cartridge length 300 Winchester magnum

[taptap]

Hi All,
Almost ten years since I entered my details here, still a noob I'm afraid.

I have a 300 Winchester magnum bolt rifle for which I want to reload. The internet tells me maximum cartridge length is 3.34" or almost 85mm metric.
In my rifle, a Blaser R8, the bullet is nowhere near the lands. I can move (most) bullets out to at least a cartridge length of 3.40 without getting the bullet touching the lands, while still fitting the magazine and the bullet touching all of the inside of the neck of the cartridge.

Would it be a problem to lengthen a cartridge this way? Surely the maximum cartridge length wasn't specified for no reason?

I hope to learn from you.

Regards,

Bert

 

[charliehorse27]

My understanding is that SAAMI length is the standard, so all rifle manufacturers make their chambers to fit rounds measuring at least that length. As such, all factory loads will generally measure SAAMI length as well. But, that's the beauty of handloading because you then have the freedom to extend the length of the bullet out of the cartridge to facilitate whether your rifle likes .005 off the rifling, or .05 off the rifling. I also have a 300 WM, and it's throated for much longer rounds, around 3.90" OAL. This enables it to take advantage of the heavier bullets, such as 215's, and get enough powder behind them to send them fast.

Hope that helps a little.

 

[FEENIX]

Hi All,
Almost ten years since I entered my details here, still a noob I'm afraid.

I have a 300 Winchester magnum bolt rifle for which I want to reload. The internet tells me maximum cartridge length is 3.34" or almost 85mm metric.
In my rifle, a Blaser R8, the bullet is nowhere near the lands. I can move (most) bullets out to at least a cartridge length of 3.40 without getting the bullet touching the lands, while still fitting the magazine and the bullet touching all of the inside of the neck of the cartridge.

Would it be a problem to lengthen a cartridge this way? Surely the maximum cartridge length wasn't specified for no reason?

I hope to learn from you.

Regards,

Bert

Bert,

No, it is not a problem. The goal is to find the best compromise between COAL and CBTO. I have three .300 WMs; two are in the 3.53" range and one at 3.62", .015-.020" off the lands.

Ed

 

[ndking1126]

Edit: i just reread your post and you already mentioned mag length. Deleting my comment.

 

[MagnumManiac]

Standard length throat on a SAAMI chamber in 300WM is around 3.550" with normal bullets, and around 3.600" with VLD bullets.
Given a lot of rifles for the 300 have mag boxes of 3.4" or so, you need to find a COL around 3.390" down to about 3.340".
I have found sweet spots at 3.350", 3.375", 3.385" & 3.390" with conventional tipped bullets and cup & core. The VLD's 200gr & under have worked at max mag box length (minus .010") with a little powder tuning.
For longer VLD's, I have single loaded.

Cheers.

 

[taptap]

Clear answers, thanks all. I'll fire up GRTools and start loading.

Bert