284 freebore

M

Matt P

New member
Hi
Asked this in 1000yrd BR and got no responce, so I'll try here.
Looking to order a reamer in 284 Win, what is the best freebore for 175 SMK's and is it possible to get a compromise for both the 180 Berger and the 175 SMK. I have a print from PTG and the freebore is .188 for the 284 and .239 for the Shehane version being based on the same case I found this a little strange.
Thanks
Matt P
 
Matt P said:
Hi
Asked this in 1000yrd BR and got no responce, so I'll try here.
Looking to order a reamer in 284 Win, what is the best freebore for 175 SMK's and is it possible to get a compromise for both the 180 Berger and the 175 SMK. I have a print from PTG and the freebore is .188 for the 284 and .239 for the Shehane version being based on the same case I found this a little strange.
Thanks
Matt P
Click to expand...

I biuld my .284 win with .180'' this put the a base of the bullet (175mk) just levele with the sholder body juction on the casw , or in other words the bullet baering surface in the neck the , at .239'' you would only have .065 of bearing surface in the case ( for more pwder room ) i would not go over .200'' as i feel this would not leave enough bullet in the case
 
I have studied this case a little myself and i think i will go with a .210 free bore. now this is just an educated assumption on my part and i have not discussed this with dave kiff yet. I will be shooting the new berger hybrid 7mm bullets so that will determine my free bore, but i bet im pretty close at .210 give or take a little. lee
 
Matt,
I would go with the .188/.190 freebore if I was just going to buy just the reamer. Maybe you should consider getting a shorter freebore and also buy a 7mm throating reamer. That way, you can seat a bullet in an empty case to the depth you want and fit the chamber to it. I ordered mine with a .150 FB which works well with bullets in the 120/140 grain range which I use for hunting. Then with the throater I can go as long as I wish for heavier bullets.
 
You may want to load a few dummy rounds with the bullet of choice,send them to PTG and have Dave make a reamer to them. SPecify how much freebore you want. I just shortened a barrel for a cleint so he could make the weight limit at Lodi this year. It was a 284 and he is shooting it at 1000yds
 
Jim
That would be the best plan of attack but getting them to the US from Australia is a problem. You guys don't know how good you got it, having everthing so close.
Thanks
Matt P
 
Jay Cutright said:
Yes we do!!!
Click to expand...

Maybe a solution here. What if you let me know what bullet you want to use, give me the OAL of the cartridge and I send them to PTG for you with instructions for him to ship to you when done after you pay him?

I have a 284 of my own and a bunch of brass and dies.

Jim
 
The Berger 180 Grain VLD has a .481" length bearing surface. I have found the .284 shoots the 180 Berger seated no deeper than the bearing surface at the neck shoulder juncture. This is not condusive for standard magazine fit.
Nat Lambeth
 
Jim Kobe said:
Maybe a solution here. What if you let me know what bullet you want to use, give me the OAL of the cartridge and I send them to PTG for you with instructions for him to ship to you when done after you pay him?

I have a 284 of my own and a bunch of brass and dies.

Jim
Click to expand...
JIm
Thanks very much for the offer that is very generous but I sat down and did the sums, I reakon a 220 free should do the trick, once again thanks for the offer.

Matt P
 
FWIW, I have some f-class shooters who are using chambers cut with my .284 reamer and are doing very well with it. .320" neck and .180" freebore length.
 
My .284 reamer has a .3176" neck. No neck turned lapua brass loaded with a 180 grain Berger has .3125" neck. I am only allowing .005 or .0025" clearance per side for expansion during firing. Mike you are allowing .0075" or .0035" clearance per side. Jerry Terney told me you can't have to much clearance. My .284 rifles shoot good also. I beleive Charles Ballards reamer print found on 6mmBR webb site neck was .3175
There are some variations out there.
Nat Lambeth
 
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