6.5-284 cartridge overall length

[StevenCO]

I have some questions on throating of a 6.5-284.

I am trying to use 142 gn Sierra MK's to shoot 1000 yd target.

Right now I have a C.O.L.=2.928" just touching the lands.

What sort of cartridge overall lengths are people using out there for this combination?

Should I consider lengthening the throat to get closer to the 3.228" shown in the cartridge diagrams on the 6mmbr site?

Is it still the practice to embed the bullet one bullet diameter in the case?

Thanks.

 

[billmo]

Steven Every rifle will have it's own COL. Your's appears to be within specs. I would not try to do anything to the chamber. I had rather have a little shorter throat or "freebore" than longer. Most of the time when you have long freebore you will not be able to get quite as much M V because you are giving up area inside of the case. Key word is " MOST ". This is just my opinion. I hope it helps. Bill

 

[StevenCO]

Thanks for the input. My goal is to try to get to that apparent magic number of 2950 or so. Admittedly, I got a little impatient and cut a little bit of throat in it to get a O.A.L. a little over 3.000"

We'll see what happens.

 

[rcw3]

I think the issue for most 1000 yard target shooters is keeping the bearing surface of the bullet ahead of the donut area. The necessitates having a 6.5 x 284 throated so the OAL with a 142 Sierra is at least about 3.100". 3.228" would be pretty long and leave you not a lot of neck to hold onto the bullet.

2950 fps is certainly known to be a good accurate velocity with the 142's, usually somewhere around 47.5-48.5 gr of H43350 or 51-52 gr of H4831SC gets you there.

Robert Whitley

 

[StevenCO]

Thanks for reminding me about that. I had read that somewhere sometime back and had forgotten about that little problem. 3.100 it is.