Author Topic: Breech plug  (Read 1867 times)

Offline Elnathan

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Breech plug
« on: July 10, 2017, 11:57:01 PM »
Anyone know where i could find a breechplug suitable for a 1 1/8" barrel threaded 5/8x18? The ones that the usual vendors carry are either two small or threaded 3/4x16, not really suitable for a .50 caliber bore.
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Offline T*O*F

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Re: Breech plug
« Reply #1 on: July 11, 2017, 12:02:28 AM »
The larger plug is perfectly suitable.  Is your problem that your breech is already threaded for the 5/8ths plug?
Dave Kanger

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Offline Elnathan

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Re: Breech plug
« Reply #2 on: July 11, 2017, 02:45:59 AM »
You know what, I think you're right. Since the shoulder where the threads meet the bore is a stress riser, I would think that the closer to bore size the plug is the better, so long as there is enough shoulder to seal properly. 5/8" sounded better than 3/4," and since Track of the Wolf says that their .50 GM barrels are threaded for 5/8 I figured that was what I wanted....However, that doesn't work out mathematically once you add the rifling, and  since GM itself says 3/4x16 for their .50s I have to conclude that Track of the Wolf made a typo and that I'm not thinking straight.  ::)

The barrel is not yet made. This particular maker wants to fit the plug himself, but only makes the tubes and is pretty sure it isn't worthwhile for him to make the plugs when there are so many commercial plugs available. 'pears he's right...Problem solved, I guess.

This is what happens when I try to Get Stuff Done instead of think about for awhile. Sheesh.
A man can never have too much red wine, too many books, or too much ammunition -  Rudyard Kipling

Offline P.W.Berkuta

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Re: Breech plug
« Reply #3 on: July 11, 2017, 08:01:13 PM »
Why not let the barrel maker buy and fit the plug this way he gets what he wants to work with???
"The person who says it cannot be done should not interrupt the person who is doing it." - Chinese proverb

Offline David Rase

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Re: Breech plug
« Reply #4 on: July 12, 2017, 07:04:55 AM »
.50 GM barrels are threaded for 5/8 I figured that was what I wanted....However, that doesn't work out mathematically once you add the rifling, and  since GM itself says 3/4x16 for their .50s I have to conclude that Track of the Wolf made a typo and that I'm not thinking straight.  ::)


A fifty caliber barrel has a .500" bore.  With .012" deep rifling, this brings the outside diameter to .524".   5/8" = .625".  .625" - .524" = .101" so you would have approximately .050" seal all the way around.  I don't see the problem.
David
« Last Edit: July 13, 2017, 05:40:47 AM by Ky-Flinter »