M40 and M40A5 chamber specs

[wboggs]

Can anyone furnish the chamber dimensions on these rifles?
Thanks
Bill

 

[Phil McGrath]

Just a guesstimate, more than likely just a plane old M852 reamer

 

[wboggs]

Phil
Do you.know the neck diameter, leade angle and length, and throat on that reamer?
Thanks
Bill

 

[cmillard]

It's an m118LR chamber

 

[Phil McGrath]

Phil
Do you.know the neck diameter, leade angle and length, and throat on that reamer?
Thanks
Bill

No once apron a time I did, the leade is cut for the 168SMK profile. However you also brought up M40A5 and that would have a M118LR chambering, personally there are better reamers, I like the Obermeyer Match and that’s what my M40A1 clone uses.

 

[wboggs]

Thanks Phil. I think we will need a chamber cast. We are constrained by an oal to fit the magazine so we don't have a lot of seating options to run 155 or 175 gr bullets.
Also, it has a 1:11.25 twist.
I appreciate your time answering my question.
Bill

 

[6bra1k]

Thanks Phil. I think we will need a chamber cast. We are constrained by an oal to fit the magazine so we don't have a lot of seating options to run 155 or 175 gr bullets.
Also, it has a 1:11.25 twist.
I appreciate your time answering my question.
Bill

i just sent in a dummy round for a new 308/7.62 x51 reamer
it is a 95 palma with throat set for a 175 tmk at 2.82.
mag length no turn neck lapua small primer brass
it put the throat almost at the case neck!
i think you could do the same with the 175 smk with the 11,25

 

[wboggs]

i just sent in a dummy round for a new 308/7.62 x51 reamer
it is a 95 palma with throat set for a 175 tmk at 2.82.
mag length no turn neck lapua small primer brass
it put the throat almost at the case neck!
i think you could do the same with the 175 smk with the 11,25

With the 175 at 2.82 and throat at almost the case neck, what do you calculate the distance from bullet ogive to rifling is? Sounds like you have no freebore.
Thanks
Bill

 

[wboggs]

Addendum
What is your leade angle and length?

 

[6bra1k]

Addendum
What is your leade angle and length?

less than .008 jump, 1.5* no idea what throat length is

 

[wboggs]

less than .008 jump, 1.5* no idea what throat length is

Thanks