'Clumping' Retumbo--Kirby/anyone?

[jmden]

Yesterday afternoon, I shot a few more rounds from an older 8lb. jug of Retumbo that from which I used to used a 101g load at ~2980fpsMV. At 99g I was 2880 and still showing too much pressure for my tastes. Odd thing is that the FED215M primers, which I understand to be 'soft' compared to many other primers, show no cratering with any of these loads and the edges of the primer are nice and round as well with all of these loads, but I'm getting various degrees of ejector pin marks on the caseheads.

 

[bigngreen]

I've been amazed more than once after getting a barrel "clean" then taking a few strokes with some KG abrasive cleaner then go in with a carbon solvent and get a patch back with thick carbon. I can see this with the bore scope as well, after all my cleaning with brushes and very good cleaners there will be carbon. It also fits for the load being hot after setting and the carbon absorbing moisture and tightening the bore up, just a thought!!!

 

[jmden]

I've been amazed more than once after getting a barrel "clean" then taking a few strokes with some KG abrasive cleaner then go in with a carbon solvent and get a patch back with thick carbon. I can see this with the bore scope as well, after all my cleaning with brushes and very good cleaners there will be carbon. It also fits for the load being hot after setting and the carbon absorbing moisture and tightening the bore up, just a thought!!!

I don't have KG, but I do have some JB. Do you have a recommened procedure? Normal cleaning routing then scrub (back and forth in short strokes working your way down the barrel?) or just push a few patches down the barrel with JB?

 

[bigngreen]

I work it in short strokes for the first 8 inches or so then I run a very wet patch of carbon solvent to pull it out and soften it more. I started doing this after looking at my barrels with a bore scope and seeing that the copper was gone from the end of the barrel but the chamber end had grey carbon left in the first 8-10 inches.

It's worth a try just to make sure!

 

[jmden]

Did a normal cleaning routine again. Let the barrel soak for a few minutes with Sweets afterwards. Essentially zero copper from the Sweets. Patched a few times with Eliminator and then put JB on a patch careful to get it all over the patch and ran it back and forth a few times in the firs few inches and then a bit as I pushed it out the barrel end. Ran a few more patches of Eliminator with essentialy zero carbon showing on any of it. Going to the range soon with another reduced load to see how it does...pretty frustrating.

 

[jmden]

Hodgdon is reporting that the powder I sent them is within spec. They asked for and I sent 600g of Retumbo. Their control lot, in a 300RUM with 180g bullet, has an MV of 3305. My powder shot 3291 I was told. Sure is a mystery.

RL33 arrived and hope to start working up a load tonight.

 

[BMF]

I noticed it clumping in its container a few weeks ago. Granted its about 2yrs old, but its stored in a dry place. Regardless, it doesnt seem like it should clump in the container!

 

[jmden]

I noticed it clumping in its container a few weeks ago. Granted its about 2yrs old, but its stored in a dry place. Regardless, it doesnt seem like it should clump in the container!

Have noticed the same from last two 8lb jugs over the last 4 years or so. Hodgdon says it's not a problem when called.