Author Topic: Is my flash hole too high? (Read 2793 times)

J-team · « **on:** July 16, 2018, 01:39:50 PM »

Have been building an English Sporting rifle and being the impatient type, as I got the lock inlet and flash hole done I tried to test fire it.

Got more than 50% flash in the pan. Main charge is FFFg and primed with FFFFg. Flash hole it 1/16" and it is relieved in the back to 1/8" only leaving about 0.030" land. The pic doesn't show but the pan is quite deep.

This is my first flintlock build (other than a pistol some years ago). Opinions please?

flehto · « **Reply #1 on:** July 16, 2018, 02:37:45 PM »

Outside of the fact that the frizzen lip won't cover the TH, I'd enlarge the TH to .067 {#51 drill} and then check it out. ....also fully fill the pan w/ prime. If the percentage of ignitions improves. , but still not to your satisfaction, enlarge it further.

I take it that the TH has an unhindered path to the charge.....breechplug in the way? Also, what type of breechplug do ypu have.....seems like there's something behind the actual breech end of the bbl and the TH isn't forward enough?.....Fred

Mike Lyons · « **Reply #2 on:** July 16, 2018, 02:57:25 PM »

50% flash in the pan is where I would start. Sounds like your flint might need turned around or adjusted.

Mike Brooks · « **Reply #3 on:** July 16, 2018, 03:46:35 PM »

I could never get that particular lock to work worth a hoot.

rich pierce · « **Reply #4 on:** July 16, 2018, 04:06:38 PM »

It sounds like you are getting consistent or 100% pan ignition but the gun only fires 50% of the time. If so, the lock is clearly not the problem. Advice above on enlarging the touch hole slightly, making sure there’s a clear path to main charge, and using plenty of prime is right on.

I do think the touch hole is too high. A custom liner could fix this easily if you could get one turned for you, with plenty above the countersink to allow you to screw it in and out with a screwdriver or a wrench. Leave it solid not coned. Screw it in all the way. Drill the touchhole lower. Remove it and countersink it, centered on the touchhole, from the backside. Do some fiddly filing or grinding of the cone as desired. Re-install, cut flush, and now your touchhole is where it should be.

You might even ask Jim Chambers if he has any that are not coned.

Hungry Horse · « **Reply #5 on:** July 16, 2018, 04:55:28 PM »

That lock has a pan plug on the bottom of the pan cover. That plug has a small notch in it to allow the pan flash to quickly enter the touch hole. If the touch hole is to high ( which it is) the plug covers at least part of the touch hole. You might try enlarging that notch a little, and maybe you can channel the flash toward the touch hole.

Hungry Horse

Mike Brooks · « **Reply #6 on:** July 16, 2018, 05:12:19 PM »

Looks like some sort of chambered breech, probably where the problem actually lies. I've seen touch holes that high work well.

rich pierce · « **Reply #7 on:** July 16, 2018, 06:02:05 PM »

Quote from: Mike Brooks on July 16, 2018, 05:12:19 PM

Looks like some sort of chambered breech, probably where the problem actually lies. I've seen touch holes that high work well.

Good eye

Frank · « **Reply #8 on:** July 16, 2018, 06:06:16 PM »

Get a stainless countersunk machine screw. Bore/drill a cavity in the screw. Screw in your barrel and trim to fit so it doesn’t protrude into the bore. Screw into your barrel, cut off and file flush, then drill the flash hole at the proper height.

Bob Roller · « **Reply #9 on:** July 16, 2018, 07:40:16 PM »

Quote from: Mike Brooks on July 16, 2018, 03:46:35 PM

I could never get that particular lock to work worth a hoot.

I have made a number of them that seem to work well. Precise fitting parts and a heavily preloaded
mainspring will make these work like they should.I am considering making a few more once I get my
right eye working. The left one had a cataract removed and an implant installed and the right one is
still waiting.Glasses are almost useless now.The last of these locks I made I got the externals from L&R minus
their frizzen spring and undrilled for it. I installed a Chambers late Ketland frizzen spring and it worked fine and
looks much better.It adds about $30 to the cost of the lock.Externals cost about $100 from L&R and the Late
Ketland spring is about $30 and my labor is $150 which it's been for years.

Bob Roller

Craig Wilcox · « **Reply #10 on:** July 16, 2018, 07:48:57 PM »

Bob Roller - you will do fine with that cataract removal/replacement - had mine done a few years back, and for the first time could actually see leaves on trees 100 yards away.
Your near vision is gonna suck tho - you WILL need reading/working glasses!

Your metal and lock work amazes me! You seem to be quite the perfectionist in your field. I would not know how to "tune" a frizzen or main spring, or even if they were misbehaving!

Thanks for all the help yu give to our ALR groiup - much appreciated!

Daryl · « **Reply #11 on:** July 16, 2018, 07:49:07 PM »

The vent on my 20 bore is really high- about identical to yours J-Team. I fill the pan with 4F- ignition is super.
Can't really see it here, though, but by the height of the middle of the flat above the lock, it should be evident the vent is high, above the horizon line.

J-team · « **Reply #12 on:** July 16, 2018, 11:29:15 PM »

Thanks for the replies. To be clear, I am getting 100% pan ignition, but only 50% main charge ignition. So I'm happy with the lock, it sparks well.

I'll start by filling the pan more and if that doesn't work, I'll look at re doing the insert at a lower position. I have some room to move and could make a bigger one and adjust the centre down a bit in the process.

Mike Brooks · « **Reply #13 on:** July 16, 2018, 11:53:35 PM »

The vent liner is more than likely not the problem, changing it out isn't going to help. The problem is your patent breech, either it's all crudded up or the powder isn't getting down to the touch hole. You probably need to enlarge the powder chamber.

Bob Roller · « **Reply #14 on:** July 16, 2018, 11:56:55 PM »

When you pour the powder down the barrel and seat the ball,can you see any powder granules inside
the flash hole? They should be visible and the flash from the pan should give nearly percussion ignition.
If you don't see powder then there is an obstruction of some kind.

Bob Roller

jerrywh · « **Reply #15 on:** July 17, 2018, 03:17:56 AM »

Set the barrel down a little. Open the touch hole to about .072

Randall Steffy · « **Reply #16 on:** July 17, 2018, 04:28:20 AM »

Personally, I think that based on what we can see from your picture, externally all is fine. The touch hole location in particular and the apparent size of the touch hole should work well. If you could fit a number drill to the touch hole and turn it by hand, see how deep you can reach into the barrel and what you hit, obstruction wise. I would really want to see the inside of the barrel in the location of the touch hole to give a reasonable diagnosis. A look see with a bore scope would be the ticket. Or pull the breech plug. Like some others, I am thinking "obstruction."

J-team · « **Reply #17 on:** July 17, 2018, 04:43:16 AM »

Ok, definately no obstruction as I made the breech plug myself and fitted the flash hole with it removed from the barrel. There is a clear path from flash hole to powder chamber.

I didn't make a conscious effort to look to see if I could see powder through the flash hole when loaded, I will next time.

Will look at enlarging the chamber as Mike suggests, currently it is 0.400" diameter and extends just past the flash hole, what diameter do you suggest? I might even just get in there with a carbide burr and bias it towards the flash hole (?). Will be a couple of weeks before I can shoot it again though as I have other commitments filling in the next 10 days or so.

smylee grouch · « **Reply #18 on:** July 17, 2018, 06:52:18 AM »

.400 seems to me to be OK, is the front of the plug where the hole is coned or funneled a little? Your powder sounds like it's bridging up and not falling into the chamber every shot. Pour your powder down slower and see if that helps.

Mike Brooks · « **Reply #19 on:** July 17, 2018, 03:24:20 PM »

Quote from: J-team on July 17, 2018, 04:43:16 AM

Ok, definately no obstruction as I made the breech plug myself and fitted the flash hole with it removed from the barrel. There is a clear path from flash hole to powder chamber.

I didn't make a conscious effort to look to see if I could see powder through the flash hole when loaded, I will next time.

Will look at enlarging the chamber as Mike suggests, currently it is 0.400" diameter and extends just past the flash hole, what diameter do you suggest? I might even just get in there with a carbide burr and bias it towards the flash hole (?). Will be a couple of weeks before I can shoot it again though as I have other commitments filling in the next 10 days or so.

I don't know what caliber your gun is, that's going to be important. I have experience with shotguns. The ones I did had chamber holes that were tapered (non parallel sides) and had rounded shoulders at the front of the chamber. Shape and size of the chamber is critical. I found it helps to be highly polished as well.

Bob Roller · « **Reply #20 on:** July 17, 2018, 03:56:32 PM »

Quote from: Craig Wilcox on July 16, 2018, 07:48:57 PM

Bob Roller - you will do fine with that cataract removal/replacement - had mine done a few years back, and for the first time could actually see leaves on trees 100 yards away.
Your near vision is gonna suck tho - you WILL need reading/working glasses!

Your metal and lock work amazes me! You seem to be quite the perfectionist in your field. I would not know how to "tune" a frizzen or main spring, or even if they were misbehaving!

Thanks for all the help yu give to our ALR groiup - much appreciated!

Craig,
Thank you for the nice comments on my metal working.As I have stated several time on this
forum,what you see in my lock work tells one and all what I think of myself but the REALLY
important thing is what I think of the person who orders it.My business method of NO PAY
until the work is ready to send speaks for itself.Flintlocks are a peculiar thing and I try to
adjust the frizzen spring so it will resist opening and the flint can get a "bite"into the steel
and then a decent "scrape' on the way down.All of this is dependent on the power of the
mainspring and a precise fit of the mechanism.I am fussy about this and I test the lock
by holding the sear out of position and rocking the cock back and forth.All that should be felt
is the pressure of the mainspring.The spring should be strong but not stiff.Limber and active
is the best way I can describe it.
IF anyone gets a benefit from my posts then they are certainly welcome to take advantage of them.
I am glad to help if possible.
With regard to my visual problems,I was 44 before I got my first pair of reading glasses and
I am looking forward to being able to use a micrometer without double checking.My next visit
to the eye surgeon I on the 26th of this month but I will try to see her before then if possible.

Bob Roller

Craig Wilcox · « **Reply #21 on:** July 17, 2018, 04:42:08 PM »

Thanks for the advice on checking the lock operation. My lock, Chambers Dale Johnson, appears to be working great, and is very smooth.

I try to learn something new each day, and this is today's "learning moment!"

Craig

Bob Roller · « **Reply #22 on:** July 17, 2018, 04:48:04 PM »

Anyone that quits learning is dead from the neck up and that's NOT good.
To me,seeking knowledge from people who I am certain have it is a delight
in life to me.Cars,Guns,Vintage aircraft,BIG steam locomotives,machines of
all kinds get my attention.Bringing an idea to a successful conclusion is one
of the biggest pleasures to me.

Bob Roller

Acer Saccharum · « **Reply #23 on:** July 17, 2018, 04:49:12 PM »

J-team, one of the most critical things is that the main charge is reaching the touch hole. When you load and ram the ball home, the vent should be packed with powder grains. If you're using 2F, often a grain is wedged in the flash hole.

If you're not getting this consistently, the right angle between the touch hole bore and the chamber bore should be rounded off so that the load can more easily go around the corner. If it's a sharp transition, it's a restriction to powder flow.

You will have to pull the plug, and quite possibly the liner, to get at this detail properly.

L. Akers · « **Reply #24 on:** July 17, 2018, 05:31:54 PM »

I agree with Mike that the chambered breech may be part of the problem, but not the breech per say. I have made many chambered breeches, Nock and Manton, and have no trouble with either style. However, I have found they can be persnickity about loading procedure. Mr. Roller touched on this. If the powder charge is dumped en-mass into the barrel it arrives at the breech en-mass and wedges itself into a clump that does not enter the chamber. Try trickeling a bit of the powder charge into the barrel before dumping the rest en-mass. This will allow powder to enter the chamber and run to the touch hole. Bumping the lock side of the stock will also help move powder to the touch hole. And, as Mr. Roller said make sure you can see powder at the touch hole. I would not enlarge the touch hole or the chamber.

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Author Topic: Is my flash hole too high? (Read 2793 times)