Hot loads in older shotguns?

[Potashminer]

"clear signs" - would be nice if that were always the case - about "cracks" or "splits" are usually the clearest signs that it does NOT fit properly. Many that I look at have an end grain showing it has been "pounded" on by recoil - sometimes the gun was designed to anticipate that - sometimes not. I have a Schultz and Larsen rifle that appears as if the wood bedding is sort of "crushed" to be glassy smooth - no evidence of epoxy bedding - I believe that one is perfectly fine, although it likely looks different, than when it was new.

 

[sillymike]

1955 is not a old old shotgun either.

I clicked on the thread half-expecting something from the late 1890s early 1900s, with either 2" or 2 1/2" chambers and Damascus barrel...

 

[canvasback]

Seems like the best thing do do, will disassemble the gun later and see how the action fits in it's cut out.
Are there any clear signs to show the action is no longer fitted properly in the stock?

Well probably the best way to tell is a version of smoke fitting, which is how gunmakers know where to file for the final fitting of various steel parts. You apply some easily transferable coating, in the old days smoke from a kerosine lamp, fit the parts together, then disassemble and look and see where they touched and where they didn’t touch. Then file the “high” points, repeating the process till you achieve the fit you want. It’s a slow process, but can result in incredible levels of fit and finish.

In your case, you would apply the “smoke”, reassemble, then disassemble to see where it’s touching and where it isn’t. Where it isn’t touching is where you would want to built up the epoxy base.

 

[TimberPig]

Really?
So is the pressure across all 12ga 2.75" the same no matter what type of shot/slug used? And is velocity determined by the type of gunpowder used or how many grains is loaded?

Yes, the maximum average pressure is the same across all 12ga 2.75” loads no matter what is loaded in it. Others have posted the details of this, but no matter what the velocity it is shooting at, the pressure is held to the same level across all loads.

 

[0faustus0]

Yes, the maximum average pressure is the same across all 12ga 2.75” loads no matter what is loaded in it. Others have posted the details of this, but no matter what the velocity it is shooting at, the pressure is held to the same level across all loads.

BULL*HIT !!!!

Max pressure for 2.75” loads has not changed over the years .... but individual loads will exhibit different pressures.

Just open a reloading manual ... and have a look at the different loads and the different pressures.

Many loads operate at around max pressure .... 11,500 psi .... but then there are as many loads that operate at much lower pressures .....

A quick scan through the Advantages Manual reveals that there are several 12ga 2.75” load that operate at 6,900 psi ....

6,900 psi and 11,500 psi is quite the difference ..... !!!

 

[guntech]

Got my hands on an old Mossberg 195 12ga bolt action shotgun manufactured between 1955 - 1958.
I want to use it for deer hunting but I'm concerned with what loads these older shotguns can handle does the 1300-1400FPS range sound about right for the upper limit?

My biggest concern is the wood stock cracking the risk of the bolt flying back into my face should be minimal as these Mossbergs were known for being built like tanks.

It will handle any factory load made today. Not so sure about home made hand loaded hot...

 

[canvasback]

BULL*HIT !!!!

Max pressure for 2.75” loads has not changed over the years .... but individual loads will exhibit different pressures.

Just open a reloading manual ... and have a look at the different loads and the different pressures.

Many loads operate at around max pressure .... 11,500 psi .... but then there are as many loads that operate at much lower pressures .....

A quick scan through the Advantages Manual reveals that there are several 12ga 2.75” load that operate at 6,900 psi ....

6,900 psi and 11,500 psi is quite the difference ..... !!!

I could be wrong but I think Timberpig was referring to standard commercial loads, from makers like Federal, Winchester, Remington, Kent etc., not reloads. Of course there are commercial specialty loads that are low pressure, usually clearly labeled as such and with a premium price tag.

 

[0faustus0]

I could be wrong but I think Timberpig was referring to standard commercial loads, from makers like Federal, Winchester, Remington, Kent etc., not reloads. Of course there are commercial specialty loads that are low pressure, usually clearly labeled as such and with a premium price tag.

I wish all of the manufacturers would advertise the pressure of their loads .....

A standard commercial 1oz Foster slug .... the same identical slug (and same wad, same hull) .... being propelled at 1600 fps .... and in a different offering being propelled at 1200 fps .... will likely exhibit different pressures ..... wouldn't you agree?

I can't imagine a manufacturer designing a lower velocity load just so that pressures are equal .....

 

[TimberPig]

While the actual pressure a load develops may vary somewhat, factory or reload, the maximum average pressure for a 2.75” 12 ga load doesn’t change based upon velocity. The limit of allowable pressures stays the same, and powder charges and burn rates are varied to achieve safe pressures and the desired speeds for a given load.

Faster loads don’t automatically mean higher pressures, nor do lower speeds mean pressures are lower. If a gun is safe with normal factory ammo, it will be safe with any standard factory ammo. If it isn’t safe with regular factory ammo loaded to standard pressure limits, low pressure loads may or may not be safe either. Barring problems or being in poor shape, the gun in question if in good shape should be capable of digesting any factory loaded 2.75” 12 ga ammo safely.

 

[TimberPig]

I could be wrong but I think Timberpig was referring to standard commercial loads, from makers like Federal, Winchester, Remington, Kent etc., not reloads. Of course there are commercial specialty loads that are low pressure, usually clearly labeled as such and with a premium price tag.

This is exactly what I was meaning. Factory ammo, other than special low pressure loads are limited to being under SAAMI maximum average pressure limits, and are held under these limits. In order to get clean burns, most loads will be closer to but under these limits to get good performance. Factory ammo is using non canister powders and they will adjust the charge to achieve the allowable pressures and the desired velocity for the load. Only special low pressure loads are going to be substantially lower pressure than regular factory loads, all the rest will be operating at very similar pressures, regardless of velocity, shot charge or slug weight etc.

 

[Big Bad]

In my preteen years, some older rural kids found out they could blow up their grandfathers' shotguns by using modern loads in them: long lengths of string were used. I sort of remember the type of gun involved, they were so heavy we kids thought they had cast iron barrels and were basically regarded as worthless. The pretext given the parents was testing them for safety but there were bragging rights involved. I trust nothing priceless was lost.

 

[Potashminer]

I wish all of the manufacturers would advertise the pressure of their loads .....

A standard commercial 1oz Foster slug .... the same identical slug (and same wad, same hull) .... being propelled at 1600 fps .... and in a different offering being propelled at 1200 fps .... will likely exhibit different pressures ..... wouldn't you agree?

I can't imagine a manufacturer designing a lower velocity load just so that pressures are equal .....

Sounds sensible, but there could be other reasons?? Maybe is cheaper to make the 1200 fps load - more profit in it? But most makers are going to stay below SAAMI Max Pressure - Pressure and velocity tend to go together if there are no other changes in the load - same primer, same wad, same powder, same hull - once you change one thing - change powder burn rate, change primer, change hull, change wad - is about no more correlation between pressure and velocity - as was mentioned - is multiple examples in loading manuals of one or two items being changed, and significant pressure difference, but about no velocity difference - and vice-versa - more (or less) velocity with not much change in pressure.

So far as I found out - is several "types" of pressure - graph out a cartridge as it it firing - as is now possible with pieziometric measuring - time horizontal in ms, and pressure vertical - it is the "peak" that is going to take your firearm apart - it is the volume under that curve that is going to give you the velocity of the "projectile". So, can have very fast rise to a high "peak" and not much volume under that curve - not much for speed, but likely stressing your firearm significantly. The idea of many loadings is to get the "peak" to be within the "comfort zone" that the firearm can handle, and then to maximize the volume under that curve - normally to increase velocity.

 

[canvasback]

I wish all of the manufacturers would advertise the pressure of their loads .....

A standard commercial 1oz Foster slug .... the same identical slug (and same wad, same hull) .... being propelled at 1600 fps .... and in a different offering being propelled at 1200 fps .... will likely exhibit different pressures ..... wouldn't you agree?

I can't imagine a manufacturer designing a lower velocity load just so that pressures are equal .....

They don’t because the pressure generated varies between “batches” of production. The makers don’t always use identical components. Effectively they take different routes to get to the same place. If they labeled pressure, they would handcuff themselves to a specific and particular recipe. So all they are willing to guarantee is the speed and the max pressure.

A company like RST, who specializes in low pressure shells, who are much more consistent with the components they use, has no problem giving out the pressure.

 

[Ashcroft]

I wish all of the manufacturers would advertise the pressure of their loads .....

A standard commercial 1oz Foster slug .... the same identical slug (and same wad, same hull) .... being propelled at 1600 fps .... and in a different offering being propelled at 1200 fps .... will likely exhibit different pressures ..... wouldn't you agree?

I can't imagine a manufacturer designing a lower velocity load just so that pressures are equal .....

No I do not agree. Sounds logical at a glance but not true. A different powder with a different pressure curve can produce the same ballistics but at higher or lower pressures. Eg. A small amount of a faster burning powder may produce X velocity at Y maximum pressure in one particular area of a barrel.
A large amount of a slower burning powder may produce the same velocity at the same pressure albeit spread over a longer section of barrel or in a different area.
There are trade offs of course, some being how clean the load burns, where the pressure peaks, perceived recoil, powder cost. Target loads, because a shooter will shoot hundreds in a day, are designed to different parameters than hunting loads, which are designed to kill efficiently.
Target loads need to throw very even, consistent patterns, burn very clean with low recoil. Because they are produced and sold in the millions ( or billions) a powder savings of a penny per round adds up to big money. High velocity is not needed nor wanted but to achieve the other goals a physically small charge of fast burning powder producing higher pressures is used.
Hunting loads need heavy payloads at high velocities. They are used in relatively small quantities, production cost, clean burn, recoil, are not factors of importance. They normally use large charges of very slow burning powder to achieve these goals. The pressures of these loads may or may not be higher than a given target load but all factory loads, regardless of the intended use will conform to SAAMI and CIP standard maximum pressures even though the components may differ greatly. Think….Rifles typically operate in a maximum pressure range of 40,000 to 60,000 PSI. Rifle barrels are thick. Rifle actions are very strong.
Shotguns operate at 6,000 to 12,000 PSI. Shotgun barrels are VERY thin. Shotgun actions are strong enough for the intended ammo but far weaker than riflle actions. Bottom line, don’t confuse pressure with velocity without including the other relevant factors.

 

[sillymike]

I kind of doubt every shotshells produce the same pressure... But I'm pretty darn sure that all commercially available ammunition in Canada would meet the SAAMI Z299.2 (Voluntary Industry Performance Standards for Pressure and Velocity of Shotshell Ammunition for the Use of Commercial Manufacturers.)
- https://saami.org/wp-content/upload...Z299.2-Shotshell-2019-Approved-2019-04-23.pdf

 

[0faustus0]

No I do not agree. Sounds logical at a glance but not true. A different powder with a different pressure curve can produce the same ballistics but at higher or lower pressures. Eg. A small amount of a faster burning powder may produce X velocity at Y maximum pressure in one particular area of a barrel.
A large amount of a slower burning powder may produce the same velocity at the same pressure albeit spread over a longer section of barrel or in a different area.
There are trade offs of course, some being how clean the load burns, where the pressure peaks, perceived recoil, powder cost. Target loads, because a shooter will shoot hundreds in a day, are designed to different parameters than hunting loads, which are designed to kill efficiently.
Target loads need to throw very even, consistent patterns, burn very clean with low recoil. Because they are produced and sold in the millions ( or billions) a powder savings of a penny per round adds up to big money. High velocity is not needed nor wanted but to achieve the other goals a physically small charge of fast burning powder producing higher pressures is used.
Hunting loads need heavy payloads at high velocities. They are used in relatively small quantities, production cost, clean burn, recoil, are not factors of importance. They normally use large charges of very slow burning powder to achieve these goals. The pressures of these loads may or may not be higher than a given target load but all factory loads, regardless of the intended use will conform to SAAMI and CIP standard maximum pressures even though the components may differ greatly. Think….Rifles typically operate in a maximum pressure range of 40,000 to 60,000 PSI. Rifle barrels are thick. Rifle actions are very strong.
Shotguns operate at 6,000 to 12,000 PSI. Shotgun barrels are VERY thin. Shotgun actions are strong enough for the intended ammo but far weaker than riflle actions. Bottom line, don’t confuse pressure with velocity without including the other relevant factors.

Ashcroft, I get your point and I agree that velocity alone is no indicator for pressures.

However, the point was made here in this thread that all 12ga 2.75” loads operate at the same pressure …. factory loads or reloads … and that is just not true …..!!

Here is just one example ... the Winchester AA12FL ‘Low noise Low recoil’ load has been independently pressure tested at 6,200psi.

And the Winchester Super Sport Sporting Clays 1 1/8 oz. load has been tested to operate at 11,660psi …. so slightly above max pressure.



Modern 12ga 2.75” loads will operate anywhere in between lets say 5,000psi and max pressure 11,500 psi.

However, without independent pressure testing it is difficult to identify which commercial loads operate at the lower end of this pressure range and which loads operate at the upper range and towards max pressure.

 

[Ashcroft]

Ashcroft, I get your point and I agree that velocity alone is no indicator for pressures.

However, the point was made here in this thread that all 12ga 2.75” loads operate at the same pressure …. factory loads or reloads … and that is just not true …..!!

Here is just one example ... the Winchester AA12FL ‘Low noise Low recoil’ load has been independently pressure tested at 6,200psi.

And the Winchester Super Sport Sporting Clays 1 1/8 oz. load has been tested to operate at 11,660psi …. so slightly above max pressure.



Modern 12ga 2.75” loads will operate anywhere in between lets say 5,000psi and max pressure 11,500 psi.

However, without independent pressure testing it is difficult to identify which commercial loads operate at the lower range of this pressure range and which loads operate at the upper range and towards max pressure.

I must have missed something, I didn’t see any point made that all 12 ga 2 3/4” loads operate at the same pressure, but that they conform to the same maximum pressure limits, not at those pressures. Shooters have no way of testing their ammo for pressures, new firearms themselves are proof tested to withstand a specific proof overload and therefore we know that all shotguns as produced will safely digest all specified factory ammo as produced. Specialty lower pressure, low noise, low recoil, lower velocity ( not the same thing) ammo also falls within these limits although pressure is not indicated unless it is specialty low pressure ammo for older guns. Not so different for rifle ammo specs, the maximum allowable pressure is published but the actual pressure uf the ammo in your box is not marked on the box. For shotgun reloads there are thousands of reliable tested load combinations, not hard to meet your requirements. Fly on your own, deviate, substitute, interpolate at your own risk, your eyes and fingers.

 

[canvasback]

Ashcroft, I get your point and I agree that velocity alone is no indicator for pressures.

However, the point was made here in this thread that all 12ga 2.75” loads operate at the same pressure …. factory loads or reloads … and that is just not true …..!!

Here is just one example ... the Winchester AA12FL ‘Low noise Low recoil’ load has been independently pressure tested at 6,200psi.

And the Winchester Super Sport Sporting Clays 1 1/8 oz. load has been tested to operate at 11,660psi …. so slightly above max pressure.



Modern 12ga 2.75” loads will operate anywhere in between lets say 5,000psi and max pressure 11,500 psi.

However, without independent pressure testing it is difficult to identify which commercial loads operate at the lower end of this pressure range and which loads operate at the upper range and towards max pressure.

Not difficult at all to know which commercial loads operate at the lower pressure range. I buy almost exclusively low pressure rounds. Have for the last 10 years. In that time I've picked up at least 6000 rounds of low pressure shells. Because of the cost and the difficulty sourcing them, and because I need them in 12, 16, 20 and 28 ga, I'll try just about anything to see if it's any good. In almost every case, low pressure loads, and by low I mean under 8000 psi, are almost always described as "low pressure" in company literature. They may not tell you the exact target pressure but they are clear that it's a low pressure round. Typically, without the low pressure labeling/description they would have a hard time justifying the extra cost of the box.

As far as what's been posted here, I didn't see anyone state that reloads are all up at the maximum pressure levels and when I made a post to clarify the ambiguous language, the poster who wrote the ambiguous language responded and clearly made his point. Perhaps you missed that. He clearly stated he was referring to standard commercial loads. As an aside, better that people are a little confused about pressure levels and come away with the idea that all loads are at 11,500 psi so perhaps they might exercise caution when attempting to fire old or damaged barrels.

 

[struff55]

Any commercial load will be within limits of industry specs as far as pressure 2:34” or 3” slug or shot . That’s the short and skinny .
The biggest issue with the firearm in question is the strength of the stock of memory serves me correct it is a bolt action shotgun with no recoil lug and basically being held together with a 1/4” bolt as a action screw it has no other support I can say with most certainly the stock will fail with repeated firing
As far as the pressure question I have been loading shot shells since I was 14 years old I’m 67 I load to the lowest pressure with the best FPS listed with lead pellet energy kills birds FPS 1150-1300 with steel 1450-1700 FPS velocity kills birds

 

[Gibo]

I believe the Mossberg models 185, 190, and 195 all use an integral recoil lug attached to the action (https://www.gunpartscorp.com/gun-manufacturer/mossberg/shotguns-mossberg/190kb)
the later 385/390/395 models have a detached one (https://www.gunpartscorp.com/gun-manufacturer/mossberg/shotguns-mossberg/390ka)

The 300 series that use beech wood has had issues with cracking over time due to exposure to moisture which beech is worse at handling then walnut.