Go and no-go gauges

Discussion in 'Firearms' started by oil pan 4, Jul 11, 2020.


  1. oil pan 4

    oil pan 4 Monkey+++

    After watching people blow up guns on youtube a few weeks ago I ordered a set of go and no-go gauges.
    I figured really messed up head spacing could blow up your gun.
    So they came in and I tried them out.
    On my FN upper the go gauge barely goes into battery, the no-go gauge doesn't go into to battery. My 12 moa upper the no-gauge almost goes into battery, it get real close.
    Big difference between the 2 uppers.
    Then for my mini14, the no-go gauge goes into battery...
    So head space matters.
    Looks like there's only about 0.015'' difference between the 2 gauges.
     
    Tully Mars, Gator 45/70, SB21 and 3 others like this.
  2. duane

    duane Monkey+++

    Not only for head spacing, they are a must for ammo reloading as well. In a second or two, get all the measurements to the cartridge standard. If you are reloading your own semi ammo, case length is all you need, but if you want to use the ammo in several different weapons or others use it, it has to chamber and fire safely. The case gauges are designed to do that. If you assemble a rifle from parts or buy a new rifle, it is real handy to have them checked out with go no go gauges. Excellent topic and all too many people in the ak and ar fields for the most part ignore checking the headspace out...
     
  3. Oddcaliber

    Oddcaliber Monkey+++

    Definitely handy to have if you DIY gunsmith. Rather mess up a headspace gauge than a gun any day.
     
    Gator 45/70 and snake6264 like this.
  4. Cruisin Sloth

    Cruisin Sloth Special & Slow

    My Gauges are not 15 thou difference
    more like (in imperial measurement .0012 to .0016 ) difference .
    So a Ten thou .010 space , will not fit a .010 gauge but will fit the Go/No gauge at 9.94 .
    All Imperial since here , I do metric.. As they get thicker , the range increases .
    REMEMBER THESE ARE TIME EXPIRED AFTER USE OF MANY TRYS ..
    Measure them to check .
    Fixing / rebuilding turbines etc , we are tight too a C hair ;)

    Sloth
     
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  5. Tempstar

    Tempstar Monkey+++

    Consider an Overall Length Gauge as well. My .308 went from useless to my favorite bolt gun because I bought one.
     
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  6. duane

    duane Monkey+++

    There is a gauge that will show if your reload is being sized to standard and a caliper will give you overall length. They say that in a sense it gives you your head spacing as the fired brass will form to the actual size of the chamber. Real handy in setting up the die when reloading and makes standard ammo out of once fired brass. .L.E. Wilson Case Length Headspace Ga 22-250 Remington https://www.midwayusa.com/product/101827769

    I find them very handy when reloading range brass or buying bulk brass that hasn't been resized or even checking resized brass.
     
    Last edited: Jul 12, 2020
    Oddcaliber, Gator 45/70 and HK_User like this.
  7. hot diggity

    hot diggity Monkey+++ Site Supporter+++

    I have at least one rifle that closes tight on a no-go, but not on a field gauge. The field gauge is the absolute safe limit for chamber dimensions before a barrel set back is necessary.
     
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  8. Ura-Ki

    Ura-Ki Grampa Monkey

    Hornady makes a nifty chamber gauge that can check all sorts of specs if you want it to, really worth the small expense if your into precision reloading and really pushing things, it will help your rifle tell you where it really wants to be!
     
  9. Brokor

    Brokor Live Free or Cry Moderator Site Supporter+++ Founding Member

    When it comes to AR's, this is pretty much all you need to know:

    Of course, if you do get into "no-go" land, there's no way to adjust headspace, so a new barrel refit would probably be in order unless it's a new build you've done yourself, in which case you would probably need to seek a gunsmith or think about returning your barrel or bolt. There should be no issues with a new rifle out of the box, as it has been fully tested. I've never run into a headspace issue on an AR, but legend has it that it can happen.
     
    Gator 45/70 likes this.
  10. hot diggity

    hot diggity Monkey+++ Site Supporter+++

    90% of the people who have had guns blow up at my local range have been reloaders who under or overcharged their loads or used the wrong powder with the same outcome. The other 10% were shooting modern ammunition in antique firearms that were not designed for it. Hornady .45-70 Lever Evolution in a Springfield Trapdoor worked for exactly one round.

    I have heard Enfield shooters claim that long headspace made recoil of .303 British more severe, but I've never experienced it and can't see how it would make a difference in anything but fired case size.
     
    Gator 45/70 likes this.
  11. Ura-Ki

    Ura-Ki Grampa Monkey

    AR's can be shimmed, but it's not often to need to do one, usually the 308s are the ones that might need adjusting! Obviously, for performance reasons, it's a nice way to tune a rifle!
     
    Gator 45/70 likes this.
  12. oldman11

    oldman11 Monkey+++

    I have two trapdoors that I shoot. Is rememington 45-70 ammo alright to shoot in them? I have been shooting the cowboy ammo and do not want to be shooting blackpowder ammo. They both have been checked out and are in good shape. I would appreciate your opinion.[flag]
     
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  13. Gator 45/70

    Gator 45/70 Monkey+++

    Minis are famous for loose headspacing and eating pretty much anything thrown into to em.
     
  14. Ura-Ki

    Ura-Ki Grampa Monkey

    [​IMG]
    [​IMG]
     
    Gator 45/70 likes this.
  15. BTPost

    BTPost Stumpy Old Fart,Deadman Walking, Snow Monkey Moderator

    The real question that must be answered is “What is the Metallurgy of the Breach & Barrel of your 45-70 Rifles? Is there enough metal in the Breach & Barrel, and is the Hardness & Strength of those parts sufficient to withstand the Pressures of a Full Boat Smokeless Powder Loading, including a 200% overPressure, because some Idiot gave you a Double Charged Round, and you did not know it...Not a lot of GunSmiths are capable of doing those calculations, to give you a True Answer... Many just look at the weapon, and make an educated GUESS.... The cool thing about BP is, it is almost impossible to overcharge a BP firearm, and have it blow up in your face, due to the Burn Rate of BP in a semi-enclosed space, and Grain size of the BP used in the the Loading. (The barrel is open on one end). If you do Double the BP Charge, you just blow 1/2 the BP Load out the muzzle, in a BIG Flash, and the extra Powder, burnt and unburnt, is scattered out in front of you... One can calculate the Maximum BP Loading for a particle Breach/Barrel, and anything more than that is counter-productive as far as muzzle velocity and muzzle energy is concerned...But it sure looks pretty on the 4th of July...
     
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  16. ghrit

    ghrit Bad company Administrator Founding Member

    You are going to need to know when those two were manufactured. Best bet is send the serial numbers to remmie and ask. Messy it may be, but the holy black will add to the cowboy fun.
     
    Cruisin Sloth, Gator 45/70 and Ura-Ki like this.
  17. Ura-Ki

    Ura-Ki Grampa Monkey

    Are these Originals, or re-pops? Depending on who made them, ( especially Remmy) will make a hell of a difference! Made in Spain, might be iffy, might be fantastic! If they are Factory Remington, they should be able to handle "Standard" Black Powder loads from the period, which today would be safely equaled by a 58 to 65 gr charge of modern equivalent FFg under a 385 grain cast conical! If there is any doubt as to the manufacture of said, then I WOULD NOT EVER run modern smokeless ammo through these, ONLY Holy Black, with the preference toward Goex FFg, but you could also safely run Hodgdon 777 Silver powder, which is almost the same as Goex, just don't crunch a projectile over it with ANY pressure, may have to adjust your charge weight accordingly!

    BTW, it's damn near impossible to get a full spec 70 grain load of modern powder under a conical in this chambering, you need a Sharps or simmiler quality replica, or modern Winchester or Marlin lever to be able to crunch in a full 70 grain charge safely! Honestly, it's not worth it!
     
  18. oldman11

    oldman11 Monkey+++

    Both are originals,one a carbine the other a rifle,both in very good shape.The reason I asked was I want to kill a deer with one just to show what a old gun can do. A old man in a town south of me died and left these. I bought both for $700.00 each along with two rem rolling blocks. The rolling blocks were a carbine in .44-40 and a rifle in 7mm. I love old guns.
    [flag]
     
  19. oil pan 4

    oil pan 4 Monkey+++

    Well I swapped the barrel on that 12moa upper. The new barrel and original bolt barely go into battery with the go gauge and with the no go gauge it doesn't even try.
     
    Gator 45/70 likes this.
  20. oil pan 4

    oil pan 4 Monkey+++

    Now that I know I have tight chambers I'm thinking I can use the go gauge to set up the sizing die for easier sizing and longer brass life.
     
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