Short trimmed case issues

[Brad Cayton]

I've been working with a microgroove, 336. I tried the Lee,170 FN, Lyman 311041 and NOEs 311-165 RD, sized .310 and .311. Powders were 2400, 3031, Varget, Reloader7 and H4895. I wasn't satisfied with any load but the NOE, RD did the best but I had to seat it deep and crimp with a LFC die to use it and would shoot an average 5 shot group of 3 3/4" at 100 yards.

I searched for a fix on the board and see where this has been an issue with the Ranch Dog in some rifles. I decided to trim the cases to be able to crimp in the crimp groove and the boolit shoots great with it just touching the lands. But... I had to trim the case to 2.00, .029 shorter than spec. I saw one post warning about getting a lead ring by using brass too short.

My question is, has anyone used cases this much shorter than the spec. trim length and did it cause problems?

[Tatume]

Hi Brad,

In my Marlin 30-30, bullets from the Lee C309-170-FN mold sized 0.310 and lubed with LBT Blue Soft work wonderfully. They are very accurate when run at full 30-30 speed using IMR 4895. I use data from http://www.hodgdonreloading.com/ for the Sierra 170 grain bullet. Cartridges chamber perfectly when bullets are seated to the crimp groove. My advice is to keep cases at the correct length and adjust until they work. Then you don't need to worry about short-case issues.

Take care, Tom

[Brad Cayton]

Thanks for the reply Tom. I'd really like this use this RD boolit. The Marlin will keep 5 in less than 2"@ 100 with R7, better than factory rounds. I dug up some old post where some trimmed their cases to make the boolit work so that's why I tried it. I'd have to find the post again but I seem to remember that Ranch Dog recommended to do just that. Others said to used the Lee factory crimp and crimp over the front band but mine doesn't like that. I really don't want to get the chamber lengthened.

I'll keep at it. Thanks again

[Tatume]

Shooting shortened cases can cause the build-up of a carbon ring in the chamber. Usually it is very easy to remove. Just clean as normally, using a brass brush. Don't worry about using shortened cases. They'll be fine.

[Brad Cayton]

Great to hear! Thanks Tom