Hammer blow back

[jimmy82]

Well, got done building my .45 cal chunk gun and 40grs of 3F will recock the gun when I fire. While I find this kind of convenient I doubt it is good for the lock.

I believe I already know what might be causing this. But I will put it out to you guys for your opinions. When building the gun I noticed that the hole in the nipple was partially blocked due to bad machining (not the tip but the small hole that is next to the powder).

So I beveled the hole. The hole is now significantly larger then any nipple I have ever seen and I believe it is allowing much more gas to escape. Thus pushing the hammer back.

If I had to venture a guess, I would say the hole is around 1/16" maybe a little larger.

My next course of action is to replace the nipple and see how it goes.

 

[BEP]

Sounds like your "next course of action" should/will cure your problem. Good luck.

 

[roundball]

So I beveled the hole. The hole is now significantly larger then any nipple I have ever seen and I believe it is allowing much more gas to escape. Thus pushing the hammer back.

You got it.

 

[reddog]

Replace the foolish nipple!!!

 

[silverfox]

You don't need a large hole in your nipple for and underhammer. It's direct into the powder chamber get lots of flash to the powder and lots coming back the other way also. Change your nipple and the problem will go away. If not find one of the sealed systems.
Fox :hatsoff:

 

[Zonie]

The actual "thru hole" in a nipple should be about .028 or .004 smaller than 1/32 of an inch.

If the actual hole ended up around 1/16 inch (.0625) it has an open area that is 5 times greater than it should be. :shocked2:

 

[Keppy]

That can be a very dangerous. One of the sidehammer rifles I bought used, had a nipple drilled out. I had clean and checked everything out I thought. I had not noticed it until the first shot and saw burnt powder around the hammer area. I had also felt some on my face. I will never make that mistake again. It was a mild load so it didn't cock it but must have blown by. The person who had it before me was trying to use pellets in it because there were still some in it when I bought it. The first thing I will do now when buying any used rifle is throw away any hotshot nipples and replace the nipple. No need for them if you use the real stuff.

 

[roundball]

"...The first thing I will do now when buying any used rifle is throw away any hotshot nipples..."

Everyone needs to do what they feel is best of course...but I am totally confused by the above statement...Hotshot nipples were not the cause of your problem...any nipple that had been drilled out would have resulted in the same conditions.


A Hotshot nipple is a brand name of a nipple that has a slightly longer body for a more efficient cap burn, and a tiny hole in the side at the very top of the nipple (covered by the cap)...it's purpose is pressure regulation for more shot to shot consistency, and a side benefit is that the spent cap expands so it does not stick to the top of the nipple as spent caps can sometimes do.

 

[renovato]

I had the exact same problem on an old double barrel pistol. The nipples had too big of holes too, and when I replaced them, the problem ended. You done got it figgered out. :v

 

[jimmy82]

Awesome, thx guys. Gonna have to check out Gander if I can ever make it out of work before dinner time. I have a hot shot on my TC back in NE, works pretty well. I don't remember seeing one at Gander but I'll have to poke around. Might have to order one from track.

 

[roundball]

Awesome, thx guys. Gonna have to check out Gander if I can ever make it out of work before dinner time. I have a hot shot on my TC back in NE, works pretty well. I don't remember seeing one at Gander but I'll have to poke around. Might have to order one from track.

TC has them as well...1/4" x 28

 

[Pork Chop]

Heck the local Wal Mart carries the TC nipples. They are in Flint River packaging, but they are TC.

 

[Keppy]

"...The first thing I will do now when buying any used rifle is throw away any hotshot nipples..."

Everyone needs to do what they feel is best of course...but I am totally confused by the above statement...Hotshot nipples were not the cause of your problem...any nipple that had been drilled out would have resulted in the same conditions.


A Hotshot nipple is a brand name of a nipple that has a slightly longer body for a more efficient cap burn, and a tiny hole in the side at the very top of the nipple (covered by the cap)...it's purpose is pressure regulation for more shot to shot consistency, and a side benefit is that the spent cap expands so it does not stick to the top of the nipple as spent caps can sometimes do.

:surrender:
roundball
Its was a bad choice of words. That is a term that I and others use up here to decribe drilled nipple. Should have said' "First thing I do is throw away any nipple that has been drilled out." And the reason I believe is that they try using pellets in them.

So hope your not confused now. :grin:

 

[roundball]

It was a bad choice of words. That is a term that I and others use up here to decribe drilled nipple. Should have said' "First thing I do is throw away any nipple that has been drilled out."

Got it...like a slang term about something having been "hotrodded"...throw out the hotrod nipples

 

[indiana bill]

I have a cva mountain rifle from the 70's and shot it for several years and then the hammer started to blow back to half cock.
I had it checked out by several gunsmiths,including the one at Friendship,replaced the nipple,had the hole to the breech checked out,and it finally came down to a weak spring.When that was replaced with a stronger spring,all was well.

 

[smo]

You might want to look at the length of the nipple I think I recall reading that a nipple that is to long {threaded end} will cause hammer blow back also. :v

 

[Dave Rosenthal]

NEW NIPPLE!!

From time to time, when you clean the thing, look at the orifice size. When it burns (they all do in time) you will notice your groups opening-up some, especially at longer ranges, even before the hammer comes back on you. It's like a pressure relief valve...it maintains a consistant pressure in the bore.

A weak spring will also cause this, but since this is a new build, it's the nipple.

Good luck and MAKE SMOKE!! :hatsoff:

Dave