Unusual Circumstance - Looking for Input

[Dude]

Thanks necchi.

I went looking through my notes and found this - I think it was something Idaho Ron or Lewis wrote:

TOW Hotshot = .026"
BACO Platinum = .024"

Optimum size for black powder = .024"
Optimum for Pyrodex = .034" (worn out at .038-9")

From what I recall, worn out for black is around .035"

 

[necchi]

From what I recall, worn out for black is around .035"

Good question.
But nipple wear can't really be quantified like that.
The actual damage that happens is referred too as "gas cutting".
Shooting the gun creates massive pressures intended to expand gasses behind and send a stationary projectile in a certain direction,, aka: down the bore.
But those gasses don't care with way they go, they just wanna expand. They'll take the easiest route, that's for sure,,
but they also put pressure out the reverse-side,, the nipple.
Un-like the flint locks open flash hole that let's those gasses out through a small hole, the only thing holding those gasses back in a cap lock is the nipple AND the pressure of the hammer against the nipples cap.
It fails. "some" gas leaks out the back. (period). Even with a new nipple.
It's a physical impossibility that has been changed only by the advent of "cartridge" guns and historical development leading to current.
Such is; traditional,,,
Those hot gasses affect not just the orifice but the face of exposed metals also. The personal/individual care of this precise piece while in use, and the personal/individual care of the load variables by each owner all affect how much gas is afforded to the nipple's exit point for those gasses

Gadd's! it too late,, I'm rambling,,
Get this part,: If the hammer "blows back",, your already 100 shot's past where you can get the best accuracy.
With proper care, load development, and proven accuracy,,,,,, that "accurate load" you had will begin to fail,, your groups will open,, long before the hammer blows back.

 

[DuncNZ]

Change the nipple as suggested , a blowback hammer can quickly become a broken hammer or broken lock internal parts ,
Another thing with nipples that burn out , as they wear they change the pressure in the bore and thus alter your trajectory .

 

[TFoley]

I've had great success with Butler-Creek nipples over the years. I get mine from The Gun Works in Springfield, OR, easy when we only live around a 20-minute drive away...

 

[Christophero]

On Sunday I had an unusual circumstance with the Lyman GPR 54 that I purchased (first GPR and 54 caliber) last October. The nipple that came with the rifle was not any good, the rim was no longer even where the hammer strikes. Upon a misfire the last evening of muzzleloader season due to that issue I have since ordered a brand new nipple from Track of the Wolf. Brand New. The first thing I noticed upon opening the package is how large that orifice is in the new nipple. It has not failed to fire once since it was installed.

Sunday afternoon I pulled out a can of FFg given to me by a friend sometime back. The dwindling FFFg stash is getting low, this is a 54 with a PRB and it was time to use it. Mind you, this is the first time I've used FFg in 33 years. With all the comments about GPR's being more accurate with higher charges I loaded 100 grains under the Ball. (This is the first time I've ever loaded 100 grains of anything into any rifle I've owned). The recoil wasn't bad, but then I noticed this:

That's right, Hammer Blow Back. Notice the BRAND NEW NIPPLE, albeit a bit dirty after firing that first shot. I backed it off to 90 grains FFg with no further issues in that range session. At the end of the day I fired two PRB's with 95 grains to check, The hammer was still sitting on the nipple. This was not a Hot Shot nipple, just the regular one offered for the GPR on the TOW's nipple page.

This is the first time I've had hammer blow back on a cap lock since shooting 90 grains of FFg in my 50 caliber T/C Renegade with a Maxiball over 30 years ago. Oh, by the way, that was a brand new gun in 1988 when that happened.
I'm not saying worn out nipples cannot cause hammer blow back, but I won't camp out on that as the only reason this happens. Nipples are cheap enough to swap out as you trouble shoot the different possibilities for this occurrence. I'll do as I did before and lower the charge weight and keep enjoying my rifles without the blow back issue.

 

[Notchy Bob]

Yesterday I was shooting my Thompson Center, 45 caliber, percussion, Hawken rifle. I was using .445 patched, round ball. I was looking for lighter loads to help preserve my gun powder supply. I was using 40 grains, 35 grains and 30 gains of Pyrodex, P powder. My rifle has a set trigger. When I shot using the set trigger the hammer would fly back and **** the gun. (I have owned this gun for about 2 years and it has never done this before). ---- This is where the unusual circumstance occurred, when I shot the gun without using the set trigger the hammer did not automatically ****. --- Has anyone experience such a thing? I know of the usual reason, the nipple hole being too large. I did not modify the nipple in any way. It is fairly new. --- I have shot this gun two or three hundred rounds and this is the first time something like this has happened. I have previously used 60 or 70 grains of Pyrodex or Goex and did not experience this. ---- Any input would be appreciated.

I have a .54 caliber custom rifle that does that. I've only had it out once, and was shooting 60 grains of FFg under a .520" ball (the bore is undersized). The usual culprits in that scenario are an oversized flash hole and/or a weak mainspring. However, I don't think either of these conditions apply in my case, and it is puzzling. You and I were both shooting relatively low powder charges, and I'm wondering if the light load may have something to do with it. Maybe the lower charge has difficulty generating enough energy to overcome the inertia of the ball, and relatively more gas jets out through the flash hole. That's my hypothesis.

This probably doesn't happen when you don't set the triggers and shoot as with a single trigger because the continuous pressure of your finger on the trigger holds the sear arm up and pivots the sear nose down, so it can't engage the notches in the tumbler. The hammer may fly back, but the sear won't engage so the hammer drops back down. Set triggers "kick" the sear arm up, but don't hold it up. The sear spring then makes the sear engage the tumbler when the hammer moves back down.

Best regards,

Notchy Bob

I don't know if this will contribute anything useful to the discussion or not, but...

I took the custom .54 caliber Hawken rifle referenced in the quote above back to the range a couple of days ago. When I cleaned the rifle after the previous session, I took a close look at the nipple, and I believe it is a HotShot. I still haven't figured out who made the lock, but I suspect it was either L&R or Davis. The first time out, I was shooting a light load of 60gr (that's sixty grains) of Goex FFg and a .017" ticking patch lightly lubed with SPG. This rifle has a GRRW barrel with an undersized bore, so I was shooting .520" swaged balls. I was getting hammer blowback on about two out of three shots, and the single recovered patch had a clean, bore-sized hole and was smouldering, about to start a grass fire.

The second time out, I replaced the nipple with an old but un-used one from a batch my Dad had acquired some time in the late forties or fifties. The cone was sized for #12 caps, but I still have a half-dozen or so tins of Alcan #12's from a case (ten tins) we bought in about 1968. A couple of days previous to this shooting session, I used a double boiler to melt a tin of Dixie's Old Zip Patch Grease, which is a blend of mutton tallow and beeswax, and saturated a supply of the .017" ticking patches, as well as a quantity of .54 caliber wool felt wads, bought dry from RCM/Ox-Yoke. Patches and wads absorbed a LOT of lube.

At the range, I used the same, light powder charge as before, 60gr of Goex FFg, and the same .520" balls. This time, I put in a wad first, then pushed the patched ball down with it. Loading went well, and I think I fired twenty shots with no wiping needed at any point. We won't talk about accuracy... My vision has deteriorated over the years and at this point I'm just happy to keep 'em in the black.

There was no hammer blowback at any time. In fact, the caps were still intact, and I had to borrow a set of pliers from another shooter to remove the spent caps from the nipple. The caps pushed on the nipple and seated easily, and there were no mis-fires at any time. I think caps used to be made of much thicker material than is used now, and we wonder how the old-timers in the field dealt with spent caps adherIng to the nipple back in the day. In any event, there was no hammer blow-back!

However, I think I may order one of the Ampco nipples with the small orifice from Buffalo Arms, as suggested in one of the previous posts. These ought to be sized for #11 caps, also. I would just as soon conserve my old #12's.

Best regards,

Notchy Bob

 

[Lonewalker]

You mentioned light loads, curious is the light load enough powder to at least fill the patent breech ?? Are you actually putting ball and patch against powder or do you have a gap with the light load

 

[Notchy Bob]

You mentioned light loads, curious is the light load enough powder to at least fill the patent breech ?? Are you actually putting ball and patch against powder or do you have a gap with the light load

Thanks for your comments.

I can assure you, the ball was seated. By actual measurement, this load column is 1-3/8” high. With no compression, the over-powder wad and patched .520” ball combined would take up no more than 5/8” of that. The rest would obviously be powder. I use a gauge to assess the amount of ramrod protrusion for every single load. I carry a wooden mallet to the range with me, and if there is any doubt as to whether the ball is seated or not, a couple of taps on the end of the rod ensure the ball is where it needs to be, and it is verified with the gauge. This kind of consistency is necessary for safety as well as accuracy.

This rifle may very well perform better with a larger powder charge, and I suspect it will, but that’s yet to be determined. However, when I first started shooting muzzleloaders 60+ years ago, the generally recommended starting load for most rifles was one grain of powder per caliber, e.g. 54 grains for a .54 caliber rifle. There was not a lot of published information and, of course, no Internet at all then, but this is what I remember reading. The idea was that you start low and work your way up. When Horace Kephart conducted his famous field test of an original .53-.54 caliber Hawken, his starting load was 41 grains! He did try progressively larger powder charges, however, and eventually quit after shooting a load of 205 grains. I had a flask with a 60gr spout handy, so that’s what I used for a “getting acquainted” load with this rifle.

Original Hawken rifles, and some of the accurate reproductions, don’t really have a powder chamber in the patent breech. The flash channel is drilled directly, albeit at an angle, from the base of the nipple seat to the face of the breechplug. This is only possible with a short threaded section on the breechplug. I don’t know, but I think my rifle probably has an L&R breechplug, with a longer threaded shank, so it probably does have a small chamber or “powder well.” I don’t have a bore scope to see it, though, and I can’t see it with a bore light.

So, I appreciate the comment and the questions. Safety first and always, but yes, there was plenty of FFg in there to fill any chamber or powder well in the patent breech, even with the relatively light 60gr charge.

Best regards,

Notchy Bob

 

[Lonewalker]

Thanks for your comments.

I can assure you, the ball was seated. By actual measurement, this load column is 1-3/8” high. With no compression, the over-powder wad and patched .520” ball combined would take up no more than 5/8” of that. The rest would obviously be powder. I use a gauge to assess the amount of ramrod protrusion for every single load. I carry a wooden mallet to the range with me, and if there is any doubt as to whether the ball is seated or not, a couple of taps on the end of the rod ensure the ball is where it needs to be, and it is verified with the gauge. This kind of consistency is necessary for safety as well as accuracy.

This rifle may very well perform better with a larger powder charge. That’s yet to be determined. However, when I first started shooting muzzleloaders 60+ years ago, the generally recommended starting load for most rifles was one grain of powder per caliber, e.g. 54 grains for a .54 caliber rifle. There was not a lot of published information and, of course, no Internet at all then, but this is what I remember reading. The idea was that you start low and work your way up. When Horace Kephart conducted his famous field test of an original .53-.54 caliber Hawken, his starting load was 41 grains! He did try progressively larger powder charges, however, and eventually quit after shooting a load of 205 grains. I had a flask with a 60gr spout handy, so that’s what I used for a “getting acquainted” load with this rifle.

Original Hawken rifles, and some of the accurate reproductions, don’t really have a powder chamber in the patent breech. The flash channel is drilled directly, albeit at an angle, from the base of the nipple seat to the face of the breechplug. This is only possible with a short threaded section on the breechplug. I don’t know, but I think my rifle probably has an L&R breechplug, with a longer threaded shank, so it probably does have a small chamber or “powder well.” I don’t have a bore scope to see it, though, and I can’t see it with a bore light.

So, I appreciate the comment and the questions. Safety first and always, but yes, there was plenty of FFg in there to fill any chamber or powder well in the patent breech, even with the relatively light 60gr charge.

Best regards,

Notchy Bob

Excellent that is not a concern then
Happy shooting

 

[hanshi]

The only time I've had hammer blowback, IIRC, was with my old tried and true underhammer. Normal load was 60 grns of 3F. All seemed okay up to 70 grains but over that resulted in occasional blowback. Once the load passed around 75 grns the blowbacks became frequent. But part of it was the design of underhammer rifles which fire the cap directly into the main charge with no angles for the flame to travel.

 

[DuncNZ]

. I think caps used to be made of much thicker material than is used now, and we wonder how the old-timers in the field dealt with spent caps adhering to the nipple back in the day. In any event, there was no hammer blow-back

I just put the edge of the spine of my knife under the lip of the cap and twist ,that usually gets the cap off no worries

 

[OldSmoky1967]

On Sunday I had an unusual circumstance with the Lyman GPR 54 that I purchased (first GPR and 54 caliber) last October. The nipple that came with the rifle was not any good, the rim was no longer even where the hammer strikes. Upon a misfire the last evening of muzzleloader season due to that issue I have since ordered a brand new nipple from Track of the Wolf. Brand New. The first thing I noticed upon opening the package is how large that orifice is in the new nipple. It has not failed to fire once since it was installed.

Sunday afternoon I pulled out a can of FFg given to me by a friend sometime back. The dwindling FFFg stash is getting low, this is a 54 with a PRB and it was time to use it. Mind you, this is the first time I've used FFg in 33 years. With all the comments about GPR's being more accurate with higher charges I loaded 100 grains under the Ball. (This is the first time I've ever loaded 100 grains of anything into any rifle I've owned). The recoil wasn't bad, but then I noticed this:
View attachment 126788
That's right, Hammer Blow Back. Notice the BRAND NEW NIPPLE, albeit a bit dirty after firing that first shot. I backed it off to 90 grains FFg with no further issues in that range session. At the end of the day I fired two PRB's with 95 grains to check, The hammer was still sitting on the nipple. This was not a Hot Shot nipple, just the regular one offered for the GPR on the TOW's nipple page.

This is the first time I've had hammer blow back on a cap lock since shooting 90 grains of FFg in my 50 caliber T/C Renegade with a Maxiball over 30 years ago. Oh, by the way, that was a brand new gun in 1988 when that happened.
I'm not saying worn out nipples cannot cause hammer blow back, but I won't camp out on that as the only reason this happens. Nipples are cheap enough to swap out as you trouble shoot the different possibilities for this occurrence. I'll do as I did before and lower the charge weight and keep enjoying my rifles without the blow back issue.

I use hot shot nipples all the time with no blowback in the same rifle. I never shoot more than 70 grains BP, though. I have another that I have a musket nipple on. No mis-fires on either and no blowback. I think if you change that nipple like you said, you will be fine.

 

[johnfrommd]

I'm more inclined to blame you problem on the nipple. Is the hammer spring at full strength or weak?

I too think it is the nipple being worn out that is causing this.