New 6 BR build which reamer

[expiper]

Would anyone know the FB to get out of the donut on a .243?

the neck on a .243 is ~the same as a Dasher,,,so the same FB would be applicable....,,,,just remember with those short necks the FB that works well with 105 class bullets is not necssarily good for 68 gr benchrest bullets,,,,,I use a .120 on my .243's and jump the lil' bullets,,,,Roger

 

[urbanrifleman]

the neck on a .243 is ~the same as a Dasher,,,so the same FB would be applicable....,,,,just remember with those short necks the FB that works well with 105 class bullets is not necssarily good for 68 gr benchrest bullets,,,,,I use a .120 on my .243's and jump the lil' bullets,,,,Roger

Thank you sir!!!

 

[urbanrifleman]

the neck on a .243 is ~the same as a Dasher,,,so the same FB would be applicable....,,,,just remember with those short necks the FB that works well with 105 class bullets is not necssarily good for 68 gr benchrest bullets,,,,,I use a .120 on my .243's and jump the lil' bullets,,,,Roger

Based on what I am reading here .120" on standard 6Br is probably more than is needed. But it does work like a charm on mine. If I were to do it again, I would simply buy the one from Bullets.com and skip the wait.

 

[Alex Wheeler]

The br has .080 more neck than a dasher. So to keep the same distance from the boat tail junction to the doughnut, you would subtract .080 from your dasher fb. So .120 in the dasher would be equal to .040 in the BR. So by using a .100 free bore your actually .060 farther away from the doughnut than in your .120 dasher.

 

[GrocMax]

FYI JGS usually stocks the 'CIP spec' 6BR Norma reamer, which is I believe .093" FB and no-turn neck for blue box brass. Its significantly cheaper than a custom. Works good on light varmint bullets as well.

You'd think Lapua factory ammo would be set up for a CIP spec chamber.

 

[fm1947]

.100 freebore .272 neck

Why do you recommend .272 neck, I just had one built, .272 neck, 1/7.5 twist , my reason, I'm just tired of turning necks over the years

 

[urbanrifleman]

The br has .080 more neck than a dasher. So to keep the same distance from the boat tail junction to the doughnut, you would subtract .080 from your dasher fb. So .120 in the dasher would be equal to .040 in the BR. So by using a .100 free bore your actually .060 farther away from the doughnut than in your .120 dasher.

This is very informative.

Why do you suppose the same freebore is being recommended for 6 br as for Dasher by some many people? They are radically different. I will say this I think my other reamer for 6Br was .060" FB and I was hitting the donut.

 

[Alex Wheeler]

Most guys want to seat the bullet up the neck to maximize powder capacity. This has the effect of reducing neck tension however which is why I shorten them up a little if theres room. Most barrels are past their accuracy prime long before you would run out of neck and competitors pull them off as soon as they see accuracy loss so thats not an issue. Reamers dont always match the print. Everyones human. Freebore error seems to be the biggest culprit.

 

[urbanrifleman]

When you look at the reamer print, how do you determine the freebore from the print?

 

[newbieshooter]

When you look at the reamer print, how do you determine the freebore from the print?

.104 freebore

 

[urbanrifleman]

.104 freebore

View attachment 1028914

Thank you so much!!!

 

[Fire Dog]

I will make a suggestion, call JGS and ask for them to send a print of reamer #1262. Thank me later.....

The #1262 is the reamer that was used on my Eliseo R-5 and I currently hold the range record of 10 shots in a 1 3/4" at 300 meters... Shot #8 was just out a touch or it would have been 10 inside of 1 1/2"...!
I liked this result so much that I have bought a #1262 reamer from JGS.. They often have this in stock so there is no waiting. I also have a PTG reamer in 6BRAI and that is a winner but it also required 10 weeks wait and currently when I ordered some "Go/No Go" gauges in mid June they were finally delivered last week...!
Also consider a reamer from:
Dave Manson Precision Reamers
8200 Embury Road
Grand Blanc, MI 48439 USA
1-810-953-0732 (tel) 1-810-953-0735 (fax)
www.mansonreamers.com
Their "Stock" reamer has a .105" Free Bore and the JGS has a Free Bore of .0940"
PTG does not have any "Stock" reamers and everything is made to order and hence the waiting time...
Both of the mentioned reamers are .272" No Neck Turn reamers.
Hope this is helpful... {:~)

 

[Fire Dog]

The short answer is buy your reamer from JGS. I have had great luck with my 6BR which has an .080 throat. Shoots awesome with everything from 87 gr to 105 gr.

Paul

www.boltfluting.com

JGS #1262 reamer has No Neck Turn .272" and Free Bore of .0940"
This chamber in an Eliseo R-5 has shot me a range record of 10 in 1.75" at 300 meters... Good enough!