*Minimum* pressure?

[gnbrotz]

I know my reloading manuals offer suggestions for a starting load, and a max load, but what pressure/velocity on the low side should I be aware of? I want to load some lighter loads (reduced recoil) for my son to shoot, but I don't want to go so light that an auto-loader won't cycle, and I certainly don't want to have to deal with a bullet lodged in the barrel!

For this application, I'm working with 9mm, and have both plated/jacketed bullets as well as unjacketed soft lead cast bullets.

[Guns N'at]

I know my reloading manuals offer suggestions for a starting load, and a max load, but what pressure/velocity on the low side should I be aware of? I want to load some lighter loads (reduced recoil) for my son to shoot, but I don't want to go so light that an auto-loader won't cycle, and I certainly don't want to have to deal with a bullet lodged in the barrel!

For this application, I'm working with 9mm, and have both plated/jacketed bullets as well as unjacketed soft lead cast bullets.

What weight cast bullets are you wanting to use, and what propellants do you have and want to use? Personally, I never try to go much below service type velocities with jacketed, only using cast for lighter intensity loadings.

Playing with recoil spring rates can help with lower recoiling functioning, even then, I really don't like to go much less than 975-1000 fps avg with 125 grain cast in 9mm, but it can be done. For ultra low recoil, I have started to size my 100 grain .367" "Makarov" bullets down for use in my 9mm's, but have not worked up any minimum data as of yet. Curious to hear what you are working with.

[knight0334]

Just watch out with some powders. Too low of a charge can cause the same reaction as an overcharge - kaboom.. It's called "chamber ringing". If there is too much air space, or too little of a charge - the powder will flash burn and expand at a higher velocity causing the gun to KB.

Be sure to research your powders for light loads before applying them. Blackpowder is notorious for charges with airspace, but there are also smokeless powders that will do the same.

[Guns N'at]

Just watch out with some powders. Too low of a charge can cause the same reaction as an overcharge - kaboom.. It's called "chamber ringing". If there is too much air space, or too little of a charge - the powder will flash burn and expand at a higher velocity causing the gun to KB.

Be sure to research your powders for light loads before applying them. Blackpowder is notorious for charges with airspace, but there are also smokeless powders that will do the same.

Can you supply some potential combinations for 9mm that you think would cause "ringing"?

Ringing is definitely a possibility when using a filler that does not allow its proper flow from the case on firing, i.e. hardened farina used in reduced rifle loads... Acts like a plug that "rings" the barrel. I can't think of any big name current published 9mm data using any propellant listed that would do more than squib at very light charges. Ringing and detonation which you seem to be referring to are not the same, with detonation referring to as I'm sure you know the charge not performing as intended at low charge weights, and basically acting as an explosive, not propellant.

Can't say I believe either phenomena would happen in 9mm with any reasonable propellant selection. Could velocity spreads be terrible with really light charges in a range from Bullseye-Power Pistol, yep. Chance of sticking a bullet, yep. Ring a chamber/'blow up", with super light charges in the above named range and a "normal" OAL for a given bullet; not IMO and experience.

[knight0334]

BlueDot will do it. If you undercharge with BlueDot you will ring the chamber. I know this from first hand experience. It will happen with other powders too if there is too much airspace and/or not enough charge to create a uniform expansion of gases - which is one reason why powder manufacturers have a minimum load, not just because of the squib factor. The crimp of the bullet and/or the swaging of the bullet to the bore is enough to keep the expansion contained, thus will ring the chamber.

This happens not just with handguns, but also with long gun cartridges. It is not solely a factor when fillers are used, but also when there is too much space in the cartridge and not enough powder.

http://www.recguns.com/Sources/VIIE4.html

[Guns N'at]

BlueDot will do it. If you undercharge with BlueDot you will ring the chamber. I know this from first hand experience. It will happen with other powders too if there is too much airspace and/or not enough charge to create a uniform expansion of gases - which is one reason why powder manufacturers have a minimum load, not just because of the squib factor. The crimp of the bullet and/or the swaging of the bullet to the bore is enough to keep the expansion contained, thus will ring the chamber.

This happens not just with handguns, but also with long gun cartridges. It is not solely a factor when fillers are used, but also when there is too much space in the cartridge and not enough powder.

http://www.recguns.com/Sources/VIIE4.html

Blue dot in 9mm will "ring" the chamber? I know, and have read a lot concerning strange phenomena in other applications, most notably very "slow" ball propellants used in micro charges in moderate to large capacity rifles. This very question was why I wrote Hercules back in 1984, asking about the phenomena of "detonation". This post shows that letter:

http://forum.pafoa.org/1475265-post-27.html

I did use poly filler with some loads, but even my 5 grain Bullseye/150 grain 06 cast loads worked just fine without it. Although on the 'quick' end, I'll drive 125 grain cast bullets from my 9mm's using 9/10's grain of Bullseye to examine the rifling pattern, and this is just above squib in my guns. Bullets are caught undamaged in a wad of flannel rags.

[knight0334]

Blue dot in 9mm will "ring" the chamber? I know, and have read a lot concerning strange phenomena in other applications, most notably very "slow" ball propellants used in micro charges in moderate to large capacity rifles. This very question was why I wrote Hercules back in 1984, asking about the phenomena of "detonation". This post shows that letter:

http://forum.pafoa.org/1475265-post-27.html

I did use poly filler with some loads, but even my 5 grain Bullseye/150 grain 06 cast loads worked just fine without it. Although on the 'quick' end, I'll drive 125 grain cast bullets from my 9mm's using 9/10's grain of Bullseye to examine the rifling pattern, and this is just above squib in my guns. Bullets are caught undamaged in a wad of flannel rags.

I ruined a S&W 459 with an undercharge of BlueDot. I also screwed up a NEF .357 Handi experimenting with low charges. ...I knew the risks, but I was testing out loads from the ground up. I fully expected to frag the Handi rifle in the testing, the S&W 459 was a worthless POS to begin with - so I tested 9mm loads in it hoping to mess that gun up. (my form of revenge on an item - I dont trade things away, I destroy them the rest of the way)

[Guns N'at]

Interesting experience with low weight BD charges in 9mm. I have used BD in 9mm on the other end, but even then I don't like it. I remember when Alliant issued a fairly stern warning about it because of pressure issues retested from their own data. This is from the "Firearms forum"

http://www.thefirearmsforum.com/atta...1&d=1217100233

I have tried it in other pistol cals, and never liked how it performed. I have however found it to work well in 'magnum' type 12 gauge shotshell loads.

[knight0334]

My Colt Python 357 liked BD in the mid-range to max loads. ..even with 125gr bullets that they now warn about. At low weight loads, I got some weird deviations in velocity with 125gr and 158gr bullets. ...which is why I tested them out on a cheap "Handi" rifle.

I've heard and read about other powders doing the same in various cartridges. I'm more leery of under charges in light and medium frame guns than I am heavy charges in heavy framed guns. I'm sure there are powders out there that aren't as sensitive to light loads or air space, but the thought should be in someone's mind when seeking light loads.

[shooter357]

I know my reloading manuals offer suggestions for a starting load, and a max load, but what pressure/velocity on the low side should I be aware of? I want to load some lighter loads (reduced recoil) for my son to shoot, but I don't want to go so light that an auto-loader won't cycle, and I certainly don't want to have to deal with a bullet lodged in the barrel!

For this application, I'm working with 9mm, and have both plated/jacketed bullets as well as unjacketed soft lead cast bullets.

I use 700x with my cast lead bullets. I have noticed that there is a lower recoil with it.