Shotgun cartridge potency. Increased over the decades?

P

Pond James Pond

New member
I am planning to try out my two shotguns tomorrow. They both belonged to my Grandad and they pretty old (50-60 years old). One is a 16g single shot, the other a 12g semi.

Of the two, I can see myself shooting the 12g more and so my question is largely regarding this one.

I have bought some 12g birdshot cartridges (shot weight is 34grams of 0/0 by Nobel Sport). I basically want to see if it cycles correctly.

However, in general, will the powder charges and projectile weights have changed massively since these were produced?

In other words, is there some kind of potency level I should stay below in order to not run the risk of damaging this little piece of family history?

If so what is the way of identifying this level?

My guess is that ammo has increased in power thanks to improvements in metal grades and strength of the guns produced.

Thanks.
 
For openers, you say that you have some birdshot cartridges loaded with 34 grams of 0/0. I am not sure what you have, but it sounds like you have some 00 (double ought) buckshot.

The 34 grams is probably the weight of the powder. Different powders can have more or less energy per gram, which is why equvalent loads may have more or less powder depending.

I rarely use buck and am not sure, but 34 grams seems to be a tad on the heavy side. What is your 12 gauge chambered to use; 2-3/4 or 3" shot shells? Be careful. 3 may fit a 2-3/4 chamber, but not when the petals of the shell unfold. Firing a 3 in a gun designed for 2-3/4 can result in dangerously high barrel pressures.

Shot shell boxes should be marked with equivalents, which tells you the powder's equivalence to an old black powder load.

I don't believe that total projectile weights have changed that much, but depending on the use you may need more boom boom to accomplish the same mission. Often regulations require steel shot and I undrstand, but may be totally wrong, that becasuse steel shot is less dense more muzzle energy is needed for some purposes, like hitting high flying fowl.

This may help. http://en.wikipedia.org/wiki/Shotgun_shell

You may want to post the make and model of your gun and specify that shotshell.
 
Last edited:
I've had a quick look online, and the shotgun (A Verney Carron Luigi Franchi Automatic) is 12/70, so that means I need 2 3/4 inch cartridges....

I've checked and my cartridges are 70mm, so OK on the cartridge length front. Here is a link to the cartridge manufacturer. It should land you on page 4 of the 12g results list. Just scroll down to the green Nobel Speed.

I did not ask for super light loads as I read somewhere that this model needs some punch to cycle properly, but if I've been sold some ridiculous over-kill nuclear magnum loads, tell me now, as I don't want to reduce my Grandad's gun to pieces!!! :eek:

The 16g is a single shot Beretta from the '50s... I got these for that one: SMI standard. It is the only result when searching under 16g...
Presumably if I slide the cartridge into the chamber and it fits, flush with the face, it should be OK, no?

Again if you feel that is too much boom-boom for a 60 year old shotgun, please tell me!! :o
 
Presumably if I slide the cartridge into the chamber and it fits, flush with the face, it should be OK, no?
Click to expand...

NO NO NO

loads of older guns are 65mm, and 70mm shells fit into those so be aware. prolly not blow up the gun but it is not made for those.

it should read the kind you need on the barrel
 
Nothing that I can see on the barrel, apart from "16".

What if I measure the depth of the chamber with a caliper?

For it to take a 70mm cartridge do I need greater length in the chamber? At the moment, it measures 70mm down to a sloped lip in the barrel. It is not a stepped edge, but rather a throat, like in the cylinder of a revolver.

The Beretta is a Model 412, 16 cal if that helps...

So.
Can anyone advise on the suitability of the cartridges I've bought? Good to go?

(Goodness!! Why can't a 12 just be a 12 and a 16 be a 16....:confused:)
 
Last edited:
I SERIOUSLY doubt that 34 GRAMS is the powder charge as opposed to the shot charge. Even 34 GRAINS would be a whale of a charge

34 GRAMS is a 1-1/8oz load

Shotgun hull length is the FIRED length. 70 is 2-3/4, 65 is 2-1/2, 60 is 2"

In other words, is there some kind of potency level I should stay below in order to not run the risk of damaging this little piece of family history?

If so what is the way of identifying this level?
Click to expand...

The 16 should have proof marks which will state pressure, maybe payload, and hull size
 
i don't know the answer. You indeed have 2-3/4 inchers, but I do not know if that model or your barrel is rated for a magnum load. This reminds me of when I was sold magnums for a 12 gauge manufactured in 1908 and I showed the idiot at the gun store the old single shot. I knew nothing about shotguns, then and, fortunately, I never shot it. I would not shoot them in your's until you have the answer.
 
What if I measure the depth of the chamber with a caliper?

For it to take a 70mm cartirdge do I need greater length in the chamber?
Click to expand...

the chamber is made for the shot when fired, the 65 becomes roughly 70mm that is why the 70 fits

shooting 70mm in a 65mm gun can cause higher gas pressures and whatnot, the most likely thing that will happen is that yo won't get the spread/coverage you wold excpect, but I can't recommend it. the least that will happen is that you will shot your gun loose de to the higher gas pressure

it will be hard to measure because the chamber gradually cones out into the barrel.
 
Seems I got 3 answers as I was editing my last post... :o

You indeed have 2-3/4 inchers, but I do not know if that model or your barrel is rated for a magnum load.
Click to expand...

OK, so the cartridge size is OK, but are they magnum loads, based on that link? I don't think they are, as the cartridges I've got did not come up in the "heavy loads" listing and they have no 12 Mag products...

If they are not, then it should be OK in my gun, no?

The 16 should have proof marks which will state pressure, maybe payload, and hull size
Click to expand...

I don't see anything that might give that sort of info. The only proofmarks on the Beretta are 3 stamps, each with a star above it. The first is a crest type stamp, the next reads "PSF", and finally the last reads FINITO. Pretty self-explanatory... What they might say about pressures, though... :confused:

This is turning into a right puzzle...
 
Last edited:
I did not ask for super light loads as I read somewhere that this model needs some punch to cycle properly, but if I've been sold some ridiculous over-kill nuclear magnum loads, tell me now, as I don't want to reduce my Grandad's gun to pieces!!!
Click to expand...

the problem most older semis have is with 24gram trapp/skeet ammo

28-32 should be fine

ammo should be labeled with a US nr, that is the standard, us7, 8, or 9 is practise ammo and perhaps for some smallish birds, it is the size(and number of) pellets, the higher the nr the smaller pellets

above 32 is when they start using terms like express, magnum and so on.

if the gun is really old you should look for proofmarks
http://www.shotguns.se/html/italy.html

well your edit suited my link greatly, finito so we know it is for smokeless powder atleast:)

I would recommend e-mailing the guy behind that site if you have further questions, he is an expert on shotguns, even recently wrote a book, I am sre he could help you
 
... under the forearm
Click to expand...

Bingo! :cool:

This was written under the forearm. Does this tell you anything?

What looks like "K", followed by 0.775. Then there is 18.6 stamped above 70 (presumably the hull length). Finally there is 16.5, written over 17.1.

Make any sense?
 
if the gun is really old you should look for proofmarks
Click to expand...

The proof marks for the Beretta single shot, I've posted in my penultimate post. It is a 1946 design. It was made in '54. From what I've worked out this evening, the Model 412 was an entry level 16g. Looks very nice, though...

The VC 12g is more recent, probably from the 60's. I'll see what I can see on it.

I'll also have a look for any number codes for the ammo, although all the information should be on the link I post earlier...

Hopefully, this will lead to the answers, and these guns can be shot for the first time in about 30 years!! :eek:
 
and not knowing anything about the semi...

there is probably an O-ring that will need replacing, maybe a magazine spring that is rusted to bits aswell, after 30 years of not being used.

you will probalby need to "experiment" in how it will need to be oiled to cycle properly, some guns wants to be drenched, some just a dash on certain parts and so on.
 
On the semi, everything moves very freely and there was no sign of rust on either of them. Testimony to my Dad's excellent storage duringhis stewardship!!

Anyway the VC only seems to have a crossed swords stamp, with "PT" beneath them. That is it...

Husqvarna:
Thanks for all the input so far. Hopefully, I can work things out by tomorrow. The cartridge sizes are OK, and if these are middling to low-end loads, I think all will be OK. A bit more research on the Nobel Sport cartridges for now, I think!!
 
Last edited:
Update:

I've found the stamp for the Verney Carron. The stamp is two crowns set above "PT", and with a sort of lightning bolt motif below that and translates as "Standard final smokeless re-enforced proof 15646 psi"

The stamps for the Beretta tell me a little less: There I've only found that the gun is good for smokeless powder.

Great link, there, Husqvarna!!

The Nobel Sport cartridges are classed as "Traditional 12G" and "Tradintional 20-16".

I don't think these are firebreathers. It should be OK.
 
FWIW, The last significant power change to shotshell ammo, other than elongation ( to 3" or 3-1/2" shells ) was in 1926.

AFAIK, Both of your shotguns should have 2-3/4" (70mm) chambers.

"16.5" & "17.1" are bore measurements, indicating the amount of constriction, i.e., choke.

Your Beretta 412 was known as the Folding Companion - the loads shot through it should take it's light weight into consideration.

Your Verney Carron Luigi Franchi Automatic is a clone of the Franchi AL-48, a long-recoil autoloader -
and while it's safe with all 2-3/4" loads, the bevel on the friction ring around the mag tube, just ahead of the recoil spring (under the forend wood) MUST face in opposite directions for heavy (magnum) or light loads -
or -
shooting heavy loads with the bevel in the "light load" position will damage the forend and maybe the receiver; shooting light loads with the bevel in the "heavy loads" position may cause misfeeds.


.
 
Last edited:
"The 34 grams is probably the weight of the powder."

Uhm... I'd say it shouldn't be.

34 GRAMS of powder would be a bit over 524 GRAINS of powder.

34 GRAMS of shot, however, is just shy of 1 and 1/4 ounces.
 
You must log in or register to reply here.
Back
Top