Uberti 1849 pocket blowback

[JCB]

I recently purchased a new uberti 49 pocket revolver. It's a nice gun and shoots a good group. The only problem I have with it is the hammer is being blown back during firing causing the cap to fall under the hammer. I've changed the nipples with the ones from totw. I also tried heavier made mainsprings. I even tried two mainsprings stacked on top of each other. Nothing has solved the problem. The only thing I haven't tried is treso nipples. Would these be an improvement over the ones totw sales? Or is there something else I can do to fix this problem?

 

[M. De Land]

How wide is the cylinder gap between the barrel and cylinder face?
How well aligned are the chambers with the bore?
How tight is the bore in relation to the ball diameter used?
You may be pressuring up from one or more of reasons noted above and need to make some adjustments.

 

[JCB]

Md. Thanks for the reply. Those are things I haven't thought of. It was my understanding that blowback was caused by to weak of mainspring or nipples with to large of flash hole. As far as cylinder alignment it's good. I'm using a .321 ball which shaves a very small amount of lead when seated, so I wouldn't think that would be a problem. And as cylinder barrel gap goes I'm not sure, but it's something I'll check out. I assume the more gap I have the less back pressure I'll get.

 

[M. De Land]

Those two items you mentioned are the first place to look when primers are blown off but since you had already addressed them it's time to look further.
I would slug the bore if I were you and also measure the diameter of the chamber mouths.
If the ball is say .005 larger than the barrels groove diameter after being sized by the chamber mouth at loading, it will increase pressure when fired through.
Yes, the larger the cylinder gap the less pressure will be transferred to the nipple.
Most percussion revolvers need a good .006 gap to not tie up with fouling and should not have over .010 or so.
One more thing, are you sure the primers are being blown off or is the hammer pulling them off with the safety pin notch under the nose when cocking for the next shot?

 

[Smokey Plainsman]

You might want/need to install a "cap post" on the frame. This is a small pin the sits between the hammer and cap, so when the cap blows, the pin keeps it from falling back into the hammer channel.

 

[JCB]

Md
I'll take your advice and check both areas you mentioned. Somehow I was able to get five shots off once with out a single cap jam after installing the new nipples. I usually take the cylinder out and reload using a press. I may be putting the wedge in to tight leaving little gap, I usually get it pretty tight. I can see where that could be a problem. I plan on shooting it some time this weekend I'll let you know what happens. And yes pressure is causing the hammer to come back before I recock it.

 

[JCB]

Earl
I've seen the cap post before and thought it was a good idea, but not sure how to go about installing one, especially in such a small framed gun.

 

[Kansas Jake]

One other thing not mentioned, is what size caps are you using and are they a snug fit while still going on the nipple? Trying a different brand or size of cap may help.

 

[M. De Land]

I had that very thought when I woke up this morning but assumed that would be the first thing checked and there was no mention of misfire or chain fire trouble which usually accompanies wrong size cap use.

 

[Zonie]

For what it's worth, I'd say that 90 percent of the time when I fire one of my C&B pistols, the cap is blown all to hell. I consider it very rare for a cap to stay on the nipple.

That said, yes, sometimes the fragments will end up down between the hammer and the frame. Not much that can be done about that.

This problem is most noticeable with the Colt revolvers.
That's why Colt added the groove in the recoil shield.

It didn't prevent the problem but most of the cap fragments do get swept out thru the groove when the gun is recocked.

This problem of the cap ending up down in front of the hammer is fairly rare with the Remingtons, Whitneys and Rogers & Spencer closed frame pistols because the frame pretty much blocks off the area of the hammer. The "working end" of the hammer on these guns passes thru a small opening to hit the cap and the small opening pretty much blocks off the fragments.

 

[JCB]

The caps are something I had thought of, but not messed with yet. I'm currently using remington no. 10's. They do fit well. I believe track recommends cci 11's, but I don't have any and don't know of where I can get any locally. I do have plenty of rws 11's that I plan on trying.

 

[Kansas Jake]

Another question, you mention in your original post that the hammer is being blown back when fired. Is it catching at half **** or coming back down on the bare nipple. Sorry of that phrase.

As noted it isn't unusual for caps to sometimes be blown apart on firing and pieces falling into the innards. I often hold my Colt replicas side ways as I **** them after firing the first shot to prevent pieces from falling into the works.

 

[JCB]

Well I got a chance to shoot some this afternoon. I was able to get a number of shots off with no issues using rws 1075 caps and double stacked mainsprings which made it way harder to pull back the hammer than I like, so I don't believe I can live with that. I tried the same caps with a single mainspring and It would not set off the caps. I believe I've tried about everything that's been mentioned so far with out any real solution. I'm going to try and find some cci#11's and try that. I'm really running out of options it would seem.

 

[JCB]

Jake
The hammer is not coming back to half **** but coming back down on top of the spent cap that's been blown back between the hammer and the frame. Im familiar with caps being blown apart and jamming things up after pulling the hammer back, but this is not the problem I'm experiencing.

 

[M. De Land]

Well, you sure have me scratching my head! Wish you lived next door so I could get a gander at it.
Interesting post though and appreciate the opportunity to learn something new.
Perhaps you might buy one high end nipple of a different brand just for a test and see if there is any change.
I like the ones with the vent holes just below the cone.
These would relieve back pressure some what.

 

[roadgrader]

Have you tryd backing down the powder charge? Stacey

 

[JCB]

Md
I appreciate your advice. I'll keep working with it until I find a solution. When I do I'll let you know what works.

 

[JCB]

Roadgrader
Altering the powder charge was the first thing I tried. It didn't help any.

 

[Capt. Thomas]

Have you tryd backing down the powder charge? Stacey

That was going to be my next question, what powder and charge are you using? I have a Uberti 49' shooter as well as my Great, great, great Grandfathers original 49' Colt. I run 600 or so rounds a year through the Uberti and 50 or so through the Colt. I have had this problem with both of them and a few others, my Great Granddad who taught me to shoot at age 8 (with the Colt) taught me that you have to try a lot of different things to find what makes each gun happy.

Differences in powder, variations in caps, even from one mfg batch to another sometimes all make a difference. My colt doesn't like RWS caps of any type with any powder and will blow back. It also doesn't like Pyrodex P with CCI's... any of them but runs fine on RS, Swiss & Black MZ with Rem #11's or P & Winchester 11's. The Uberti is just the opposite and likes CCI & RWS 11's and any powder I throw at it as long as it's 12 grains or less. More and it may / may not blow back. The orig. Colt I don't load more than ten grains of anything. My Ruger Old Army's and original '58 Remington's run anything pretty much and don't blow back but splatter caps to kingdom come on almost every shot no matter what I try! My original Colt Navy's & 60's are a 50/50 toss up.

My opinion is the fit of the caps both diam. and seating depth on the nipples varies widely and makes a definite difference as well as I feel the RWS caps are a hotter cap and may increase chamber pressure with a given load. Just my thoughts and opinion based on 40 years of experience and 220 plus years of learned information from my forefathers who lived or died by whether or not the arms were reliable.

Capt. Thomas