Pietta 1851 Navy .36 Cylinder Problem

[expat_alaska]

Noob here again. Need to learn from all of the sages.

I have a Pietta 1851 Navy .36, 4 months old, never fired (except for many dry-firing sessions using a strip of moosehide to protect the nipples).

The cylinder is developing a very pronounced .001"-.002" "burr" in the tapered area after the cylinder slot where the bolt locks the cylinder at full hammer cock. The pistol has been maintained with copious amounts of oil. The bolt shows no sign of wear at the cylinder stop contact points.

What think ye?

Jim

 

[swathdiver]

The bolt is outta time, engaging too early and the hand is pushing it into place.

 

[expat_alaska]

So, how do I correct this, other than sending it to Goon?

 

[Prairie Dawg]

Pietta bolts typically do not fit the cylinder notches and must be thinned a bit.
Otherwise they peen the edges of the notches.
Larsen Pettifogger wrote an article about tuning Pietta cap guns, and this point was addressed.
http://www.theopenrange.net/forum/index.php?topic=5659.0
--Dawg

 

[expat_alaska]

Time to study. Thanks for the heads up!

Jim

Edit: I used a round needle file to remove the peening and cold blued the offending white metal scars. I have dry fired it about 300 times since and have no further problems. The bolt locks up with the cylinder timing very well. Is this just an off-the-normal break-in problem? I really do not want to mess with the bolt thickness unless absolutely necessary, as that will misalign the cylinder with the barrel forcing cone.

Comments?

 

[44 Dave]

After you check the bolt fit in each cylinder notch (got to take the bolt out of the gun) and you find it is still dropping early, back to the drawing board.
The bolt may be dropping off the cam on the hammer early, adjusting the bolt spring tension may help. It should take a little less than 5# to push the bolt back even with the water table at full cock.

 

[expat_alaska]

Thanks 44 Dave.

I will check on everything you guys give me.

 

[Old Fuff]

Please conduct a little experiment:

1. Remove the barrel and cylinder.

2. Slowly bring the hammer back to full-cock.

3. Now see if you can rotate the hammer further back until it hits the back strap.

Or:

1. Remove the barrel and cylinder.

2. While holding the trigger back, cock the hammer until it hits the back strap, and then hold it

3. Release the trigger, and slowly lower the hammer until it engages the hammer's full-cock notch. Estimate how far the hammer rotates, if it does.

 

[expat_alaska]

Please conduct a little experiment:

1. Remove the barrel and cylinder.

2. Slowly bring the hammer back to full-cock.

3. Now see if you can rotate the hammer further back until it hits the back strap..

Yes, guesstimating about 1/16th inch at the backstrap.

Or:

1. Remove the barrel and cylinder.

2. While holding the trigger back, cock the hammer until it hits the back strap, and then hold it

3. Release the trigger, and slowly lower the hammer until it engages the hammer's full-cock notch. Estimate how far the hammer rotates, if it does.

Barely 1/64th" at the backstrap, if that. Very tight, IMO. Your call.

I am looking for answers and NOT looking to argue.

 

[Old Fuff]

I am looking for answers and NOT looking to argue.

Neither am I, I'm looking for clues, and you just eliminated one possibility, which is good.

Now if you want to continue, remove the stocks, mainspring, trigger guard, trigger & bolt spring, and cylinder bolt. While holding the remaining frame assembly with the attached backstrap upside-down, align one of the notches in the cylinder up with the little window in the frame where the bolt used to be.

Then rotate the hammer back until it hits the backstrap, while watching the cylinder turn. When the cylinder comes up to the next notch does it stop before it reached the notch (unlikely), stop at the notch, or go past it?

 

[Skinny 1950]

The best solution to this problem is to quit dry firing it.