13.5-1 Twist 6BR Reamer

[urbanrifleman]

Ok, so I scored a 13.5 4 land Krieger barrel and was going to cut it for 6BR. I have a generous supply of 70 TNTs and 70 and 55 Varmageddons. My reamer is 272 neck and 125 freebore. I would really like something cheaper, but I am afraid ordering a reamer with less freebore might be quite a while on backorder.

I might just use my 125 reamer. Even out to the lands there is still a lot of bullet in the case.

 

[Phil]

Call and see what`s available, those 55`s will want a ZERO freebore reamer for sure......

 

[urbanrifleman]

Really I would like a ZERO 272 neck. Anyone? Anyone? Bueller?

 

[geraldgee]

I bought a reamer with .070 FB to shoot 80-90gr bullets in my 6BR. My Dasher shot the 105 gr Hybrids with .104 FB. Not saying it can’t be done but not sure how much bearing surface you’ll have in the case neck.

 

[urbanrifleman]

The 70 grain bullets are quite long. The 125 reamer I have works fine for those. Of course, not for the 55s.

 

[gunsandgunsmithing]

Ok, so I scored a 13.5 4 land Krieger barrel and was going to cut it for 6BR. I have a generous supply of 70 TNTs and 70 and 55 Varmageddons. My reamer is 272 neck and 125 freebore. I would really like something cheaper, but I am afraid ordering a reamer with less freebore might be quite a while on backorder.

I might just use my 125 reamer. Even out to the lands there is still a lot of bullet in the case.

I would double check something. No way there's much(any) bullet in the neck of a .125 fb 6br, at the lands with those 55's. The 70s won't have much..probably about 1/16".

 

[urbanrifleman]

No way there's much(any) bullet in the neck of a .125 fb 6br, at the lands with those 55's.

70s are much longer than 55s. The flat backs like the Varm and TNT have more in the neck than some heavier boat tails. The 55s would not be seated to the lands. They would have to jump.

 

[LHSmith]

70s are much longer than 55s. The flat backs like the Varm and TNT have more in the neck than some heavier boat tails. The 55s would not be seated to the lands. They would have to jump.

Sorry, I've been away from the site for a few hours. What is this new flat back bullet design? Hard to keep up with the technology anymore.
And , yes, i did a search (not google) and found nada.

 

[urbanrifleman]

Sorry, I've been away from the site for a few hours. What is this new flat back bullet design? Hard to keep up with the technology anymore.
And , yes, i did a search (not google) and found nada.

These are not new. I was just saying the 70s (I have TNTs and Nosler Varmageddon) are flat backs and they shoot well with the long throat. Although, I suppose not ideal. That is why I started the thread.

 

[gunsandgunsmithing]

This is what a 74gr Berger looks like in a .098 free bore, at the lands. They haven't made this bullet for several years now.

 

[urbanrifleman]

That looks right.

Like I said, I was thinking I need a shorter FB for these.

 

[Dusty Stevens]

Grizzly used to keep the correct zero fb reamer in stock youd want. Check with all the other usual suspects too like ptg and jgs and manson. Its usually a stocked item

 

[urbanrifleman]

Grizzly used to keep the correct zero fb reamer in stock youd want. Check with all the other usual suspects too like ptg and jgs and manson. Its usually a stocked item

Will do.

 

[geraldgee]

The 70 grain bullets are quite long. The 125 reamer I have works fine for those. Of course, not for the 55s.

Excerpted from - http://www.6mmbr.com/kiffreamer.html

Q: Without revealing any trade secrets, what throat lengths do you recommend for a 6mm BR case?

We normally go with a 1.5 degree lead angle, unless the customer wants something different. For 60-68gr bullets we recommend a .060" freebore. For the 80gr bullets, .080" is a good setting. For the 100-107gr VLDs, a .115" -.120" freebore will allow you to get the base of the bullet up out of the doughnut area. This will save you lots of aggravation over the life of the barrel.

 

[urbanrifleman]

Excerpted from - http://www.6mmbr.com/kiffreamer.html

Q: Without revealing any trade secrets, what throat lengths do you recommend for a 6mm BR case?

We normally go with a 1.5 degree lead angle, unless the customer wants something different. For 60-68gr bullets we recommend a .060" freebore. For the 80gr bullets, .080" is a good setting. For the 100-107gr VLDs, a .115" -.120" freebore will allow you to get the base of the bullet up out of the doughnut area. This will save you lots of aggravation over the life of the barrel.

I had read that once before. Good reference!!! So, I was thinking that a 0 freebore is 1/8" shorter than mine. That would put the 70FB say... 250 thou at most in the neck. That still isn't anywhere near the donut on a 6BR.

 

[LHSmith]

Still no luck on flat back search, but I did find chamfered back bullets are now available:

 

[urbanrifleman]

70 TNT

 

[urbanrifleman]

70 Varmegeddon

 

[KMart]

Several years ago I ordered a 6 br reamer from Kiff and spoke to him directly. My barrel was a Krieger, 13.5 twist. His spec for that reamer is something he called a "blue box" no turn. 2.704 neck and a zero freebore. It shot everything up to 80 gr Berger FLAT BASE bullets very well. The 80 grain bullet seated with the base about 1/2 the way down the neck, seated into the lands.

 

[gunsandgunsmithing]

Several years ago I ordered a 6 br reamer from Kiff and spoke to him directly. My barrel was a Krieger, 13.5 twist. His spec for that reamer is something he called a "blue box" no turn. 2.704 neck and a zero freebore. It shot everything up to 80 gr Berger FLAT BASE bullets very well. The 80 grain bullet seated with the base about 1/2 the way down the neck, seated into the lands.

The Berger 80fb(flat base) and 105vld have basically the same bearing surface length.

edit...the 80 has a bit more but I've seen lot to lot variation of .040"
http://www.bergerbullets.com/pdf/Quick-Reference-Sheets.pdf