308 Chamber?

M852 is a popular chpice, 1.5 degree per side and a little tighter in the body than the popular Obermeyer. Use a removable pilot.
 
Take a piece of once fired brass, size it with your dies and load your bullet of choice. Choose your reamer based on the loaded round or better yet, have a reamer built to your specs.
 
M852 or the Gamboa, but most importantly, what bullets will you be using because many chambers are generally Palma dimensions for 155 grain bullets. You may want a 308 Match if using VLDs
 
Last edited:
I haven't totally decided yet on what bullet I am going to be using but am thinking I would like to use one of the Berger 185's, but I got to talk to some locals to see what they suggest around here out to 1000 yards. If I get something that will allow me to shoot the 185's does that necessarily mean they wont shoot 155's ?
 
50/50. Something chamber to shoot 185 will be a fairly long throat, the 155s will be much shorter and depending on the bullet used may not like making that big of a jump to the lands
 
I contemplated this for a long time myself a decided that i wanted to shoot the Palma bullets for ftr 155 or triple nicks because of the very high BC. lots of great results from Canadian shooters. I purchased a US team Palma reamer for my project however considering the Canadian team Palma design just some very slight differences.
 
I wouldn't bother with a palma chamber if going with 185s (great bullets by the way) remember too that some palma reamers are meant for use in palma bores (.298" X 3065, 307 or .3075"). Yes, you will still be able to use palma bullets, and make them work well. I would talk to your gunsmith and see what match spec 308 reamer he has. More than the chamber, I would make sure the throat is optimized for the 185's
 
I found that the Obermeyer had great results in tangent ogive bullets (think Sierra) and the M852 had great results with secant ogive (think VLDs like Lapua, Matrix and Berger). Tried swapping with mixed results and gave up, as I already had something that worked.
 
Neither thr M852 or Obermeyer require neck turning which is mostly considered passe, except in BR. Recently did testing with 155, 167 and 185 Lapua factory with M852 in Hart 1-12", 27" OAL, Barmard S, Dolphin stock. Shot well.
 
Most .308 reamers that have "Palma" in their name are made with very short throats. For example, one common one is the "Warner 95 Palma", which is also known as "WTC Palma" (WTC = Warner Tool Company). It was made so that an old Sierra 155 (#2155) seated at 2.775" COAL would just touch (more or less) the lands. This is because for the Palma Match in 1995 in New Zealand, that was the ammo that was being supplied. That chamber worked very well then, and as a result it is still around and is still quite a popular reamer. In my opinion it is a bit of a sub-optimal choice; it's OK for some of the 155s (Sierra #2155 and 2156; Berger VLD and 155.5 Fullbore), but its throat is much too short for some of the 155 target bullets (specifically the Lapua 155 Scenar) and is too short for many of the heavier bullets you might want to use in FTR.

My rifles are chambered in .308 Obermayer, because that was more or less state of the art in 1993 when I got started (see how long and strong inertia is in the shooting world??!!!) The Obermayer's throat is about .030" longer than the "Palma" reamers, however the Obermayer is still a "short-ish" throat reamer. It works very well for the Sierra 155s (both), the Berger 155 and 155.5s. One can get a Lapua 155 to shoot OK in it, but it is much much shorter than optimal for a Lapua 155 or for one of the heavier longer match bullets.

Reamers that are identified as "Bisley" usually have throats .030" to .050" longer than an Obermayer. They are called "Bisley" because the are intended to comply with "Rule 150" that is in effect for shooting TR at Bisley (your chamber is supposed to have a long enough throat such that a test round does not touch your rifling). "Bisley"-chambered guns give very good results with all of the 155s that I have mentioned. And as the longest-throated of the reamers I have mentioned so far, they are the better choice for the bullets that need longer throats (Lapua 155, and the various heavier target bullets).

Reamers with throats longer than the "Bisley" types are also available. If you go out and do research on what the very best FTR shooters are using, they'll tell you what works well with their Berger 185LRBTs etc.

You should avoid any reamer that is tight-necked or needs to have the brass neck-turned. Personally I think it is dangerous to build a fullbore target rifle with a neck tighter than .343" - not that you as a knowledgeable shooter will necessarily run into trouble with it, but it is an accident waiting to happen if/when someone someday chambers a piece of military ammo with a neck on the thick side (e.g. various South American surplus ammo) and you actually get an interference fit.

You could choose a "Bisley"-class or slightly-longer throated reamer, and get very good results with it. You could reasonably expect such a rifle to shoot the following very well:
- Sierra #2155 (there'll be lots of jump, but it's a pretty jump-tolerant bullet)
- Sierra #2200 (168 HPMK), in handloads or as factory ammo. A lot of jump, but it's quite jump tolerant. It's not a long range bullet, but it is probably the single most commonly available bullet in factory match ammo.
- Sierra 175HPMK. Not the world's highest performance bullet, but a very sound and solid bullet. Available in factory match ammo, and useable to 1000 yards
- Berger 155.5 Fullbore and 155 Hybrid - two very high performance 155s, which can shoot quite well with some jump.
- Lapua 155 Scenar - often a very fussy bullet to get to work, but once you do it is absolutely first-rate. It is the oldest super-high-performance 155, and it is still in the same league (dragwise) as the very best 155 target bullets.
- Berger 155 LRBT and 185 Hybrid ought to shoot very well for you
- Sierra 190 HPMK is very much a middle-performance bullet, but it is a dead-reliable classic target bullet.
 
Daniel that is almost brilliant, the only other reply I have read to a question such as this is the link to the 6SLR chamber that robert whitley provided in his article of the 6SLR where he shows the reamer prints and then goes over the choices of bullets and how they will perform with this choice of reamer,

I am amazed at how well folks claim they can shoot with just throwing bullets into a chamber they know nothing about, it is very interesting to REALLY KNOW the DETAILS about the various reamers involved, I know a number of gunsmiths want ot know the bullet you are intending to use (or able ot buy) in order ot CHOOSE the proper reamer for the application,

I also understand that this is OLD NEWS to most educated gunsmiths but to the uninitiated competitor this IS GREAT


thanks to the masses print this off or save it to your harddrive and once the knowledge is learned you will make better choices for your next shooting project,

thanks again, (it also saves Peter and maybe ATRS time in explaining a choice or reamer with bullet selection)

2013 may just be a good year to enjoy our hobby

Jefferson
 
rnbra-shooter said:
Most .308 reamers that have "Palma" in their name are made .....................................................- Sierra 190 HPMK is very much a middle-performance bullet, but it is a dead-reliable classic target bullet.
Click to expand...

Very Well Said Daniel.

One detail I have not heard mentioned is the chamber/throat dimensions that should be considered when loading through magazines
either internal or detachable, there is no sence in restricting the OAL when these feeding systems will require short OAL's to function reliably
hence the large jumps for the bullets with some of these chambers. True that some bullets tolerate jumps better than others but i have found that lot variations alone can also be factors and at the end of the day the closer the better for it is a rare instance when increasing the jump increases your accuracy although it is certainly possible.
Personally I went with a JGS Palma 95 on my first 308 and continue to enjoy the benefit of allowing me to feed through a magazine and also
benefit from its accuracy advantages. of coarse this does not apply when single shot rifles are on the line.
BB
 
Daniel,
If I remember correctly the Bisley Rule 150 came into effect about 1999 or 2000. My Obermeyer chambers have passed the test each time in three different rifles.
 
What do you guys think of this one from PTG ?

FTR Reamer with .342 neck and .123 freebore
(Un turned Brass, Single Shot)
 
You must log in or register to reply here.
Back
Top Bottom