Min or Max Saami Spec Reamers

Discussion in 'Gunsmithing' started by gunaddict, Aug 15, 2011.

  1. gunaddict

    gunaddict Well-Known Member

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    I am going to order some new Brux barrels and I have a couple of questions concerning reamers.I do not want to turn necks. . Contours will be #4, 26 inch long and #5's, 27 1/2 long. Barrels ordering for 300wsm, 300 ultra, 338 ultra. Bullets I am going to use:TTSX's 165gr- 300wsm, 200gr TTSX's-300 ultra, 225gr TTSX's- 338 ultra. One gunsmith has min saami spec reamers and the other one has Max saami reamers.
    1: Which reamers do you gunsmiths use? Min saami spec or Max saami spec reamers?
    2: What freebore do you recommend on the ultras?
    3: If i go with a shorter freebore what are the pros and cons?
    4: Am I going to loose velocity going with a shorter freebore with increased pressure?
    5: Both gunsmiths use PTG reamers.
    Any other things I might have missed.
    Thanks Todd
     
  2. J E Custom

    J E Custom Well-Known Member

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    A lot of good questions.

    1= I use standard SAAMI Reamers. There is no such thing as a minimum and a maximum SAMMI.
    They are eather SAMMI or not. What they are talking is something other than SAMMI like
    tight necks, or a change in free bore, lead angle ETC. These are called custom grinds/reamers.
    I do not recomend any custom reamer unless the person has special needs and knows how
    to deal with them.

    2=I recomend standard free bores on all high pressure cartriges like the Ultras and the WSMs,
    because they keep the pressure under control and allow higher velocities.

    3=Shorter free bores increase pressure and lower velocities.

    4=Normally you have to reduce the powder charge and will lose velocity at safe pressures.
    (A good example is the big 378 based Weatherby cartriges like the 30/378). If you do away
    or reduce it you will not be able to shoot Weatherby factory ammo because it is loaded for
    maximum velocity and will be over loads in the modified chamber.

    5=PT&g. Clymer and Dave Manson all make good reamers.

    A side note: most gunsmiths have a reamer charge (You may not see it but it's in there most
    of the time) or they rent reamers that may be ok or they could be bad. I recomend that if you
    are going to the trouble to build a/several custom rifles. Buy the reamer new and keep it so if
    you ever re barrel the rifle you have the same reamer. and if you dont re use it you can sell
    it for more than half the price of the reamer especially when it has been used only once.

    The gunsmiths should not object to you furnishing your own reamer if it is new.

    A new reamer is some of the best money spent. (Standard reamers are around $100.00).

    There is one other thing about out of SAAMI spec. reamers. The dies should be custom to work
    well. and all standard dies are based on "Standard Reamers".

    Just my opinion for what it's worth.

    J E CUSTOM
     

  3. EddieHarren

    EddieHarren Well-Known Member

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    I would disagree with JE. If you go to the SAAMI specs manual, you will see chamber drawings and the dimensions for nearly every cartridge that exists. Most of the dimensions are give with a + or - measurement. This allows all manufacturers to keep their products as universal as possible.
    If you order a Min. spec. reamer, and plan on using factory ammo, you may encounter some ammo that will not chamber in your rifle. Since you are going the "custom" route, I would assume that you are going to handload your ammo. If this is the case you should be fine with a Min. Spec. reamer.

    P.S. If you think SAAMI is SAMMI, buy a box or, bag of any reloading component and start measuring. You'll soon discover the + or - I referred to earlier.
     
  4. J E Custom

    J E Custom Well-Known Member

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    Sorry: I would have to disagree with that because the SAMMI spec gives a dimension +/- for the
    manufactures to build there ammo to so it will fit in any chamber. There is little or no tolerance
    for the reamer maker.

    The Reamers are a different story. The reamer makers have a spect that they have to build
    to in order to call it a standard reamer.And unless you ask for something different from the reamer
    manufacture you will get a SAMMI Dimension reamer that is within .001 to .003 of there Specs.

    The ammo makers can deviate much more. Winchester is one of the ammo makers that load
    all of there ammo much smaller to fit in any chamber.

    The point is that if you want a standard "SAMMI" reamer it will be as close to the SAMMI spec
    as possible or within the reamer makers quality standards.

    Ammo and dies are like you said they are not always right or even close to the SAMMI standards.

    My explanation was about the reamers, Not the ammo or the die tolerances.

    I have ordered many reamers and have ask about subtle changes and they said that will be a
    custom reamer because it is not SAMMI spec.

    In all fairness to your response though, I have never ask for a Min or Max SAMMI spec reamer
    Because I would be afraid of what the reamer makers response would be.

    At best, if you don't mind paying more for a reamer you can ask for anything. but it requires
    re-programing their equipment, thus the extra cost.

    I am Not being argumentative just trying to clarify the difference between a standard reamer
    and a custom reamer.

    J E CUSTOM
     
  5. BountyHunter

    BountyHunter Writers Guild

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    Call Dave Kiff at PTG and ask about a "minimum SAAMI" spec reamer for your cartridges. He will gladly explain what that is.

    tell him the bullets you plan on shooting and he will tell you what reamer specs he recommends. He will email you copy of the reamer prints so you can compare and make your own decisions.

    BTW he provides minimum SAAMI spec reamers all the time to the 1k crowd, so it is pretty common. Do not worrry.

    BH
     
  6. ken snyder

    ken snyder Well-Known Member

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    David Kiff, to the best of my knowledge will manufacture chamber reams to practically any dimensions imaginable, he has made several wildcat reams for me. I think the non descriptive terms of min and max are the culprit. Once a ream no longer complies with the specs it is no longer sam, but is based on sam. I use the adjustable length throat reamers and set the seating length where I want the bullet to stuff at. Weatherby makes their freebore so long that I almost always shorten them but factory ammunition is not a good idea and the barrels are not engraved as being a weatherby cartridge they are marked with diameter and wildcat, an example would be .338 Wildcat instead of 338-378 because they are no longer a 338-378 even if you cant tell the difference by looking at them.
     
  7. gunaddict

    gunaddict Well-Known Member

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    I will call Dave Kiff Monday and ask him what he recommends. I was wanting to order my barrels Monday. Thanks for your help.
     
  8. EddieHarren

    EddieHarren Well-Known Member

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    JE, I, like you, build rifles for a living. On most, if not all, of the rifles, that I build for serious competition, I specify "Min Spec" reamers. On the Law Enforcement rifles I use "Standard SAAMI" reamers.
     
  9. ken snyder

    ken snyder Well-Known Member

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    Hello Eddieherrin, nice to read your thread. When you say minnimum what are you reffering to? The entire chamber, length, taper, neck diameter and its length, freeboore length, and then chamber them with zero headspace. I'm haveing a hard time understanding how a Ream could be called anything without actual specifications. I honestly can't think of a single benefit tight chambers provide with factory ammunition. For the handloader any difference totally dissapears other than neck O.D. and freebore length. After fireforming the cartridge to chamber differences are the sole property of the dies and practices of the person makeing the handloads.
     
  10. EddieHarren

    EddieHarren Well-Known Member

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    I'm speaking of all case dimensions. I want to say again, I only use "Min Spec" reamers for serious competition rifles. I would not use a "Min Spec" reamer on a rifle that will be using factory ammo or, a rifle to be used in law enforcement.
    When ordering a reamer for a benchrest rifle, all of the case dimensions are specified. Neck dia., case dia. at the base and the shoulder, length, lead, freebore and lead angle.
     
  11. J E Custom

    J E Custom Well-Known Member

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    +1
    Thank you Eddie !!!!

    You said it better than I did.

    If it is anything other than SAMMI spec. It is not standard there for it is not SAMMI, but custom,
    based off SAMMI dimensions.

    J E CUSTOM
     
  12. BountyHunter

    BountyHunter Writers Guild

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    The SAAMI answer is real simple for anyone to see for themselves. Go to the SAAMI website and look at the reamer drawings for a cartridge and you will see two distinctly different drawings. They will be for the minumum and maximum specifications for that cartridge.

    So yes there is really a min and max SAAMI specification for each cartridge.

    For example, on the 30'06 neck diameter is spec'd from .3404 to .3397 and body diameter from .4708 to .4698. Now add the .010 SAAMI variance in headspacing. That is also why you use GO and NO GO gauges to determine IF the chamber is cut to be within those two specifications.

    Every SAAMI factory cartridge is required to be able to fit in the minimum SAAMI chamber cut with a minimum spec reamer. So a minimum SAAMI chamber is required to completely safe for a factory cartidge, just on the minimum side. Read the SAAMI specs for cartridges and you will see that is 100% accurate.

    So yes it is safe to fire any factory cartridge in a minimum SAAMI spec chamber.

    You will find most dies are cut to size minimum SAAMI fired cases also, but not always. You can and will find variances inbetween die mftrs.

    So if you want a real loose chamber go max SAAMI.

    This is another reason to have your own reamer cut to your specs or at least what the reamer mftr says will work best for your application and bullet rather than risk a max SAAMI reamer being used.

    BH
     
  13. Edd

    Edd Well-Known Member

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    I don't think that is correct. You are looking at two different things, cartridge specs and chamber specs. The cartridge dimension is a maximum dimension and the chamber dimension is a minimum dimension.

    Example:
    The 30-06 cartridge has a maximum .200" base diameter of .4698" with a -.008 acceptable. Most new cases will measure around .465"

    The chamber has a minimum .200" diameter of .4708" with a +.002 acceptable.
     
  14. shortgrass

    shortgrass Well-Known Member

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    That is exactly what the SAAMI print says. +.002 on dimentions of .050" or greater, unless specified otherwise. SAAMI s' web site w/prints is easy to find, just be sure you're looking at the correct drawing, the chamber not the cartridge. The top print is for the cartridge, the bottom one for the chamber.