Relationship between maximum load, velocity, & recoil

Status
Not open for further replies.
O

orpington

Member
Joined
Jan 17, 2014
Messages
1,153
From the below excerpt of published .32-40 loading data:

upload_2022-12-11_20-19-20.png

For example, two loads I recently handloaded, using a 170 grain jacketed bullet:

1. Powder is IMR 4227. Load was midway between the suggested starting grains of 14.0 and 16.5 grains, at 15.0 grains, and the velocity would be somewhere between 1034 and 1340 feet per second.

2. Powder is IMR 3031. Liad was halfway between the suggested starting grains of 25.0 and 28.0 grains, this being 26.5 grains, and velocity would be somewhere between 1512 and 1845 feet per second.

So, the LOWEST IMR 3031 velocity is 172 feet per second greater than the GREATEST velocity achieved by the MAXIMUM published load for the IMR 4227 powder. Also, the recoil felt for my two loads was significantly greater for the IMR 3031 load vs the IMR 4227 load.

So, given the maximum load is much milder than any of the IMR 3031 load, why is the maximum IMR 4227 load limited to 16.5 grains of powder?

I am well aware that different configurations of powder have different burn rates and different masses achieve a certain velocity, based on the powder, but, beyond this, how is this all interrelated and why would a perceived milder load for a given powder be maxed out well below the perceived stouter load using a different powder?
 
So there are two numbers important in recoil and generally only the first is given any attention. The pounds of force and the velocity. The velocity is the number that has a big impact how you perceive the recoil. Larger numbers here makes you perceive a sharper recoil vs just a push. With faster powders you will see a lower pounds number and higher velocity, because the powder peaks faster and then drops off.
 
Unless they list pressures there is no way to tell what is limiting the maximum load. Powders burn at different rated and perform differently. But the most probable reason not to use more of a given powder is that you will be over pressure and could blow up the gun. Some powders work better for mild loads and some work better for faster loads

Pick a caliber that is listed in the Hodgdon reloading data center and look at the pressures associated with the different loadings of different powders.

Recoil increases with the product of the mass of the bullet times the velocity of the bullet. Thus increasing withe the bullet weight or the bullet velocity with the same weight bullet will increase recoil.
 
orpington said:
From the below excerpt of published .32-40 loading data:

View attachment 1120469

For example, two loads I recently handloaded, using a 170 grain jacketed bullet:

1. Powder is IMR 4227. Load was midway between the suggested starting grains of 14.0 and 16.5 grains, at 15.0 grains, and the velocity would be somewhere between 1034 and 1340 feet per second.

2. Powder is IMR 3031. Liad was halfway between the suggested starting grains of 25.0 and 28.0 grains, this being 26.5 grains, and velocity would be somewhere between 1512 and 1845 feet per second.

So, the LOWEST IMR 3031 velocity is 172 feet per second greater than the GREATEST velocity achieved by the MAXIMUM published load for the IMR 4227 powder. Also, the recoil felt for my two loads was significantly greater for the IMR 3031 load vs the IMR 4227 load.

So, given the maximum load is much milder than any of the IMR 3031 load, why is the maximum IMR 4227 load limited to 16.5 grains of powder?

I am well aware that different configurations of powder have different burn rates and different masses achieve a certain velocity, based on the powder, but, beyond this, how is this all interrelated and why would a perceived milder load for a given powder be maxed out well below the perceived stouter load using a different powder?
Click to expand...
Well, I can’t give the “scientific” reason but if you look at the testing information, the lab used a Winchester Model ’94 to gather all of their data. Now, it’s also interesting to note that the tables don’t show any pressure tests. Even more interesting is the testing criteria: accuracy and observation. The conclusion I am lead to by all of this is that the testing methodology and the conclusions of the lab are what the data shows. They stopped adding powder when the results were less optimal. Reduced accuracy, sticky extraction, flattened primers - observational evidence.
 
Sort of an apples to oranges comparison, IMR 4227 is marketed as a magnum pistol powder while IMR 3031 is pretty much optimal for mid-case capacity rifles (.308) and lever gun loads.

IMR 4227 is just a bit slower than H-110 and Lil Gun on most burn charts, IMR 3031 is a good bit slower than H-110/Lil Gun but it is pretty fast for rifle powders. Two completely different powders will have two completely different safe min-max load ranges and different performance expectations.

The load data you compared is a prime example why you should never, ever use load data from one powder and assume the same charge weights carry over to another powder. Much pain and misery can easily follow if one does such a thing. :(

Stay safe.
 
Over the years I have become much more "picky" about the load data I prefer to use.

The load data in the OP is exactly the kind of data I dislike the most. It combines the lack of pressure data (meaning pressure instrumentation was probably not used) with a cartridge that has a SAAMI rating where "pressure signs" are near useless for assuring a load does not exceed SAAMI ratings.

I loaded 170s for the 32-40 many decades ago. I remember load data being very scarce. Back then, I probably loaded them hotter than I would now.

Quickload is not a reliable substitute for pressure tested load data, but sometimes it can be very useful in comparing loads. All of the loads below are "near max" for pressure. You can see that "optimum" powders give more velocity and use bigger charges than the "faster than optimum" powders like the 4198s, 4227s, 2400, Unique & Universal.

Code: 
Cartridge          : .32-40 Win.
Bullet             : .321, 170, Speer FN 2259
Seating Depth      :  .565 inch
Cartridge O.A.L. L6: 2.500 inch = 63.50 mm
Barrel Length      : 24.0 inch = 609.6 mm

C A U T I O N : any load listed can result in a powder charge that falls below minimum suggested
loads or exceeds maximum suggested loads as presented in current handloading manuals. Understand
that all of the listed powders can be unsuitable for the given combination of cartridge, bullet
and gun. Actual load order can vary, depending upon lot-to-lot powder and component variations.
USE ONLY FOR COMPARISON !

Powder type          Filling/Loading Ratio  Charge    Charge   Vel. Prop.Burnt P max  P muzz  B_Time
                                      %     Grains    Gramm   fps     %       psi     psi    ms
---------------------------------  -----------------------------------------------------------------
IMR 3031                           102.6     26.1     1.69    2018    90.3    29823    4008   1.508
IMR 4895                           101.6     27.6     1.79    1983    81.0    29823    3912   1.523
Hodgdon BL-C2                       97.4     28.9     1.87    1983    82.5    29823    3945   1.522
Hodgdon H335                        88.4     26.2     1.70    1972    87.7    29823    3765   1.528
Winchester 748                      93.6     27.4     1.77    1971    83.8    29823    3830   1.525
Hodgdon H4895                       97.7     26.6     1.72    1970    82.4    29823    3797   1.531
Hodgdon H322                        92.9     24.5     1.59    1970    89.5    29823    3696   1.528
IMR 4198                            86.5     21.1     1.37    1931    95.5    29823    3307   1.532
Hodgdon H4227                       77.6     19.3     1.25    1908    98.1    29823    3117   1.547
Hodgdon Benchmark                   91.8     24.6     1.59    1901    85.0    29823    3400   1.569
IMR 4227                            76.1     18.9     1.23    1880    97.2    29823    3033   1.562
Hodgdon H4198                       82.5     21.1     1.36    1868    89.4    29823    3125   1.568
Alliant 2400                        58.4     15.1     0.98    1827   100.0    29823    2534   1.603
Alliant UNIQUE                      51.1      9.0     0.58    1516   100.0    29823    1462   1.775
Hodgdon Universal                   48.1      8.4     0.54    1445   100.0    29823    1300   1.839
 
Last edited:
Pressure data was notoriously absent from my source. It’s a Lyman manual from about 1970. I have the most recent one and the one before that, but .32 - 40 data is not included in those manuals. Which is curious, as much more obscure rounds are included, such as .40 - 65.

As that wasn’t included, I couldn’t address it. I’m guessing the maximum loads achieve maximum pressures desired, as per P Flados post?

I think I was implying, when I created this post, is that there is a direct relationship between pressure and recoil, and that since the IMR 4227 load has much less recoil than the IMR 3031 load, then why is the maximum load what it is, especially since the velocity of the maximum IMR 4227 load is lower than the starting load for IMR 3031.

I never exceed maximum load data, so that’s not a concern, but I’m loading for a Savage 1899 which has a stronger action than a Winchester 1894.
 
P Flados said:
Over the years I have become much more "picky" about the load data I prefer to use.

The load data in the OP is exactly the kind of data I dislike the most. It combines the lack of pressure data (meaning pressure instrumentation was probably not used) with a cartridge that has a SAAMI rating where "pressure signs" are near useless for assuring a load does not exceed SAAMI ratings.

I loaded 170s for the 32-40 many decades ago. I remember load data being very scarce. Back then, I probably loaded them hotter than I would now.

Quickload is not a reliable substitute for pressure tested load data, but sometimes it can be very useful in comparing loads. All of the loads below are "near max" for pressure. You can see that "optimum" powders give more velocity and use bigger charges than the "faster than optimum" powders like the 4198s, 4227s, 2400, Unique & Universal.

Code: 
Cartridge          : .32-40 Win.
Bullet             : .321, 170, Speer FN 2259
Seating Depth      :  .565 inch
Cartridge O.A.L. L6: 2.500 inch = 63.50 mm
Barrel Length      : 24.0 inch = 609.6 mm

C A U T I O N : any load listed can result in a powder charge that falls below minimum suggested
loads or exceeds maximum suggested loads as presented in current handloading manuals. Understand
that all of the listed powders can be unsuitable for the given combination of cartridge, bullet
and gun. Actual load order can vary, depending upon lot-to-lot powder and component variations.
USE ONLY FOR COMPARISON !

Powder type          Filling/Loading Ratio  Charge    Charge   Vel. Prop.Burnt P max  P muzz  B_Time
                                      %     Grains    Gramm   fps     %       psi     psi    ms
---------------------------------  -----------------------------------------------------------------
IMR 3031                           102.6     26.1     1.69    2018    90.3    29823    4008   1.508
IMR 4895                           101.6     27.6     1.79    1983    81.0    29823    3912   1.523
Hodgdon BL-C2                       97.4     28.9     1.87    1983    82.5    29823    3945   1.522
Hodgdon H335                        88.4     26.2     1.70    1972    87.7    29823    3765   1.528
Winchester 748                      93.6     27.4     1.77    1971    83.8    29823    3830   1.525
Hodgdon H4895                       97.7     26.6     1.72    1970    82.4    29823    3797   1.531
Hodgdon H322                        92.9     24.5     1.59    1970    89.5    29823    3696   1.528
IMR 4198                            86.5     21.1     1.37    1931    95.5    29823    3307   1.532
Hodgdon H4227                       77.6     19.3     1.25    1908    98.1    29823    3117   1.547
Hodgdon Benchmark                   91.8     24.6     1.59    1901    85.0    29823    3400   1.569
IMR 4227                            76.1     18.9     1.23    1880    97.2    29823    3033   1.562
Hodgdon H4198                       82.5     21.1     1.36    1868    89.4    29823    3125   1.568
Alliant 2400                        58.4     15.1     0.98    1827   100.0    29823    2534   1.603
Alliant UNIQUE                      51.1      9.0     0.58    1516   100.0    29823    1462   1.775
Hodgdon Universal                   48.1      8.4     0.54    1445   100.0    29823    1300   1.839
Click to expand...
I would also like to note that the difference in predicted velocity is 138fps between the highest velocity powder, IMR 3031 and IMR 4227. That’s not a very big difference. The I-4227 load is predicted to offer a 97%+ burn completion rate versus 90% for the I-3031; and, the I-3031 is a 102% fill (compressed load) while the I-4227 load has some space under the bullet. The I-4227 load requires 7.8gr less powder, which means it stretches your supplies better.
If all a shooter cares about is chasing the velocity rabbit down the numbers hole, then none of the above matters. However, for the shooter who wants to use less powder that burns more efficiently and leaves less unburnt kernels in the barrel, at a lower cost, for a less than 10% loss of velocity, there’s some grist for the Ol’ thinking mill in the above.
 
orpington said:
Pressure data was notoriously absent from my source. It’s a Lyman manual from about 1970. I have the most recent one and the one before that, but .32 - 40 data is not included in those manuals. Which is curious, as much more obscure rounds are included, such as .40 - 65.

As that wasn’t included, I couldn’t address it. I’m guessing the maximum loads achieve maximum pressures desired, as per P Flados post?

I think I was implying, when I created this post, is that there is a direct relationship between pressure and recoil, and that since the IMR 4227 load has much less recoil than the IMR 3031 load, then why is the maximum load what it is, especially since the velocity of the maximum IMR 4227 load is lower than the starting load for IMR 3031.

I never exceed maximum load data, so that’s not a concern, but I’m loading for a Savage 1899 which has a stronger action than a Winchester 1894.
Click to expand...
Like I said previously, the labs back then were looking for accurate and reliable results. They didn’t chase numbers or test with fixtures. Start at the starting load and work up to the most accurate, safe, reliable load for your rifle. The target and action will tell you where that is. Recoil energy is going to be a variable with faster powders because they stop producing expanding gas while the bullet is still going through the bore. The bullet will decelerate slightly, reducing felt recoil.
 
I think what started this discussion is that I got a more accurate grouping with my IMR 4227 loads than my IMR 3031 loads. Not significantly different, but the IMR 4227 load was better. But, at 50 yards vs 100 yards, the IMR 3031 load continued to climb, whereas the IMR 4227 load was dropping at 100 yards. As both loads were in the middle of the range, I can create a bit hotter load using IMR 4227 and hopefully retain accuracy while diminishing the drop at 100 yards.
 
orpington said:
I think what started this discussion is that I got a more accurate grouping with my IMR 4227 loads than my IMR 3031 loads. Not significantly different, but the IMR 4227 load was better. But, at 50 yards vs 100 yards, the IMR 3031 load continued to climb, whereas the IMR 4227 load was dropping at 100 yards. As both loads were in the middle of the range, I can create a bit hotter load using IMR 4227 and hopefully retain accuracy while diminishing the drop at 100 yards.
Click to expand...
The 4227 was giving you better bullet opteration, but less velocity. That meets with your observations. If the accuracy falls off while you add powder then a shift to imr 4198.
 
orpington said:
I think I was implying, when I created this post, is that there is a direct relationship between pressure and recoil, and that since the IMR 4227 load has much less recoil than the IMR 3031 load, then why is the maximum load what it is, especially since the velocity of the maximum IMR 4227 load is lower than the starting load for IMR 3031.
Click to expand...

There is no direct relationship between peak chamber pressure and recoil. A higher pressure load can easily produce less recoil than a lower pressure load.

The 4 things used to calculate recoil are: weight of the bullet, velocity, weight of the powder charge, and the weight of the gun. Pressure is not part of the formula because it is irrelevant.

See the link lordpaxman posted for a recoil calculator.

and see; https://en.wikipedia.org/wiki/Recoil
 
Riomouse911 said:
Sort of an apples to oranges comparison, IMR 4227 is marketed as a magnum pistol powder while IMR 3031 is pretty much optimal for mid-case capacity rifles (.308) and lever gun loads.

IMR 4227 is just a bit slower than H-110 and Lil Gun on most burn charts, IMR 3031 is a good bit slower than H-110/Lil Gun but it is pretty fast for rifle powders. Two completely different powders will have two completely different safe min-max load ranges and different performance expectations.

The load data you compared is a prime example why you should never, ever use load data from one powder and assume the same charge weights carry over to another powder. Much pain and misery can easily follow if one does such a thing. :(

Stay safe.
Click to expand...
IMR 4227 has been around longer than the “magnum pistol.” I copied this from another site about IMR Powders:
“IMR # 1204 powder appeared in 1925 for short lever action cartridges like the .25-20, .32-20, .38-40, and .44-40. Grains of 0.025-inch diameter were 0.021 inches long with 8% DNT coating. IMR # 4227 replaced IMR # 1204 in 1935 for small capacity cartridges like the .22 Hornet, .25-20 and .32-20. Grains of 0.024-inch diameter are 0.023 inches long with 6.5% DNT coating.”
The interesting thing about this is, the parent powder, IMR 1204, was made for the OP’s cartridge of choice, .32-40. But when the new and improved powder, IMR 4227, was introduced to replace it, that cartridge was delisted as a primary use. That could mean a lot of things - and I don’t want to speculate - but I-4227 remains a very good choice as a multi-use rifle powder and was recommended for the .32-40 at least into the 1970’s.
 
So, the LOWEST IMR 3031 velocity is 172 feet per second greater than the GREATEST velocity achieved by the MAXIMUM published load for the IMR 4227 powder. Also, the recoil felt for my two loads was significantly greater for the IMR 3031 load vs the IMR 4227 load.
Click to expand...

There are 4 factors that determine recoil. Plug in the numbers here to see the difference in real numbers.

ShootersCalculator.com | Recoil Calculator

Weight of the rifle
Weight of the projectile
Velocity of the projectile
Weight of the powder charge

The total weight of the 170 gr bullet and 15 gr of 4227 was 185 gr
The total weight of the 170 gr bullet and 26.5 gr of 3031 was 196.5 gr.

The 3031 powder was pushing 11.5 gr more bullet + powder out the barrel and doing it 172 fps faster. That is going to recoil a LOT more.
 
AJC1 said:
there are two numbers important in recoil
Click to expand...

Four, in fact. Then the rest is calculable. Bullet mass, powder mass, bullet muzzle velocity, and rifle mass.

Total ejecta momentum, recoil velocity, and free recoil energy are all calculable from those 4 numbers.

Obviously, felt recoil and blast sensitivity aren’t really calculable.
 
orpington said:
I think what started this discussion is that I got a more accurate grouping with my IMR 4227 loads than my IMR 3031 loads. Not significantly different, but the IMR 4227 load was better. But, at 50 yards vs 100 yards, the IMR 3031 load continued to climb, whereas the IMR 4227 load was dropping at 100 yards. As both loads were in the middle of the range, I can create a bit hotter load using IMR 4227 and hopefully retain accuracy while diminishing the drop at 100 yards.
Click to expand...

One of the most consistent loads I ever worked up, and that would be velocity and SD numbers, not necessarily accuracy, was with IMR4227 in my .348WCF... we're talking single digit SD. This load was at the upper reaches of pressure for that bullet/powder combination, but I think the whole reason it put up such good numbers was because it burnt 100% vs not quite as good numbers with the same bullet and IMR4198 or IMR3031. IMR4227 is an excellent powder for mid-level loads with cast rifle cartridges. As the powder slows down... with first IMR4198, and then IMR3031... the velocity picks up, sure, but with lower pressure overall... and a less consistent burn. As a result, because I use the .348 for longer shots, I normally use IMR3031 as my standard powder, even under cast.

orpington said:
So, given the maximum load is much milder than any of the IMR 3031 load, why is the maximum IMR 4227 load limited to 16.5 grains of powder?
Click to expand...

Because whatever their parameters or goals for that bullet/powder combination was, it was met at 16.5grn. As was mentioned, they don't list pressure of any sort on that data, so we don't really know how they arrived at that load limit.


If part of your load development includes a velocity threshold, like mine did for the .348, find a powder that will meet that velocity without redlining the load. In my case, even though IMR4227 gave me the best numbers, it didn't meet my velocity goal... only IMR3031 did. Even IMR4198, my favorite cast rifle powder, wouldn't get me there.
 
Your post peeked my curiosity. Did a quick search through load data.com.

It appears IMR 4227 is very inefficient in that bullet weight in the 32-40. I saw data on the same loads you mentioned, but unfortunately no pressure data.

But using Lee load data, 13,5 grains of IMR-4227 pushed a 204 hard cast grain bullet at 1369 using only 13.5 grains. The pressure is 16,300 CUP.

Less powder, heavier bullet, higher velocity. I don’t remember the barrel length.

I searched several different groups of load data for the 32-40 and the only ones I saw that had pressure measurements was Acurate (AAC) and Lee. But I didn’t open every one.

.
 
Status
Not open for further replies.

Similar threads

O
  • Locked
What specifically determines MAXIMUM grains (or load)?
Replies
16
Views
1K
Jesse Heywood
Jesse Heywood
O
  • Locked
Maximum loads for a .30-06, based on bullet?
Replies
6
Views
661
41 Mag
4
Eb1
  • Locked
Question about Max Loads on Hodgdons Load Data
Replies
5
Views
591
steve4102
steve4102
Mr_Flintstone
  • Locked
Load not in new manuals
2
Replies
27
Views
2K
Jim Watson
J
JEB
  • Locked
30-30 load data needed
Replies
10
Views
3K
Kernel
K
Back
Top