9mm compressed loads will it work?

[6bg6ga]

I recently purchased a 9mm S&W 669 and now I have to reload for it and I don't have the experience with this round. Anyway use what you have,right? I have Unique powder and some 160gr RN from a Magma mold. I loaded up some 160's sized to .357 which is what I use in any 9mm. The bullet measures .746 for length and the OAL is 1.147 which leaves .401 This results in a compressed load with 3.1 gr of Unique powder.

Thoughts on the safety of this load. No, I'm not going to purchase another mold so please don't go there.

Attachment 115133Attachment 115134

[6bg6ga]

The internal volume of several 9mm cases seems to be .573 so the powder is compresses by .059

[dubber123]

I'd have to do some measuring, but I think you are fine. I have been shooting 155 gr. with 3.5 grs. of Green Dot, a faster powder. Again, I would have to do a little more looking, but I don't hear any alarm bells.

[6bg6ga]

At the risk of sounding stupid I will go ahead and ask this question. Does compressing the powder change the burn rate?

[6bg6ga]

I come up with following measurements internal volume .581

Powder takes up .284 leaving .289 left

Bullet is seated to .343 meaning the powder is compressed by .059

[Love Life]

Is 3.1 gr of powder a must? Is it the minimum load?

Why not just start lower and work up using standard load development procedures?

[6bg6ga]

Since I cannot find any data for a 160gr bullet I'm making a guess that 3.1 grains would be a nice starting point to allow the gun to function and feed.
Lymans 49th lists a 147 gr lead bullet with a starting point of 3.2 gr of Unique.

[BruceB]

Lyman #43 has data for Unique and a 160-grain cast bullet.

Starting load is 3.5 grains for 710 fps, and max is 4.5 grains for 990 fps.

[6bg6ga]

Lyman #43 has data for Unique and a 160-grain cast bullet.

Starting load is 3.5 grains for 710 fps, and max is 4.5 grains for 990 fps.

Thanks for the info.

[DrCaveman]

Im not 100% sure, but the only powder i know of that changes burn rate when compressed is Trail Boss

A little compression can be a good thing, since you know there is no air space and there should be great shot-to-shot consistency. This is assuming that your load is not over pressure, because the recipe is listed or the burn rate is suitable for application. I think it's pretty hard to get Unique to run over pressure in 9mm, it is a high pressure cartridge and very small to boot, and unique is fluffy

I run a VERY compressed load of sr4756 in my 9, and while it seems hotter than most loads, ive found it listed in books. Mostly older speer...

[6bg6ga]

Im not 100% sure, but the only powder i know of that changes burn rate when compressed is Trail Boss

A little compression can be a good thing, since you know there is no air space and there should be great shot-to-shot consistency. This is assuming that your load is not over pressure, because the recipe is listed or the burn rate is suitable for application. I think it's pretty hard to get Unique to run over pressure in 9mm, it is a high pressure cartridge and very small to boot, and unique is fluffy

I run a VERY compressed load of sr4756 in my 9, and while it seems hotter than most loads, ive found it listed in books. Mostly older speer...

Thanks for the info.

I was able to down load #44 Lymans off the web for free and it also lists a 160gr bullet and 3.5 gr of Unique. I know now that 3.1 is a safe load no signs of flattening of the primer and no case stress. Just not used to compressing powder.

[sixshot]

The 9mm is a small capacity, high pressure case & switching brass can give or take big pressure swings.

Dick

[9.3X62AL]

I've had good service from 9mm loads with compressed charges of Unique and Blue Dot.

Even the "conventional weight" 120-125 grain bullets get seated somewhat deeply in the diminutive 9mm case. I know you said "Don't go there", but my long years of enjoyment of the 9mm cartridge have borne out for me that the 120-125 grain bullet weight might be its single-best bullet. The cost of a Lee 2-cavity 125 grain truncated cone bullet mould is so reasonable that it seems you are cheating yourself out of performance limiting the 9mm to those over-weight castings. The Lee 125 TC can REALLY shoot, too.

[6bg6ga]

I have a Magma 125gr RN bullet so I don't want to purchase any hand molds. I like the over weight 160's

[tazman]

I have a Magma 125gr RN bullet so I don't want to purchase any hand molds. I like the over weight 160's

I have a lot of molds for the 9mm. 2 are in the larger category. 1 is a Lyman that drops at 145 grains. The other is a Lee that drops at 156 grains. Both shoot extremely well in my 9mm. The Lee mold was specifically designed for the 9mm/38super and loads at full 9mm oal specs..

[6bg6ga]

I'm sure there are a lot of good hand held molds out there but unfortunately I'm setup with a Mark IV so the molds must be either Magma or Ballisti-Cast. My bullets for the 9mm are either going to have to be the 125rn or the 160rn 38/357 molds I have.

[tazman]

I wasn't suggesting that you buy another mold. My point was that I have had good performance from larger than normal boolits and I think your project is worth persuing.
I can't suggest load data because I haven't seen a container of Unique in over a year.

[casterofboolits]

My normal 9mm load is the H&G #275 over a medium load of Blue dot. Since I'm low on BlueDot right now I decided to try Accurate #7 and ended up with a compressed load that actually deformed the nose of the SWC. This caused me to switch to a smaller charge of Accurate #5 which cured the problem. The #7 will be regulated to the 38 Super.

I have also intensified my search For BlueDot!

The Magma 160 grain RN loaded over BlueDot was my first successful major IPSC load in an unsupported Colt barrel that showed no pressure signs at all.

I prefer the 125 to 135 grain boolits for 9mm.

[6bg6ga]

I wasn't suggesting that you buy another mold. My point was that I have had good performance from larger than normal boolits and I think your project is worth persuing.
I can't suggest load data because I haven't seen a container of Unique in over a year.

I realize that you were supplying me good information and I do appreciate that. Right now I have purchased several new guns and I don't have any extra spending money for a while. I'm sitting on 1.5 lbs of Unique and have been told its an excellent 9mm powder and that only leaves me with Red Dot and Bullseye for the 9mm with my 231 reserved for the 45acp.

[tazman]

I can't get any of those powders around here yet. I would have to rely on posted data and an educated guess.
I would agree that unique would work better with the heavy boolit than your other options.