Discolored Brass-Are My Loads Too Light?

[gerrym526]

Guys,

I've been reloading for a few years now, and have been frequently encountering brass discoloration (obturation is the term-I think). Found in other threads in the reloading forum that this is typically caused by loads being too light.
Here's my situation-
-loading 9mm 124 gr FMJ round nose, using Berry's Bullets (plated, not jacketed)
-4.7gr Power Pistol.

Hornady's reloading guide recommends 4.3-5.7gr of Power Pistol for 124gr FMJ RN-so I'm within their safe range
Speer recommends 5.6-6.4gr of Power Pistol (with their bullets)
Lyman recommends 5.1-5.7gr of Power Pistol (for 125gr HP, no load data for 124 RN)

Question 1-Are my loads too light?

Question 2-If I increase the load, do I need to switch from plated (e.g. Berry's) bullets to jacketed (e.g. Hornady, Speer) because of the increased pressure? Reason I ask the 2nd question is that when I reloaded Berry's in 357 mag with Blue Dot recently, the plated bullets shattered and shards came out the cylinder openings. Guys at the range said I should stop using plated bullets for magnum loads and switch to jacketed.

Thanks for the help.
Gerry

 

[Toprudder]

Too little pressure can cause the brass not to expand and form a gas seal, which will lead to dark, sooty cases. Depending on how sooty, I probably wouldn't worry too much about it, though. If you want to keep velocity down but not have sooty cases, then switch to a faster burning powder.

I've experienced the problem you mention with your 357 mag, except mine was in 44 mag. Yes, I switched to Zero JSP bullets for all my 44 mag loads now. They don't cost much more than plated. But in 9mm, plated should be fine up to max charges.

 

[1KPerDay]

Some powder and bullet combos scorch more than others. Yes, increasing the charge may help, but it doesn't harm anything and if the load is accurate and does what you want, don't worry about it, IMO.

 

[Walkalong]

-loading 9mm 124 gr FMJ round nose

Berrys isn't "FMJ". FMJ suggests jacketed. But you noted that which was helpful.

Question 1-Are my loads too light?

That's a little bit light, you can always bump it up a couple of tenths and see if the brass comes out clear. It doesn't hurt anything, just takes longer to clean up the brass and the gun.

Question 2-If I increase the load, do I need to switch from plated (e.g. Berry's) bullets to jacketed

No, at 4.7 or 5.0 Grs Power Pistol the Berrys are fine.

Reason I ask the 2nd question is that when I reloaded Berry's in 357 mag with Blue Dot recently, the plated bullets shattered and shards came out the cylinder openings. Guys at the range said I should stop using plated bullets for magnum loads and switch to jacketed.

Full Magnum loads from a revolver is a whole nother animal. High pressure with cylinder throats and a forcing cone to navigate. Some plated bullets do fine at near full .357 Mag levels, some don't, and some revolvers won't shoot them well period.

 

[ArchAngelCD]

I've been reloading for a few years now, and have been frequently encountering brass discoloration (obturation is the term-I think).

No, incorrect definition. Obturation is the bullet and or brass expanding to seal off the gasses produced by the powder burning. As for the brass discoloration, you are probably correct, too little pressure. Like said above, if you want to keep the velocities down but also prevent the soot to go a faster powder. (W231/HP-38, Zip, AA#2, W244, WST)

Good luck.

 

[kmw1954]

Here's my situation-
-loading 9mm 124 gr FMJ round nose, using Berry's Bullets (plated, not jacketed)
-4.7gr Power Pistol.

Hornady's reloading guide recommends 4.3-5.7gr of Power Pistol for 124gr FMJ RN-so I'm within their safe range
Speer recommends 5.6-6.4gr of Power Pistol (with their bullets)
Lyman recommends 5.1-5.7gr of Power Pistol (for 125gr HP, no load data for 124 RN)

Question 1-Are my loads too light?

Thanks for the help.
Gerry

1st question, are those 9mm bullets, other than the Berry's, Jacketed, plated or lead? True jacketed bullets usually require a hotter charge than plated or lead which could explain the difference with Speer and Lyman.

Looks like Alliant lists 5.8 - 6.4gr for the Speer Gold Dot. So I would guess you are at the low end. Try to bump it up a grain or two or go to a faster powder.

 

[Average Joe]

I fired factory new ammo, and had the same result. If your loads are accurate, and cycle the action, don't worry about it, wash them or tumble them , they come clean again.

 

[sparkyv]

Yes, increasing the charge may help, but it doesn't harm anything and if the load is accurate and does what you want, don't worry about it, IMO.

^^^This^^^

 

[Drail]

This is the reason God gave us tumblers and corn cob...... Don't worry about it as long as every bullet is clearing the bore.

 

[egd]

If you do decide to try a jacketed bullet I recommend Rocky Mountain Reloading. They make their own jacketed bullets and the quality is awesome. And the price is very good. List (for 124 rn) is $82 per K shipped. and being a member of this forum gets you another 5% off. Use code thehighroad5.

 

[vaalpens]

Your load seems a bit low, but it will also depend on how deep your bullet is seated.

Power Pistol is very accurate for me in 9mm, even with plated bullets. I don't know what COL you are loading at, but the following loads are using the Xtreme 124gr FP bullet which is loaded with a COL of 1.060" . The bullet length is about .526", so you can calculate if the Xtreme bullet is seated deeper than your Berrys RN bullet or not. The deeper it is seated the more pressure you will have.

9mm, SP2022, 3.9"
Case: WCC
COL: 1.060"
Xtreme, 124gr, FP, PowerPistol, 5.3gr, CCI500
Average: 1022
ES: 20
SD: 8.3
Force: 288
PF: 126
Velocities: 1013, 1028, 1020, 1033, 1016
Grouping @ 15yd: 0.633"
Test Date: 12/26/2017

9mm, SP2022, 3.9"
Case: WCC
COL: 1.060"
Xtreme, 124gr, FP, PowerPistol, 5.6gr, CCI500
Average: 1062
ES: 18
SD: 6.7
Force: 310
PF: 131
Velocities: 1061, 1056, 1074, 1062, 1061
Grouping @ 15yd: 0.465"
Test Date: 12/26/2017

 

[gerrym526]

Guys,
Thanks for all the good advice.

I'll bump up the Power Pistol load to 5.0-5.2 and see how it works.

To Vaalpens question-currently my COL is 1.115 based on what hornady and Speer recommend (noting that seating the bullet deeper will increase pressure significantly).

I'll also be trying some jacketed bullets for comparison-thanks for the recommendation to Rocky Mtn reloading-I'll give their products a try.
Gerry

 

[LiveLife]

9mm 124 gr ... Berry's Bullets (plated, not jacketed) ... 4.7gr Power Pistol.

Are my loads too light?

Yes.

Below Speer load data is fairly close to your load as Speer TMJ is thick plated RN bullet (which can be pushed to full jacketed load data) while Berry's regular plated bullet is rated to 1200 fps and I had good results to mid-range jacketed load data (accuracy deteriorated above mid-range jacketed load data) - https://www.thehighroad.org/index.p...ng-at-25-50-yards.808446/page-3#post-10470195

https://www.speer-ammo.com/download...m_caliber_355-366_dia/9mm_Luger__124_rev1.pdf

124 gr Speer TMJ Power Pistol OAL 1.135" Start 5.6 gr (1033 fps) - Max 6.4 gr (1157 fps)

As others posted, I would increase powder charge towards Speer start charge of 5.6 gr. If your working OAL is shorter than 1.135", I would decrease powder charge by .2 - .3 gr.

 

[someguy2800]

Flake powders like power pistol, 700x, and bullseye always tend to leave sooty cases in my experience at any pressure but shoot excellent. Just means you have to tumble a bit more.

If you really don’t like it try titegroup. You can’t even tell the cases have been fired.

 

[someguy2800]

Oh and I shoot 5.2gr power pistol behind both Berry’s and RMR FMJ’s with great success. Your load is fine too.