Ruger MarkII m77 300 win mag. freebore??

[Moose hunter]

I was trying to determin the freebore on my ruger using the rcbs precision mic. I found the freebore(distance bullet sits away from rifle lans) was to great to measure with the mic. When a rifle has excessive freebore how do you determin the best cartridge oal for the best accuracy. I could use the dummy round and my calliper to find the oal of chamber but i dont see any benefit since i really cant sit the bullet close because of the excessive freebore. I am new to relaoding and have seen some loads listed with the cartridge oal but have also read freebore has an effect on overall accuracy.

Thanks for any help.

 

[Andy]

Seat a bullet into a sized, empty cartridge case, so it's just held by the neck, and then chamber it, using the bolt to seat the bullet further into the case. That OAL will be with the bullet hard into the rifling lands. If it's short enough to load into the mag, seat it say 50 thou deeper for reliable chambering, and that's a good length for accuracy. If you try this and the bullet doesn't move, then you have a whack of freebore. In that case, seat the bullet so it's gripped by the full length of the neck and go with that. The 300 Win Mag has a short neck so that's about the minimum.

 

[Moose hunter]

Thanks Andy. I didnt know Rugers had alot of freebore. I will try what you said. Andy i figured it thanks to you.

Thanks again.

 

[762shooter]

Freebore

Thanks Andy. I didnt know Rugers had alot of freebore. I will try what you said. Andy i figured it thanks to you.

I believe its a magnum thing, intended to reduce the initial pressure spike. For instance, the factory Weatherby magnums all have a lot of freebore.

 

[b72471]

Ruger and freebore

In hunting rifles, freebore does not mean the rifle will be less accurate. Weatherby has freebore in their rifles and they are accurate rifles.
Freebore is a bit of a safety edge in keeping chamber pressures a bit lower.

 

[browndusti]

I have a ruger m77 mk11 heavy barrelled target gun in 220 swift, it also has a lot of frrebore. in fack so much that it is impossible for me to seat a bullet out in the lands becasue in order to do so the bullet wouldn't be in the casing. i played with the oal until i found a load that shot good and chambered easy. i don't think freebore has any affect on accuracy as it will shoot 5/16 groups of five at 100 yards.

 

[Mush]

My Ruger Mark II 77 300 WM is the same as you . Can't find the COAL. I used the standard cartrige overall lenght.

Mush