What happens with too low of a charge in shotshell load?

[arakboss]

With a cartridge load for a rifled firearm, bad things can happen if a charge is low.

What is the likely result of an undercharged shotshell load?

If using brass 12ga cases with large pistol primers, will primers begin to show flattening as charge levels get too high?

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[WillametteWill]

I read this and felt the words, "Hold my beer," were to follow, especially with a 3am post.

 

[drstrangelove]

The result is a Pfff, with shot rolling out the muzzle and maybe a stuck wad. The reason it's not a risk for air detonation is the process for crimping the shotshell pushes the wad down against the powder, leaving no air gap. If you don't realize there may be a wad lodged in the barrel, the next round chambered may open up your patterns explosively by barrel rupture.

 

[P7M13]

Undercharged = reduced load.
Shotguns aren't built for the pressures required to flatten primers. Your face will be flattened / rearranged first.

 

[arakboss]

The result is a Pfff, with shot rolling out the muzzle and maybe a stuck wad. The reason it's not a risk for air detonation is the process for crimping the shotshell pushes the wad down against the powder, leaving no air gap. If you don't realize there may be a wad lodged in the barrel, the next round chambered may open up your patterns explosively by barrel rupture.

This what I was hoping to hear. I suspect I can start pretty low and just check for a clear barrel between each firing. I will be using a break action shotgun, so checking the barrel will be easy.

 

[arakboss]

Undercharged = reduced load.
Shotguns aren't built for the pressures required to flatten primers. Your face will be flattened / rearranged first.

What signs do you look for?

 

[Certaindeaf]

This what I was hoping to hear. I suspect I can start pretty low and just check for a clear barrel between each firing. I will be using a break action shotgun, so checking the barrel will be easy.

Unless it's a powder that doesn't tolerate reduction like H110 which could lead to an extreme pressure spike.

 

[arakboss]

Unless it's a powder that doesn't tolerate reduction like H110 which could lead to an extreme pressure spike.

I will be sticking with fast powders starting with Red Dot and Ramshot Competition.

Edit I also have a jug of e3 powder which might work better for low velocity loads.

 

[arakboss]

I am looking for light recoil subsonic loads that can be loaded using brass cases and with whatever wads, nitrocards, overshot cards etc that I have on hand or can make at the dining room table.

Most load data provided by powder manufacturers, is very specific about each component to be used. If you know of a source with low recoil, subsonic load data that allows flexibility with components being used, let me know.

 

[P7M13]

What signs do you look for?

I don't - more accurately, haven't. I load shotgun by the book. The recoil of my gun tells me all I need to know.

 

[arakboss]

I have the CBC cases which according to this article will may help me keep loads safe.

"In the CBC shells, the smokeless powder charges produce considerably reduced performance because, in effect, we're dumping a 12-gauge powder charge in an 11-gauge shell. The increased volume as the wad column moves forward keeps pressure and velocity low."

Handloading Brass Shotshells Pt. 2 | Load Data Article

<p>This article was taken from <i>Handloader</i> magazine issue 267.</p> <p>Next is the loading procedure. One of the things uncovered in all this is that brass shells can generate higher velocities than paper or plastic, all other things being equal...</p>

loaddata.com

 

[DirectDrive]

We called them "bloopers"
The shot column comes out, seemingly like in slow motion and plops on the ground after 15-20 feet.
Cartoonish.
Stop shooting immediately and check for a stuck wad !

 

[gmerkt]

I am looking for light recoil subsonic loads that can be loaded using brass cases and with whatever wads, nitrocards, overshot cards etc that I have on hand or can make at the dining room table.

Some years ago, I experimented with loading 20 ga. brass hulls. It's a somewhat different proposition than loading plastic hulls. You need to get the right oversize wad materials. You also need to get the wad pressure done right, or you can have the same kind of result as an insufficient charge.

In some ways, shot shell reloading calls for greater precision than centerfire.

Ballistic Products Inc. was my source for oddball shot shell supplies. If you're doing it by hand on the dining room table, you might want to get one of those shot shell vises. For plastic hulls, also a roll crimp tool, which is easier and more precise that trying to do a star crimp without a press.

 

[gmerkt]

Loading shot shells one at a time without a press, I used an arbor press from Harbor Freight to get wad pressure.

These days, the only shot shells I load are specialty rounds in 28 ga.

Your powder selection will be governed by payload weight. Don't sub powders without giving it some thought.

 

[P7M13]

Some years ago, I experimented with loading 20 ga. brass hulls. It's a somewhat different proposition than loading plastic hulls. You need to get the right oversize wad materials. You also need to get the wad pressure done right, or you can have the same kind of result as an insufficient charge.

Good info. I've never considered brass hulls.

Ballistic Products Inc. was my source for oddball shot shell supplies.

The only place I have found 16ga hulls.

@arakboss , I have a rarely used HF arbor press you're welcome to borrow.

 

[dangerranger60]

What signs do you look for?

Under and overpowered shot loads will not pattern so that you can predict [ read that aim] where your shot column will pass.
Over pressure loads will have a Donut pattern with no or hardly any shot in the center.
Under power loads will have a rainbow arc that you would have to aim way above the target to hit it.
Both of these are at much less pressure than would be needed to blow up the gun.
So if you put up a pattern board and are getting nice round patterns, you are probably in your guns pressure range.

Once you are getting nice round patterns at 25 yds move back to 35 yds, and you may have to refine your loads more, and again at 40 and 45 yards.
There are a couple ways to pattern shot.
Put up a 30" sheet of paper and fire one shot at its center, and you will get a pattern for that one shot. Or hang an old bed sheet with an aiming spot in its center and keep shooting at that one aiming point till you open a hole. The second method gives you an average point of impact over several shots.
I have made several underpowered snake loads, only because they only have to be accurate to 10 or 15 feet. and they don't have the report that is damaging to my ears if I had to shoot in or under a building. Good Luck DR

 

[CLT65]

This won't be terribly helpful to you since you're using brass cases, but I know what over-pressure loads look like in plastic hulls.

Many, many years ago when I was first getting into reloading, I seriously overcharged some cases- ladder test but with the wrong powder. I was young and dumb. The crimp petals were increasingly ironed out as the charge increased, as well as significant report and recoil. The last hull came out of the chamber with the crimps completely ironed flat. Amazingly, that old Mossberg took the abuse in stride. I still have it, 30+ years later.

Speaking of squib loads, a friend called me a few years ago, said he'd blown up his shotgun, or rather blown open the last six inches of the barrel like a banana peel on a Bugs Bunny cartoon. He was calling me because the ammo he used was some that I had loaded for his dad a LONG time ago (his dad was a good friend, one of the few I would share ammo with).
ADDED- I gave his dad this ammo long after my aforementioned misadventure, well after I knew how to properly assemble safe shotshell ammo.

It really concerned me, until he said how it blew up. I told him that he'd had something stuck in the barrel. No, couldn't be, he said, must have been overloaded ammo. I said nope, that type of failure only occurs as a result of something in the bore.

He later admitted that he and a buddy had been screwing around with the ammo, doing things like cutting it open and replacing the lead shot with marbles and nails. Yep, that could do it.

Fortunately nobody was hurt, and all they had to do was cut a few inches off the barrel and move the sight back, made a 28" barrel into a 20" barrel.

 

[Jay Walk]

What signs do you look for?

Gross disfiguration and radical reconstructive surgery.

 

[RX-79G]

Does the load data have a minimum start load? Maybe don't ignore that?

 

[gmerkt]

Good info. I've never considered brass hulls.

I think hobby reloaders who are loading full brass hulls with black powder have better success that those trying it with smokeless.