Fast vs Slow

[Wheeljack]

Well I'm one of those guys that can't seem to feel the difference between powders or just can't make up my mind.   I load 147gr plated bullets in my 9mm.   It seems I have a choice of over 50 powders.   I would like to know your feelings about the difference between fast and slow powders.  What can I expect from, say Alliant Red Dot vs Alliant Blue Dot.   I'm not asking about brands so much as burn rates.  Are there things to look out for in fast and slow powders.   Slower powder with heavier bullets??  I'm not looking into the bulk of the powder or pouring issues right now.  I have been loading to a range of high 880's or low 900's fps..  Can I load faster and safer, using a slow powder?                           

[Hi-Power Jack]

The number of grains of powder plays a role in recoil - the lighter

the load (faster powders), the less recoil.

 

Of course, a small powder charge can increase the danger of

a double charge, so you have to be "on your game", and have 

a reliable light source, and LOOK into each and every case

before you seat the bullet ...   BUT, you should be doing that

anyway.     

[oteroman]

Your last question - YES
Ditto Hi-Power Jack.


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[oteroman]

Several good powders for more speed.
Take a look at WSF as an example


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[4n2t0]

I load WSF for 9mm minor.

 

As an unscientific test I stagger load a magazine with two loads that produce the same velocity out of my gun (3.4gr TG and 3.9gr WSF) and I still haven't found anyone who can feel a difference.

 

[Wheeljack]

I guess I was asking, given that I load 147gr bullets, plated, in my 9mm, what is the difference, advantage, warnings, between a fast power and a slow one.   Like, what is the advantage of using Alliant Red Dot vs Alliant Blue Dot?   With either one, say I was loading for a minimal Powder Factor, 125.

 

 

Edited July 19, 2017 by Wheeljack

[oteroman]

Really personal preference.

Just realize that you can identify faster powders and slower powders but frequently powders with very close burn rates have unique behavior.

Some fast powders can be dangerous with heavy bullets if you are not careful with your load development (Clays).

 

[4n2t0]

55 minutes ago, Wheeljack said:

I guess I was asking, given that I load 147gr bullets, plated, in my 9mm, what is the difference, advantage, warnings, between a fast power and a slow one.   Like, what is the advantage of using Alliant Red Dot vs Alliant Blue Dot?   With either one, say I was loading for a minimal Powder Factor, 125.

 

 

 

Some talk about the perceived felt recoil advantage of fast powders but as I mentioned earlier you'd be hard pressed to feel a difference when loading to minimum PF in 9mm. With that said I guess the only real "advantage" between fast and slow powders would be charge weight. Using my previous example 1 lb. of TG @ 3.4gr would yield approximately 2058 rounds while 1 lb. of WSF at 3.9gr would only yield 1794 rounds. Why do I choose to load WSF? Simple, it's versatile, available, and cheap. I'll buy anything (except VV) if the price is right.

 

I'm not sure what your looking for here but it will all go bang and hopefully a hole appears somewhere down range.

 

P.S. Listen to oteromam about the unique behaviour thing but almost all the "usual suspects" can be made to work with proper load development (says the man currently having problems with WST/147gr, lol.).

Edited July 19, 2017 by 4n2t0

[Wesquire]

Different powders create gas and pressure at different rates. Powder weight means very little. What is relevant is what that powder does to pressure. Fast powders have a quick peak, but the powder burns quick and does not keep creating gas. Because of this, the average pressure for fast powders is lower than for slow powders. The less gas and the slower the gas is going means less recoil. However, the differences are small.

[wrench459]

The slower powders will need a compressed charge in some cases.

[4n2t0]

1 hour ago, Wesquire said:

Different powders create gas and pressure at different rates. Powder weight means very little. What is relevant is what that powder does to pressure. Fast powders have a quick peak, but the powder burns quick and does not keep creating gas. Because of this, the average pressure for fast powders is lower than for slow powders. The less gas and the slower the gas is going means less recoil. However, the differences are small.

 

Interesting. I thought that each powder, depending on its makeup, will have its own set of unique characteristics. e.g. Lyman's data for a 147gr TMJ indicates that TG (very fast) produced 31,900 @ 3.6gr (983 ft/s) and WSF (fairly slow) produced 30,800 @ 4.4gr (983 ft/s). I understand that fast powders have a quick peak but I didn't know that the pressure produced would be lower than that of slower powders.

Edited July 20, 2017 by 4n2t0

[wrench459]

Do you load @ 1.115?

[4n2t0]

Sometimes, why?

[Wesquire]

38 minutes ago, 4n2t0 said:

 

Interesting. I thought that each powder, depending on its makeup, will have its own set of unique characteristics. e.g. Lyman's data for a 147gr TMJ indicates that TG (very fast) produced 31,900 @ 3.6gr (983 ft/s) and WSF (fairly slow) produced 30,800 @ 4.4gr (983 ft/s). I understand that fast powders have a quick peak but I didn't know that the pressure produced would be lower than that of slower powders.

 

The peak will be higher with fast powders, but the average pressure will be lower.

[4n2t0]

9 minutes ago, Wesquire said:

 

The peak will be higher with fast powders, but the average pressure will be lower.

 

Cool, you learn something new everyday. Thanks.

 

I would assume that the average pressure in slow powder being higher is a product of time, correct?

Edited July 20, 2017 by 4n2t0

[Wesquire]

5 minutes ago, 4n2t0 said:

 

Cool, you learn something new everyday. Thanks.

 

I would assume that the average pressure in slow powder is a product of time, correct?

Yes, and it is still combusting after the bullet leaves

[Wheeljack]

It seems that a slower powder yields a faster bullet at maximum pressure.  My slow powder charge fills less than half the shell and a double charge is just below the rim, but it's not a maximum charge.

 

 

The slower powders should work best with the longer barreled guns.  I think the same is true for heavier bullets. 

[IDescribe]

To clarify something -- you don't feel pressure in recoil. Recoil is energy.  Pressure is force.  Pressure drives the bullet down the barrel.  This develops kinetic energy in the bullet.  Recoil energy is the reciprocal of that bullet's energy (every action has an equal and opposite reaction), mitigated by the mass of the gun as a whole, plus the movement and mass of the slide additionally, the movement of which spreads the recoil over time.  You can in fact have a higher peak pressure load recoil less than a lower pressure load.  In fact, that's the whole point of using faster burning powders -- lower recoil at the expense of higher peak pressure.  

[IDescribe]

18 hours ago, Wheeljack said:

Well I'm one of those guys that can't seem to feel the difference between powders or just can't make up my mind.   I load 147gr plated bullets in my 9mm.   It seems I have a choice of over 50 powders.   I would like to know your feelings about the difference between fast and slow powders.  What can I expect from, say Alliant Red Dot vs Alliant Blue Dot.   I'm not asking about brands so much as burn rates.  Are there things to look out for in fast and slow powders.   Slower powder with heavier bullets??  I'm not looking into the bulk of the powder or pouring issues right now.  I have been loading to a range of high 880's or low 900's fps..  Can I load faster and safer, using a slow powder?                           

 

Wheeljack, to your original post:

 

"Well I'm one of those guys that can't seem to feel the difference between powders or just can't make up my mind."

If you can't feel the difference between fast and slow powders, then you haven't shot a particularly fast powder next to a particularly slow powder with the same bullet in the same pistol at the same power factor.  The difference in feel there is significant.  Whether or not the recoil difference is going to make much difference in your shooting or stage scores at minor PF is a different question, and I would suggest that the difference there is not as large as would be indicated by how people chase faster and faster powders for softer and softer recoil, but the difference is real, and the difference in feel between fast and slow powders is quite noticeable when you compare them side by side.

"Slower powder with heavier bullets??"
Remember the positive feedback loop I mentioned in the previous post?  Peak pressure is the pressure we want to control for safety's sake, and bullet mass has an effect on pressure.  More mass equals slower acceleration, slower acceleration equals a more slowly expanding combustion chamber, and a slower expanding combustion chamber equals a faster increase in pressure.  For this reason, you will hear that common wisdom and/or "best practice" is to use slower powders for heavier bullets.  It's good advice in most applications.  But in minor PF action shooting, it's not applicable.  There are some super fast powders like N310 and Nitro 100 and Ramshot Comp that published load data suggests are ill-suited for minor PF (of course, people are using them happily anyway), and heavier bullets may increase concern with those super fast powders, but for the most part, if a powder is appropriate for 9mm minor with a light bullet, it's equally appropriate with a heavier bullet.

"I have been loading to a range of high 880's or low 900's fps..  Can I load faster and safer, using a slow powder?"

No one can answer that if you don't tell us what powder you are using.  It may very well be perfectly safe with the powder you have now.  I load 147gr bullets in 925-940 range with faster powders as a standard practice.

"I would like to know your feelings about the difference between fast and slow powders." 

• In general, the faster the burn rate, the less powder it takes to achieve a particular velocity or power factor, and the less powder it takes, the less gas mass, and the less gas mass, the lower the recoil. So given the same bullet/powder/velocity, the faster burning powder produces lighter recoil. How much difference in felt recoil is worth chasing is up to the shooter, but if you're not measuring it with a shot timer, you may be tricking yourself into thinking it's a bigger deal than it is.
• Another consideration is the pressure seal.  When the gunpowder ignites, the pressure blows the case walls out to the chamber walls and creates a pressure seal.  The faster the burn rate, the faster this seal happens.  The more powder you put in the case, the faster this happens.  With any powder/pistol/bullet combo there is a charge weight low enough that your pressure seal is late, allowing burning and unburned powder to blow out around the case walls into the gun, where it can't do it's job. It's just lost powder and gas.  I prefer to use a powder that burns fast enough to get a timely pressure seal with the bullet I want to use at the velocity I want to achieve, which means I use medium-fast or fast powders for 9mm minor. 

 Overall, MY feelings -- the recoil advantage is worth using a fast powder vs a medium or slower powder, but it's not worth chasing to the absolute fastest powders.  Using faster powder means using less powder per cartridge, which means you buy powder less often.  Using a faster powder ensures a timely pressure seal, which leads to more consistent burns from one cartridge to the next.  For 9mm minor, it's worth using a faster powder.

Now, if you'll just stop using plated bullets...  

[Wesquire]

3 hours ago, IDescribe said:

To clarify something -- you don't feel pressure in recoil. Recoil is energy.  Pressure is force.  Pressure drives the bullet down the barrel.  This develops kinetic energy in the bullet.  Recoil energy is the reciprocal of that bullet's energy (every action has an equal and opposite reaction), mitigated by the mass of the gun as a whole, plus the movement and mass of the slide additionally, the movement of which spreads the recoil over time.  You can in fact have a higher peak pressure load recoil less than a lower pressure load.  In fact, that's the whole point of using faster burning powders -- lower recoil at the expense of higher peak pressure.  

This is not accurate. Pressure does increase recoil. The bullet isn't the only thing moving. Higher average pressure means more gas is being pushed, this causes recoil. Newton's third. As I said, the effect of the gas isn't huge, but it is there. The biggest difference is going to be in perceived recoil. Fast powder will be snappier, slow will be more of a push. It happens in a much smaller window than the difference in recoil you feel with varying bullet weights. The biggest advantage of the fast powder is that the recoil curve ends much sooner.

 

We are already assuming that the bullet will be going the same speed with each powder, so the only real differences in recoil are going to be the curve and the (albeit) small increase in recoil from more gas being pushed.

Edited July 20, 2017 by Wesquire

[zzt]

I choose my powder based on consistency of results.  If the chrono results do not return SDs in the single digit range, I work up another load.  As a general rule, slower powders are dirty and inconsistent at low pressures.

 

If you find one side of the case blackened after firing, your pressure is to low.  Either up the charge, or switch to a faster powfer.

[Wesquire]

2 hours ago, IDescribe said:

 

Wheeljack, to your original post:

 

"Well I'm one of those guys that can't seem to feel the difference between powders or just can't make up my mind."

If you can't feel the difference between fast and slow powders, then you haven't shot a particularly fast powder next to a particularly slow powder with the same bullet in the same pistol at the same power factor.  The difference in feel there is significant.  Whether or not the recoil difference is going to make much difference in your shooting or stage scores at minor PF is a different question, and I would suggest that the difference there is not as large as would be indicated by how people chase faster and faster powders for softer and softer recoil, but the difference is real, and the difference in feel between fast and slow powders is quite noticeable when you compare them side by side.

"Slower powder with heavier bullets??"
Remember the positive feedback loop I mentioned in the previous post?  Peak pressure is the pressure we want to control for safety's sake, and bullet mass has an effect on pressure.  More mass equals slower acceleration, slower acceleration equals a more slowly expanding combustion chamber, and a slower expanding combustion chamber equals a faster increase in pressure.  For this reason, you will hear that common wisdom and/or "best practice" is to use slower powders for heavier bullets.  It's good advice in most applications.  But in minor PF action shooting, it's not applicable.  There are some super fast powders like N310 and Nitro 100 and Ramshot Comp that published load data suggests are ill-suited for minor PF (of course, people are using them happily anyway), and heavier bullets may increase concern with those super fast powders, but for the most part, if a powder is appropriate for 9mm minor with a light bullet, it's equally appropriate with a heavier bullet.

"I have been loading to a range of high 880's or low 900's fps..  Can I load faster and safer, using a slow powder?"

No one can answer that if you don't tell us what powder you are using.  It may very well be perfectly safe with the powder you have now.  I load 147gr bullets in 925-940 range with faster powders as a standard practice.

"I would like to know your feelings about the difference between fast and slow powders." 

• In general, the faster the burn rate, the less powder it takes to achieve a particular velocity or power factor, and the less powder it takes, the less gas mass, and the less gas mass, the lower the recoil. So given the same bullet/powder/velocity, the faster burning powder produces lighter recoil. How much difference in felt recoil is worth chasing is up to the shooter, but if you're not measuring it with a shot timer, you may be tricking yourself into thinking it's a bigger deal than it is.
• Another consideration is the pressure seal.  When the gunpowder ignites, the pressure blows the case walls out to the chamber walls and creates a pressure seal.  The faster the burn rate, the faster this seal happens.  The more powder you put in the case, the faster this happens.  With any powder/pistol/bullet combo there is a charge weight low enough that your pressure seal is late, allowing burning and unburned powder to blow out around the case walls into the gun, where it can't do it's job. It's just lost powder and gas.  I prefer to use a powder that burns fast enough to get a timely pressure seal with the bullet I want to use at the velocity I want to achieve, which means I use medium-fast or fast powders for 9mm minor. 

 Overall, MY feelings -- the recoil advantage is worth using a fast powder vs a medium or slower powder, but it's not worth chasing to the absolute fastest powders.  Using faster powder means using less powder per cartridge, which means you buy powder less often.  Using a faster powder ensures a timely pressure seal, which leads to more consistent burns from one cartridge to the next.  For 9mm minor, it's worth using a faster powder.

Now, if you'll just stop using plated bullets...  

 

Powder weight has nothing to do with gas mass unless the composition of the powder is the same. 3.0gr of one powder could easily produce more gas than 3.5gr of another.

Edited July 20, 2017 by Wesquire

[Wheeljack]

Ghost:  Oh boy!  I guess my slow powder is headed for the grave yard, when I run out of it.  Next to find a faster powder and one that pours well.   I liked HP-38 but I also like trying different powders.  One thing leads to another.  I thought plated were a compromise between lead and jacketed.  What do you like in bullets??  I liked lead but felt I was  not seating them well.  I use an M die now and think it would work well with lead. 

[IDescribe]

1 hour ago, Wesquire said:

This is not accurate. Pressure does increase recoil. The bullet isn't the only thing moving. Higher average pressure means more gas is being pushed, this causes recoil. Newton's third.

 

Higher pressure means more gas is being pushed faster, but it's still not the pressure that increases the recoil, it's the energy of the moving mass of gas.  It's no different than the recoil created by the bullet, except that one is a mass of gas, and the other is mass of metal.  If you had a metal container strong enough to contain the pressure of some powder charge without stretching, and you held the container while the powder was ignited, you wouldn't feel it press against your hand at all, despite the rapid increase in pressure internally.  Pressure doesn't recoil.  It's the energy of the moving masses that creates recoil, and yes, that's Newton's Third.

[IDescribe]

1 hour ago, Wesquire said:

 

Powder weight has nothing to do with gas mass unless the composition of the powder is the same. 3.0gr of one powder could easily produce more gas than 3.5gr of another.

...unless the same or similar, and the resulting gas mass from one smokeless powder to the next is quite similar by powder weight.  You're not going to find two powders where one takes 3.0gr and the other takes 3.5 to move the same bullet to the same velocity in the same pistol AND the two loads recoil the same.  The 3.5gr charge will always have more gas mass and will always recoil more, despite reaching a lower peak pressure.