I worry bout medium burners like 4895 and 4198 layning in that culvert of a case and detonating (flash over). Id rather have the small amount of paper base detonate as its meant to
Loading the 577
- Thread starter morgangrinder
- Start date
I worry bout medium burners like 4895 and 4198 layning in that culvert of a case and detonating (flash over). Id rather have the small amount of paper base detonate as its meant to
The problem in using smokeless in the 577 Snider is threefold:
- the bore diameter is large;
- the cartridge volume is large; and
- the action strength is low - I like to treat it like a shotgun action and keep pressures, i.e. 12K psi
The slower the smokeless powder, the higher the pressure at which it will reliably ignite. Fast Pistol powders can be reliable at as low as 5K psi, while the fastest of rifle powders, e.g. H4895 don't work well at much under 20 K psi. I've found H4198 to be about the slowest powder that can work in the Snider, but I found H4227 to be less reliable even though it's usually quite a bit faster than H4198 in many powder burn rate tables. So yea, HS-6, which is typically showing up as even faster might (probably would) work well, but I haven't tried it.
My biggest concern is that almost all reloaders asking for load data for the Snider don't have a chrony and have no intention of buying one. I'm not about to recommend a load I haven't tried myself in the Snider, because I always work up over a chrony as it's my best measure of pressure.
As for 1100 fps, that was the MV where I thought that the pressure was around 12K psi with Unique, so if you use powders like Unique or faster, you will not see MV's faster than 1100 fps unless you operate at higher pressures.
- the bore diameter is large;
- the cartridge volume is large; and
- the action strength is low - I like to treat it like a shotgun action and keep pressures, i.e. 12K psi
The slower the smokeless powder, the higher the pressure at which it will reliably ignite. Fast Pistol powders can be reliable at as low as 5K psi, while the fastest of rifle powders, e.g. H4895 don't work well at much under 20 K psi. I've found H4198 to be about the slowest powder that can work in the Snider, but I found H4227 to be less reliable even though it's usually quite a bit faster than H4198 in many powder burn rate tables. So yea, HS-6, which is typically showing up as even faster might (probably would) work well, but I haven't tried it.
My biggest concern is that almost all reloaders asking for load data for the Snider don't have a chrony and have no intention of buying one. I'm not about to recommend a load I haven't tried myself in the Snider, because I always work up over a chrony as it's my best measure of pressure.
As for 1100 fps, that was the MV where I thought that the pressure was around 12K psi with Unique, so if you use powders like Unique or faster, you will not see MV's faster than 1100 fps unless you operate at higher pressures.
- Location
- Iroquois Falls ON
I have been having better results this season with my Sniders.
Any load development should be done with a chrony for sure. In my work up I started with a low charge and worked up until I had full case obturation and stopped at that point. My theory is that a charge that just barely obturates the thin Magtec brass should not hurt the gun. Interestingly that happens at 1000 or so FPS with both Unique and Universal. I didn't use that process with 5744 because I got the data from the powder manufacturer. I did drop their recommendation by 10% though.
I use no filler of any kind with the three above mentioned powders and I do not crimp. One of the things that I learned is the pistol primers (recommended for Magtec brass) do not work well when that big Snider hammer falls. I have not had one delayed fire since I switched to rifle primers and accuracy has improved greatly. I also found that neck sizing only is the way to go.
Last season with my #3 (the one that gave me the poorest results) My best 5 shot group at 50 yards was about 6" but I could not do that consistently. This season on my last shoot I got four 10 shot groups in a row all under 4".
Any load development should be done with a chrony for sure. In my work up I started with a low charge and worked up until I had full case obturation and stopped at that point. My theory is that a charge that just barely obturates the thin Magtec brass should not hurt the gun. Interestingly that happens at 1000 or so FPS with both Unique and Universal. I didn't use that process with 5744 because I got the data from the powder manufacturer. I did drop their recommendation by 10% though.
I use no filler of any kind with the three above mentioned powders and I do not crimp. One of the things that I learned is the pistol primers (recommended for Magtec brass) do not work well when that big Snider hammer falls. I have not had one delayed fire since I switched to rifle primers and accuracy has improved greatly. I also found that neck sizing only is the way to go.
Last season with my #3 (the one that gave me the poorest results) My best 5 shot group at 50 yards was about 6" but I could not do that consistently. This season on my last shoot I got four 10 shot groups in a row all under 4".
Rather than use smokeless, I have loaded and shot .577 snider with Pyrodex RS without any apparent problems. I ran some different powders thru my internal ballistics program and I didn't feel encouraged to experiment with smokeless. I will stick with the smoke and flames for that rifle.
303EppsFan
CGN Regular
- Location
- Almonte,Ontario
Indeed they are. However I my case I had no LP primers on hand and so used LR. My gun works fine with them. I use Pyrodex and a .600 cal. round ball.
