Hammer blow back

[FRJ]

I've been shooting my new barrel with my hunting load and it is very accurate. Today I went out to shoot it again and the hammer was blowing back to half cock. The load was 110gr 2F under a felt wad and a pillow ticking patch around a self cast dead soft 54 cal ball. Ive shot this load about 40 times before and never experienced blow back previously. The nipple was the one that came with the barrel, a GPR 54 cal. I changed the nipple and the blow back stopped. Its a good load and is centering clay birds at 110 yards so I'm keeping it. Any ideas on why the nipple should change in just a couple hundred shots? FRJ

[heelerau]

I have found the odd nipple burns out quickly , the flash hole enlarges over time, you can really notice it happening with musket nipples. The gass cutting a groove from the hole, most noticeable with the new style nippes that have the flash hole at the bottom. Generally the mainsprings in muskets are heavy enough to stop the hammer blowing back, but you can get a lot of cap shrapnel flying about. 
    My mate uses a Gibbs long range rifle and he has nipples cut out after a 100 odd shots or so. 

Cheers

Gordon

[Bull Shannon]

That is a pretty stout powder charge and I think it's time again for a new nipple.  I have switched my Lyman rifle over to the AMPCO bronze nipples by Treso and have been very pleased with the longevity and performance.

[Bob Roller]

 The Gibbs as well as other long range muzzle loaders operate at much higher pressures
than the round ball guns.All of the long rangers I have seen and owned had a platinum insert in
the base of the nipple to help with this burned out flash hole problem.

 Bob Roller

[heelerau]

Bob,
      I sent some titanium welding wire to my mate with the Gibbs, he is going to see if he can use it as an insert, much cheaper than platinum lined nipples. Still waiting to hear from him, will post the results if anyone is interested.

cheers

gordon

[Hungry Horse]

IMHO using 110 grins. to shoot 110 yds. is certifiable, unless you are hunting large, or dangerous game. Heavy charges put undo strain on gun parts. Gas cutting is much more common in guns that have been used with excessive charges. If you want a swift kick in the puss like magnums produce, get a magnum, and be safe.

                              Hungry Horse

[David R. Pennington]

Upgrade to a flintlock! Problem solved.

[Standing Bear]

 

[Southron]

When your hammer is "blown back" that is your nipple telling you: "Change Me NOW!!!"

I have been shooting black powder arms since 1968, have built guns and shot in the N-SSA just as long. Whenever I buy a new replica rifle or rifle-musket, I IMMEDIATELY take out the STEEL NIPPLE AND THROW IT AWAY. Generally that is the first step in a full blown "Accurizing" job.

I replace that nipple with an AAMPCO NIPPLE. These nipples look like they are made out of brass, but in fact they are made out of Beryllium. They are much tougher than steel nipples, last a lot longer and don't rust up like steel nipples.

Aampco Nipples are available from THE HOUSE OF MUSKETS and you can Google their website. They are good people to do business with and their nipples are excellent.

[dagner]

 good post  those steel nipple whith turned  sharp end will eat  your hammer face alive   also if you are getting hammer cock  make sure your theaded niplle hole is not worn out.  getting dangerous blow by . saw hammer recoked with the blow by  and over lasrt 25 yeaRS SAW 3 NIPPLES BLOWN OUT - 2 went threw the tip of baseball caps  saw hammer laying on ground twice  with hammer screw sheared off  over the years  usual culpret was  not cleaning  properly and cross threading . then  not retapping or replacing breach  saying well the bottom threads were tight
dag

[LH]

I dont have many caplocks,  but they've all got platinum lined nipples in them.  Far cheaper that way if you want consistent ignition and do more than a little shooting.  Even the Ampco nipples wear out pretty fast.  I make my own touch hole liners for the flint guns out of stainless.  I've tried Beryllium copper and a variety of other metals, but ss lasts about as long as anything.  I cone the inside with a ball end bit and leave the bore (small hole) about .020" long.  This will last about 4000 or 5000 shots.  I drill them with an .059 bit and when they grow to about .070 I replace them. 

[FRJ]

I use this rifle for Roosevelts elk and that load IS NOT excessive. In fact the factory recommended max is 120 gr. If someone wants to hunt with less so be it. I want all I can safely shoot to put the animal down with a good kill shot as quick as possible. Nothing more than I would ask if someone was killing me. FRJ

[TMerkley]

Several years ago, after I returned from Iraq, I thought I woudl try to improve ignition and reduce fouling on the nipple by drilling it out to 1/16th".  Well, I shot it and did not have any problems. Then it happened.  As I squeezed the trigger for a good accurate shot, the rifle went off as planned but when I got up and pulled the hammer back to put on half cock, it did not work.  When I got home, i pulled the lock and found that the sear was bent due to hammer blow back.  I must have still had my finger on the trigger as the hammer came back.  After about 3 hours of experimentation, I made a new sear from scrap metal and hardened it.  Problem solved and works quieter than the original.  But a hard lesson learned. 
Sometimes the hardest lessons learned are the best ones.

[JCKelly]

Heelerau, sorry to tell you this but titanium does burn like $#*!.
Titanium has a high melting point, which is nice, but it literally burns when too hot. For aerospace parts I think 600F is about max, though maybe some alloys can be used to 900F, disremember.

Anyway stay away from any titanium alloy in nipples or vent liners. I believe one other member here has experience.

The fanciest stainless that is more or less available is type 310, nominal 25% chromium 20% nickel. Next is type 309, about 22-23% chromium, maybe 12-13% nickel.

Stainless nipples commercially available will likely be 416, maybe 303, both free machining and pretty ho-hum in resisting fire erosion.

Get some 309 or 310, machines gummy but turn s-l-o-w-l-y.  Very, very slow.

[oldarcher]

I believe that two problems cause most all of the hammer blow back issues, both have been discussed here before. 
The first thing to check is that the nipple is properly installed, not cross threaded, and installed tightly.
I believe that the most common reason for excess blow by is a nipple that has eroded and allows too much gas to blow through...this can happen fairly quickly once it actually begins to erode, as more and more gas escapes through a larger and larger hole the erosion increases exponentially. Simple to fix, just replace the nipple.
My personal experience is with thread erosion.. I had been shooting an old GRRW hook breech rifle for 20 or so years, changing the nipple regularly and cleaning aggressively after each time I shot. Finally I began to notice that I was getting more blow by, I changed nipples about every 100 or so shots, so I had to investigate more carefully and discovered that with all of the use, removal, cleaning, ect. I had worn the threads on the breech badly. I re tapped the plug with an oversized tap and installed an oversize nipple and the problem was solved.
Excessive blow by is a very serious and dangerous problem, do not ignore it.  I am comfortable with 100-120 grains of powder in a .58, but the higher the charge the more likely the blow by problem will be evident (higher internal pressures). If you can't find the problem seek assistance, do not continue to shoot a rifle that is malfunctioning in this manner. At least don't shoot next to me......

[Daryl]

FRJ your load is just fine in a firearm well made of good materials and properly maintained as I'm sure your's is.  The lYman is just such a firearm.  Nipple burnout is a common factor with caplocks just as vent burnout/enlargement is normal with flinters. They merely need to be replaced when the hole gets too big.

With my own caplocks, if I fire a shot and there is no expanded cap to remove, the vent hole is now over large and the nipple is replaced. I always carry at least one extra in my small equipment bag inside the possible's bag.

[ironwolf]

  I gotta agree with Daryl, the charge is good.  Most shooters today use much too light a charge.  There's something to the old "norm" of half the ball weight in powder, try it and see for yourself.  When you develop a load based on group size, you'll almost always find the hotter ones are the tightest.
  I shoot the same charge at all ranges because that load was developed for group size, it's hot and subsequently shoots flatter than lesser charges and is more consistant

  Just my tuppence,   KW

[Daryl]

  I gotta agree with Daryl, the charge is good.  Most shooters today use much too light a charge.  There's something to the old "norm" of half the ball weight in powder, try it and see for yourself.  When you develop a load based on group size, you'll almost always find the hotter ones are the tightest.
  I shoot the same charge at all ranges because that load was developed for group size, it's hot and subsequently shoots flatter than lesser charges and is more consistant

  Just my tuppence,   KW

My sentiments exactly, KW.  I use the most accurate load in that particular rifle, for all ranges- except for the 14 bore. In it, I put up with sub-standard accuracy at short ranges, up to 50yards.  Past that, it takes powder to get the accurace the rifle & I are capable of producing.