Breech plug

[dstock]

What type metal should one use to fabricate a breech plug?

Doug B    God Bless

[rich pierce]

Mild steel.

[Metalshaper]

have used mild steel? people have advised 1018 - 4130.

think if I was making a LR target gun, I'd go 1137-4130 just because of the pressures involved internally??
for a conventional percussion or flint, 1018 should be more than enough..

'says the guy just making his first, from scratch BP's ' 

Respect Always
Metalshaper/Jonathan

[Elnathan]

I think the plain jane machined plugs sold commercially are 1018 mild steel. The cast patent plugs are 8620.

[P.W.Berkuta]

Here is one I made from 1018 for a left hand .45 caliber rifle.

[Hungry Horse]

 I use a grade 5 NF bolt. I cut off the head, and grind, and file,  the rear of the plug into a platform for the tang to weld to. I make sure the platform is large enough for the rear lock bolt to pass through the platform, and into the lock plate.

  Hungry Horse

[Metalshaper]

I use a grade 5 NF bolt. I cut off the head, and grind, and file,  the rear of the plug into a platform for the tang to weld to. I make sure the platform is large enough for the rear lock bolt to pass through the platform, and into the lock plate.

  Hungry Horse

I'm also doing this for a Breechplug in one of those Billinghurst kits. Fit the plug into the frame and relieved it enough to get a solid weld all the way around!
Gonna try one like you described.. Just cuz I like making things differently..

Respect Always
Metalshaper/Jonathan

[Hungry Horse]

Metalshaper, those little cheap wire feeds with the “purse strap” are the bomb for this work, almost no splatter to clean up.

  Hungry Horse

[dstock]

Thanks for all the replies. I see some fantastic work going on in your shops.
I have been using 1018 but am almost down to reordering and was curious to see what other people are using. Got to make a long one for my next project which is an over the comb mountain rifle.

Doug B   God Bless 

[Metalshaper]

HH,

 working with a 90 amp Flux wire.. works pretty good, just need the operator to get a lil more practice with it!
( last time I welded was 8th grade shop, with stick )


D stock,
haven't had a Mountain rifle build to try one of those on??


Respect Always
Metalshaper/Jonathan

[Jim Kibler]

I don't think it's necessary, but we stress relieve all cold drawn material before making breech plugs.  A litlle extra ductility and safety factor is good.  Without a furnace, just heat the stock with a torch until a dull read color and allow to slowly cool.

Jim

[Hungry Horse]

Jim, I agree about ductility, but have found low grade or ungraded bolts recently to be mostly imports, with poor thread quality, and ductility somewhere near Velveta. That’s why I use grade 5 and since its harder here to get unplated ones than plated ones, I burn off the plating in the forge, and cool them in a bucket of ashes.

  Hungry Horse

[Jim Kibler]

I guess a bolt would probably work, but in my experience the tread fit tolerance of a bolt isn't too good.  Not something I would prefer.


Jim