308 chamber dimensions

F

fozzy

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If you were having a rifle built for F class type shooting in 308 what chamber dimensions would you have the barrel reamed to? What are the advantages of a tight neck chamber as apposed to a factory spec saami chamber?
Thank you
 
fozzy said:
If you were having a rifle built for F class type shooting in 308 what chamber dimensions would you have the barrel reamed to? What are the advantages of a tight neck chamber as apposed to a factory spec saami chamber?
Thank you
Click to expand...

If you have to use .308 then use Lapua brass and Lapua 154 Scenars. Off the cuff, Use Obermeyer reamer. I would specify the following changes.. if required, as I don't know its dimensions.

Throat dia..3085, throat length .200, leade angle 3 degs.
Neck dia. .339
Base dia. at datum .472

All in Inches


NormB
 
fozzy said:
If you were having a rifle built for F class type shooting in 308 what chamber dimensions would you have the barrel reamed to? What are the advantages of a tight neck chamber as apposed to a factory spec saami chamber?
Thank you
Click to expand...
Last year I did extensive research on this very subject and found that the Kiff reamer 95 Team match, garnered the most respect amongst 308 shooters.
I bought one and it is a tight neck reamer. Totally satisfied.
Tight neck?? Accuracy... The BR guys turn their necks down to fit into a small neck chamber.
The 95 team reamer is a no turn reamer.
However another thought, if you are looking at F class, why a 308??
 
windborne11 said:
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However another thought, if you are looking at F class, why a 308??
Click to expand...

Because there are two different kinds of F Class. Unlimited F Class and Farkey Class. Farkey rifles are basically TR/Palma rifles with a bipod and a scope. Incidentally, that is how F Class originated. Mr. Farquarson was a legendary TR shooter whose eyes got too old to use iron sights. He introduced this type of competition as a way for older shooters to continue shooting competitively. That's why he originally maintained Palma rules on rifle and cartridge.
 
windborne11 said:
Last year I did extensive research on this very subject and found that the Kiff reamer 95 Team match, garnered the most respect amongst 308 shooters.
I bought one and it is a tight neck reamer. Totally satisfied.
Tight neck?? Accuracy... The BR guys turn their necks down to fit into a small neck chamber.
The 95 team reamer is a no turn reamer.
However another thought, if you are looking at F class, why a 308??
Click to expand...

I am going to use 308 because some of the shoots that I want to enter must be nato rounds. This is also going to be a clone of the M40A1, already have the take-off McMillan stock :)
 
The tight neck does squat as far as accuracy is concerned but, in combination with properly dimensioned dies, it can yield better case life.
I like to have the throat a little longer than on most Palma reamers. This so that the chamber will accomodate the heavier bullets better than the short throated chamber. You don't want to make the throat so long that you can't reach the lands with 155's though. Regards, Bill.
 
Many smiths have the Clymer M852 reamer. This is a great design originally set up for the military to use the then new Sierra match bullets in 308 ammo.

It has a standard neck diameter so you don't need to turn. A very nice throat and leade to accept all medium weight bullets.

Save yourself the cost of a 'custom' reamer as there is little to be gained especially if factory ammo may be required in some of your competitions.

Jerry
 
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