Powder Burn Rate for 9mm

[Mountain]

I would like to better understand the effect of powder burn rate on cast bullet performance in pistols such as the 9mm.

I have limited experience reloading the 9 as I produced ~3k rounds this summer using 125gr LRN bullets and 4.5gr Red Dot powder. This load chrono’d at 1130 fps and produces some lead streaks in my barrels grooves after 100-200 rounds fired. The lead cleans up fine by using a bronze brush so its not excessive.

Talking with members of my club and reading threads on this forum I see many shooters prefer to use a slower powder than Red Dot for this load. I used this powder because I primarilly use it for 12 ga. And have the remnants of an 8 lb. keg to work with.

So my question is: If I were to try a slower powder such as Unique what differences might I observe? Does anyone have any experience that they could share?

[Lloyd Smale]

dont know but i use a bunch of bullseye in the 9s and dont have leading problem. My guess is your sizing to small. try sizing your bullets to .358 and if they wont function try .357 but i wouldnt go any smaller.

[Rod B]

I have had very good results with 4.5 to 5 grains of Unique using a 124gr lead bullet.

Rod.

[Mountain]

My guess is your sizing to small.

Good Guess!

I slugged my bore 0.3562 and the bullets I used were 0.3560

I plan to test some 0.358 then based on results select a mold to begin casting my own.

[madcatter]

i think a slower powder may not give optium results if chronographed with a barrel shorter than 4.5inches.the slower burn rate will create more gas for the projectile but with a cast bullet i dont think it will gain all the charge has to give.
i have shot 4 grains in a 9mm years ago and after 200 i stopped.not only did the barrel lead the entire gun was filthy needing a pretty good teardown to clean.i just got tired of the dirt and shot brass

[Phil]

Best powder I have found for cast bullets in the 9mm Para is far and away SR4756. No leading at all and great accuracy.

Cheers,

Phil

[lefty_red]

I like RAMSHOT ZIP. 3grains give me PF and great groups.

With Reddot, I don't go over 2.7 grains.

Jerry

[9.3X62AL]

The 9mm is best treated like a "short rifle" rather than a handgun, owing to its (usually) fast-for-application twist rate and high working pressures. Slug or Cerrosafe-cast the THROAT as well as the groove diameter to set your sizing diameter. My 9mm's all have fat .356" throats, and boolits at .357" work well in terms of leading--the lack thereof, I should say. Again--like in rifles--I use fairly hard alloys (92/6/2) and soft lubes like Javelina with good success in my 9mm's.

I use a wide variety of powder speeds in 9mm. WW-231 is most often used, some Bullseye, and for high-end loads AA-7 gets the call. Most of my 9mm shooting involves 125 grainers at just enough OOMPH to cycle reliably, and the faster fuels like WW-231 and B'eye really come into their own in that application.

[dbotos]

I'm having similar issues with leading in 9mm. Currently loading 147-grain bullets (sized to 0.356") with 3.5-3.7 grains of Bullseye at an OAL of 1.150-1.160". Have slugged the muzzle, throat, and whole barrel and they all show 0.355". Going to start trying some slower powders this weekend. If that doesn't help, I may have to order a 0.357" sizing die and try that.

From what I've learned so far, these are some potential variables to play with in order to minimize/eliminate leading:

-bullet size (slugging can help determine this)
-lead hardness
-lube formulation / softness
-powder burn rate
-powder charge and resulting velocity
-crimp?

[9.3X62AL]

Dbotos--

You have a pretty good handle on the variables that can set up or cancel out leading, for sure. One of the best things I read on the subject of leading came from the late Walt Melander of NEI Handtools. His explanation appears on his company's website (now operated by his daughter Patty Melander).

www.neihandtools.com

I only give a slight taper crimp to calibers that headspace on the case mouth like the 9mm, 40 Short & Weak, and 45 ACP--just enough to take the flare out of the case wall.

[robertbank]

I shoot 124 gr lead in all my 9MM guns with no leading ever. Sizing to .357 or .358 if your bore calls for the latter will solve most of your problems.

Over my chrono 4 gr of Unique or 3.9 gr Win 231 give me the most consistent results. Loads make IPSC/IDPA power factors and are very accurate. Unique is my go to powder for the 9MM but I get excellent results with 231 as well. If you want accuracy in the 9MM and consistancy slower velocities seem to work best in my guns using lead bullets.

4.7 gr of Unique also provides very good accuarcy using lead but velocities were not quite as consistent.

Bullseye and Titegroup can also be usefull in the 9MM but Unique remains my favourite.

Take Care

Bob

[dbotos]

Dbotos--

You have a pretty good handle on the variables that can set up or cancel out leading, for sure. One of the best things I read on the subject of leading came from the late Walt Melander of NEI Handtools. His explanation appears on his company's website (now operated by his daughter Patty Melander).

www.neihandtools.com

I only give a slight taper crimp to calibers that headspace on the case mouth like the 9mm, 40 Short & Weak, and 45 ACP--just enough to take the flare out of the case wall.

Thanks. I loaded up some air-cooled ones tonight with a starting charge of IMR 800x. Keeping my fingers crossed that the slower powder will do the trick.

Found that paragraph on the NEI site:

Bullet lubricants are really not a 'lubricant' as you may think of a bearing lube. Leading is caused by the vaporization of lead by hot gasses, usually leaking past the side of the projectile and then being smeared on the side of the barrel by the projectile. The 'lube' only prevents the vaporized lead from tinning the steel barrel. The properties of the 'lube' therefore must be opposite that of a tinning flux. It also must help seal the projectile to the barrel either as a solid or a semi-solid under heat and pressure. There is a lot of 'stuff' out there and we're still looking. Let us know if you have an idea for some 'good stuff'.

My crimp is a light one, so I'm going to assume it's not a factor - for now.

[Mountain]

All good comments and interesting info...Thanks.

I'm trying to better understand the rate that pressure builds and its effect on performance when comparing different pistol powders.

I am going to try two changes: Larger diameter bullet and less powder by working up a few small lots and testing.

[robertbank]

Handbook of Cartridge Reloading by Hornady Vol 1 not only has various loads listed but comments as to which powders seem to work the best when they did the tests. You need not take what they say as absolute but here is what they had to say about the 9MM. From Page 635.

"Powders that worked exceptionally well in our test weapon were Hercules Unique, Winchester 231, and AA#2. AA#2 produced the highest veloicites of all powders tested with the 90, 100, 115, and 124 gr bullets while AA#7 and Blue Dot gave the highest velocities with the 147 grain bullet. Velocities differences between 4" and 5" barrels were negligible."

Take Care

Bob

[dbotos]

Slower powder did the trick! My barrel hasn't been this clean since I was shooting plated. :drinks: Here's the load I shot today:

Lyman 356637 - 147 grain flat nose bevel base - sized to 0.356
~14 BHN
4.4-4.8 grains 800x
1.150-1.160" OAL
Winchester small pistol primers
light crimp with Lee FCD
60/40 beeswax/criso lube with graphite
948-1010 fps

Think I might try a little less powder since I only need 850+ fps to make power factor. For now, I'm just happy not to have any leading. :mrgreen:

[robertbank]

Well done! With the right size of bullets the 9MM is pretty hard to lead up. From my experience I get better accuracy using 124 gr bullets but the term is relative.

Take Care

Bob

[9.3X62AL]

Good news, that! I share Robert's fondness for the 120-125 grain slugs in the 9mm, they've always shot well for me in this caliber, both jacketed and cast.

[NVcurmudgeon]

Anybody besides me have trouble getting 800X to meter well from a measure? Ken Waters' comprehensive series on the .45 ACP indicated that 800X was excellent in both velocity and accuracy with cast boolits of several weights. When the article came out, c. 15 years ago, I tried 800X, and found it to meter so inconsistently that it scared me off. I wasn't about to go back to weighing pistol powder charges, that's how I got my start, back in the poverty-stricken days.

[dbotos]

Anybody besides me have trouble getting 800X to meter well from a measure? Ken Waters' comprehensive series on the .45 ACP indicated that 800X was excellent in both velocity and accuracy with cast boolits of several weights. When the article came out, c. 15 years ago, I tried 800X, and found it to meter so inconsistently that it scared me off. I wasn't about to go back to weighing pistol powder charges, that's how I got my start, back in the poverty-stricken days.

What kind of tolerance you looking for? The charge range I posted above was with a Lee Pro Auto Disk powder measure using the 0.57 cavity. When I first opened the bottle the other night, I found the 800x flakes almost comically large, having only used Bullseye before for pistol loads.

[NVcurmudgeon]

dbotos, I expect thrown charges of pistol powder to be wthin 0.1 grain, or in the real world would accept 0.2 in the case of a coarse, slow burning, pistol powder. IIRC, 800X was more like 0.5 off, a whole scary grain, counting overs and unders! It has been 15 years, and I kept no records, but disposed of the powder pronto.

[dbotos]

Not sure how much powder measure technology has changed in the last 15 years or if IMR has changed the powder formula at all, but it might be worth giving it a try again. You could always trade it to someone who has better luck with it if it doesn't end up working for you.

[NVcurmudgeon]

Not sure how much powder measure technology has changed in the last 15 years or if IMR has changed the powder formula at all, but it might be worth giving it a try again. You could always trade it to someone who has better luck with it if it doesn't end up working for you.

You raise some good points, but the few "elephant loads" that I need are easily available in factory offerings. Meanwhile the same old RCBS Uniflow, and Hornady Pistol Measure are still working just fine. One or the other accurately meters any powder except 800X that I have tried.