Universal Clays - 38 special problem ??

[Win]

According to Hodgdon web page, the max load for .38 using 158 LSWC using Universal powder is 4.5 grains. This is supposed to give 900/950 + fps.

Using this load in mixed brass and Federal primers, a trip to the range today showed 590 fps over the Chrony with a 4 inch S&W using this load. The primers looked fine, so no excess pressure and fired cases dropped free with no effort. Also, recoil was mild.

So, this appears to be a LESS THAN MAX load by a wide margin. Does Universal Clays powder vary that much by lot?? Has anyone else experienced this? Any thoughts on how much to bump the load up?

Thanks for any suggestions.

 

[Win]

According to Hodgdon web page, the max load for .38 using 158 LSWC using Universal powder is 4.5 grains. This is supposed to give 900/950 + fps.

Using this load in mixed brass and Federal primers, a trip to the range today showed 590 fps over the Chrony with a 4 inch S&W using this load. The primers looked fine, so no excess pressure and fired cases dropped free with no effort. Also, recoil was mild.

So, this appears to be a LESS THAN MAX load by a wide margin. Does Universal Clays powder vary that much by lot?? Has anyone else experienced this? Any thoughts on how much to bump the load up?

Thanks for any suggestions.

 

[johngalt]

4.6 gr Universal, 158 gr LSWC shot from my 642 feels pretty stout. I don't have a chronograph though.

 

[M29since14]

Does Universal Clays powder vary that much by lot?

It is not a direct comparison, but I have shot a lot of Universal in 20 and 28 gauge skeet loads and I like it so well it is all I use. It has been very consistent, in my experience. I weigh charges frequently and never see enough variation to make me consider changing bushings. My loads chronograph consistently, and are within a few fps of the published data.

I have never used it in .38 Specials but can't see why it shouldn't do a good job.

 

[fly rodder]

Win,
I've been using Universal for years with Federal primers and a 158 plated Rainier FP which is very similar to lead. 4.6 should produce a respectable, clean burning load and I frequently shoot 5 grains as a 38 plus.

You may have a bad batch of powder, but i bet its something with either your powder dispenser or scale.

 

[marlin.357]

Didn't mention the OAL. Published max loads are with the shortest OAL.

 

[OKFC05]

Another thought:

Are you sure the chrono info was correct?
Were you far enough back so the shock wave was not an issue? (too close gives low readings)
Did you check it against another gun/load?

 

[Cary]

That is quite a bit lower than one would expect. Hodgdon tested that load with a 7.7" test barrel with no BC gap.
Cary

 

[Alk8944]

Win,

You need to do more chronographing. Rarely, if ever, will a book load deliver anything near the velocity listed. In rifles maybe, semi-automatic handguns, sometimes, but revolvers, never. Same goes for factory published data.

What you report is somewhat extreme, though.

This goes for ALL powders. OKFCO5 made a good point. You should be no closer that ten feet to the start screen, otherwise the start can be triggered by the gasses preceding the bullet and the stop by the bullet. This changes the effective spacing of the screens by a large percentage and results in low readings. Even this distance will give instrumental results only 1-3 FPS lower than actual muzzle velocity, hardly enough to worry about correcting for.

 

[handgunner356]

That does seem low even from a 4". I'm running about the same 4.5grs Uni, 158gr CPFP Rainier, 1.440"OL and see 750fps out of a 6". That load shoots good and falls on par with what I see with factory loads in the same gun/chrono setup. Test barrels are always higher and from what I've tried I see around 150fps lower than the book in 38/357 Universal loadings.

 

[Steve C]

There's no way that load should be so slow. I'd expect something around 800 fps + from a 4".

Double check your loads, pull a couple and check the charge weight. Check to make sure you didn't grab a slower powder by accident. I'm assuming that your 590fps result was an average from 5 or more rounds. It it was just one round over the chrono you may have just light charged that particular one.

What kind of results where you getting from other loads fired over the chrono on the same outing? I generally use a .22lr as a base line test to see if the chrono is producing reasonable results, just in case the battery has gotten rund down or something else is off.