Powder for 9mm carbine loads

Your carbine like most every 9mm carbine is a blow back action. The bolt and spring weights are based on standard 9mm loads and powder ranges. Why do I state this you might ask?

Using too slow of a powder can have the bolt opening BEFORE the pressure has dropped enough and can cause case bulging or case failure. I have seen this with +P loads and with slower powders like Blue Dot and AA#7. You can find pictures on the net if you search for them. I'm not saying it WILL happen in your gun but it is a very real possibility.
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THIS!

We are already seeing several people have problems due to their ignorance of the 9mm blowbacks and balancing the system and load. Case ruptures, case head separations, gun damage, etc. Some manufacturers 9mm carbines are generally sprung heavy, some very light.
 
So the carbines (or some at least) have ammo limitations more so than typical 9mm handguns?

Hopefully these lower limits are clearly stamped into the gun itself.

Alternatively,
gun makers could engineer the carbine to function with SAAMI spec ammo including +P, and handloads at least to standard pressure specs.
 
I have used HS-6 and like it a lot, enough so that it's already one of my standard loads and I have a fair amount loaded up now. Once you hit the sweet spot with HS-6 it's a very nice powder with great accuracy. Lately in my pistols though I've mostly been using Clays, super accurate, very economical, and nice soft recoil. The HS-6 has a much snappier recoil making rapid fire a little less accurate for me. I can put 50 rounds rapid fire at 7 yards into a 2 1/2" hole all day long with my P07 using the Clays handloads. Love it.
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Since you already have some, if it were me it would be the first powder I would try. I like HS-6 because I load for .40 S&W (for me) and 9mm (for my wife) and it works great in Both. In reference to another post about it being dirty, it is one of those powders that cleans up at near max. And it isn't as snappy as CFE Pistol which I also use.
 
Jim Watson:"Power Pistol is good, I wonder if it has the same manly flash and bang in a carbine as a pistol."

I think that will depend on the barrel length. In the 9mm Hi Point carbine length, I cannot see it flash much.

Jim Watson: "I would say the optimum powder would be the one that a case full was the maximum pressure load."

I would add that the best powder for me is one that will function the action across the entire (Lyman) load range, and has a density characteristic that you cannot get enough in the case to overpressure no matter the case brand. Havent found one like that for 9mm but in 223, IMR 4895 fits the bill nicely.

MarkCO: "Some manufacturers 9mm carbines are generally sprung heavy, some very light."

Can you suggest an example of one that is sprung very light ? I am curious about that.

random guy: "Alternatively, gun makers could engineer the carbine to function with SAAMI spec ammo including +P, and handloads at least to standard pressure specs."

I suspect they do that now.

The following loads have been tested a bit, carbines used were Hi Point (995 TS) 9mm, Uzi 9mm, Lage 11 9mm, the latter being the shortest barrel at 8.5 inches. Primers were CCI 500. OAL for all loads was set to 1.145 inch. While bullet weights are different, note that the 115 grain Win are hollow base, thus the higher seating allowed to match the 124 grain seating. (These are standard pressure, not +P)

1. 115 gr. Win FMJ RN-HB over 5.5 gr. Ramshot Silhouette
2. 124 gr. Montana Gold FMJ RN over 5.5 gr. Ramshot Silhouette

3. 115 gr. Win FMJ RN-HB over 6.3 gr. Alliant Power Pistol
4. 124 gr. Montana Gold FMJ RN over 6.3 gr. Alliant Power Pistol

A functional comparison was made using a 1911 style 9mm (Rock Island) and a Glock 19. None of the firearms failed to cycle except for the Hi Point, which had two failure to feeds which were determined to be magazine related. 50 rounds per firearm. (The 50 round test was repeated for the Hi Point using different magazines)
 
Thanks all, good info. One thing I do, I use a brass catcher so I can easily inspect all my brass for pressure signs as I work up any loads. The idea of using too slow of a powder and having issues due to it being a blowback carbine is something I hadn't considered, although I don't plan on using anything slower than Power Pistol and do work up my loads carefully so it most likely wouldn't be a problem for me. But, still something nice to know and watch out for.
 
My personal thoughts would be hs6. It is almost certainly the densest, slowest burning powder that can be used in a nine, producing higher velocities than most other powders, and it will be very efficient in your load. You should not go above any +p loads. Your system isn't gas operated and isn't any stronger than a typical heavy handgun, imo.
 
random guy: "Alternatively, gun makers could engineer the carbine to function with SAAMI spec ammo including +P, and handloads at least to standard pressure specs."

I suspect they do that now.
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Makes sense but reportedly owners are blowing out caseheads somehow, in some carbines.

Maybe we can get some specifics on these events.
 
If the thing is a blowback, that's not a reason for the case failures, just to be clear. Many firearms operate as blowback designs that carry full power loads.

A blowback system requires a few things. First, it has to have a heavy weight breech block that holds its place against the pressure for a brief moment, holding in place until the pressure spike is over. It has to have a heavy spring, to add further resistance. The spring must also work to absorb all of that rearward movement possible, so that the bolt doesn't hammer against the receiver.

Blowback systems that don't work on occasional guns are going to generally be because of ammo or spring, if all other things are equal. Using ammo with slow burning powder or some similar issue can delay the pressure spike until the bolt is already moving. A bolt without enough mass or a spring thAt is sloppy can cause the bolt to slide backward during the pressure spike.

If a blowback system has a reasonably well supported chamber and it routinely blows out case heads, the probable, and almost certain answer is that the bolt is retracting early, while the pressure in he case is still high enough to tear the brass.
 
I have been using 5.9 gr of HS-6 with a 124gr HiTec coated bullet for over a year with good results in both my pistols and the carbine. I've also used the same charge with Extreme copper coated as well. I've shot well over 500 rounds of each of these loads with no problems. I'm going to have som time off coming up and will report back how well the PowerPistol works.
 
Power pistol should work well, I've used it before, but switched to another. I've still got five pounds. Loading a few grains at a time takes a very long time to empty a can.
 
random guy: "Maybe we can get some specifics on these events."

That would be very useful if you find some.

briandg: "Many firearms operate as blowback designs that carry full power loads."

This. All of the carbines I used for load development testing are +P rated.

briandg:"The spring must also work to absorb all of that rearward movement possible, so that the bolt doesn't hammer against the receiver."

The carbines I use for testing have a recoil buffer to prevent this. As a side note, what happens during recoil can be modeled with cycle rate calculations. Just because it is a semi-auto does not mean cycle rate does not apply. The primary determining factor for cycle rate is counter intuitive a bit. Making changes to the spring constants do not have as much of an effect as you would think. Making small changes to the bolt mass is where the drastic changes occur. Let me example what I am trying to communicate.

briandg: "If a blowback system has a reasonably well supported chamber and it routinely blows out case heads, the probable, and almost certain answer is that the bolt is retracting early, while the pressure in the case is still high enough to tear the brass."

I am inclined to agree as long as the case is not seeing overpressure, like unto a triple charge of bullseye. Re-stating for a standard pressure, I think your description is good but I would be inclined to correct that problem by increasing the bolt weight until the case bulge goes away. No ammo or spring change necessary.

jetinteriorguy: "One thing I do, I use a brass catcher so I can easily inspect all my brass for pressure signs as I work up any loads."

Danger will robinson ! You are exhibiting the early signs of becoming as anal as I have about load testing. Pressure signs in pistol calibers requires a tea leaf reading talent. I create and label and organize such testing in multiples. I generally test 3 to 5 firearms at a time, same caliber test loads, laid out vertically, and study them under a good, bright lamp. That's when they begin to talk to you like a rifle case can. You also need a reliable bench mark load fired in each weapon as well. Example, row one shows one case with a bright extractor mark. Row two adds two more with bright extractor marks.... to firing pin crater mark changes, pin- hole primer edge leaks(magnifying glass),and so on.
 
I once had a very normal load blow out at the case base. A middle range load of accurate two. The brass was bad, the metal was crystallized. The thing tore out and peeled counterclockwise, leaving a fingernail sized shred of brass hanging off.

The thing fit the chamber exactly. It honestly popped open down inside the actual heavy web, and tore upward.

It was the most freakish event I've ever seen.
 
Does a blowback 9mm tend to stretch brass more than a locked breech? If so, this could be an issue with repeated firings of the same brass or even on the first firing.

Aside from the variable of brass composition and condition, the main factors in safety would seem to be pressure to time after ignition and bolt movement to time after ignition. It would be great to see these functions plotted for any gun and load in question, looking for consistent and minimal exposure of unsupported brass to high pressure.

Obviously blowback can work even under considerable pressure but it lacks some of the regulating devices of locked breech designs and is more delicately balanced.
 
Thanks all. Good stuff, definitely things to consider. I always stay well within manufacturers published loads and only load for accuracy, not for the highest velocity. I have found over 30 some years of handloading the most accurate load are usually found in the middle range of published data. Probably the best thing I've gleaned from this is not to think of the carbine so much as a rifle, but more of an enhanced pistol. Just a means of extending a pistol rounds usability out to a longer range, in my mind basically about a 50 yd limit is good. I'm heading to the range tomorrow with my PowerPistol loads and will report the results.
 
for briandg, I trust that neither the shooter nor the gun was adversly impacted by that blow out ?

random guy: "Does a blowback 9mm tend to stretch brass more than a locked breech?"

My experience has been that both action types actually shorten the brass. Resizing the brass streaches it out a slight bit. My longest experiment in the area was 17 reloads of selected brass. Over that experiment, the long term effect of the fire-shorten, resize-streach, was that over the 17 reloads, there was a cumulative shortening, meaning the test cases ended up slightly shorter than when they were new. I had discarded around 50 percent for various reasons by the time reload 17 was fired. While I could have carefully prepared the remainder for another reload, the work necessary to do so was becoming exponential. Case rim dings had become gross, the case head-stamps had become unreadable, and the prior reload (#16) had resulted in a significant number of case discards due to neck splits. While I had expected to wear out the primer holes, I do not recall discarding a case due to that. Early discards after just a few reloads were due to insufficient case-neck tension, and were from the same brand. These types of efforts are fun but you need to take good notes and a few photos cause memory just won't do it.

For jetinteriorguy, my experience with 9mm carbines leads me to recommend that you avoid lead and even plated bullets if you shoot a lot. FMJ only unless you like spending more time cleaning and less time shooting. Also I would say that 100 yds is really pushing the 9mm in a carbine. Also if you like power pistol, don't neglect the silhouette loads. They are opposites. Power pistol is the flashy, silhouette does not flash (well it does in the IR range but not visible.)
 
Over that experiment, the long term effect of the fire-shorten, resize-streach, was that over the 17 reloads, there was a cumulative shortening, meaning the test cases ended up slightly shorter than when they were new.
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Got to admit, I didn't see that coming. I'd call that very good case life. Your 124 gr loads in particular are plenty healthy and use powders which are toward the slow end of optimum (best for performance). The fact that you had no case head separations or blowouts says a lot. Your blowback systems are obviously working quite well.

Brass is moving around to some degree but probably not the way I imagined. It would be interesting to section a case after such an endurance test as yours and compare to new. Might be nothing noticeable at all though.

The few carbine blowups I've found are often with factory ammo which varies in quality and ballistics. The blowups are probably most likely a product of poor firearm design and/or marginal ammo. Guns will have varying degrees of chamber support, chamber pressures vary greatly as does brass itself. Bolt and spring weight will surely vary.

My original thought on this subject was to take the Mythbusters ultimate approach of making the failure happen (theoretically at least). What factor would most easily do this? I'd guess that powder burn rate would be well down this list, at least among those powders which are appropriate to the cartridge to begin with.
 
High rolls, there was no injury, no damage. I looked at that thing and thought about it for days, sectioned cases, used a microscope, even, and can't understand why it happened like it did.

I wound up with soot all over my hand, and my hand tingled for hours. When you look at case blowout photos, nothing even remotely looks like mine. The drip started at the very heaviest part of the case and peeled upwards to fold over the exposed chamber ramp.

I sometimes wonder if that case head would have separated in a more fully supported chamber.
 
The shortening brass always sounds ridiculous, but it's pretty well documented to be correct by various "researchers".

With any weapon that rests on the case mouth, pressure will push it back to the breech booth before the case walls can stick to the chamber walls. Any stretch from friction would be minimal. It would require a very rough chamber to draw the brass out.

This comment doesn't apply to bottle necked shoulder seating cartridges, the interior ballistics aren't even remotely similar.

In the reloading process, we resize, and that compresses the brass and will literally reform it on the molecular level, over many cycles, it will have forced the entire brass tube inwards and downwards, and with resizing, it probably does some really strange stuff as the expanding gasses try to push the inner surface forward, expands the tube outwards, and then the outer surface is crushed inward and downward.,
 
When the round is fired the case expands outwards against the chamber. This stretches the brass diametrically. When you size the brass the length is not constrained so the stretched brass is squeezed toward the case mouth which is the easiest flow path for the brass.

In the last 45 years of reloading I have never had cases shorten regardless of their shape. I run all my cases through the trimmer with each reload and there are always some that trim, even if it is just a scrape on the case mouth.
 
Finally got to the range with my PP loads. Whoa, even at the lowest level of 5gr I had primer flow, tried 5.2 and saw a substantial increase so I shut it down. Now I'm not 100% sure it's due to over pressure since this is the first time I've ever use S&B small pistol primers and wasn't sure if maybe they tend to run on the soft side, but the recoil seemed substantial enough to just shut it down. At least accuracy was good at 5gr. I think I'll try the same range from 5.00 to 5.9 with CCI small pistol primers and see what happens. I'm also going to reduce my start load by .5 gr and try the S&B primers up to the 5gr mark, and will start the CCI primers at the 4.5gr mark as well. I did shoot several of my standard 5.9gr loads of HS-6 with very good results. As for shooting HiTec or Copper coated bullets, I've put thousands of them through all my pistols and the carbine with no noticeable ill effects. I do clean my guns every few hundred rounds, but that's just something you should do anyway IMHO. I don't believe in cleaning them after every shooting session but don't like to neglect them either. Guess I just believe in taking proper care of my equipment.
 
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