Quantcast
  1. Sign up now and join over 35,000 northwest gun owners. It's quick, easy, and 100% free!

solution for poor man's throat/muzzle gauge?

Discussion in 'Rifle Discussion' started by smurf hunter, Aug 9, 2010.

  1. smurf hunter

    smurf hunter Auburn, WA Active Member

    Messages:
    294
    Likes Received:
    35
    When looking over milsrup rifles, and comparing them - is there a quick and dirty means to check the muzzle and throat for wear? I've seen throat gauges on midwayusa in the $50 range, but that seems spendy given the task.

    Somewhat related, how to check the head space when in a shop, show, etc?
     
  2. Creeper

    Creeper Ravensdale, WA. Member

    Messages:
    246
    Likes Received:
    22
    If you're not an experienced reloader, and I'm guessing you're not, you'd be better off and much safer just buying some inexpensive Forster "Field" gauges in the calibers you'll be inspecting for purchase.
    When you consider that a headspace gauge is an accurately machined, durable and consistently reliable measurement device and that most Forster headspace gauges are under $30, and you can always sell them for near what you paid for them... it ain't so bad. :p

    The alternative to simply investing in the gauges is, believe it or not, far more expensive and time consuming.

    Cheers,
    C
     
  3. madcratebuilder

    madcratebuilder Ardenwald, OR Well-Known Member

    Messages:
    1,278
    Likes Received:
    175
    Carry some ammo for the caliber you are looking at, stick the bullet in the muzzle end, that well tell a little. Throat erosion takes some more tooling that is normally expensive. It's a good idea to check the head space, gauges can be found used and some new ones are very reasonable. Okiegauges are good and cheap.
     
  4. Spitpatch

    Spitpatch Forest Grove, Oregon Well-Known Member

    Messages:
    1,801
    Likes Received:
    836
    I think his question as I read it was in regard to throat and muzzle erosion in the rifling rather than headspace guages.

    While I would certainly consider throat erosion (and/or muzzle erosion) as a factor in buying any used gun, I would not necessarily employ it as a litmus test. And we must show the distinction between the two: Throat erosion is caused by hot gasses combined with the violence that results from the rifling taking a stationary bullet from the chamber and instantly grasping it to spin and travel. Muzzle erosion is usually caused by external factors (rust from carrying in the rain, etc.) The muzzle is the portion of the barrel most exposed to the external. Both can be partially caused by corrosive powders and primers coupled with inadequate cleaning.

    I am somewhat amused by ads in my specialized magazines such as "Rifle" and "Handloader", that are selling what is called a "Bore Scope". A very expensive and very well-made precision product that amounts to a 90-degree microscope on the end of a large needle, that one can insert into a barrel and inspect each and every inch of the rifling at close quarters.

    A very thoughtful looking, well-groomed and bespectacled gentleman is shown examining his rifle barrel with the product, and depending on the ad in that particular issue, he remarkably discovers either throat erosion or pitting in a used barrel, or shoddy finishing evidence in a new barrel. (They show the microscope pictures hailing his discovery.)

    Although it is not said, the implication is, that if you find this in your barrel, and you are thoughtful, well-groomed and bespectacled, and financially solvent enough to have invested in this product, you would obviously make the prudent decision to NOT buy this gun, because you know for certain it will not shoot worth a plugged nickel.

    Such is simply not true at all. Certainly, all the above flaws often can have a detrimental effect on accuracy. Certainly, these flaws should be considered toward one's purchase decision. But just as certainly, these flaws may have no detrimental effect at all on the gun's accuracy.

    If I were looking for a good used .22-250, .220 Swift, .264 Magnum, or .25-06 for example, I would most definitely be interested in examining the gun for throat erosion. This can be seen with a good bore light and perhaps the aid of reading glassses. The rifling will show evidence of "washout" where it begins just ahead of the throat. If throat erosion has not begun, the leading edges of the lands should be easily seen as sharp.

    But my examination for throat erosion in this family of calibers would be toward the knowledge that at some point, throat erosion WILL have an effect on accuracy: NOT necessarily that it already HAS in this particular gun. I would know that if minor erosion was present, the gun may shoot just fine, (maybe even better than brand new) but the life of the barrel in my possession would be shorter than one that showed no erosion.

    If I had the wherewithal (and perhaps here I am exposing some sour grapes) to purchase a "Bore Scope", and thoughtfully examined each gun prior to purchase with it, and made that my determining factor on my decison, I would have rejected out of hand my Savage Model 23D .22 Hornet. It's 70-year old barrel shows a good 3-inch section that is horribly pitted, visible to the naked eye, and even a cleaning patch drags in that section.

    And it shoots groups that average .65"

    I would also sell my Browning B78 .25-06 that I know I burned the barrel on while trying to put down a wounded pronghorn, firing 12 rounds through it as fast as I could get on target. Throat erosion is starkly evident, even without the aid of me looking thoughtful, well groomed and bespectacled with a "Bore Scope".

    And targets from it nowadays are better than when it came out of the box.
     
  5. smurf hunter

    smurf hunter Auburn, WA Active Member

    Messages:
    294
    Likes Received:
    35
    Good thoughts. I'll make this more practical...

    I'm at a sporting good store, pawn shop, or similar place with a variety of 60+ year old Mausers, Mosin Nagants, Enfields, etc.

    I might have in my pocket a small, but bright flashlight, and bullets/rounds for the calibers in question.

    I know I can't catch everything, but what can I look for?
     
  6. Spitpatch

    Spitpatch Forest Grove, Oregon Well-Known Member

    Messages:
    1,801
    Likes Received:
    836
    Sorry, smurf. I went long. But the paragraph with the calibers in it (.22-250,etc.) has a suggestion for you.

    Problem: VERY difficult to guage barrel condition unless the barrel is pristinely clean. Problematic when looking at a gun off a rack in a store, especially of military type and not recent vintage.

    As to muzzle wear, again this is usually from external influence, and if the external of the muzzle (and crown) looks unaffected by previous rust, etc., chances are the internal is good.

    If you are a serious buyer, and in a real gun store, I would think the proprietor would supply you with moderate equipment to at least swab the bore a bit to get a better look at it.

    If he is thoughtful, well-groomed and bespectacled, he may even have a "Bore Scope"!:laugh:
     
  7. smurf hunter

    smurf hunter Auburn, WA Active Member

    Messages:
    294
    Likes Received:
    35
    I think there may be an inverse relationship between a cheap price and a thoughtful, well-groomed and bespectacled seller. :)
     
  8. coop44

    coop44 Tacoma ,WA Well-Known Member

    Messages:
    2,608
    Likes Received:
    987
    I completely agree