Custom throating

Discussion in 'Gunsmithing' started by jmason, Nov 21, 2008.

  1. jmason

    jmason Well-Known Member

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    Are there any advantages or disadvantages to a custom throat?

    If you were to custom throat, how would you select a COAL?
     
  2. britz

    britz Well-Known Member

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    I don't want to misrepresent myself, I am also an amature when you look many of the guys on this site, but I'll reply and tell ya what I know (think) ;)

    If you are trying to develope a rifle for a certain use/ bullet and want to maximize the powder capacity of the cartidge and also have it so you can seat bullets to the desired distance from your lands than custom throughting is the way to go. take a 260 rem and a 142gr smk for instance: if you simply seat the bullet in a case to chamber in a factory chamber than you will have to seat the bullet way into the case reducing the capacity for powder and slowing your round down. On the other hand if you have a short action rifle and you want to shoot this round, you may want to think about the lenght of your magazine if you inted to make a repeater. I hope to someday make a 260 throughted for a 139 or 142gr pill out of a long action rem 700.

    Another case in point: If you intend to make a 300wsm into a dedicated varmint rifle shooting a 135gr smk bullet, than you may want the trought set so you can seat the short bullet in the case comfortably and still have it almost touch the lands for a accurate load. (I can't imagine myself ever doing this, but I am sure it has been done).

    If you are pretty sure that you want to use a certain bullet than I would go to the gunsmith with a caseing of your caliber w/o powder or primer and a bullet seated to your desired depth and talk with him/her to find out what the optimal distance to ogive will be for your inteded use. At least that is what I intend to do when I make my custom (some day lol).

    Good luck!
    Mark.
     

  3. Clark

    Clark Well-Known Member

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    I have a custom .223 reamer with a shorter throat, so short bullets can reach the lands.

    I have a 45acp throater reamer, for throating in a separate step, with custom tight chambers.
     
  4. Rustystud

    Rustystud Well-Known Member

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    PT&G Piloted reamers cost me $152.00 to my door. They cut a specific throat depth depending on how they are ground. Remember it is easier to remove metal than put it back. A piloted PT&G throating reamer cost $69.00 to my door. With a short throated reamer one can use a throating reamer and custom cut their throats to any depth desired. It is as simple as that.

    Rustystud
     
  5. Ballistic64

    Ballistic64 Well-Known Member

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    The other advantage to a custom reamer is that the throat will be much tighter than on most any factory chamber.
     
  6. Rustystud

    Rustystud Well-Known Member

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    I am well aware of that I chamber about 300 barrels per year. I have 1.5 degree throating reamers for 22, 6mm, 6.5, 7mm, and 30 cal.

    I buy all my reamers with throats .0005 over bore diam Factory chambers are .001 to .0025 over bore diameter. I buy all my reamers with short throats and custom cut them to the desired depth.

    Nat Lambeth
     
  7. Ballistic64

    Ballistic64 Well-Known Member

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    Im sure you are aware of that Nat,but last I looked you werent the one asking the question at the top of the thread.:rolleyes:
     
  8. learjet

    learjet Active Member

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    looks like theres quite a few of u guys here who can help me out w a stevens 223. atm, w any bullet ive tried so far(various 55g varmint and fmjs, s69mks) if i seat them to maximum magazine length for my AR15, they are jumpin .1" to the lands in my stevens. i cant get this rifle to shoot for squat w the long jump. if i was to order a custom reamer, could / should i order one with a standard throat, but no cutting area for leade/freebore? my plan(btw im very open to suggestions) is to take .050 off the back of the barrel w my friends lathe, then rechamber w a reamer like the one i described above, which should cut my freebore in half. if i still cant get the accuracy i want i can continue to shorten/rechamber as necessary. im just researching my problem atm, and trying to plan a reasonable course of action. of course im learning in the process. im not lookin for a benchrest chamber/rifle, just id like the savage to shoot an honest MOA w ammo that will function through my ar. any recomendations? am i thinkin on the right track?
    thx!

    lear
     
  9. Ballistic64

    Ballistic64 Well-Known Member

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    Why not just load a longer oal for the stevens and see what bullet it likes? If I had to limit my load for the stevens dependent on the AR oal,rather than buying a reamer,Id send a dummy round for the AR to shilen or pacnor and just install a match grade barrel.All youll need to install it is a barrel nut wrench.JMO
     
    Last edited: Dec 11, 2008
  10. learjet

    learjet Active Member

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    im limited by the OAL for AR mags, not chamber. 2.250

    thx

    lear
     
  11. Rustystud

    Rustystud Well-Known Member

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    Need More Info...

    Lear:


    First, clean your rifle with both carbon solvent and copper solvent.

    Second, Don't expect two different rifles made by two different manufactures for two different purposes automaticlly to shoot the same ammo.


    Most ARs are throated long and loose. Recently Remington and Savage have been throating their rifles long also. Because of magazine length issues the heavier and VLD bullets have been hand loaded since they are shot single shot in matches. The 223 has gone throught an evolution. In the begining they were loaded with 50-55 grain bullets and shot with a 12-14 twist barrel. Today they are loaded with bullets from 69- 90 grains and barrels from 6.5- 9 twist. I would not expect to get the best accuracy in a bolt gun with loads developed for a gas gun. Get your rifling twist and your throat for the bullet you are going to shoot.

    For the bolt gun I suggest you get a custom barrel from one of the top makers, have it chambered with a reamer with the throat length cut for the bullet being shot. I would recomend , Kreiger, Bartlien, or RockCreek for cut rilfing and Broughton, Lilja, or Shilen for button rifling. I would suggest you get your reamer from Dave Kiff at Pacific Tool and Gauge. I would suggest Lapua brass in the bolt gun.

    Have your action trued, including having the bolt lapped. You might get a Rifle Basix Sav-2 Trigger also. I suggest Ken Farrell rings and bases.

    You will see a world of difference in an custom lapped barrel. Your Stevens is capable of shooting in the .2s and .3s at 100 yards.

    Rustystud
     
    Last edited: Dec 12, 2008
  12. learjet

    learjet Active Member

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    thx guys....ive got 2 tricked out bolt guns now, that i shoot LR. both are savages, a 308 w a mcgowen tube, and a 300wsm that shoots very well, after simply bedding the action in a nicer stock

    please understand, im not lookin for match accuracy in either the ar or the stevens 223. the ar is a carbine the kids shoot for grins, and i pop groundhogs around the barnyard with. it shoots an honest 1.5moa w 55g vmaxes, its quick, light, and easy to point. it serves its intended purpose well. ill never be single loading it, or shooting matches with it.

    the stevens 223 i hope will someday be my cheapo LR practice rifle. all i need from it is 1 moa to 600yds w ammo that will shoot 1.5 moa in the ar. i believe if i reduce the freebore in the stevens its possible it will shoot well enough to serve its intended purpose.

    hence im thinkin i can order a no freebore, standard neck reamer, and simply set the chamber forward. is this a practical idea? ive got less than $200 in the stevens, i dont mind buying the reamer, but i want to make sure i get the reamer i need the first time

    thx again

    lear
     
  13. Rustystud

    Rustystud Well-Known Member

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    I would not spend 1 dime on a factory barrel. I would attempt to find a load for the twist of the factory barrrel. You might try some black hills 69s, 77s and 80s. I'll bet your gun has a 1:9 OR 1:8 twist barrel. The black hills bullets are longer bullets and are seated out further.

    If you go to the extreme of rebarreling get a throat ground for a specific seating depth. Dave Kiff can accomodate you with this at PT&G.

    Rustystud