Not enough powder?

[dcdornac]

I of course am a CA shooter of somewhat short duration (2 yrs) and I have a question. I am currently loading 4.4 grns of Unique under a 125 grn RNFP lead bullet. According to my Speer manual it lists a 125 grn (jacketed) .38 spl bullet to be loaded at max with 5.7 grns of Unique with a start charge of DNR (do not reduce). At 4.4 grns am I too light and therefore running the posssible risk of a bullet lodged in the bore with such a light bullet? Should I go to a 158 grn bullet which seems to be the standard? Thanks!

[Delmonico]

The simple answer is if the lab that developed the data says not to use it, then don't.

More complicated is Unique needs a certain amount of pressure (like most powders) to burn right, yep you stand a good chance sometime of sticking a bullet in the barrel.  If you can't find established data for a load from a reliable source it is not a good idea to strike out on your own.  I'd be blunter, but I think I offended the last one.

[Delmonico]

  Only one?  WM

No I'm sure more than one.

[Forty Rod]

No I'm sure more than one.

Hey, a guy's gotta have a hobby, right?   

[rickk]

The light end of the range for Unique is determined by when the ignition gets erratic. When you get there, you will notice both erratic ignition  (perceptible ignition delays sometimes)  and a reduction in accuracy. You can reduce the bottom end number a little bit by switching to a magnum primer.

I shoot thousands of rounds a year using the same charge as you in 44 Magnum using magnum primers. I am using normal weight bullet for the caliber (240 Grains), not light weight as you are. The ignition feels very consistent and the accuracy is superb. With non-magnum primers the accuracy drops noticeably.

For what it's worth, I shoot SWC's and seat the bullet deep enough that the shoulder is pretty much even with the case mouth rather than crimp into the crimp groove, reducing the internal volume a bit.

My assumption about the dominant reason erratic ignition with Unique is that the variation in exposed powder surface from round to round becomes too great at some point.  This is just a "gut feeling" based on some experiments I did with gun position just prior to shooting. With slow burning ball powders (H110 for example) there definitely is a minimum pressure needed for proper ignition, if if you do not provide that minimum pressure the powder will actually start to burn and then go out, resulting in misfires, hangfires, squibloads. Been there, done that...I can actually make squib loads with regular consistency with H110, and in fact made some on purpose for use in an NRA safety course demonstration.   I haven't experienced that  degree of aggravation with Unique.

[Delmonico]

And it all boils back to one should use the data that the experts have developed for our use.  There are other powders that will do what he wants to do and have printed load data for them.   

[J.D. Yellowhammer]

There are other powders that will do what he wants to do and have printed load data for them.   

Trail Boss comes to mind. Burns fast and occupies enough room in the case so that it gets consistent ignition. I usually load about middle of what IMR recommends--gives a decent velocity. But it smells a little weird...

Compare how TB fills the case. With the other powder the primer is firing over the powder instead of touching off the bottom of the column. That can cause all kindsa problems.

[Delmonico]

I've never used Trailboss but from what I've seen and read it's as close to fool proof for pistol loads as any nitro powder can be. 

[J.D. Yellowhammer]

I've never used Trailboss but from what I've seen and read it's as close to fool proof for pistol loads as any nitro powder can be. 

I like easy and fool proof. That's why I use TB and black powder (not together--separate loads). No double drops with TB or it overflows the case. And what could be simpler than black? Fill the case and go. 

[Delmonico]

125 GR. CAST LRNFP    IMR    Trail Boss    .358"    1.445"    3.0    753    11,600 PSI    5.3    952    13,400 PSI

Hodgedon's data for 125 gr cast and Trail boss, looks like it would do what the OP want's to do quite fine and no guessing.

[dcdornac]

Don't worry Delmonico, you didn't offend me. I simply wanted to say that my Speer manual lists 4.0 grns of Unique as a starting charge for that 125 grn lead bullet with 4.6 grns being the max, so I could hardly say that I was guessing at a proper load. Thanks.

[joec]

I'm a big fan of Trailboss loading in my 45 Colt and 45-70 Gov rounds. I find them both accurate with light recoil. Here is right from IMR - Trailboss PDF. I've personally found the middle of the min/max is a pretty good place to start.

38 SPECIAL
Case: Winchester Twist: 1:18.75"
Barrel: 7.7" Trim: 1.145" Primer: Winchester SP

Bullet: 125 GR. LRNFP Dia. .358" COL: 1.445"

Trail Boss 3.0 753 11,600 CUP -  5.3 952 13,400 CUP
------------------------------------------------------------------
Bullet: 158 GR. LSWC Dia. .357" COL: 1.455"

Trail Boss 2.7 661 11,400 PSI  - 4.2 804 13,700 CUP
-------------------------------------------------------------------
357 MAGNUM

Case: Winchester Twist: 1:18.75"
Barrel: 10" Trim: 1.285" Primer: Winchester SPM

Bullet: 125 GR. LRNFP Dia. .358" COL: 1.580"

Trail Boss 3.5 874 14,900 CUP - 5.3 1035 17,900 CUP
--------------------------------------------------------------------
Bullet: 158 GR. LRNFP Dia. .358" COL: 1.610"

Trail Boss 3.2 754 16,500 CUP  - 4.2 865 20,400 CUP

[J.D. Yellowhammer]

I'm confused. You quote 2 different loads. Is the difference a copper jacket vs. lead?  If Speer lists 4.0 gr as a start, why did you ask if 4.4 was too light?

Like Del said, if 4.4 is less than the minimum charge for whatever bullet you're using, then you're courting trouble.

According to my Speer manual it lists a 125 grn (jacketed) .38 spl bullet to be loaded at max with 5.7 grns of Unique with a start charge of DNR (do not reduce). At 4.4 grns am I too light and therefore running the posssible risk of a bullet lodged in the bore with such a light bullet?

my Speer manual lists 4.0 grns of Unique as a starting charge for that 125 grn lead bullet with 4.6 grns being the max, so I could hardly say that I was guessing at a proper load. Thanks.

[Trailrider]

Jacketed bullets require more force to engrave the rifling on the jacket than even the hardest cast bullet. Since force is equal to the pressure times the area of the bullet base, this is directly related to the weight of the powder charge. Unique and Universal are medium-burning pistol powders. As such, they require a minimum of about 5,000-7,000 psi (NOT CUP) to initiate and sustain STABLE combustion.  As was pointed out, if the pressure falls too low, the powder may go out.  But a WORSE phenomenon is what can happen if the bullet jumps out of the case with insufficieint force to engrave the rifling on the surface, and hits the forcing cone with little enough force that the bullet becomes stuck in the forcing cone, rather than going further down the barrel. If that happens and the powder happens to be smouldering in the case, it may "take off". Under certain conditions, the bullet may not get restarted down the barrel (it takes more force to start a stuck bullet than one that has a running start). It is possible that the pressure can exceed the rupture strength of the case, resulting in gas cutting of the steel in the chamber, which can result in the top of the gun departing for parts unknown! 

Therefore, DO NOT REDUCE THE CHARGES BELOW THAT SPECIFIED FOR CAST BULLETS.  Another solution is to switch to a faster-burning powder, such as Clays or Bullseye, BUT STAYING WITHIN THE RANGE SPECIFIED BY THE PUBLISHERS OF THE DATA! Trail Boss is an excellent powder, but my tests have shown you still get better consistancy with loads NO LIGHTER than the MIDDLE OF THE SUGGESTED RANGES. If this still produces too much recoil for you, then I suggest switching to a smaller caliber.  Ride careful, Pard!

[joec]

I'm confused. You quote 2 different loads. Is the difference a copper jacket vs. lead?  If Speer lists 4.0 gr as a start, why did you ask if 4.4 was too light?

Like Del said, if 4.4 is less than the minimum charge for whatever bullet you're using, then you're courting trouble.

If you are referring to what I posted no, it is min. and max. load. In other words don't go below the lowest and don't go past the second. I also assumed you are talking about CAS loads which it is my understanding none allow jacketed bullets, but could be wrong on that.

[Cumberland Mtn John]

Your right there.  CAS(SASS) does not allow jacketed bullets at all.  Just plain olde lead and lead alloys.
Cumberland Mtn John

[J.D. Yellowhammer]

If you are referring to what I posted no, it is min. and max. load. In other words don't go below the lowest and don't go past the second. I also assumed you are talking about CAS loads which it is my understanding none allow jacketed bullets, but could be wrong on that.

The two quotes that I posted in my reply were from the original poster, dcdornac.  He first said that 4.4 gr was less than Speer's starting load, then said that the Speer starting load was 4.0 gr.  I was trying to figure out the inconsistency. Was he talking about different projectiles? I hope he'll clear it up.

And yes, you're right, CAS does not permit jacketed bullets. Furthermore, SASS has mandatory min/max velocities which need to be considered when reloading for matches.  I can't remember the min's, but without looking at the rule book I think max veloc for pistols is 1000 and max for rifles is 1400. 

[dcdornac]

Sorry for the confusion guys. I WAS talking about two different projectiles (jacketed vs lead) and was taken by the disparity of the different recommended charges for the two (5.7 of Unique for jacketed vs 4.0 for lead) thinking 4.4 was not enough powder even for a midrange load of a 125 grn lead bullet. Thanks.

[Delmonico]

And as in the beginning, it all boils down to "IF THERE IS NO LAB TESTED DATA TO SUPPORT THE LOAD THEN DON'T DO IT." 

I'm going to add, "IF YOU HAVE TO ASK, IT'S MOST LIKELY NOT A GOOD IDEA." 

[Pettifogger]

Even with published data you still get some head scratchers.  I've been shooting Trailboss in .45 and .357.  I loaded some 125 grain .38 Specials right at the mid-point (4 grains) of the recommended loads on the Trailboss website.  Got several rounds that went off but blew out LOTS of unburned Trailboss.  Looked like confetti at a New Year's parade.  Those Trailboss flakes are big.  Will have to do a little investigation on seating depth, crimp, bullet shape etc.