.243 what reamer

[Mt.Boy]

Depends what mag size you run. The 115's are long and end up seated pretty deep in standard sa mags

It's a older Mauser action I will have to measure it.

 

[Mt.Boy]

Not really in the grand scheme of things. Freebore of .200-.250 is common in some cartridges. I believe it was mentioned, but the SAMMI chamber will shoot anything up to 100grainers very well. If you are wanting to jump into the heavies like 108,109, or 115s call your preferred gunsmith and see what he recommends. Or you can solicit some advice here for smiths that guys have used for a 243 build with heavies in mind. Fwiw my 243 I had built I used a SAMMI reamer with 105 Amaxs and got very acceptable performance (2950fps).

With .177 freebore I would think you could load them out pretty long

 

[sierracharlie338]

Not the 105s in my rifle. They were well into the case.

 

[Mt.Boy]

Not the 105s in my rifle. They were well into the case.

Was it due to your mag length.

 

[sierracharlie338]

Was it due to your mag length.

Nope they were .020 off the lands and fed fine from the mag

 

[Mt.Boy]

Nope they were .020 off the lands and fed fine from the mag

How far in to the case was the 105

 

[Mt.Boy]

My mag box measures 2.950

 

[sierracharlie338]

How far in to the case was the 105

A good ways. Can't measure it because I don't have the gun anymore

 

[WmBob]

Common usage of the term "freebore" generally refers to a cylindrical section of the chamber just ahead of the neck transition. A SAAMI .243 has no cylinder and transitions right into the tapered throat therefore in common usage has zero freebore. Take the 25-06 and it has what is commonly called freebore, a cylindrical section between the neck transition and the tapered throat/leade. The SAAMI 25-06 in common terms has .105" freebore, the .243 has zero. Be careful of the terms and what they might mean.

 

[Mt.Boy]

Common usage of the term "freebore" generally refers to a cylindrical section of the chamber just ahead of the neck transition. A SAAMI .243 has no cylinder and transitions right into the tapered throat therefore in common usage has zero freebore. Take the 25-06 and it has what is commonly called freebore, a cylindrical section between the neck transition and the tapered throat. The SAAMI 25-06 in common terms has .105" freebore, the .243 has zero. Be careful of the terms and what they might mean.
View attachment 421804View attachment 421805

Ok I get that. But some are saying the 243 sammi has 0. And some saying more not sure what to go by

 

[WmBob]

Ok I get that. But some are saying the 243 sammi has 0. And some saying more not sure what to go by

If you travel around the internet, talk to people at matches, your gunsmith, etc…. you'll find almost universally that "freebore" is defined by a cylindrical (parallel on the reamer print) section after the neck transition angle. If it transitions right into the the tapered portion of the "throat" "leade" with no cylinder it has no or zero "freebore". Refer to the SAAMI chamber drawings above and you'll see what I am pointing out.

As I mentioned earlier you have to be careful as to what the neck transition angle is. The most common is 45° but you'll find many that are not. Most custom reamers are 45° but more lately are showing up that are not. This will effectively change the distance to lands even if the "freebore" numbers are the same but the transition angle is not.

I'll also throw out that different throat/leade angles will have a noticeable effect as to distance to lands. The most common custom angle is 1°30". If you go steeper or shallower your distance to lands will increase or decrease. So be aware it's not all apples to apples out there.

 

[Mt.Boy]

If you travel around the internet, talk to people at matches, your gunsmith, etc…. you'll find almost universally that "freebore" is defined by a cylindrical (parallel on the reamer print) section after the neck transition angle. If it transitions right into the the tapered "throat" with no cylinder it has no or zero "freebore". Refer to the SAAMI chamber drawings above and you'll see what I am pointing out.

As I mentioned earlier you have to be careful as to what the neck transition angle is. The most common is 45° but you'll find many that are not. Most custom reamers are 45° but more lately are showing up that are not. This will effectively change the distance to lands even if the "freebore" numbers are the same but the transition angle is not.

Thanks.pretty sure I understand now. Appreciate the help