Sooty Necks

[Herb D]

Having swithed from H870 to Retumbo in my 300 RUM Iam now seeing very black carboned necks on my cases -something I've never experienced in 40 years of reloading.
What gives?

[royinidaho]

Just 2 comments/questions:

870 and other slow burning ball powders at lower pressures burn quite dirty. At higher pressures this doesn't occur. From what little Retumbo and H1000 I've shot it may be the same with them.

Also I have experienced dirty necks when shooting US 869 at so so pressure.

Just my experience.

[Hicks]

Funny, I noticed the same thing this weekend after shooting my 7mm RUM with Retumbo. Never really noticed that before, but then again I've never had a large capacity round like this either.Hicks

[crittergitter]

Same story on my new 338/ 300 Ultra that I am breaking in. Sooty necks with Retumbo, a little better with US 869, but not much.

I am curious what kind of performance RoyinIdaho is getting with US869 in the 338 RUM.

[royinidaho]

Originally Posted by crittergitter

Same story on my new 338/ 300 Ultra that I am breaking in. Sooty necks with Retumbo, a little better with US 869, but not much.

I am curious what kind of performance RoyinIdaho is getting with US869 in the 338 RUM.

101gr US 869/Rem Cases, 300gr SMK/ 2735 FPS /ES+/- 1/ SD = Zip/nadad/nothin'

[crittergitter]

I get 2828 with the same charge in the 338/ 300 Ultra in a 34" bbl, but I also get slightly flattened primers and a faint extractor mark. I was suprised by the pressure signs at that charge with the extra case capacity...but 11 fps ES is hard to argue with.

Thanks,

[dbhostler]

Herb,
This is usually a result of the bullet exiting the neck too soon after ignition before pressure can expand the neck sufficiently to seal it. You could try greater neck tension to hold the bullet longer, seat the bullet deeper into the case or use a hotter primer. At the very worse, 0000 steel wool will remove it guickly.
db