Loading Under published data

M

MightyMO1911

New member
I am wondering if, other than squibs, there is any significant danger to loading UNDER published data. Specifically, I am loading 45 auto with Bullseye and a 200 grain lswc. Alliant lists a max charge of 4.6 grains so 10% off of that would be a start load of 4.1 (rounded down). I loaded 8 rounds at 4.0 and got very favorable initial results. No squibs and each one ejected splendidly.

Now that I think about it, perhaps I am asking the wrong question. Perhaps the correct question is how low is too low? This particular load ran well enough with an extreme spread of 20 and a deviation of 7 that I am going to load perhaps 20 more and re-test. So I doubt I go any lower with this particular load. But. In the future, other than squibs and cycling the pistol, is there any hazards?
 
How low is too low? I can tell you from my experience that it is much different between revolvers and semi-auto pistols and also, much different between lead bullets and jacketed/plated.

If every single bulley
EVERY SINGLE TIME
is getting out of the barrel... then you are safe.

If the gun also feed, extracts and ejects, then you are good to go.
 
I have shot 45 cal soft round Lead balls in a 45acp 1911 with NO powder, just the large pistol primer.
The gas escapes super sonic and the bullet goes through cardboard.
That is loud and lethal, but will not cycle the action.
Moving up the scale of stuck bullets... soft swaged bullets have less friction in the bore, hard cast more... Jacketed bullets want a couple grains of powder, or they will get stuck.
More guns blow up from too little powder than too much. If you shoot hot ammo when there is a bullet stuck in the barrel, things blow up.
Wimp loads with H110 with no crimp have problems because the powder does not burn.
Bullseye always burns. I want enough so the bullet does not get stuck, and it would be deluxe if there is enough powder to cycle the action.
When bullets get stuck, there is the danger of the bullet wedging in the bore and getting harder and harder to pound out. That is mostly jacketed bullets, which require more powder to not get stuck. So stay away from jacketed bullets with wimp load experiments.
CAUTION: The following post includes loading data beyond or not covered by currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assume any liability for any damage or injury resulting from use of this information.
SAMMI and published load data work together to find a 10% range of recommended loads from start to max.
But I have found through experimentation that often there is a 300% range over which the gun can be continuously operated.
 
Your only real risk is squib rounds ( and firing a 2nd round in a blocked barrel )....never a good idea !! If you are doing some rapid fire drills...maybe you'll catch that squib round...maybe you won't ...that's the risk !

Not cycling the gun...is not that risky / you'll catch it.

How far below published Min can you go ...I don't know ( I have been curious enough to test a few rounds..( single fire )....to see if I can go 5 - 10% below the published MIN ...and they were fine / but will it be fine with every powder out there (No )....with every gun (No)...with a dirty gun (No)...

so why risk it ...?? What are you trying to accomplish ??
--------------------------
If you want reduced recoil...find a different powder and bullet combination !
If you want to use less powder...try a different bullet..or a different powder !
If its just an academic exercise ....do it cautiously, and make sure you test it in single fire mode...!
 
Probably more often than guns blowing up from stuck bullets is going to be barrels being BULGED as the result of firing another round behind a stuck bullet. Depending on the model of pistol, it can sometimes be a bear to get the pistol apart but the "fix" can be as easy as a new barrel. But this is not something you want to do at all!

Low powered rounds from revolvers is a tougher and more common business.
The flash gap between cylinder face and forcing cone allows a lot of (much needed!) pressure to escape which makes a stuck bullet all the more likely.

It has been my experience that folks who try to treat plated bullets with kid gloves (especially in revolvers) will find themselves in this situation eventually. I know this because I have done this.
 
Too low with Bullseye in the 45 acp with a 200 grain lswc bullet is when the action fails to cycle and/or a bullet sticks in the barrel.
Lyman Cast Bullet Handbook 4th Edition list for 45 ACP and 200 grain cast SWC bullet #452460 a starting load of 3.5 grains of Bullseye with a maximum load of5.6 grains of Bullseye.
I personally never go below the minimum starting load from a Lyman manual when dealing with semi-auto's. There is usually a reason a starting load is given...like the action will not reliably cycle or the powder will not get a proper burn below that charge.

So your 4.0 grain load is above the minimum starting , nowhere near max. and should be just fine. Looks like it cycles in your gun, bullets are hitting the target and is accurate to boot.
Good job selecting a load!

Gary
 
I am wondering if, other than squibs, there is any significant danger to loading UNDER published data.
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Yes, there is, BUT ONLY with certain powders and load combinations. Look in the manuals and you can find certain combinations that have the warning "do not reduce".

The reason is that under certain conditions some powders can produce a pressure spike (serious overpressure) when UNDER LOADED!

This has been most noticed in large magnum rifle cases and underloads of certain slow powders. In effect, the cartridge "detonates" and can destroy a gun, and injure the shooter.

With medium speed and faster powder, this appears not to ever happen, and it only happens with SOME slow powders, and only when conditions are "just right". The last I heard, while they are working on it, this "light load blow up" has not been consistently replicated in lab tests. In other words, its rare, and we can't get it to happen regularly enough to be able to study it well enough to figure out exactly why it happens when it does, and why an identically loaded round does not do it. SO since it is a proven fact that sometimes, though rare, it can happen, the manual caution us.

and just FYI, the 10% reduction advised when you first load a particular set of components is meant to be a reduction of 10% below the listed STARTING LOAD, NOT the listed MAX load. Its perfectly safe, unless the manual specifically warns you not to do it with a given powder and load.
 
I can tell you from my experience that it is much different between revolvers and semi-auto pistols and also, much different between lead bullets and jacketed/plated.
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It has been my experience that folks who try to treat plated bullets with kid gloves (especially in revolvers) will find themselves in this situation eventually. I know this because I have done this.
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Well stated Sevens. And this is why it erks me to no end when I read posts advising people to load plated bullets to lead data. :mad:

Getting back to our OP, he's got a lead slug with a semi-auto. There shouldn't be much problem dropping to 4.0gn B'eye. I've seen people in action pistol competitions where their 45 ACP's are shooting some very mild rounds - to the point where you can see the slug sailing through the air, under the right lighting conditions.

Someday, I plan on doing what the OP is doing and make my 1911 a pure target shooter. Most likely, I'll be using a soft recoil spring and some very mildly loaded rounds. Someday. That's the plan anyway. I've got other irons in the fire right now.
 
Thanks for the replies, everyone. This is a learning process for me and I know there is danger when going over published data so I just wondered if the opposite was also true. I learn best by doing, not that I will routinely go below, if ever really, but I wanted to ensure that if I ever did there weren't any dangers lurking that I was not aware of. This load gave some really good numbers on a 10 shot string so I am going to load perhaps 30 or 40 more and see if the numbers come out close to the same. It accomplished everything I wanted. Light recoil and consistent numbers.
 
I am loading .45 ACP with 200 gr cast or coated bullets and 3.3 gr Bullseye for about 650 fps so as to shoot IDPA ESP with .45s.
That takes a reduced recoil spring, a 12 lb "type A" made by Wolff for Brownells works well in my guns.

Other fast burning powders like Solo 1000, Clays, Trail Boss, and 700X will also load way down like that, but you have to be careful of metering large flake powders in light loads. A vibrator on the powder measure is a big help.
 
I am interested in this same subject. My question is how about the case not expanding and blow by around the case. I have had this issue even with Federal factory ammo in my 460xvr. I was under the impression that it was critical to expand the case enough to seal the gasses.
 
Jim I am glad you mentioned the recoil spring. I was wondering about that too. I currently have either a 17 or 18 pound spring (can't remember which) and I wondered the role that might play. Maybe I will get a back up 17 pound and keep a lighter one on hand as well.

BoogieMan blow by around the case is something I was also watching for. This combination didn't display that, though.
 
I think that if you are doing your low-end testing and shooting on to paper targets and you are willing to go slow and methodically, your risk level for something terribly wrong is extremely low.

If you can test these loads such that there is no chance you will take another shot UNLESS you have confirmed the bullet has exited the barrel (a hole in the target is plenty of evidence) then you will be safe.

If one bullet does NOT exit the barrel and remains stuck, this is not ideal but it does not have to be a catastrophe. A lead bullet is simply not all that hard to remove -- especially from a semi-auto pistol where the barrel can be pulled out of the gun which will allow you proper access to tapping the slug out.

The risk and the danger is all associated with firing another round behind a stuck bullet. When this happens... the best result you can typically hope for is a bulged barrel. The column of air between the two slugs gets compacted and pressurized and a bulge is the result. And the worst result is some serious overpressure event where parts go flying.

But neither of those necessarily have to occur --IF-- you know that you have no obstruction in the barrel for each shot.

How many of these rounds is a proper "test" ? Well, you'll have to determine that. I would think a couple hundred... and I would be sure to start my testing over from scratch when tried in ANY other pistol than the primary one.
 
I am loading .45 ACP with 200 gr cast or coated bullets and 3.3 gr Bullseye for about 650 fps so as to shoot IDPA ESP with .45s.
That takes a reduced recoil spring, a 12 lb "type A" made by Wolff for Brownells works well in my guns.
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Like Jim Watson, a lot of people run loads very similar to this in IDPA.

That said, I would advise going below this velocity - and only with lead slugs. I would not advise these low velocities with plated or jacketed - not at all.

And like Sevens said: Make sure your projectile has exited the barrel on each and every shot. And you must have a certain amount of risk tolerance.

By the way MightyMo1911: Do you have a chronograph?
 
Too low can cause weird pressures that cause the powder to detonate vs burn. .1 below minimum won't do that.
A squib load, powered by the primer alone, will send the bullet into the barrel. Next shot, unless you catch it, will cause the barrel to bulge and stop the pistol functioning.
 
[\quote]By the way MightyMo1911: Do you have a chronograph?[\quote]

Yes sir, I bought one a few weeks ago. Which has been a blessing and a curse it seems. Lol. While I am learning a lot and am fascinated by the results, it seems to be raising more questions than answers. I figure I will just continue what I am doing and address them one at a time, as they arise.

This post specifically. It is not my desire to load the absolute lightest load I possibly can and routinely play below published data, but I am not nearly as concerned with going under as I am over. But I am interested in the hazards of playing on the low end. It helps.my understanding of how this all works and correlates.

I should probably start a new thread but since I started this one I will go ahead and hijack my own thread. :)

I developed a load that does run best at the max charge but comes in 50fps faster than published. Now, I know velocities are goimg to vary greatly due to numerous reasons, but since this is on the high end should I assume the increased velocity is a sign of over pressure?
 
Yes sir, I bought one a few weeks ago. Which has been a blessing and a curse it seems. Lol. While I am learning a lot and am fascinated by the results, it seems to be raising more questions than answers. I figure I will just continue what I am doing and address them one at a time, as they arise.
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Ah yes. Now I remember your post from a few weeks ago.

It is not my desire to load the absolute lightest load I possibly can and routinely play below published data. But I am interested in the hazards of playing on the low end.
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Got it. Loading for IDPA and target levels has me playing below published data quite a bit. It's not that uncommon. It's just important to know the potential problems that may occur (much of which has already been addressed in this thread).

I should probably start a new thread but since I started this one I will go ahead and hijack my own thread.
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I'm pretty sure it's okay to hijack your own thread :D

I developed a load that does run best at the max charge but comes in 50fps faster than published. Now, I know velocities are going to vary greatly due to numerous reasons; but since this is on the high end, should I assume the increased velocity is a sign of over pressure?
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No. I wouldn't. It's not uncommon to get velocities that exceed the published results in the order of 50fps, or even a little more. In my recent post regarding 10mm/180gn/AA7, I mentioned that my velocities exceeded that of published results (and their test barrels were longer), and I went on to mention that it was of little concern with me. Just a reference point.

That said, I'm curious what load you're talking about; and what were your results?
 
As an aside. Feel free to call me Don if you like, as opposed to typing out my screen name.

Did you happen to start the 10 mm thread you mention? I would like to read that. There are clearly very knowledgeable people on this forum but yours in particular I look for.

The load I refer to is the one I started a thread on a couple weeks ago regarding the 230 grain sierra jhp and Unique. I do still need to do more testing but my secondary, preliminary test gave results very similar to my first go round. I do not have my notes with me but as I recall, I settled on a charge of 6.8 grains of unique yielding 948 fps. The sierra books lists that at 900.

In that I stated ibwas looking for a minimum of 850. I intentionally avoided stating why that velocity because I will be using it for a carry round (and may or may not regret letting that cat out of the bag now) so actually was extremely happy this given load is performing best where it is. However. More testing to come. And since I just lost my train of thought I will just hit post.
 
Oh no, I have no intention of going higher with this load. In fact, I was considering dropping it a little but, since this increased velocity is of no concern, I will leave it where it is and continue testing. On a good note, I will not shoot a ton of this load. I am currently searching out a consistent practice load utilizing a 230 gr lrn with a similar recoil profile.
 
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