Author Topic: Flat Breech Testing Finished (Read 9426 times)

Larry Pletcher · « **on:** February 20, 2009, 03:57:54 AM »

Steve Chapman and I finished off the tests on the flat flint breech today. We used a variety of vent systems provided by Dan Pharis and Jim Chambers. By now we think we have the flat breech pretty well rung out.

The chart below provide averages for the various liners. We timed them cleaning very carefully and also dirty. On the dirty trials we started clean but did nothing at all between trials. Seating the sabot became increasingly difficult and caused a sharper sound on the "dirty" trials.

vent type-------------------------clean---------------------------dirty

Phariss Chambers style-------------.0405--------------------------.0433
Phariss .055-.101*-----------------.0398--------------------------.0474
Phariss (large w ext cone)----------.0309
Chambers WL .064----------------.0370--------------------------.0400
Chambers WL .064 ext cone**------.0377

Chambers WL .064 ext cone--------.0510 -- ffg as barrel powder
Chambers WL .064 ext cone--------.0660 -- One try ffg in barrel and pan

*Liner has vent of .055 and counter-bored inside to .101
** Exterior Cone is very slight

We had fun trying to see if we could get some good pics. We basically held done the button and let it fly. We uploaded the shot that caught the ignition and the one that followed.

Note the sparks flying in the second pic.

This shot is just after the barrel fired. You can see fire just beyond the shield.

Again sparks on all sides.

You might note the haze developing in these last two shots.

Regards,
Pletch & Steve Chapman

chapmans · « **Reply #1 on:** February 20, 2009, 05:18:16 AM »

I find it amazing how much fire is generated by 3/4 of a grain of priming powder in the pan, and also how much muzzle flash by only 20 gr from the main charge. I am very much enjoying these experiments and am very much looking forward to the next round. I wonder if Goex would generate more flash and more smoke?
Steve C.

Levy · « **Reply #2 on:** February 20, 2009, 05:11:41 PM »

I've always heard that blk pwdr fouling could be used to give something that old look. It must work, look what it did to that new car in the background.

James Levy

Daryl · « **Reply #3 on:** February 20, 2009, 07:17:58 PM »

Interesting experiments, Larry - as always - but - wondering if you could do a test using a .065 to .072' vent. This is the sizing normally used by us with Chamber's vents. I shot for a while with both pistol and rifle with unaltered vent - sub-1/16" and opened them up to about .070". There was a marked improvement with 'most' shots and no flash-in-the-pans with larger vent holes. The 'factory' vent gave some missfires due to it's small size and 'seemingly' fouling blocking the hole, whereas they are virtually nonexistent with larger vents.

I replace the vent when the pan 'self primes'. This test can only be done with a closed frizzen. Someone will usually say that thing's really blowing out the vent and that's when the 'test' is done - and only then for one shot.

One other 'thing' when kids, we burned off considerable black powder in Dad's shop - then he noticed his machinery starting to rust from the 'smoke' (we assume) adhering to the oiled surfaces. Most tools gained a nice 'patina' although he wasn't impressed withthe 'niceness' of it all.

Would you explain this one please? " Phariss (large w ext cone)----------.0309 "
also - the use of 2F in the pan is not surprising on that the timing was double or almost double the others. With one lock of mine, the Siler, I notice a big difference using 3f for prime, but not with the L&R Dickert lock. It is exceptionally fast with both 4F and 3F.

I wonder if that old car will suffer from these 'tests'. I guess you can tell I'm not too concerned about the 'tools'-

Darkhorse · « **Reply #4 on:** February 20, 2009, 07:24:30 PM »

I've long suspected that that 4F in the pan and 3F down the pipe was faster than using the coarser grains.
Of course my senses could probably use recalibrating seeing as I''ve used them for so long without proper maintenance.

Dale Halterman · « **Reply #5 on:** February 20, 2009, 07:26:43 PM »

What is that car, anyway?

Regarding the size of the hole in the white lightning liner, I recall Jim making the statement somewhere - possibly on this site - that the hole in the liners is deliberately undersized, so the builders can drill them out to the size they want. I believe that Jim said he recommends a 1/16" hole, but I'm not sure about that.

Dale H

Larry Pletcher · « **Reply #6 on:** February 20, 2009, 08:25:24 PM »

Dale,
The car is a '31 Model A Ford Tudor. A very nice running car that was restored by my wife's dad. As Daryl commented I need to give it a cleaning. The humidity was very low, so the car appears to be covere with dust. as soon as the weather warms a bit we'll get it clean. There are two more cars there too, a '26 Model T and '25 Dodge Bros. Both of these have covers.

Jim send his liners out under 1/16 as you suggest. The one we used would pass a .055 bit. We discussed which size bit we wanted to use. We narrowed our choices to a #52 (.064) and a #51 (.067). We decided on the .064 because we could always drill it out later, but couldn't drill it smaller later on.

Daryl,
If we would have chosen the #51 if would have fit your range. That can still be done. I don't mind larger vents, in fact agree that they are more forgiving when it comes to fouling that can be a pain with small vents.

The "Phariss (large w ext cone)" is a cylinder hole that will pass a .089 bit. It has a large exterior cone. As you can see it was VERY fast. The exterior cone may have had a part, but I think the HUGE diameter was the reason it was fast. I expect that while the speed was great, the dia. is more than most shooters, myself included, would choose to use. (One reason I like a little larger vent is to allow a pipe cleaner for cleaning. Another is to allow trickling prime into the barrel if I dry ball. Of course I never do that.)

One thought Steve and I had as we worked was that the Chambes liner was as fast with no cleaning. I speculate that it would be hard to be faster than a WL liner without drilling a HUGE hole. I tend to think that one great advantage of Jim's liners is their ability to function well even when in situations where it is not kept clean.

Regarding the 10 ffg trials. The average time was slower but the times were as consistent as the fffg. We obviously tried to eliminate variables to get consistency, but we were still impressed with the narrow range of the numbers. We had an oddball trial at times, but generally the trials were very tight.

Regards,
Pletch

Daryl · « **Reply #7 on:** February 20, 2009, 09:29:08 PM »

TKS, Pletch - about .076" to .080" is the largest I've allowed mine to get. After loading, I can look at my Chamber's vent and see powder granuals sitting in the inner cone, almost touching the outside of the vent. Ignition seems almost instantaneous. Once I start to see scattered powder granuals in the pan fouling and frizzen fouling as I go to re-prime, I do the 'test', loading with a closed frizzen, cock at 1/2 postion. Although we consider this practice to be very dangerous, it was the way military rifles were loaded when using paper ctgs. millions of them.

I have gone to 2F at about .076" vent size to keep the powder 'inside'. A larger vent does decrease lock time - BUT - the vent must be plugged when loading - every time.

Candle Snuffer · « **Reply #8 on:** February 21, 2009, 04:25:49 AM »

Always enjoy reading the results of these test Larry & Steve.

While we're on the subject of vent holes,,, does anyone know what the common vent hole size was used in the Brown Bess Muskets when they were made new?

Was there a required vent hole size set by the British Army?

Daryl · « **Reply #9 on:** February 21, 2009, 08:28:07 PM »

Any holes I've seen in original Bess's were huge due to erosion, of course. None appeared to have ever been repaired and I doubt any were. The existing muskets went through a long life during a time when vent liners became popular, yet all appeared to be worn out, drilled holes.

Acer Saccharum · « **Reply #10 on:** February 22, 2009, 05:43:41 AM »

Well, this is exciting. Thanks, Larry, Steve, and Dan.

Daryl, with a large touch hole, have you ever plugged the touch hole with a toothpick or feather before pouring the powder down the bbl? I am not asking because I know the answer, but because I have an .078 touch hole on my shooter, and wonder if this practice would improve the consistency.

I look forward to the Nock tests.

Nock-nock. Who's there?

Tom

Daryl · « **Reply #11 on:** February 22, 2009, 06:30:36 PM »

Tom - we had to do that with the little .40 with the blown vent once we discovered the loss of powder out the vent when seating the ball. Having to plug a vent before loading is a pain in the butt. I prefer to be able to check to see if the gun is loaded, by looking at the vent. With a .070" vent, I can see the granules of 3f (or 2F) sitting there, but when loading, I know I lose 0 to 3 granules of powder when the ball is seated - I can put up with that. HA!

As I noted in Ken's thread, if an accuracy load is established with a certain vent size, enlarging the vent, thus reducing the velocity will cause enough change as to demand a 'new' accuracy load. Velocity is only part of the accuracy equation - barrel harmonics are another and how the recoil of changing loads 'strikes' the stock and the stock movement prior to the ball's departure, all that stuff. This is why most guns don't shoot to the same sights for everyone - minor to major point of impact changes - even modern ones in which the bullet is almost in the target before the gun begins to move. Only 'part' of that impact change is in the way we 'see' the sights.

Dphariss · « **Reply #12 on:** February 23, 2009, 07:38:08 AM »

Its going to be a week or more before I get home and I will have some comments.
But no time really now.
I would have bet the chambers style I made would have been faster than the counter bored type. But I have had good luck with the counter bored type in the past.
I wonder is the distance from the inner cone to the pan is not the key here.
For reasons not important here I replaced a 5/16 WL with one I built that is very similar. I have not found any difference in the ignition but I think its slightly different than the one I sent off with the breeches. I make lot of one off stuff and the breeches I sent were simply "hacked out" and sent one day when I got motivated.
I think I said once before, this is great...

Dan

Acer Saccharum · « **Reply #13 on:** February 23, 2009, 05:50:37 PM »

Larry, I missed how you are igniting the powder. Glowplug, or resistance wire?

Thanks for the photos....they are really neat.

Hey, will that blackpowder fouling screw up your computer?

Acer

Larry Pletcher · « **Reply #14 on:** February 23, 2009, 06:25:39 PM »

Quote from: Acer Saccharum on February 23, 2009, 05:50:37 PM

Larry, I missed how you are igniting the powder. Glowplug, or resistance wire?

Thanks for the photos....they are really neat.

Hey, will that blackpowder fouling screw up your computer?

Acer

We heat a copper wire with a torch and touch it to the pan prime. The trick is from Bill Knight.

After each session I use compressed air on the keyboard, wipe off the case, and wash off the screen. Other that that I don't do much. Earlier we used to hear concerns about air particles messing up a disk drive. So far no experience with that.

Regards,
Pletch

rich pierce · « **Reply #15 on:** February 23, 2009, 08:41:39 PM »

I am asking this too late but did you consider using a plain vent hole for comparison? Those tests were probably done in a previous round of testing, I am guessing. Can you post the numbers if you have them?

Larry Pletcher · « **Reply #16 on:** February 23, 2009, 09:20:50 PM »

Quote from: richpierce on February 23, 2009, 08:41:39 PM

I am asking this too late but did you consider using a plain vent hole for comparison? Those tests were probably done in a previous round of testing, I am guessing. Can you post the numbers if you have them?

Hi Rich,
Yes, I reported on straight vents in April 2000 (correction) MuzzleBlasts and didn't do them this session because that had already been done. Before the week is out I had hoped to upload that article on my web site. It's the only one I haven't done. I had trouble finding all the photos. I'll get back to ALR with a straight vent chart later today and try to get the article ready this week.

In the '90 testing I used Goex ffffg for priming. The current testing was done with Swiss Null B. So, it's not quite a fair comparison, but will have to do for now.

Regards,
Pletch

Acer Saccharum · « **Reply #17 on:** February 27, 2009, 04:45:47 AM »

Daryl · « **Reply #18 on:** February 27, 2009, 06:06:07 PM »

Thanks for the picture, Tom. There was another that I missed collecting, on Nock's patent. I really don't like #4, but #1, #7 and #6 show promise. As long as my flat breech plugs and whitelightning liners work, I'll stick with them.

roundball · « **Reply #19 on:** February 28, 2009, 06:51:58 AM »

I recently had a fixed tang patent breechplug made with the lower internal design of #7, but with a bit larger upper powder chamber and beveled mouth of #1 & #4.

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Author Topic: Flat Breech Testing Finished (Read 9426 times)

chapmans

Levy

Daryl

Daryl

Candle Snuffer

Daryl

Daryl

Daryl

roundball