Chronographed - Underwood 38 Spl +P “Keith” 158 gr SWC

[Hi-Speed]

Chronographed a ten shot string of Underwood’s 158 gr “Hard Cast Keith” 38 Special +P

Firearm: Ruger 4 5/8 in Blackhawk
Load: Underwood 158 gr “Hard Cast Keith” SWC 38 Special +P (#734, advertised 1,250 fps)

10 shots:
Hi 1249 fps
Lo 1235 fps
Avg 1241 fps
ES 14
SD 4

Notes: I was amazed at the consistency (checkout the ES/SDs) and power of this 38 Spl +P. Hats off to Underwood for an excellent load. This load rivals my standard 357 Magnum load using 2400 but Underwood is at 38 Spl +P pressures! I will not even try to duplicate Underwood’s 38 Spl +P load. It’s velocity as far as I’m concerned can only be duplicated using 357 Magnum cases and the appropriate magnum level powders…but then you would have a 357 Magnum and not 38 Spl +P!

Underwood, and Buffalo Bore for that matter, must have some very talented ballisticians to develop powder formulas to meet these velocities within SAAMI specs. Here is pic of the Underwood box and ammo sample (sorry for its upside down orientation, doesn’t show up that way in my photo log)

[Divil]

Very impressive velocity, consistency and pressures. The main consideration here is that in addition to professional ballistic engineers with industrial pressure sensing lab equipment is that the powder used is probably some proprietary blend not available to the handloader.

[Hi-Speed]

Very impressive velocity, consistency and pressures. The main consideration here is that in addition to professional ballistic engineers with industrial pressure sensing lab equipment is that the powder used is probably some proprietary blend not available to the handloader.

Yes Sir, spot on, very well said!

As a commercial loading, it tops any of the big three factory 158 gr JSP 357 Magnum loadings in velocity and has the advantage of using a hard cast bullet…all along at 38 Spl +P pressures!

[Hi-Speed]

Not to be a rain shower on the parade...

I have always seen on the reloading forums that "chamber pressure = velocity". To the point on some other forums they will have knife fights debating that the extra .01 grains of powder will give you an extra 50 fps

However, didnt someone prove that the the buffalo bore +p 38 special with those velocities was actually 38-44 ammunition?

Yes, 38-44 velocities at 38 Spl +P pressures…I’ll stick with what Underwood and BB are stating since they have expert ballisticians coupled with accurate test equipment and lab environments to ensure that their loads are what they advertise.

[DougGuy]

Wonder what those loads would clock out of a 2" snubbie?

[Hi-Speed]

Wonder what those loads would clock out of a 2" snubbie?

I have 10 left from the box I opened yesterday…they are not getting near my S&W 442. I also purchased two boxes this afternoon from MidwayUSA…great deal and half the price of Buffalo Bore’s version (I chronographed ten of these this morning, great load in its own right and more controllable in my Ruger Blackhawk compared to Underwood’s load (which is nearly 80 fps faster in my Ruger 4 5/8 in)).

[Targa]

38+p in name only. Those are .357 mag in .38 brass..

[Wireman134]

Wonder what those loads would clock out of a 2" snubbie?

North of 1,000fps

[Sgt H]

1241fps with a 158 grain from a 4 5/8" barrel, definitely 357mag territory. I would be suspicious of the 38 +P pressure claim propriety powder or not. There is no free lunch so to speak.

[racepres]

1241fps with a 158 grain from a 4 5/8" barrel, definitely 357mag territory. I would be suspicious of the 38 +P pressure claim propriety powder or not. There is no free lunch so to speak.

^^^ This
and ...of course...Why...when shooting thru a 357 mag anyway????

[ddixie884]

Hi-Speed, if you are going thru Lake Havasu some time you should get a hold of Larry Gibson and get him to run 10 of those thru his Contender with the pressure trace on it and find out what the real pressure is on that load...........

[RJM52]

Thank you for posting the data...the load is at least 100 fps faster than the original .38-44s loads. Running 1250 fps from your 4 5/8" Ruger the original .38-44 loads were only running 1115 with a 158 grain bullet from a 5" barrel.

It has been my opinion for decades that the .38 Special, and .44 Special for that matter, have been severely underloaded by the major ammo companies because of the age of the rounds and the very early gun available for them. Guns made after WWII had a vastly better quality of steel and heat treatment than those made before the war. Colt certified their D-frame Detective Special (all steel) for the .38-44/High Speed loads. If J-frame Smiths and Ruger LCRs can be chambered for 9mm that has a pressure rating well over 30k psi and the same guns are also made in .357 Magnum how can these gun when chambered in .38 Special not take the same pressures...just because there is .38 Special stamped on the barrel and SAAMI says so...

Will it blow up an aluminum frame 442/642, no but it would probably stretch the frame or crack the frame under the barrel a is common with these guns...

It would be interesting to know exactly what the pressure is for the BB and Underwood loads...

Thanks again...Bob

[RJM52]

Thank you for posting the data...the load is at least 100 fps faster than the original .38-44s loads. Running 1250 fps from your 4 5/8" Ruger the original .38-44 loads were only running 1115 with a 158 grain bullet from a 5" barrel.

It has been my opinion for decades that the .38 Special, and .44 Special for that matter, have been severely underloaded by the major ammo companies because of the age of the rounds and the very early gun available for them. Guns made after WWII had a vastly better quality of steel and heat treatment than those made before the war. Colt certified their D-frame Detective Special (all steel) for the .38-44/High Speed loads. If J-frame Smiths and Ruger LCRs can be chambered for 9mm that has a pressure rating well over 30k psi and the same guns are also made in .357 Magnum how can these gun when chambered in .38 Special not take the same pressures...just because there is .38 Special stamped on the barrel and SAAMI says so...

Will it blow up an aluminum frame 442/642, no but it would probably stretch the frame or crack the frame under the barrel as is common with these guns...

It would be interesting to know exactly what the pressure is for the BB and Underwood loads...

Thanks again...Bob

[Larry Gibson]

"It would be interesting to know exactly what the pressure is for the BB and Underwood loads..."

Send me 12 rounds of each and I'll test it. PM me for address.

[GooseGestapo]

Actually getting those velocities at +P pressures isn’t that hard!
What’s difficult is assuring that when doing so you don’t actually exceed SAAMI pressures and get into low .357mag territory.

Back in late ‘70’s, I worked with a fellow caster and reloader that “discovered” H4227. He used some older data from a long ago Lyman manual that called for around 12.5gr of H4227. This accomplishes what Underwood is doing.
Difference is, they have access to chronographs and pressure measuring equipment.

Buddy claimed the 1,200fps loads just fell out of the Mod-15 chambers. Later, I worked for another agency and used same load for a Model 65 with cast lead SWC-HP, because they too, dropped from the cylinder, but shot POA and were VERY accurate.

Underwood isn’t exactly reinventing the .38Special +P. Just resurrecting it!

[ddixie884]

Larry tested two of these Underwood loads. Maybe he will post his resulting data when he gets time.

[GLynn41]

remember there is no free lunch -- only so much room in a hull- change pressure curves etc -- still that is a high pressure load for a .38 and close in fps to some .357 as was pointed out-- and yes i will try them-- I want a kimber 3'' in the future -- and the 150 ish gr hp sounds good at at that speed. I used to shoot a lot of 173 gr Keiths over 13.5 gr of 2400 -in a .38 special- do not remember the pressure but not normal .38 special load
My S&W 28 is what I will use for now and it will be ok with them. I shoot a lot of Remington 158 hp but they are maybe 900 fps will look later. thanks for the thread-

[RJM52]

Thanks VERY much to Larry for doing the testing...they were right around where I thought they were going to be...

The same loads from Buffalo Bore are the loads I carry in a S&W 649, 60-1, 60-10, 67, Heavy Duty and a Colt Diamondback when out with them...

Bob

[Silvercreek Farmer]

I’d be interested in the powder charge weight and appearance if anyone is willing to pull one down. No desire to duplicate, I just enjoy the exercise.

[Larry Gibson]

My report to ddixie884 with the info Silvercreek Farmer requested;

Finally got it done!,, Many personal difficulties the lat 8 months which is just the way life is. Then when I did start testing a couple weeks ago had technical problems with the test barrel/gauge. After a couple attempts to discover the problem I finally just removed the old gauge and installed a new one. That fixed the problem. Testing went well yesterday.

I first ran a "reference factory load" [Speer 158 lead SWC] through the test barrel with new gauge. That ammo (have several boxes all the same lot) Has proven to be quite uniform giving average psi's of 14,300 - 14,600 psi. The psi measured yesterday was 14,400 which was exactly the same psi as the old gauge had give with the last test a year+ ago. Thus all was well with the new gauge. I then ran 10 rounds of my standard 357 Magnum load through it. That load previously averaged 35,000 psi +/- and yesterday it measured 35,600 psi, well within the test to test variation of that load.

I then tested both of the Underwood factory rounds you had sent to me. Both proved to be excellent performers giving very low ES/SD for velocity an pressure. Accuracy at 50 yards was also excellent. I was using the test Contender (7.94" barrel) in a Ransom rest. Ambient temp was 75 degrees with a humidity of 15%.

The Underwood 158 Hardcast Keith +P load ran 1336 fps with ES/SD of 16/6 fps. The psi averaged 28,500 with an ES/SD of 0 !!!! yes, that was ZERO variation in pressure, all 10 pressures measured the same....thus the very low velocity ES/SD. Accuracy at 50 yards was a, just under, 2" group.

Cartridge specifications:
Starline 38 SPL +P cases
Unkown SP primer
5.5 gr of a very fine ball powder
161 gr PC'd SWC bullet, BHN measured on base and nose at 17-18, .3575 - .358 diameter
Cartridge OAL; 1.423"


The Underwood 158 LSWCHP load proved to be just as goo running 1314 fps with an ES/SD of 28/9 fps. The psi averaged 28,400 with an ES/SD of 200/100 psi. Accuracy at 50 yards was just over a 2" group.

Cartridge specifications:
Starline 38 SPL +P cases
Unkown SP primer
8.5 gr of a very fine ball powder
158 gr PC'd SWC bullet, BHN measured on base at 8, .356 diameter
Cartridge OAL; 1.431"

Note; the PC on both bullets was a dark blood red.