I need to order a 6br and 308 reamer for f-class gun
- Thread starter coyote
- Start date
Chinbullco
Regular
- Location
- NW Alberta
Chamber Reamers
Order them to fit Lapua brass and the bullet that is your first choice for the shooting you do. Leade should be short enough to bump rifling with bullet seated fully into neck.
Order them to fit Lapua brass and the bullet that is your first choice for the shooting you do. Leade should be short enough to bump rifling with bullet seated fully into neck.
I think for starters you need to ask yourself which bullets you are going use. For F/TR if you’re going to use the 155’s and decide later to try the 185’s or heavier you will have freebore issues. Same with the 6mm bullets shooting 95’s then thinking the 115’s might be your answer.
Here is an article that may prove helpful http://riflemansjournal.########.com/2011/07/cartridges-308-heavy-bullet-conundrum.html
As maynard has pointed out neck turning can be a pain and lots of folks in F/TR ask for reamers with no turn necks. (neck of .341 to .345) or at least 5thou clearance from your loaded round. F open guys seem to like tighter necks and skim turning. Too each their own. I have heard talk (haven’t tried it myself) for F/TR where guys are getting reamers with max saami spec in 308 so that they can stuff as much powder as they can. (might need custom dies)
Even the type of brass plays a part which brand you are shooting
My advice would be to talk with PTG or JGS the reamer guys tell them what you are trying to do and what discipline you are competing in. they will have a list of questions and are far more knowledgeable and familiarity with what you may need.
Here is an article that may prove helpful http://riflemansjournal.########.com/2011/07/cartridges-308-heavy-bullet-conundrum.html
As maynard has pointed out neck turning can be a pain and lots of folks in F/TR ask for reamers with no turn necks. (neck of .341 to .345) or at least 5thou clearance from your loaded round. F open guys seem to like tighter necks and skim turning. Too each their own. I have heard talk (haven’t tried it myself) for F/TR where guys are getting reamers with max saami spec in 308 so that they can stuff as much powder as they can. (might need custom dies)
Even the type of brass plays a part which brand you are shooting
My advice would be to talk with PTG or JGS the reamer guys tell them what you are trying to do and what discipline you are competing in. they will have a list of questions and are far more knowledgeable and familiarity with what you may need.
I am still going 7mm ,these reamers are for a few other jobs.
One of the reamers is to rechamber my 6br and the 308 well lets just say I need one lol .
I'm still not sure what 7mm to go with kind of up in the air on this one.
For the 6br I already was going with 6br norma I thought there was a match reamer with tighter specs and regular reamer.
rnbra-shooter
CGN Ultra frequent flyer
- Location
- New Brunswick
I have a JGS .308 Obermayer (state of the art 20 years ago ;-). My only complaint about it is that the throat is too short to use Lapua 155s well (ideally the throat should be about .150" longer for them). That's not as big a drawback these days though as the other peer bullets (Berger 155.5 and Sierra #2156) work well out of it.
For safety reasons I would avoid using an "intermediate-tight" neck, by which I mean something smaller than .343" but large enough to perhaps allow a piece of factory ammo to plausibly chamber. If you have a .333" neck there is no risk of you, or a friend borrowing your rifle, or somebody you sell your rifle to, or a friend of somebody you sell your rifle to, of chambing a piece of factory ammo because it simply won't fit at all. But if you have a .336" or a .340" neck, then there is a very real possibility of just the wrong things happening and having an accident happen.
While by BR standards Obermayer chamber is "wrong" and also "unnecessarily sloppy", it does shoot quite accurately. The necks of my fired brass are .343", I run them into a neck bushing die (.336 for my out-of-the-box Lapua brass if I recall correctly). Even though by BR standard I am working the neck way too much, it does not have a noticeable effect on my brass life; I have no idea if they'll go 10 reloadings, or 20, or 30, but I don't have any cracked necks and it simply isn't an issue.
If I were buying a .308 reamer these days I'd probably buy one of the newer reamers designed for Target Rifle shooting. Some of them have slightly longer throats (they are designed to pass Bisley's "Rule 150"). Or even more likely I'd get a copy of the Kiff reamer made for the 2011 Canadian Palma team, some good work went into that.
A nice thing about using a somewhat-longish leade is that you can shoot all three of the good 155s (Lapua 155, Berger 155.5, Sierra #2156, and also possible the new Berger 155 Hybrid but the jury is still out on whether that is an easily shootable bullet or not), and you can also shoot the Berger 185-BT (which I think more and more F-TR shooters are going to move to), or the 210-class and the upcoming 230-class target bullets.
For safety reasons I would avoid using an "intermediate-tight" neck, by which I mean something smaller than .343" but large enough to perhaps allow a piece of factory ammo to plausibly chamber. If you have a .333" neck there is no risk of you, or a friend borrowing your rifle, or somebody you sell your rifle to, or a friend of somebody you sell your rifle to, of chambing a piece of factory ammo because it simply won't fit at all. But if you have a .336" or a .340" neck, then there is a very real possibility of just the wrong things happening and having an accident happen.
While by BR standards Obermayer chamber is "wrong" and also "unnecessarily sloppy", it does shoot quite accurately. The necks of my fired brass are .343", I run them into a neck bushing die (.336 for my out-of-the-box Lapua brass if I recall correctly). Even though by BR standard I am working the neck way too much, it does not have a noticeable effect on my brass life; I have no idea if they'll go 10 reloadings, or 20, or 30, but I don't have any cracked necks and it simply isn't an issue.
If I were buying a .308 reamer these days I'd probably buy one of the newer reamers designed for Target Rifle shooting. Some of them have slightly longer throats (they are designed to pass Bisley's "Rule 150"). Or even more likely I'd get a copy of the Kiff reamer made for the 2011 Canadian Palma team, some good work went into that.
A nice thing about using a somewhat-longish leade is that you can shoot all three of the good 155s (Lapua 155, Berger 155.5, Sierra #2156, and also possible the new Berger 155 Hybrid but the jury is still out on whether that is an easily shootable bullet or not), and you can also shoot the Berger 185-BT (which I think more and more F-TR shooters are going to move to), or the 210-class and the upcoming 230-class target bullets.
You've gotten good advice so far- but I'll add my $0.02. I have 2 barrels chambered w/ a Bisley Rule 150 but a .341 neck. This is snug, as Daniel mentions- 0.004-0.005 clearance on Lapua brass- but I think you would find that it is about the most common. You will have to decide about risk.The throat is definatly a jump for the 155 bullets, w/ the exception of the 155 Lapua, which can be seated to the lands. The same chamber works great with the 185 BT, but is short to be optimum for the 210's. If I was doing it again, I'd be tempted to order a a short throat, and a throating reamer so you can lengthen your throat if you decide to try the longer, heavier bullets.
I sent a couple of 155.5 and 185 BT dummy rounds with my last 2 barrels to be chambered at the same time and left the dimensions up to the 'smith. It came back with a .341 neck, snugger than the 150 in the base, and a bit shorted in the throat. I think it's about ideal for up to 185's...
I sent a couple of 155.5 and 185 BT dummy rounds with my last 2 barrels to be chambered at the same time and left the dimensions up to the 'smith. It came back with a .341 neck, snugger than the 150 in the base, and a bit shorted in the throat. I think it's about ideal for up to 185's...
rnbra-shooter
CGN Ultra frequent flyer
- Location
- New Brunswick
It is specifically the .341 sort of necks that I was talking about. Technically speaking it is SAAMI-illegal but in practice just about every piece of factory ammo will chamber without resistance and fire safely. *BUT*, find the wrong piece of factory ammo, and you are one step closer to an accident.
In the late 1980s (I think), when Canadian TR shooting was done with issued ammo (either IVI or DA), efforts were made to find chambers that would shoot the crap ammo better. Creighton Audette came up with a reamer with a .340" or .341" neck. Some time later these rifles ran into problems with non-IVI and non-DA ammo (it could have been one year when Bisley had the ammo loaded in Portugese or Finnish brass).
I don't think that shooters like coyote or mpwolf are at risk of not noticing this sort of thing. It's just that this sort of tricky tight neck is sort of a time bomb in the system, if the barrel ever gets sold on to somebody else or used by somebody else who might not be fully aware of all the implications behind a "just-slightly-too-tight" neck.
BTW we all know how well mpwolf's rifle shoots so simply copying that would be a pretty good starting point.
In the late 1980s (I think), when Canadian TR shooting was done with issued ammo (either IVI or DA), efforts were made to find chambers that would shoot the crap ammo better. Creighton Audette came up with a reamer with a .340" or .341" neck. Some time later these rifles ran into problems with non-IVI and non-DA ammo (it could have been one year when Bisley had the ammo loaded in Portugese or Finnish brass).
I don't think that shooters like coyote or mpwolf are at risk of not noticing this sort of thing. It's just that this sort of tricky tight neck is sort of a time bomb in the system, if the barrel ever gets sold on to somebody else or used by somebody else who might not be fully aware of all the implications behind a "just-slightly-too-tight" neck.
BTW we all know how well mpwolf's rifle shoots so simply copying that would be a pretty good starting point.
It is very hard to talk about specific sizes of necks etc because some reamers don't match what the print says. I have a Palma 95 reamer from Pacific Tool that cuts way undersize to the point where you can't buy dies small enough to work. I use it as a rougher and clean up with a JGS Palma 95 reamer. Both prints are the same and designed by the same guy. Bottom line is talk to the reamer maker and tell him what you want to do, and buy a quality reamer. It may cost a bit more but is small change in the price of the rifle.
