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View Full Version : What Leade Length For .260 Rem. Improved


Senderofan
10-30-2009, 05:03 PM
TGIF Gentlemen:

I was wondering if those of you who have a .260 Rem. Improved...and have knowledge of their chamber specs...could share with me how much leade they have? I started loading up some ammo for my .260 Improved and noticed my 140 gr. SMK's are seated 0.590" into the case.....not far from being halfway. This will be a problem when trying to load to full house improved rounds. I failed to appreciate that the reamer I purchased was designed for rounds that would work in a magazine...so I have a throater ordered but need to figure out how much more length I should expect to add...just to get a sense. My gunsmith will be doing the work...but this round is something he hasn't worked with much.

Thanks in advance,

Wayne
savageboy
10-30-2009, 10:52 PM
I just received my Shilen Sel Match 260AI 8 twist 28.5" length bull barrel custom order and went thru exactly what you are talking about. I ended up adding an addl 80 thou. freebore- or a total OAL of 2.880" vs. 2.80" for the SAMMI spec. That length will get the VLD's and long 139Gr. Lapua's out further of the case, allow for throat erosion and chasing the lands over time if I want but still leave enough of the bullet in the case, etc. and allow for more powder room. The trade off is that you have to single load. I do anyways, so no prob for me.
I sent Shilen 2 dummy rounds that I made up. As for the technical reason that I made it that length- ready for this- I kept seating the bullet deeper and deeper until it "Looked Right" when I held a Berger or Lapua bullet next to the dummy round for proper seating into the case depth for my likes. So I eyeballed it! It seems right to me, and its such that I will not have donuts. So time will tell.
Senderofan
10-31-2009, 07:57 AM
Thank you very much for the information...I greatly appreciate it! Currently, with loading 140 gr. SMK's, I'm getting a C.O.L of 2.745"...which appears to be a standard .260 Rem length. Will end up having to do the eyeball method as well....but at least we have an idea of where to start.

Thanks again,

Wayne