Reliability vs Accuracy

[northmn]

I just read the thread on coning which convinced me that the current vents are the best design, ie inside coned.  Other threads have pointed out that 1/16" drilled vents or less are the most accurate.  However, I had a Brown Bess that was about as reliable as a percussion and must have had at least a 3/32" vent.  I am about to make a 10-32 vent for a 25 as suggested by Dpharsis but plan on using a small touchhole due to bore size.  I figure that if I get a flash in the pan on a trophy bull squirrel I can live with it.  However in big game rifles one gets into another area.  The Bess had a very large lock that paired a very large flint up against a very large frizzen.  The amount of spart is likely not so important as getting adequate spark.  I noticed also that Daryl suggested a .07 vent hole.  When I chronograped the .07 did not give up much to my .0625 vents.  Been wondering if a 5/64 would not be a better hunting vent in the larger hunting rifles?  Also maybe making a rifle using some of the larger locks such as the early 1800's military rifles would not be all that far fetched.  They would be slower but likely would go bang. 

DP

[rich pierce]

I think that in a smallbore, vent position, barrel wall thickness, etc would be the main issues.  It's probably a good idea to use a small custom liner to get the powder close to the pan.

In my last build (.58 caliber D weight) I drilled the vent 5/64 and did not use a liner.  It shoots reliably with a large Siler-sized custom lock and I do not notice delayed ignition compared to guns I've made and shot with various touchhole liners.

Larger locks can be more reliable or easier to use in the field, mostly because they are easier to prime with gloves, in cold weather, under hurried conditions, especially if you prime from the horn.  But locks are so variable that a well-tuned small lock will generally out-perform and be more reliable than an average large lock, and vice versa.

[Acer Saccharum]

I prefer a large lock for a hunter. As Rich points out, the physical size makes for faster and more positive operation with cold fingers.

You also want a good batch of sparks to light the prime. A good hot fire in the pan will set off the charge, almost regardless of the vent size.

But for speed of ignition, and reliability, go for large touch hole if you aren't going to use a liner (.078 or larger) . You can open this up until you get the speed you like (or, as Larry Pletcher has proven, the perceived speed).

I am always going to use a liner if I can. Eventually I will make one of those touch hole inside coner machines. Then I won't be using liners no mo'.

Good morning, y'all. This AM broke clear and chilly, so refreshing and sharp. Very exciting.

[Dphariss]

If the vent is made properly and installed properly there is little difference in reliability until the vent is pretty small. Probably under .055 or so. IMO .0625 is perfect for a hunting gun and see no reason to exceed .070 in any case. If this vent size causes problems there is some other variable causing it.
Also vents over .0625 rend to blow out powder when the ball is seated.

I have never had a good vent liner that was slower than a plain vent. It just does not happen.
An increase in vent size in a counterbored vent may increase ignition speed at least up to a point. but one would need Larry Pletcher's timing to prove it.
There are many things to consider. If hunting squirrels reliability is one thing, if hunting Gbears or Cape Buffalo the consequences of a miss or hang fire may be more serious.
The WL is nearly impossible to install wrong but needs some thinking to get the clearance between the inner cone and the pan right. ie the length of the small diameter vent. I just put in a 1/4" version and have to nearly install it flush to get what I wanted for a length in this regard. The "web" if you will needs to be about .030 or a little less. To thin and the metal around the actual vent will overheat and turn black internally. With the Nock breeches cleanout screw one learns things since its possible to see the inside of the liner after its been used for awhile...
I have only test fired the rifle with the 1/4" WL 8 shots but even with the stock WL vent size, .055 IIRC it never missed or hung. If it is not reliable it will be up to the owner to decide. The rifle BTW will be used in an area where Gbears view gunshots as dinner bells....

Velocity loss is not necessarily the problem its the deviation from the average velocity the hurts. This goes up with increases in size in both percussion and flint ignition.

A good lock goes bang regardless of size. The Manton style lock (from TRS castings) I have has a small frizzen and is very reliable and fast. The shop made lock on my D King Hawken is smaller than the L&R lock TOW calls an Ashmore and its fast and reliable and looks far better on a flint Hawken since the "Ashmore" more is the size of the late percussion locks and is too big for an early J&S. The DK lock accepts a L&R  TOW "Bailes" frizzen very nicely BTW.
The small Siler is a very reliable lock so installing a big lock looking for reliability is probably a mistake. The big lock is also more likely to jar the rifle during the ignition cycle.
Dan

[Roger Fisher]

If the vent is made properly and installed properly there is little difference in reliability until the vent is pretty small. Probably under .055 or so. IMO .0625 is perfect for a hunting gun and see no reason to exceed .070 in any case. If this vent size causes problems there is some other variable causing it.
Also vents over .0625 rend to blow out powder when the ball is seated.

I have never had a good vent liner that was slower than a plain vent. It just does not happen.
An increase in vent size in a counterbored vent may increase ignition speed at least up to a point. but one would need Larry Pletcher's timing to prove it.
There are many things to consider. If hunting squirrels reliability is one thing, if hunting Gbears or Cape Buffalo the consequences of a miss or hang fire may be more serious.
The WL is nearly impossible to install wrong but needs some thinking to get the clearance between the inner cone and the pan right. ie the length of the small diameter vent. I just put in a 1/4" version and have to nearly install it flush to get what I wanted for a length in this regard. The "web" if you will needs to be about .030 or a little less. To thin and the metal around the actual vent will overheat and turn black internally. With the Nock breeches cleanout screw one learns things since its possible to see the inside of the liner after its been used for awhile...
I have only test fired the rifle with the 1/4" WL 8 shots but even with the stock WL vent size, .055 IIRC it never missed or hung. If it is not reliable it will be up to the owner to decide. The rifle BTW will be used in an area where Gbears view gunshots as dinner bells....

Velocity loss is not necessarily the problem its the deviation from the average velocity the hurts. This goes up with increases in size in both percussion and flint ignition.

A good lock goes bang regardless of size. The Manton style lock (from TRS castings) I have has a small frizzen and is very reliable and fast. The shop made lock on my D King Hawken is smaller than the L&R lock TOW calls an Ashmore and its fast and reliable and looks far better on a flint Hawken since the "Ashmore" more is the size of the late percussion locks and is too big for an early J&S. The DK lock accepts a L&R  TOW "Bailes" frizzen very nicely BTW.
The small Siler is a very reliable lock so installing a big lock looking for reliability is probably a mistake. The big lock is also more likely to jar the rifle during the ignition cycle.
Dan

Your statement regards blowing out powder is certainly true.  My smoothy w/a liner was doing it's thing on regular basis til the vent 'grew' in size due to a rough pick. Until she shot low and lost 2 f 'outta' said vent. a 5/64th fell in and a 3/32 with a bit of a shove would have.  Changed the liner and only pick when I must then @!*% careful!

[northmn]

3f will dribble through a .07 vent.  Some time ago I found that it works best for me to insert the pick before loading. Pour in the powder charge and seat the ball.  That seems to pack the charge enough to prevent the 3f from self priming and I semed to get fewer flashes in the pan.  I have a L&R late style English lock that is an excellent sparker.  I just wonder about the earlier style locks.  Is a large Siler more reliable than a small one and are the larger fowler locks more reliable yet?

DP

[rich pierce]

Rough touchhole picks are everywhere.  There are tools for sale that look like awls and they call them vent picks.  They should ream a touchhole out to 1/8" in about 5 uses.  I will only use a feather, smooth wood or copper or brass polished smooth.

[northmn]

I remember many using a welding torch pick set.  They may also make good reamers.  I use brass for a pick.  When I load at the bench I have often used round toothpicks.  One of the things that inspired me to start this little thread was my interest in military rifles as I used to collect bolt milsurps.  I started watching the Sharpe's series of shows starting with Sharpes Rifles, about the 95 British rifle unit in the Napoleon wars.  They actually use Bakers.  I looked up the Baker in Baily's book on British military arms and saw a rifle that would be a b---h to shoot very accurately but that would likely be pretty reliable.  At about the same time our military adopted the Harpers Ferry rifles, and the Europeons got into using them.  The Germans had a version of what we call Jaegers before.  Actually the word Jaeger means hunter and a Jaeger rifle would make an interesting example for this discussion. 

DP

[Daryl]

DP - I've some to the conclusion to drill out tight, new WL vents to a maximum of 1/16" - .0623" and replace them when they grow to about .073".  Even my pistol showed pretty good and fast ignition with a new White Lightening liner at about .052" or whatever they are - small, anyway.  At the samll size, I did have too many flashes in the pan so I opened it to .070" and instantly, had more reliable ignition, where any flash ended in ignition. In the rifle, with larger pan capacity, flashes in the pan pretty much always ending in ignition, unless there is a bit of fouling in the vent hole, which does happen with 2F, but not 3F powder.  This happens in my .40, which uses 2F in the summer months, but doens't happen in the winter, with 3F when flash results in a shot fired.

[Jimmy82]

This happens in my .40, which uses 2F in the summer months, but doens't happen in the winter, with 3F when flash results in a shot fired.

What state are you in?  Might this be an ambient humidity issue as well?  I know Nebraska is much more humid during the summer then the winter.  North Carolina on the other hand is humid all the dang time.

[Daryl]

Jimmy - mental state? Ask Tom.

I live in the physical centre of BC, hense the flag.  Our average humidity is about 50%, rarely gets over 80% and sometimes runs in the low 20's.  When we shoot the trail here, as yesterday, the fouling around the pan and on the barrel's breech is snow white most of the time. It virtually has to be raining or almost raining before that fouling obsorbs water and turns black.