What do you consider the freebore?
- Thread starter bsumoba
- Start date
I normally thought that too, but if we are simply looking at the distance from the case to the lands, then it should include the 0.016" distance between the case and the start of the freebore, no?
That is the dimension I call out as free bore when I order a reamer. Doesn't mean I'm right, though.
You have to call out free bore diameter, too. The part you are referencing is a different diameter than the free bore. I'm by no means claiming to be an expert.
You have to call out free bore diameter, too. The part you are referencing is a different diameter than the free bore. I'm by no means claiming to be an expert.
T & V @ 0.2514” along with diameter G & I @ 0.2844”.
It’s where the bullet’s chambered between where the case mouth ends and before the rifling begins at the lead @ I.
@ 0.0004” over groove size I’d call this a ‘tight throat’ design; I have a 7mm wildcat w/ 0.0005” throat-over-groove that shoots very well indeed.
It’s where the bullet’s chambered between where the case mouth ends and before the rifling begins at the lead @ I.
@ 0.0004” over groove size I’d call this a ‘tight throat’ design; I have a 7mm wildcat w/ 0.0005” throat-over-groove that shoots very well indeed.
So is U & V the "lead" and T & V the "throat", and free bore is lead + throat?
the taper from the neck dia to the begining of the free bore/lead is not hard to define
when you look at basically all chambers
there is always a taper from neck dia to "lead"...even in a 0.000 lead
so the freebore is 235, the total distance is longer
a zero free bore/lead with still have a taper from the neck dia.
when you look at basically all chambers
there is always a taper from neck dia to "lead"...even in a 0.000 lead
so the freebore is 235, the total distance is longer
a zero free bore/lead with still have a taper from the neck dia.
Last edited:
swd
Silver $$ Contributor
This^^ And I agree that's on the tight side. I'd rather see .0005"-.0007"
No, I don’t include lead length in the throat length. Quite simply, throat is from where case mouth ends (often some distance back from where chamber design has case neck diameter begin its taper to freebore diameter) up to the point where lands begin their taper at the start of the lead. Where freebore ends at the front, lead begins.
Shot well for me in multiple big matches.
No reason it shouldn’t. Just noting a personal preference for throat diameter that allows free gas passage while also minimizing any loaded bullet runout that might otherwise affect bullet’s entry to the lead. With long bullets seated out, a tight throat will aid concentric alignment.
Most people's definition is that of SAAMI's (below) which is the part of the bore that's free of rifling :
FREE BORE
A cylindrical length of bore in a firearm just forward of the chamber in which rifling is not present. Associated with bullet jump.
Some folks will disagree for numerous reasons.
It's the .2844" diameter .2350" long section in front of the chamber mouth.
FREE BORE
A cylindrical length of bore in a firearm just forward of the chamber in which rifling is not present. Associated with bullet jump.
Some folks will disagree for numerous reasons.
It's the .2844" diameter .2350" long section in front of the chamber mouth.
Last edited:
That plus the distance the case is trimmed short of the max chamber neck length.
There's freebore and throat. The throat is the tapered part. If your determining touch I would think it includes both.
swd
Silver $$ Contributor
If that's same reamer you've been using all along I've seen it shoot plenty of times. Sounds like your GTG then!Shot well for me in multiple big matches.
The distance from case mouth to the chamber mouth, where freebore starts, has oft times been termed "case mouth clearance" like the "case head clearance" from bolt face to case head. Both with cartridge full forward in the chamber when fired.
I've heard that rimmed and belted cases can have "shoulder clearance" when fired.
If you check SAAMI chamber specs, you may learn some cartridge chambers' have zero freebore. 300 Win Mag and 30-06, for example.
Last edited:
TRUE save for commercially available rifle chambers where SAAMI rules the day.
Again true, ‘cause reloading for performance allows tailoring ammunition specs to get maximum performance. Going one step beyond includes custom-spec chamber profiles, and/or ‘throating’ reamers used to ‘tune’ freebore length to the Nth degree to get the best results for your efforts. The exact opposite of ‘off the shelf’ products.
And why forums like this one are such a valuable resource for us!
Similar threads
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.