6mm Br - no-turn neck ?

[Dingus]

What diameter would a no-turn neck be? Would .270 require neck turning with Lapua brass?

Dingus Americanus

 

[dantiff2]

A .270 requires turning. That's what I shoot. Go with a .272 for a no turn..It's about the tightest you can go without turning.(minimal clearance)



Dan

 

[james in ky]

.272 is a no turn .270 you would need to turn

 

[Dingus]

Thank you!

 

[jackie schmidt]

Actual Dimension

I have a loaded Factory Lapua Round in my hand, (105 Scenar), and it measures .270 at the smallest spot around the neck, and .2704 at the largest spot around the neck.

That means it needs a minimum .272 chamber neck.

Do keep in mind that the Factory Loading features a bullet that has no "gas ring". This same case loaded with a typical Benchrest Flat Base Match Bullet will show about .0005 less clearance.

With a .272, you might be getting a little on the tight side........jackie

 

[Jeffreytooker]

271 Neck

I have a loaded Factory Lapua Round in my hand, (105 Scenar), and it measures .270 at the smallest spot around the neck, and .2704 at the largest spot around the neck.

That means it needs a minimum .272 chamber neck.

Do keep in mind that the Factory Loading features a bullet that has no "gas ring". This same case loaded with a typical Benchrest Flat Base Match Bullet will show about .0005 less clearance.

With a .272, you might be getting a little on the tight side........jackie

Jackie:

I have a new barrel which has a .271 neck. The chamber was cut with a FTG reamer. I have made a dummy cartridge with new (unfired) Lapua 6MM BR Norma brass and a Sierra 107 Match King. Neck was resized with a .268 bushing. The front of the neck reads .2689", and midway back on the neck reads .2692". The cartridge fits well in my chamber and would be a good fit in a .272" neck. I called Dave at FTG this morming. His standard no turn neck is .272". He makes special order .271" neck reamers.


I would caution people out there, particularly those who are getting prefit (Savage) barrels to find out exactly what the neck dimensions are on the reamer that cut your chamber. This is a safety issue because all "no turn" necks are not the same. I will measure the neck on the first fired round out of this new barrel. Being as the neck is listed at .271", the fired neck should be about .270".

HTH

Jeffrey Tooker

 

[jackie schmidt]

Jeffery

That is a pretty big difference from the loaded Lapua Factory rounds that I have. Pretty close to .001 inch.

I do know that the 105 Scenar will measure no bigger than .2430 anywhere on it.

I would think that Lapua uses the exact same brass in their Factory Loaded rounds as they sell to Handloaders.......jackie

 

[Jeffreytooker]

Recheck

That is a pretty big difference from the loaded Lapua Factory rounds that I have. Pretty close to .001 inch.

I do know that the 105 Scenar will measure no bigger than .2430 anywhere on it.

I would think that Lapua uses the exact same brass in their Factory Loaded rounds as they sell to Handloaders.......jackie

Jackie:

I find the link below to be a bit small.

http://www.6mmbr.com/6BRFAQ.html#23415

I saw another later reference (which I can not find at present) that listed loaded Lapua necks at .269. to .2695. I checked my mic against a 107 SMK just in front of the boat tail = .2430". Rececked old dummy .2693" made new dummy (new Lapua brass neck not resized) = .2692". For whatever reason mine are smaller than your factory round.

My rounds will be a max fit for my .271 neck, and I will measure each one before FF. With as close as I am working I measure all loaded round necks before FF. It is a caution I was given when learning to make 30 BR brass for a .330" neck.

Jeffrey Tooker

 

[Dingus]

My reason for asking, the local shop has a M700 with a shilen barrel in 6mm BR, with a .270 neck. Had thought it might be a good platform to start out in, but I don't want to mess with turning necks (not that sophisticated yet).

Thanks,

Dingus Americanus

 

[alinwa]

I also shoot a .271 nk. but I agree that .270 is a weird size. "MOST" loaded rounds would fit it but some wouldn't.

I personally would use it in perfect safety because I'd measure each neck but more importantly YOU CAN FEEL IT if you're thumbing a cartridge into a too-tight neck. This ain't rocket science. If the neck's too tight the round won't go into it. It's important to pay close attention right as the bolt handle drops, I have had chambers which were SHORT that were hard to feel.

As far as SAFETY goes, there's no such thing as "too tight" until you're actually crimping the mouth of the case onto the bullet. If it chambers without undue force it's safe to fire. All the crap about "a speck of dirt" or "a grain of powder" is just speculation IME, no one can cite an actual factual instance where a hunk of crud "caused a pressure spike"..........That said, a .270nk is probably just asking for heartache without proper tooling. I don't think it would shoot well with pressure ringed bullet regardless.

opinionsby


al

 

[fx77]

I've a BAT with Hart barrell no turn .272 neck

 

[Rflshootr]

No to hijack

But what freebore length should I get for 95-105 vld's?

 

[Rflshootr]

Thanks Lynn. I already have a 6mm throater so I'm good to go if I need longer.

 

[P1ZombieKiller]

free bore

But what freebore length should I get for 95-105 vld's?

RFL,

Only problem I have with free bore on my 6br is that now I want to try to shoot some 90's and I have to jump them pretty far.

 

[Rflshootr]

Zk

What amount of freebore does your rifle have?

 

[Rflshootr]

Lynn

Thanks Again
I ordered my reamer today from Kiff and decided to go with .090 freebore as you recommended. After looking at the bearing surface lengths, I think that will be the best choice for me especially having a throater if need be.