revisit the 3.5 Bullseye load?

[Outpost75]

Larry. Will pack and send Remington HBWC bullets. Also some Magtec 158 LRN.

Sorry for the delay. I simply forgot!