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Discussion Starter #1
When selecting a powder to reload with, how closely should pressure be used as a selector with trap loads, primarily 16yd. trap reloads?

Here is the data I have found using an STS hull, Rem primer, figure 8 wad, and 1-1/8 of shot for a 2-3/4 Dram (1145fps) load.

From the lowest pressure to the highest:

800x: 7,200psi (no data with Rem. primer, I substituted Win. primer)

Green Dot: 7300psi

SR7625: 7,400psi (no data with Fig.8 wad, I substituted RXP12 wad)

PB: 7,500psi

American Select: 7,600psi

Rex II: 7,868psi

Unique: 8,200psi

International: 8,600psi

Clays: 7,900LUP (what is up with that? Hodgson used psi for everything else) I think LUP is "average" pressure not the max pressure as these numbers list (I think) so I put it here

700x: 9,000psi

Red Dot: 9,200psi

Universal: 9,900psi

E3: 9,930psi

Titewad: 10,100psi

If it is, should be all we using 800x or Green Dot? How does this affect felt recoil? How does this affect a gun's life in between maintenance checks?

I have heard on this board from people that high pressure is bad for the gun but others have said a high pressure load is best. There seems to be a lot of different theories in regards to pressure.

Being everything is the same as far as fps, I would think the lowest pressure load would be the best for the gun and felt recoil due to less stress. I am not an engineer just a layman using nothing more than simple logic.

Anyone care to comment, educate, etc...?
 

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Discussion Starter #2
When selecting a powder to reload with, how closely should pressure be used as a selector with trap loads, primarily 16yd. trap reloads?

Here is the data I have found using an STS hull, Rem primer, figure 8 wad, and 1-1/8 of shot for a 2-3/4 Dram (1145fps) load.

From the lowest pressure to the highest:

800x: 7,200psi (no data with Rem. primer, I substituted Win. primer)

Green Dot: 7300psi

SR7625: 7,400psi (no data with Fig.8 wad, I substituted RXP12 wad)

PB: 7,500psi

American Select: 7,600psi

Rex II: 7,868psi

Unique: 8,200psi

International: 8,600psi

Clays: 7,900LUP (what is up with that? Hodgson used psi for everything else) I think LUP is "average" pressure not the max pressure as these numbers list (I think) so I put it here

700x: 9,000psi

Red Dot: 9,200psi

Universal: 9,900psi

E3: 9,930psi

Titewad: 10,100psi

If it is, should be all we using 800x or Green Dot? How does this affect felt recoil? How does this affect a gun's life in between maintenance checks?

I have heard on this board from people that high pressure is bad for the gun but others have said a high pressure load is best. There seems to be a lot of different theories in regards to pressure.

Being everything is the same as far as fps, I would think the lowest pressure load would be the best for the gun and felt recoil due to less stress. I am not an engineer just a layman using nothing more than simple logic.

Anyone care to comment, educate, etc...?
 

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Discussion Starter #7
800x is the same price as 700x where I buy that is my whole thought pattern behind this post.

I don't know that is why I created thread, so I can be educated on this.

I always used 700x because that is what the old man and the guys at his gun club used as I grew up so i just followed in suit. I really don't care if a is dirty as I am not using an auto although I think 700x is cleaner than Red Dot. I did read on other posts that Rex is corrosive and eats triggers but I just read that and have no experience with it. I just posted looking for info about this powder because of its economical value.
 

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Discussion Starter #8
800x is the same price as 700x where I buy that is my whole thought pattern behind this post.

I don't know that is why I created thread, so I can be educated on this.

I always used 700x because that is what the old man and the guys at his gun club used as I grew up so i just followed in suit. I really don't care if a is dirty as I am not using an auto although I think 700x is cleaner than Red Dot. I did read on other posts that Rex is corrosive and eats triggers but I just read that and have no experience with it. I just posted looking for info about this powder because of its economical value.
 

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When one examines the formula for calculating recoil, pressure is not included in that equation. However, pressure is one of the reasons that we follow the loading manuals. Just like Fords & Chevys, pick one you like.

LUP - lead units of pressure, not the same as PSI. In the pressure bbl they use a lead element & by how much it is crushed determines LUP. For PSI the piezoeletric method is used.
 

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When one examines the formula for calculating recoil, pressure is not included in that equation. However, pressure is one of the reasons that we follow the loading manuals. Just like Fords & Chevys, pick one you like.

LUP - lead units of pressure, not the same as PSI. In the pressure bbl they use a lead element & by how much it is crushed determines LUP. For PSI the piezoeletric method is used.
 

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Big Al,

LUP is an old method of measuring pressure (lead units of pressure) used with shotgun powders.

For rifles, sometimes you'll see CUP (copper units of pressure.)

Cannot be converted to psi.

Instead of a pressure transducer, they took a piece of lead at a certain length and diameter, and subjected it to the chamber pressure, and measured how much shorter the lead piece got, then converted that to a pressure (as I recall.) A description is in the old Lyman reloading manual.

Obviously, higher pressure puts a higher load on your gun every time you shoot it.

Shotguns peak pressures are around 11,000 psi. Rifles as high as 50,000 psi.

If you shoot a semi-auto gas gun (looks like you don't though), you don't want pressure to be too low, as very low pressures might not cycle the action. Also, very low pressures can sometimes result in incomplete and inconsistent combustion.

Though some may argue, pressure does not seem to have any affect on recoil.

Tim
 

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Big Al,

LUP is an old method of measuring pressure (lead units of pressure) used with shotgun powders.

For rifles, sometimes you'll see CUP (copper units of pressure.)

Cannot be converted to psi.

Instead of a pressure transducer, they took a piece of lead at a certain length and diameter, and subjected it to the chamber pressure, and measured how much shorter the lead piece got, then converted that to a pressure (as I recall.) A description is in the old Lyman reloading manual.

Obviously, higher pressure puts a higher load on your gun every time you shoot it.

Shotguns peak pressures are around 11,000 psi. Rifles as high as 50,000 psi.

If you shoot a semi-auto gas gun (looks like you don't though), you don't want pressure to be too low, as very low pressures might not cycle the action. Also, very low pressures can sometimes result in incomplete and inconsistent combustion.

Though some may argue, pressure does not seem to have any affect on recoil.

Tim
 

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Big Al, I'll stick my neck out here and venture a reply. Modern smokeless powder likes the higher pressures for an efficient and clean burn. I try to pick a powder that will provide the desired velocity with a pressure in the 9500 to 10500 psi range. Slower powders with low pressures, Below about 8000 psi, Tend to burn dirty leaving unburned powder in the barrel. Loads with low pressures also tend to be quite erratic, Esp in cold weather. I don't believe Higher pressures within SAAMI limits has any adverse effect on longevity or safety the firearm. JMHO. Jim
 

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Big Al, I'll stick my neck out here and venture a reply. Modern smokeless powder likes the higher pressures for an efficient and clean burn. I try to pick a powder that will provide the desired velocity with a pressure in the 9500 to 10500 psi range. Slower powders with low pressures, Below about 8000 psi, Tend to burn dirty leaving unburned powder in the barrel. Loads with low pressures also tend to be quite erratic, Esp in cold weather. I don't believe Higher pressures within SAAMI limits has any adverse effect on longevity or safety the firearm. JMHO. Jim
 

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Big Al,

As a made up example, lets say we had a Clays load (relatively fast burning) and a PB load (slower burning than clays) loaded to the same velocity with 1.125 oz of shot.

And lets assume the pressure curve for the Clays loaded shell, is of a shorter duration than the PB and (I think it is) that furthermore Clays reaches its' peak pressure quicker than PB (which I think it does). Then the recoil takes place over a longer period of time with the PB load, as a result the recoil with the PB could be perceived as less than the Clays.
 

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Big Al,

As a made up example, lets say we had a Clays load (relatively fast burning) and a PB load (slower burning than clays) loaded to the same velocity with 1.125 oz of shot.

And lets assume the pressure curve for the Clays loaded shell, is of a shorter duration than the PB and (I think it is) that furthermore Clays reaches its' peak pressure quicker than PB (which I think it does). Then the recoil takes place over a longer period of time with the PB load, as a result the recoil with the PB could be perceived as less than the Clays.
 

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Discussion Starter #19
So what I am reading, pressure really should not have much to do with choosing a powder its more availability, price, reputation at your club, and cleanliness?
 

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Discussion Starter #20
So what I am reading, pressure really should not have much to do with choosing a powder its more availability, price, reputation at your club, and cleanliness?
 
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