6CM vs 25CM in a 20" Rifle?

[Rancheria]

Looking to build a lightweight sheep setup. More than likely will be shooting the respective eldx bullet out of the cartridge I select but hard to ignore some of the high BC monolithic from companies like McGuire. Need the package in a 20" barrel.

 

[Harvey_NW]

In this comparison based on the fact you mentioned high BC monolithics, 6 CM is the answer for speed alone. The 25 is a bit anemic in the CM, and would be better suited in a 284 or PRC case for that type of setup. My 25 CM would only push 133's around 2,700fps damn near at pressure in a 19" bbl, my current 6 CM 20" should push a 108 over 2,900 once I finish forming brass and juice the charge up.

 

[MuleyFever]

It wont matter unless you are shooting out to the max range of the cartridges and need the extra distance.

I have both and like the 25 more. Just my preference but I like the heavier bullet.

 

[Speaks]

Have not shot the 25 but my 6cm is right now my very favorite gun.

As others mentioned 25 might be real nice if you added a bit more juice to the case. Something like a 25 PRC seems like it could be sweet. Lets hotrody than the 6UM but more than a 6.5 PRC.

 

[UnckleBob]

In this comparison based on the fact you mentioned high BC monolithics, 6 CM is the answer for speed alone. The 25 is a bit anemic in the CM, and would be better suited in a 284 or PRC case for that type of setup. My 25 CM would only push 133's around 2,700fps damn near at pressure in a 19" bbl, my current 6 CM 20" should push a 108 over 2,900 once I finish forming brass and juice the charge up.

What about the 25 RPM?

 

[Harvey_NW]

What about the 25 RPM?

Haven't done a deep dive, but on their website it shows factory ammo loaded with 133's going 3,000fps MV (no listed bbl length, assuming std 24"). It also states "40% larger case capacity over the Creedmoor", so I would expect a bigger increase, but as we know that can vary almost 200fps just by powder selection, broken in barrel, etc.

My hesitancy with that cartridge would be brass and die availability. As of now brass is not available, and when it is it will be ~2x as expensive as Lapua 6.5 PRC brass. I just don't see ANY advantage.

 

[Bluefish]

What about the 25 RPM?

Basically the same as a fast twist 25-06 or 25 (6.5) prc, but in a factory gun. Either of those is easy to do if you load. If you don’t then the 25 rpm is probably the better choice.

 

[Matt5266]

Id go for the 6 and not shoot monos unless you have too