Unique Extreme Velocity at Medium Pressure

[Silver Jack Hammer]

Looking for a 800 fps load in my Colt SAA .44 Special 4 ¾” with a 240 cast boolit. Unique is giving me extreme ranges in velocity.

6.2 gr Unique chronographs five (5) rounds at 732, 896, 719, 754,722, and 724 fps. The average is 757 fps but the extreme velocity ranges indicates the powder is not burning thoroughly at this pressure.

6.4 gr Unique chronographs five (5) rounds at 876, 809, 985, 938 and 771 fps. The average is 875 fps.

I’ve been using 5.2 gr. Bullseye for the past 25 years and have been very happy with the load, but I thought Unique might fill the case with more volume thereby reduce the chance of a double charge.

Using CCI standard non-magnum primers, mostly Remington and some Starline brass. Lyman 429447 sized .431” Alox lubed. Wheelweights because they are cheap and the volume of shooting I’m doing, plus the large and close targets used in cowboy action shooting makes wheelweights the best choice. I’m not looking for superior accuracy or high velocity. I’ve shot those loads worked up fine.

I’ve used Alliant powders exclusively for years. Probably going to try Herco next. 2400 doesn’t burn real well at low pressure 800 fps range in the short tube, nor does Blue Dot. I’m thinking I’m just going to stay with my trusted load of Bullseye.

Any suggestions?

[paul h]

While I'm a huge fan of unique, I find it typically needs to be run at a bit higher pressures for best consistancy and accuracy. My swag is in a 44 special it will really only perform it's best if you are using a 44 mag strength gun and running charges in the 8-9 gr range for ~1000 fps.

I'd suggest sticking with bullseye, it's just a steller powder for accurate lower velocity loads.

I've never used trailboss, but it has fans due to it's bulkiness.

[44MAG#1]

Yes I have a suggestion. Ease up on the Unique charges until velocities level out. If you can stay within the required vel.
You could also seat the bullet deeper if it can be to take up les space in the case.
You could also try Magnum primers.
The main thing is if you have a load that has served you well (bullseye) why try to fix something that isn't broken?
Just use more care as you get older (memory lapse) and you will be okay.

[sixshot]

Its well known that Unique burns a little on the dirty side but I shoot an awful lot of it & once in a while I clean my gun, I always clean my cylinder. 44man suggests to seat deeper if you can, thats good advice, also many times Unique needs a little more crimp to level things out a bit. Its odd but many times a big velocity difference doesn't necessarily mean the load isn't accurate, at least at cowboy action distance.

Dick

[runfiverun]

herco will be worse for what you are trying to do.
unique does have to have a pressure zone to burn clean and it's near 7grs in the special.
for the velocities you want the bullseye-red dot-clays-231 powders will be what you want.
yeah they don't fill the case full, if you want that try trail boss.
or use a safeguard like looking in the case.

[littlejack]

SJH:
You will probably get a more members here suggesting trying other different powders.
Here is another one. Hodgdon "Universal".
It tends to burn a little hotter than Unique, but does take up a fair amount of case capacity.
It meters better than Unique and burns cleaner in the loads that I have made up, i.e.
Medium .41 mag; max 45 acp, and max. 38 special.
You may like it.
Jack

[williamwaco]

I loaded the Lee TL 430-240SWC over 6.5 grains of Unique last week.
Didn't cronograph them but they grouped under 2.5" at 25 yards from my Ruger Blackhawk. Four groups of six shots each. Largest group about 2.75"

I also use Herco. It is my all time favorite for the .44 Mag. It will not duplicate the velocity of the slower powders but it is significantly more accurate.


.

[subsonic]

Experiment around. There could be some variables here causing your swings besides the powder....

Same brand of brass? Throwing or weighing and is your measure reliable with Unique? Try a different primer? Neck tension good? Boolits sloppy in the throats?

These are some things to think about before you give up on Unique.


I'd try a flake type powder that is a little faster than Unique if you find that you do want to change powders. I'm playing with 700X now and many guys like Red Dot.

[44man]

I am inclined to think case tension is all over the place due to the dies used.
I have never had a problem with Unique. It is OLD, dirty but pretty stable.
Even case tension gives even burns.

[bcp477]

You'll do better with a faster powder than Unique, given your relatively short barrel. Your Bullseye load......or you could try a powder somewhere in between Bullseye and Unique in burn rate. I would suggest HP38 or Win 231 (same powder).....or just sticking with your (already successful) Bullseye load.

[Shooter]

I have had velocity excersions with hot loads of Unique in .454 Casull. It reaches a pressure point, then seems to begin to detonate.
YMMV

[Wolfer]

Tightgroup may work for what your wanting. I was always after a little more velocity and in my 44 special I use 8 gr of unique for 1000 fps, this was a little faster than I wanted but it's where it all came together.

[44man]

I have had velocity excersions with hot loads of Unique in .454 Casull. It reaches a pressure point, then seems to begin to detonate.
YMMV
Well, the .454 is not exactly a Unique shooter! :bigsmyl2:

[paul h]

Think of finding a load in gun as similar to tuning the carburator for an engine. For a given set of cam and ignition timing for that engine (think the case you are using and bullet) there is going to be sweat spot for tuning the carb. If the carb is too rich, the engine runs poorly, if it is too lean it runs poorly.

Same with working up loads with a powder. You are not going to get consistant ignition and top accuracy with every charge of powder you try. Not enough, or too much powder and you're not at the sweet spot.

Unique is one of my favorite powders, but it is at it's best for mid level handgun loads, not the lightest handgun loads. You need enough of it in the case, and enough to build sufficient pressure before it's happy.

[Silver Jack Hammer]

Thanks for advice guys. You told me what I needed to hear. I’ve always said use the powder with the rate of burn for the velocity you want. Slow powders for hot loads and fast powders for mild loads, don’t add more fast powder if you want more velocity, move up your burn rate and stay away from minimum and maximum charges. I’m not going to fix my load of Bullseye because it’s not broken, I haven’t shot that much Unique but it works so well in my .45 Long Colt I was just surprised to see such inconsistencies in the .44 Special. My .45 Long Colt loads are 870 fps with a 250 gr 454190. 8.7 gr of Unique is the sweet spot for my horse pistols.

I’ve loaded up 5.8 gr of Herco and 6.0 gr of IMR 7625 but expect nothing worth commenting on after testing. I’ll be staying with the Bullseye for the light .44 Special loads.

[smkummer]

The 45th Lyman manual uses a Colt SAA for its 44 special load developement and while these loads exceed currect SAMMI specs., it is what I have used in my 5 1/2 in. Colt SAA for over 30 years. A light bullseye load shot a very accurate group with the Kieth bullet. And the old skeeter skelton recommended load of 7.5 grains unique with the kieth bullet is a favorite of mine, but only if I want the power such as shooting 100 yards. In both the long Colt and 44 special if you go too light with unigue, your cases start getting sooty. I too love the same charge of unique in my 45 Colt with the lyman 454190 sized to .454. Also in 38 special I only use unique for full power or plus P loads.

[MasS&W]

Herco gives me much better burns at low pressures and/or lighter bullets. I think of it as unique 2.0. Once you get a bit hotter the benefits drop off though.

[tacklebury]

No similar issue with Unique here. I use an FCD to crimp and that might help. It is possible to get a bad batch also. Try calling Alliant?

[dmize]

I just tried 7.5 grains of Power Pistol in my Ruger Flattop,VERY accurate,supposed to be in 900fps range in a 4 1/2 revolver pre Brian Pearce in American Handgunner article. Also burns a lot cleaner than Unique.

[MGySgt]

Question - As I can not find reference to a Lyman 429477 what is the boolit configuration?

I was looking in my Lyman Manuals to see your load. I thought the velocity was high. All the Lyman 240's and Unique run about 6.0 - 7 grains and velocity max's out at an average of about 800.

Are you using mixed head stamp when you are testing your velocity? I know Star Line 44 mag has less internal capitcy than Remington and Winchester.

[44man]

For fun shooting -with a 240 gr boolit in the .44 and a little heavier in the Colt, I use 7 gr of Unique. VERY pleasant and accurate. Breaking bottles at 50 yards is easy.
6.5 gr of 231 is also nice.
I have worked to max with both powders and see no need to go heavy.
Yeah, on occasion I shoot other then hunting loads, not often though.
I still like Unique.

[Jammer Six]

Been watching this thread with interest, because of the title.

Why do you think that the pressure is medium at high velocity?

Do you have pressure testing gear?

[subsonic]

He should have written extreme velocity VARIATION at medium pressure, I think?

[specops]

Looking for a 800 fps load in my Colt SAA .44 Special 4 ¾” with a 240 cast boolit. Unique is giving me extreme ranges in velocity.

6.2 gr Unique chronographs five (5) rounds at 732, 896, 719, 754,722, and 724 fps. The average is 757 fps but the extreme velocity ranges indicates the powder is not burning thoroughly at this pressure.

6.4 gr Unique chronographs five (5) rounds at 876, 809, 985, 938 and 771 fps. The average is 875 fps.

I’ve been using 5.2 gr. Bullseye for the past 25 years and have been very happy with the load, but I thought Unique might fill the case with more volume thereby reduce the chance of a double charge.

Using CCI standard non-magnum primers, mostly Remington and some Starline brass. Lyman 429447 sized .431” Alox lubed. Wheelweights because they are cheap and the volume of shooting I’m doing, plus the large and close targets used in cowboy action shooting makes wheelweights the best choice. I’m not looking for superior accuracy or high velocity. I’ve shot those loads worked up fine.

I’ve used Alliant powders exclusively for years. Probably going to try Herco next. 2400 doesn’t burn real well at low pressure 800 fps range in the short tube, nor does Blue Dot. I’m thinking I’m just going to stay with my trusted load of Bullseye.

Any suggestions?

Silver Jack,
I'm not familiar with the Lyman 429447 but it sounds more like lack of proper crimp than the powder. Unique does require a good crimp (taper or roll) for best results. I use it in .38, .357, .44 (Special and Mag) 45 ACP and 45 Colt as well as .30 rifle cast bullet loads. I understand the worry over a double load of Bullseye. Best suggestion would be Trail Boss. 5.0 grs fills the .44 Special case very well and will get you into the 750-800 fps range. Course there is always BP as well, 26-27 grs of FFF will get you into that same 750-800 fps range. Red Dot is almost the same burn rate as Bullseye but a lot bulkier and also makes a cheap alternative.

[Jammer Six]

He should have written extreme velocity VARIATION at medium pressure, I think?


Well, what has me wondering is that in the absence of pressure gear, he doesn't know anything about the pressure.

So what he has observed is variation in velocity, and he assumed that he was observing higher than expected velocity at a given pressure, rather than what the evidence seems to suggest-- higher than expected velocity caused by higher than expected pressure.

(That's all my assumption, of course. He could have CUPS gear, in which case my assumptions are all wrong. Which is why I asked the question.)

[paul h]

The way I read the op is that he figured the loads he is using are medium pressure, based on published top loads for his chambering. He's wondering why he is seeing extreme spreads in his velocity.

As I said before, in my experience unique will burn inconsistantly with lighter charges and he should find that his es drops as he increases his powder charges.

[Jammer Six]

I think I see-- but I've always taken velocity to indicate pressure. Assuming that the pressure for all the shots was the same merely because the (attempted) load was the same defeats one of the purposes of measuring velocity, according to what I understand.

Without measuring pressure, the test assumes a certains result (pressure is the same) and then measures one of the primary indicators of that result and asks "why are the indicators different when the result is the same?"

It seems to me that given the different velocities, a more logical question is "why is the pressure so different between these shots?"

[paul h]

It's a bit more complex as velocity is based on area under the curve of pressure over time. When pressure is measured and quoted, it is the peak pressure that is discussed. Just because one paticular round in say a string of 10 has the highest velocity, does not automatically mean it has the highest peak pressure, it means the pressure over time curve had the most area to accelerate the bullet while in the barrel.

When a company lists the pressure for a top load of a given powder, primer and bullet, what they are saying is that of the many shots they tested, the average pressure is as listed, and the peak pressure they detected is still in the safe range. A published pressure for a given set of components does not indicate that every round they tested had identical pressure.

To me the issue is, if you get wildly varying pressures for a given combination of components, the powder is not burning consistantly for some reason or other. I could really care less what the mean pressure and pressure spread is, so long as they are within safe limits.

[Silver Jack Hammer]

The 429667 is a newer design Lyman cowboy boolit, it has a bevel base, a single large lube groove and a pronounced crimping groove. The meplat is a large and flat to accommodate tubular magazines such as those on lever rifles. It’s available in four cavity mold blocks and is very easy to cast with. I cast large quantities just using wheelweights for high round count shooting sessions. I cast a big box of those boolits today.

When I mentioned medium pressure, I was addressing the lack of literature available on the .44 Special for Colt SAA in the medium charge levels. Seems everybody is cooking up a new charge to launch the .44 Special boolits into orbit. I am guilty of having done the same. Cowboy has a batch of shooters who load their levels down to “mouse flatulence” levels, we call those folks gamers.

I’m just looking for a decent medium velocity load and thought Unique would be the right powder, but obviously at 800 fps I’m not getting a proper burn causing erratic velocities.

Yep, I should have titled this post extreme velocity VARIATION at medium pressure
as Subsonic points out.

Brian Pearce of Handloader gives a load of 8.5 gr of Unique with a 245 gr boolit as safe in a post war SAA as 22,000 psi. That seems a bit hot, but my load of 12 gr of Blue Dot serves me very well as a hot load in the Colt. Pistol Power reportedly delivers comparable velocity at 15,500 psi. I don’t have any pressure measuring equipment so we have to trust Alliant and Brian Pierce on this.

None of this accomplishes what I am seeking. A good load at 800 - 850 fps. SR 7625 looks promising as does Herco, or maybe I’ll just stick with Bullseye. I have to spend a bit more time at the range with these powders.

[44man]

Good thinking but watch case tension. Many use a softer boolit for CA. Dies can expand brass too much for the softer boolit.
As case tension varies, powders have a more pronounced affect.

[Silver Jack Hammer]

44man, I’ve got that crimp tightened down as far as I can. First I tightened the crimp down until it was too far, then I backed it off just a bit. The 429667 has a pronounced crimping groove that I am taking full advantage of. My brass is Remington and Star Line. Trying to get out to the range with some new powders but everything else seems to be getting in the way.

On Father’s Day I did size and lube a 2’x 2 ½’ tray of my cast boolits tho.

[jwp475]

Chrono the same brand cases do not mix cases when you chrono

[44man]

44man, I’ve got that crimp tightened down as far as I can. First I tightened the crimp down until it was too far, then I backed it off just a bit. The 429667 has a pronounced crimping groove that I am taking full advantage of. My brass is Remington and Star Line. Trying to get out to the range with some new powders but everything else seems to be getting in the way.

On Father’s Day I did size and lube a 2’x 2 ½’ tray of my cast boolits tho.
Crimp does not do a whole lot to control powder burn. You can make things worse by going too far.
The .44 SP really does not need much crimp anyway. Moderate is enough.
Even case tension from one piece of brass to the other is the best control for powder and even primer pressure.

[Silver Jack Hammer]

Less crimp. Hum, sounds interesting. I've set my crimp for the Keith boolit loads. Maybe I should try less crimp. Unique works well in my .45 Colt at moderate velocities and I'm loading 454190 which does not have a crimping groove. Maybe this is the ticket.