someguy2800
Member
Hi there,
I have been experimenting heavily with winchester 296 powder (same thing as H110) in several different cartridges. I've messed with it in a lot in 357 magnum, some 44 magnum awhile ago, 30 Herrett, 357 Herrett, and most recently 357 magnum.
Some of the things I've found out about it are that a magnum primer makes a world of difference to how it works. I tested velocities and deviations with and without magnum primers in 357 magnum and 357 herrett and observed as much as a 200 fps change in velocity with different primers. I've also observed that extreme spreads generally go down and accuracy improves the closer you get to a max load. Velocities do change with temperature but not that bad in my observations.
When testing this in 357 herrett (which is a shortened and blown out 30-30) I noted that extreme spreads were very high and it was just generally inconsistent in that cartridge. I believe this was the case because even with a max load the powder only filled the case about 1/2 full. My theory was that depending on how the gun was handled the flash hole may be uncovered when the gun fires which led to inconsistent ignition.
Today playing with it in my 357 maximum I saw some unexpected findings. I have a contender pistol with a 13" 357 maximum barrel which when I had it made I specified that I wanted it to be cut with a .250" throat in order to be able to seat bullets farther out particularly the Hornady 180gr XTP. The 180 XTP has two cannelures so this gives me the option of using either cannelure, or when using other bullets I can just seat them long and not use the cannelure at all to gain some extra powder space.
After testing a bunch of powders my favorite load for this is a federal small rifle mag primer, 24 grains of Win 296, and a 180 xtp seated long in the second cannelure. This gives about 2030 fps and excellent accuracy. Interestingly upping the charge to 25 grains resulted in a slight decrease in velocity. Also the brass comes out of the gun squeeky clean, no fouling in the action, and the bore stays clean forever. These are fired cases believe it or not.
Recently I did some ballistics testing by shooting these into some water jugs and I found that these may be a bit fragile for that velocity so I decided to back down this down to about 1850-1900 fps for deer hunting. I loaded 5 up at 22 grains still in the second cannelure and shot them through the chrono. The result was just over 1900 fps but the load had very large extreme spreads of about 100 fps. The brass was also pretty dirty, notice the rim on the bottom filled with soot.
I decided to try another couple loaded down to 20 grains. The first one was so filthy I didn't even bother to shoot the rest. Velocity was only 1680 fps! Then it dawned on me that mabey I was seeing the same symptoms of having too much airspace in the case as I did with 357 herrett. So I went in the shed and seated the other round I had already loaded with the same 20 grains deeper into the second cannelure. The one with the bullet seated deeper was 1820 fps and the brass was almost clean, just from a change of seating depth! I went back in the bench and did some measure of the length of the bullet seated in the case verses the case fill at different charge weights and found something interesting. With the bullet seated out in the 2nd cannelure you can get about 23.5 grains in the case before the powder would be touching the bullet. With the bullet seated deeper in the top cannelure you can get about 21 grains in without compressing. So even with the bullet seated long and 20 grains of powder that still would have been an 85% load density. So with almost certainty the flash hole would not have been covered. From looking at the primers they both look like alot lower pressure than the 24 grain load which I'm sure is why its blowing back past the brass.
Next I tried loading 21 grains seated deep and that gave me just over 1900 fps and good extreme spreads. The brass is not quite as clean as the hot 24 grain load due to the lower pressure. Now note that this is a full 230 fps faster than the 20 grain load, with the only changes being the seating depth and 1 grain of powder.
So what did I take away from this? We know that seating depth changes pressures due to reducing the volume in the case that the powder has to expand into and we also know that some powders need high pressure in order to burn cleanly. But notice that the 22 grain load seated out, and 21 grain load seated deep both had about the same velocity, and the pressure signs on the primers looked about the same, however the 22 grain load had large velocity spreads and did not seal the brass. I think the difference is the airspace. The 22 grain load would have had 1.5 grains worth of airspace, and the 21 grain loaded seated deeper had none. My 24 grain max load was just slightly compressed. Now in 357 magnum which is a significantly shorter case I have always gotten best accuracy and extreme spread close to a max load, which coincidentally is also near 100% loading density. So in both 357 magnum and 357 maximum the best results seam to be found at 100% loading density even with two dramatically different case capacities. My take away on this is reinforcing my believe the amount of airspace in the case affects how the powder burns. This gives me a bit more to think about and I look forward to experimenting with air space with other ball powders as well. To the contrary in rifles I have often found with extruded powder a slightly faster powder that loads to about 90% density often gives best accuracy compared to powders that require full or compressed loads.
I have been experimenting heavily with winchester 296 powder (same thing as H110) in several different cartridges. I've messed with it in a lot in 357 magnum, some 44 magnum awhile ago, 30 Herrett, 357 Herrett, and most recently 357 magnum.
Some of the things I've found out about it are that a magnum primer makes a world of difference to how it works. I tested velocities and deviations with and without magnum primers in 357 magnum and 357 herrett and observed as much as a 200 fps change in velocity with different primers. I've also observed that extreme spreads generally go down and accuracy improves the closer you get to a max load. Velocities do change with temperature but not that bad in my observations.
When testing this in 357 herrett (which is a shortened and blown out 30-30) I noted that extreme spreads were very high and it was just generally inconsistent in that cartridge. I believe this was the case because even with a max load the powder only filled the case about 1/2 full. My theory was that depending on how the gun was handled the flash hole may be uncovered when the gun fires which led to inconsistent ignition.
Today playing with it in my 357 maximum I saw some unexpected findings. I have a contender pistol with a 13" 357 maximum barrel which when I had it made I specified that I wanted it to be cut with a .250" throat in order to be able to seat bullets farther out particularly the Hornady 180gr XTP. The 180 XTP has two cannelures so this gives me the option of using either cannelure, or when using other bullets I can just seat them long and not use the cannelure at all to gain some extra powder space.
After testing a bunch of powders my favorite load for this is a federal small rifle mag primer, 24 grains of Win 296, and a 180 xtp seated long in the second cannelure. This gives about 2030 fps and excellent accuracy. Interestingly upping the charge to 25 grains resulted in a slight decrease in velocity. Also the brass comes out of the gun squeeky clean, no fouling in the action, and the bore stays clean forever. These are fired cases believe it or not.
Recently I did some ballistics testing by shooting these into some water jugs and I found that these may be a bit fragile for that velocity so I decided to back down this down to about 1850-1900 fps for deer hunting. I loaded 5 up at 22 grains still in the second cannelure and shot them through the chrono. The result was just over 1900 fps but the load had very large extreme spreads of about 100 fps. The brass was also pretty dirty, notice the rim on the bottom filled with soot.
I decided to try another couple loaded down to 20 grains. The first one was so filthy I didn't even bother to shoot the rest. Velocity was only 1680 fps! Then it dawned on me that mabey I was seeing the same symptoms of having too much airspace in the case as I did with 357 herrett. So I went in the shed and seated the other round I had already loaded with the same 20 grains deeper into the second cannelure. The one with the bullet seated deeper was 1820 fps and the brass was almost clean, just from a change of seating depth! I went back in the bench and did some measure of the length of the bullet seated in the case verses the case fill at different charge weights and found something interesting. With the bullet seated out in the 2nd cannelure you can get about 23.5 grains in the case before the powder would be touching the bullet. With the bullet seated deeper in the top cannelure you can get about 21 grains in without compressing. So even with the bullet seated long and 20 grains of powder that still would have been an 85% load density. So with almost certainty the flash hole would not have been covered. From looking at the primers they both look like alot lower pressure than the 24 grain load which I'm sure is why its blowing back past the brass.
Next I tried loading 21 grains seated deep and that gave me just over 1900 fps and good extreme spreads. The brass is not quite as clean as the hot 24 grain load due to the lower pressure. Now note that this is a full 230 fps faster than the 20 grain load, with the only changes being the seating depth and 1 grain of powder.
So what did I take away from this? We know that seating depth changes pressures due to reducing the volume in the case that the powder has to expand into and we also know that some powders need high pressure in order to burn cleanly. But notice that the 22 grain load seated out, and 21 grain load seated deep both had about the same velocity, and the pressure signs on the primers looked about the same, however the 22 grain load had large velocity spreads and did not seal the brass. I think the difference is the airspace. The 22 grain load would have had 1.5 grains worth of airspace, and the 21 grain loaded seated deeper had none. My 24 grain max load was just slightly compressed. Now in 357 magnum which is a significantly shorter case I have always gotten best accuracy and extreme spread close to a max load, which coincidentally is also near 100% loading density. So in both 357 magnum and 357 maximum the best results seam to be found at 100% loading density even with two dramatically different case capacities. My take away on this is reinforcing my believe the amount of airspace in the case affects how the powder burns. This gives me a bit more to think about and I look forward to experimenting with air space with other ball powders as well. To the contrary in rifles I have often found with extruded powder a slightly faster powder that loads to about 90% density often gives best accuracy compared to powders that require full or compressed loads.
