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Gunsmithing 6BR Reamers

Tobyboy22

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Minuteman
Jan 4, 2014
160
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I'm thinking about building a 6BR for my next comp gun. Question I have is what reamer is recommended? Plan on shooting 105-108's gr bullets. I found these three prints. Two are JGS and one is PTG. Any advice is appreciated.
 

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  • 6BR #1125.pdf
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  • 1262.pdf
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  • PTG.pdf
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This one has a .116" free bore with a .271 diameter neck and a .4714 base.
1571414182885.png


This one has a .094" free bore, a .271 neck and a .4714 base
1571414200011.png


This one has a .113 free bore, a .272 neck and a .470 base.
1571414217241.png




Honestly any of the three would work well enough with a 105-108 and all three are no-neck-turn chambers. I would probably lean towards the first "JGS 1125" reamer myself with the PTG a close second as they are in a nice middle zone. Typically .104-.105 freebore reamers are the bread and butter for a 105 bullet. The middle one with a .094 would work but I would say its designed for slightly lighter bullets. A 115 is nice with a .120-.130 freebore so the jgs1125 and ptg reamers are sort of splitting that difference.
 
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I'm thinking about building a 6BR for my next comp gun. Question I have is what reamer is recommended? Plan on shooting 105-108's gr bullets. I found these three prints. Two are JGS and one is PTG. Any advice is appreciated.

What competition would you use the 6br in?I have one and have been looking for a competition.thank you,pb
 
.272 neck should be a no neck turn so keep that im mind when choosing reamer specs for 105s the .104 freebore seems to be the king .113 freebore wont make that big of a difference though and may help with those 108s.
 
This one has a .116" free bore with a .271 diameter neck and a .4714 base.
View attachment 7166269

This one has a .094" free bore, a .271 neck and a .4714 base
View attachment 7166270

This one has a .113 free bore, a .272 neck and a .470 base.
View attachment 7166271



Honestly any of the three would work well enough with a 105-108 and all three are no-neck-turn chambers. I would probably lean towards the first "JGS 1125" reamer myself with the PTG a close second as they are in a nice middle zone. Typically .104-.105 freebore reamers are the bread and butter for a 105 bullet. The middle one with a .094 would work but I would say its designed for slightly lighter bullets. A 115 is nice with a .120-.130 freebore so the jgs1125 and ptg reamers are sort of splitting that difference.
Do you see any issue with the tighter base on the PTG with respect to resizing?
 
So is a 0.271" neck still considered no turn?
General recommendations are .003 or clearance. My loaded lapua brass measures .267, some say theirs measures .269. With my .267 brass the .271 neck offers adequate clearance. With .269 brass and a .271 chamber neck you still have space... but it starting to get a bit tight. I wouldnt go smaller than a .271 neck.

Getting some brass that you want to use and measureing the neck thickness would let you make a more informed choice for your choice of components.

Do you see any issue with the tighter base on the PTG with respect to resizing?
That would depend on the die. I dont think it would be an issue but there are always caveats to everything.
Hopefully some die manufacturers would be willing to give you their dies base spec to choose an appropriate die to pair with an appropriate chamber.
 
General recommendations are .003 or clearance. My loaded lapua brass measures .267, some say theirs measures .269. With my .267 brass the .271 neck offers adequate clearance. With .269 brass and a .271 chamber neck you still have space... but it starting to get a bit tight. I wouldnt go smaller than a .271 neck.

Getting some brass that you want to use and measureing the neck thickness would let you make a more informed choice for your choice of components.


That would depend on the die. I dont think it would be an issue but there are always caveats to everything.
Hopefully some die manufacturers would be willing to give you their dies base spec to choose an appropriate die to pair with an appropriate chamber.

Thanks for the advice. I'm planning on using Lapua brass and probably Redding dies.