What causing this and how to prevent this.

[newbie1234]

Bullet: .38SPL, RMR, 125 gn, Plated, FN.
Powder: Titegroup, 4.1 gr.
AOL: 1.475
Grimp: a little bit tight.
What causing this and how to prevent this ?
Thanks You.

[Jeff213]

Pressure too low. Case is not sealing and hot gas is blowing back around the casing. Way to prevent this would be using near max charges on slower burning powders.

If it shoots good, there is no real reason to worry about it. It will foul your cylinder a little faster maybe? I don't worry about this with my 38s though.

[eaglemike]

Pressure isn't high enough to expand the case out to seal. How it looks from here, anyway. That's a common cause for soot around the front part of the case on .38 special.

[fguffey]

The case must seal the chamber, the first 'usual suspect' is low pressure.

F. Guffey

[BajaJames83]

Try a different powder.
Like the others said pressure is low
But titegroup is also very dirty

[sghart]

More powder or heavier bullet

['ol shooter]

Also, if the cases have been fired several times they will get increasingly brittle and will not expand readily against the chamber wall.

[Imageview]

[ar15barrels]

Bullet: .38SPL, RMR, 125 gn, Plated, FN.
Powder: Titegroup, 4.1 gr.
AOL: 1.475
Grimp: a little bit tight.
What causing this and how to prevent this ?
Thanks You.

Need more crimp and a little more powder.

Cartridge          : .38 Special (SAAMI)
Bullet             : .356, 125, LEE 356-125-2R
Useable Case Capaci: 17.020 grain H2O = 1.105 cm³
Cartridge O.A.L. L6: 1.475 inch = 37.47 mm
Barrel Length      : 4.0 inch = 101.6 mm
Powder             : Hodgdon TiteGroup

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.439% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step    Fill. Charge   Vel.  Energy   Pmax   Pmuz  Prop.Burnt B_Time
 %       %    Grains   fps   ft.lbs    psi    psi      %        ms

-24.4   24     3.10    697     135    8399   3304     98.0    0.794
-22.0   25     3.20    714     141    8860   3417     98.6    0.792
-19.5   26     3.30    731     148    9335   3528     99.0    0.772
-17.1   27     3.40    747     155    9822   3635     99.4    0.753
-14.6   27     3.50    763     162   10321   3739     99.6    0.735
-12.2   28     3.60    779     168   10832   3839     99.8    0.718
-09.8   29     3.70    794     175   11356   3936    100.0    0.701
-07.3   30     3.80    810     182   11892   4028    100.0    0.686
-04.9   30     3.90    825     189   12441   4119    100.0    0.670
-02.4   31     4.00    840     196   13001   4210    100.0    0.654
+00.0   32     4.10    854     203   13574   4300    100.0    0.639
+02.4   33     4.20    869     209   14159   4390    100.0    0.625
+04.9   34     4.30    883     216   14757   4480    100.0    0.612  ! Near Maximum !
+07.3   34     4.40    897     223   15366   4570    100.0    0.599  ! Near Maximum !
+09.8   35     4.50    910     230   15988   4660    100.0    0.587  ! Near Maximum !
+12.2   36     4.60    924     237   16622   4750    100.0    0.575  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 3% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 3% relative to nominal value:
+Ba     32     4.10    862     206   14089   4271    100.0    0.627
Data for burning rate decreased by 3% relative to nominal value:
-Ba     32     4.10    845     198   13053   4332    100.0    0.653

[TomReloaded]

That's what titegroup looks like.

Max charges in 9mm (about 32 kpsi) still char. Not that much, but they still do it.

[newbie1234]

Nup, this is NOT camera edit. BTW, you go lower than 4.1 gn, would you tell me is that the FMJ, Plated or Lead ?
Lee loading manual said: for Titegroup, Lead (3.2-3.8), XTP (4.3-4.6).

[newbie1234]

Also, if the cases have been fired several times they will get increasingly brittle and will not expand readily against the chamber wall.

May be this is the reason, all the cases are reloaded (by me) for around 5-10 times already.

[kcstott]

May be this is the reason, all the cases are reloaded (by me) for around 5-10 times already.

As most here have said low pressure not sealing the case in the chamber.

We have this issue in Cowboy action shooting as the loads are doing about 600-700 fps in 45 colt with a 160-180 grain bullet. the brass don't expand at that low of pressure so we anneal the brass. We only do this for the rifle loads though. pistols don't care but the rifles get cruddy fast.

[Imageview]

[Che762x39]

Bullet: .38SPL, RMR, 125 gn, Plated, FN.
Powder: Titegroup, 4.1 gr.
AOL: 1.475
Grimp: a little bit tight.
What causing this and how to prevent this ?
Thanks You.

I would go 4.4 grains of Titegroup if that is what you have.

I prefer Bullseye or BE-86 for .38 Special with a plated bullet.