6br Freebore

[VA_XTC_Shooter]

Probably not what a benchrest shooter wants, but for someone who needs to load 200-400 rounds and travel to a match and shoot them all in a weekend, it’s right up their alley.

I shoot highpower, mid and long range with the 6br, so I fall in the camp of loading a pile for a week of shooting. But shoot anything from 70 gr nosler varmint tips, Lapua 90, to Berger 105 VLD/Hybrid.

Would the 0.104" reamer have any issues with the 70s?

 

[Tokay444]

I don’t have enough experience to comment to that. Sorry.

 

[VA_XTC_Shooter]

I checked out my 105 VLD loads and took some measurements and photos. It appears the 105 Hybrid OAL to the lands is a little longer than the VLD.
Currently in a 0.094” freebore, my 105 VLD COAL to the lands is 2.341”, base to ogive is 1.737”

105 Hybrid would be 2.387” and 1.771”

both bullets appear to still seat above the neck/shoulder junction (1st photo VLD, 2nd Hybrid), so I should be good. Correct?

what is interesting though is that these numbers don’t match the reamer. The JGS reamer print has base to end of freebore (where I would consider ogive in the lands) to be 1.6778”. I partially chalk this up to the comparator used to measure ogive on my bullets.

 

[Clancy]

I have a .035 freebore and shoot the Bart’s 68 Avenger. It’s a wonderful match.
I think if I shot 55s I might go with a 0, but as long as barrel life is I don’t think you’d be in a bind either way.

 

[Dale264]

Barrel arrived and took some measurements. With the 0.060" freebore, the heel of a 112 match burner sits just above the neck shoulder junction. Same with a 105MB. From a .098"FB to a .060"FB the loaded length for most bullets needed to be seated roughly 0.045-0.055" deeper in the case depending on bullet shape. Sleeker bullets needed to be set back farther.

Took the new rig out to the range today with no load development, zeroed the scope and shot this tiny 3 shot group with some left over ammo from my last 6br. It shows promise!

 

[BigRob]

I am currently shooting 0.094" freebore with 70s to 105 berger VLDs and it shoots lights out. I am about to order a reamer for my new barrel and was planning to replicate the 0.094"

It seems the 0.104" is the off the shelf freebore for the 6BR, why? As many have shown above, its unnecessary for the 6BR 105s. Why extend freebore when not needed?

Some reference chasing or not chasing the lands. Would the difference in freebore then provide a different barrel life?

I am just trying to wrap my head around this discussion, not trying to talk down to others' opinions.

Does 0.094" put the boattail of a 105 Berger in front of the neck shoulder junction?

I'll be using Lapua cases and Berger 105 VLD Target

 

[gunsandgunsmithing]

Does 0.094" put the boattail of a 105 Berger in front of the neck shoulder junction?

I'll be using Lapua cases and Berger 105 VLD Target

Yes, in every one that I've seen. I think .060 is a little too short for all but will work with most heavies. I think the roughly .100 reamers are a great and versatile amount of fb. I can shoot 68-105 class bullets with that.

 

[BigRob]

Still talking to different gunsmiths, as this is my first full custom rifle. So 0.094"- 0.105" would work for a Berger 105.

The Smith a hour away thinks his reamer is a 0.105". The other Smith across the country has the 0.094", but has some competition shooting background and other high level shooters recommendations. I've got an email out to another Smith about 10 hrs away to see what he says

Just feeling it out yet, as all my parts won't be here till January sometime

 

[Wingnut00]

I just had a barrel set back with a .104 freebore 6br reamer. With 109 hybrids my bearing surface/boat tail junction is just barely ahead of neck/shoulder junction. And I mean barely. Hope this helps.

 

[VA_XTC_Shooter]

Still talking to different gunsmiths, as this is my first full custom rifle. So 0.094"- 0.105" would work for a Berger 105.

The Smith a hour away thinks his reamer is a 0.105". The other Smith across the country has the 0.094", but has some competition shooting background and other high level shooters recommendations. I've got an email out to another Smith about 10 hrs away to see what he says

Just feeling it out yet, as all my parts won't be here till January sometime

I use the 0.094, look at pics above you can see the 105 is above the neck junction.

 

[Dgd6mm]

0.094 freebore is enough for the 105 Berger. You have to love the length of the 6br neck.

 

[Kracken McGraw]

I just had a barrel set back with a .104 freebore 6br reamer. With 109 hybrids my bearing surface/boat tail junction is just barely ahead of neck/shoulder junction. And I mean barely. Hope this helps.

This is what I’m getting for a new build on the recommendation of the Smith for 107 Sierra’s.

 

[Wingnut00]

This is what I’m getting for a new build on the recommendation of the Smith for 107 Sierra’s.

You will like it. I wouldn’t mind .010-.015 longer but I’m happy.

 

[Flyshooter]

Okay, I had a Brux 8 twist, chambered it with my 6br 104 reamer. Shot good, so it was shot a lot because it was reliable with 105’s, 107’s and hybrids. Using varget, RL-15 or H4895..... always shot good. Where about’s hammering the steel at 600 was addictive, especially when your fellow shooters aren’t have the same level of secess as you are....it’s nice.

But eventually the throat is eroded and it’s time to change it out. Some time later the bore scope says the barrel isn’t to bad about 6” in front of the chamber and there’s enough meat left to fit it to a 700 using a nut.......hummmm.

So it was rechambered using a 6br zero free bore for varmints, at 22” it shot 55 grain bullets around 1/2 moa not nearly as good as any of the slow twist I have but decent.

One day I decided to try the heavies again, the charge has to be reduced because the bullets are along ways in the case. However it shot those 105, 107 & hybrids tight, as tight as it ever did.....who knew??
Shot it at 600 and shot nice tight groups, the FPS is down to around 2650 which is slow but for hammering steel plates makes a guy smile.
Those other fellas shake their heads and say WTH.....that short barreled floppy 700 is not normal.....I seriously tell them the zero freebore is the answer and I can fix yours for you.......haven’t had any takers yet...huh. That the facts......

 

[BigRob]

I use the 0.094, look at pics above you can see the 105 is above the neck junction.

I see the VLD is a good little bit above the neck shoulder junction, which is nice to see since I have 500 of them purchased already

Anyone have any input on the work done by Pierce Precision in Lansing, Michigan?

 

[Dimner]

Barrel arrived and took some measurements. With the 0.060" freebore, the heel of a 112 match burner sits just above the neck shoulder junction. Same with a 105MB. From a .098"FB to a .060"FB the loaded length for most bullets needed to be seated roughly 0.045-0.055" deeper in the case depending on bullet shape. Sleeker bullets needed to be set back farther.

Took the new rig out to the range today with no load development, zeroed the scope and shot this tiny 3 shot group with some left over ammo from my last 6br. It shows promise!View attachment 1244816

How did the .060 free bore end up working for you @Dale264 past your initial load dev? I'm looking to build my first 6BR. I'll be learning 300-500 yard prone off a bipod with the 70tnts and the Hornady 105's.

Not sure if the barrel in your original post is still going strong, did you have any regrets of thoughts on the 0.060 freebore?

 

[Dale264]

How did the .060 free bore end up working for you @Dale264 past your initial load dev? I'm looking to build my first 6BR. I'll be learning 300-500 yard prone off a bipod with the 70tnts and the Hornady 105's.

Not sure if the barrel in your original post is still going strong, did you have any regrets of thoughts on the 0.060 freebore?

I've got exactly 500rd down the pipe at this point (haven't gotten out to the range much lately) and couldn't be happier with the midweight bullets. It has worked well with Barnes 105s too. Most loads ended up being about 0.1-0.2gr less compared to my previous 6br barrel which was a 0.098fb.

I'm not sure I really gained anything performance wise by going with the slightly shorter freebore. Possibly gave up a little with 105s but it wasnt very noticeable. Would I do it again? Likely, because I don't shoot a ton of 105s. If I shot mostly 105s I'd go with the barrel makers standard freebore.

 

[Dimner]

I've got exactly 500rd down the pipe at this point (haven't gotten out to the range much lately) and couldn't be happier with the midweight bullets. It has worked well with Barnes 105s too. Most loads ended up being about 0.1-0.2gr less compared to my previous 6br barrel which was a 0.098fb.

I'm not sure I really gained anything performance wise by going with the slightly shorter freebore. Possibly gave up a little with 105s but it wasnt very noticeable. Would I do it again? Likely, because I don't shoot a ton of 105s. If I shot mostly 105s I'd go with the barrel makers standard freebore.

Thank you very much I really appreciate the feedback. Very helpful.