6br freebore question

[MS50]

I plan to have a 308 rebarrelled to 6br. The plan is to ask for a no turn .272 neck. The gunsmith's website states his reamer will result in .060 freebore. What is the heaviest, longest bullet I can expect to load, assuming the base of the bullet is not in the donut area? I have read related threads on 6br freebore. I'm probably kicking a dead mule, but I'm still unclear as to what is a "standard" freebore. This rifle is not intended for long range shooting exclusively, so I don't require a chamber that will accept 100 class bullets. I also don't want to limit my reloading to long, heavy bullets. Thanks.

 

[DeltaBravo]

What's the twist rate going to be? That will help decide how heavy a bullet you can use. Also, what are you using the gun for - short range BR, 600 yd, ???? All this will make a difference. I'm on my third barrel. First was an 8-twist and I could should just about anything - free bore was .104 IIRC and it was a .2704 neck for no turn. My last two barrel are both 14-twist and I shoot mainly 65/68 BTs, but that's about the limit for that twist/stability factor.

Good luck - new stuff to play with! ;D

Dennis

 

[bdale]

I plan to have a 308 rebarrelled to 6br. The plan is to ask for a no turn .272 neck. The gunsmith's website states his reamer will result in .060 freebore. What is the heaviest, longest bullet I can expect to load, assuming the base of the bullet is not in the donut area? I have read related threads on 6br freebore. I'm probably kicking a dead mule, but I'm still unclear as to what is a "standard" freebore. This rifle is not intended for long range shooting exclusively, so I don't require a chamber that will accept 100 class bullets. I also don't want to limit my reloading to long, heavy bullets. Thanks.

I would guess some where around 90 grain provided you have a 9 or 10 twist or faster.

 

[CSM19Z5M]

I just had a 10 twist 6BR varmint rifle built and it has a .272 no turn neck and .060 freebore. My rifle builder said the 10 twist would stabilize up to about 90 grain bullets in it okay. I just finished a trip out west where I shot 55 thru 75 grain VMAX and Nosler bullets and it is a laser to almost 500 yds. I'm loading up some 80 and 90 grain rounds now and will test them soon. Don't know what twist barrel you are getting so can't comment further but I wouldn't be afraid of .060 at all, depending on what your primary use will be.

 

[NorCalMikie]

Go 8 twist, zero freebore, no turn (.272). Start off with 50s and go heavier as the throat wears. (and it will) Nothing worse than loading your favorite bullets and not being able to reach the lands. (been there, done that ) Load with the bullet at the neck shoulder junction and stuffed into the lands. What donut?? Watch out for bugholes. 8) 8)

 

[MS50]

You're right, I'm misinformed on donut rings. I thought it was a ring of combustion byproducts that forms inside the case if a bullet is seated below the neck shoulder junction. My concern with the .060 freebore is that I thought I would have to seat long bullets too deep, and short bullets too shallow. I'm looking for what range of bullets lengths and weights I would be able to load with the .060 freebore. The purpose of this rifle will be medium to long range steel and target. I've observed other shooters with their 6mm's and 6.5mm's at the steel range. There's a huge difference in recoil. My .308 is a reliable shooter out to 1000yds, but it makes for a long day in the sun in the prone position. I plan to get a 1:8 barrel so that I can shoot heavier bullets. I don't need to shoot 100 class bullets. If I'm shooting at 1000yds or more, I'll use the .308.

 

[dreever]

I use a .060 freebore for long range in an 8 twist Kreiger using Berger 105 VLD's. It's easy to chase the lands as the barrel wears. In my opinion you do not need to go with long freebores. I get 2940 fps in my 26 inch barrel using Lapua brass , CCI 450's, and a reasonable charge of Varget. This combo shoots lights out in my rifle.

Danny

 

[HTSmith]

I have the .060 freebore with an 8 twist and it works great with 75 Gr Hornady's and 105 Gr Berger VLD's. I can jam them both and keep them out of the shoulder. The Berger Hybrids pushed back in the neck and didn't do to well for me. So I'd say .060 gives a lot of versatility. If you're just going for the long bullets, then I'd say go a bit more freebore.

 

[Dan Hall]

The .060 freebore won't impose very many limitations on you. Go for an 8 twist if you can but I also have a 10 twist in one of my BRs and it shoots 87 gr Berger VLDs lights out. 1/4" at 200 yards.It's a varmint slayer

Have a quality gunsmith put it all together well and you'll get 1000s of rounds of fun out of it.

 

[expiper]

OP,,,,my fav reamer for 6mmBR has .080 FB and it is perfect for everything,,,,a bbl is only going to wear .060 when shot out ,,,so I would recomend "some" FB to start with ,,unless you going to shoot the little 60-70 gr bullets,,,but with a 8 twist bbl you can shoot em all,,,,no matter what go no turn (.271 +/-) and keep the base line (.200 line) around .4705-.471",,,dont compromise,,,get your own reamer if the smith doesnt have the one you need,,,you can sell it easily later,,,Roger
EDIT,,,I noticed inquiry in later posts,,,the reason I reccomend .471 at .200 is this is aprox .003" larger than (and I reccomend NOTHING but LAPUA --the other brands are soft as aluminum )virgin brass and .003" larger than a Redding resize die,,,so the ctg brass swells .002 whnd fired and is shrunk back only .001" ,,which means good ctg life and ease of extraction and then rechambers as smooth as silk,,,,and yes this does add to accuracy ,,,there is no more accurate rifle than one that has ctgs that chamber and extract effortlessly and that are not over worked by over sizing with a resise die that is not in concert with the chamber/brass combo,,,,
,,,,I dont know the OP's load data with 87's ,,,but I use max loads of Rx-15 and try kissing the lands first (leaves a square mark on bullet) and then jumping .020" to see if there is any significant differance,,,,

 

[Changeling]

Hi Dan (little off subject), that is a neat "Gorgeous rifle! Is that one of your 6mm BR's ?


Hi expiper, why are you so emphatic about keeping the base line at .4705 - 471 is it that important to the 6mmBR relative to accuracy?

 

[joshb]

The .060 freebore won't impose very many limitations on you. Go for an 8 twist if you can but I also have a 10 twist in one of my BRs and it shoots 87 gr Berger VLDs lights out. 1/4" at 200 yards.It's a varmint slayer

Have a quality gunsmith put it all together well and you'll get 1000s of rounds of fun out of it.

Ditto, on the nice!!! Walnut. Very classy.

 

[OpossumMcMuffinDave]

The .060 freebore won't impose very many limitations on you. Go for an 8 twist if you can but I also have a 10 twist in one of my BRs and it shoots 87 gr Berger VLDs lights out. 1/4" at 200 yards.It's a varmint slayer

Have a quality gunsmith put it all together well and you'll get 1000s of rounds of fun out of it.

Dan, do you mind giving us your load and seating for the 87 gr Berger in the 1-10 twist barrel?

 

[expiper]

answer to reply #10 is bak in #9....hope this helps,,,Roger

 

[Dan Hall]

Re: 6br freebore question modified weight for the Varget!!

Sorry guys I've been busy elsewhere. The load data for the 87 Gr VLD in my 1-10 twist Dakota barrel is 32.0 Gr Varget with the bullet seated about 20/1000s ( square mark ) into the rifling and 205M primer. I got the load off this sight from MarkS. Here are some groups the rifle shot with this load.

The first group is at 200 yards and the second one is 100 yards. Both 5 shots out of the Dakota Predator seen in the previous posts. This load shoots well in all the 6BR's I've tried it in with no pressure signs. TRY IT.

 

[OpossumMcMuffinDave]

Thank you Dan.