| Author | Post |
|---|
Brian Dillard
Member
| Joined: | Thu Feb 26th, 2009 |
| Location: | Colorado, USA |
| Posts: | 74 |
| Status: |
Offline
|
|
Posted: Wed Jun 3rd, 2009 01:41 pm |
|
Great conversation, thanks to all.
However this leads me to another question. So...if say a barrell left the factory in the early 1900's with a wall thickness of .38 and on average 5-6 boxes of lead ammo has been shot per year for 100 years, what thickness would one expect the barrels to be here 100 years later.
I guess the real question is, what is the wear rate with average shooting assumed no steel shot has gone down the tube?
____________________
"hunt um up girl, find those wiley birds"
|
Don Kaas
PGCA Member
| Joined: | Tue Jan 11th, 2005 |
| Location: | Palm,PA |
| Posts: | 2720 |
| Status: |
Offline
|
|
Posted: Wed Jun 3rd, 2009 02:06 pm |
|
| .370 +/-...early fiber wads were abrasive... Rebluing and abrasive cleaning tools probably caused more wear on the outside and the inside respectively than shooting did...Many very well used 90 year old VH Parkers with original exterior finish (or lack thereof) on the barrels still measure .729-.731" in the bores indicating to me the wall thicknesses are pretty much what they were when the gun left Meriden... Modern steel shot does not wear barrels excessively due to the thick poly wads...The problem with steel shot in old gun barrels is the tendency of the barrels to bulge at the chokes due to the non-compressibility of large steel shot. Also modern steel loads tend to be very hot subsituting velocity for shot mass.
|
Brian Dillard
Member
| Joined: | Thu Feb 26th, 2009 |
| Location: | Colorado, USA |
| Posts: | 74 |
| Status: |
Offline
|
|
Posted: Wed Jun 3rd, 2009 02:12 pm |
|
Interesting...thanks Don.
I love this site...questions asked always come back with well thought out answers.
____________________
"hunt um up girl, find those wiley birds"
|
John Mazza
Member
| Joined: | Mon Feb 23rd, 2009 |
| Location: | |
| Posts: | 75 |
| Status: |
Offline
|
|
Posted: Wed Jun 3rd, 2009 02:33 pm |
|
"We've also heard that black burned slower than nitro, then the tests in the DGJ found just the opposite."
Bruce, I always heard that black powder burned quicker than nitro. In fact, it was this claim that I have always heard used to "caution" one on the use of smokeless powder in old shotguns. The claim was that the bulk of a charge of black powder (BP) burns very quickly and generates maximum pressures at the breech end of the barrel. (Of course, the pressure drops off rapidly as the charge accelerates down the barrel...) This is why old BP shotguns have those fat breeches & taper rapidly toward the muzzle.
Smokeless (SP), with it's "progressive burning" characteristics (due to chemical composition, granule size & shape, coatings, etc.) burns at a different (generally slower or "controlled") rate.
The potential "issue" is this: given the same "maximum pressure" from a BP and SP shell, what will the relative pressures be at the same points along the length of the barrel ? So, (as a hypothetical example) let's say a BP shell developed a max pressure of 7000 psig (...and this would be at the chamber), and then at 10 inches down the barrel (from the chamber) the pressure was only 3500 psig. Now, take a hypothetical SP shell that also has a chamber pressure (max pressure) of 7000 psig but, at 10 inches down the barrel, it's still producing gasses & still maintaining 5,600 psig. IF (and this is a big "if") a "thin barrel wall-loving" gunsmith made this barrel & optimized the taper for this chamber pressure AND this pressure distribution, then certain SP loads may cause problems (if not right off the bat, perhaps after extended use).
Granted - if a gun was made this way, and the proof load didn't blow it - it's probably deemed good enough. (At least when it was new...)
Early smokeless powder (like Schultze) was not quite as powerful as some modern smokless powders.
Bottom line - I shoot RST shells in my old Parkers. And in an old German hammer drilling (ca. 1904, 16 ga.) that is very light weight, I have 1 1/2 dram & 5/8 ounce BP loads that shoot well in it. So, I'm a big fan of low pressure smokeless loads in typical guns in decent shape, but in "iffy" situations, I prefer very light BP loads.
Any great science here ? No, just my 2 cents...
Just be careful out there !
|
Richard Flanders
PGCA Member
|
Posted: Wed Jun 3rd, 2009 04:09 pm |
|
John, you need to get ahold of the Sherman Bell article in DGJ where he did testing on BP loads vs smokeless with respect to pressures along the barrel length. It was indeed surprising what he found. I can't remember the results and would have to dig the reference out, but perhaps someone else can refer you to the proper issue. All I remember is that his tests seem to debunk the classic myths of how BP burns and what pressures it creates and where.
|
John Mazza
Member
| Joined: | Mon Feb 23rd, 2009 |
| Location: | |
| Posts: | 75 |
| Status: |
Offline
|
|
Posted: Wed Jun 3rd, 2009 04:13 pm |
|
I'd like to read it.
I'm open to all information sources, especially guys like Sherman Bell who have actually "tested" these theories.
Thanks !
|
George Blair
Member
| Joined: | Sat Mar 7th, 2009 |
| Location: | |
| Posts: | 10 |
| Status: |
Offline
|
|
Posted: Wed Jun 3rd, 2009 05:55 pm |
|
| John, find a copy of the DGJ, Summer 2002 which is Vol 13 issue 2. Bell's article will shed plenty of light on black vs. smokeless pressures, and burn rates. DGJ may have back issues avaliable, if not check ebay or some of the online used book stores. George
|
John Mazza
Member
| Joined: | Mon Feb 23rd, 2009 |
| Location: | |
| Posts: | 75 |
| Status: |
Offline
|
|
Posted: Wed Jun 3rd, 2009 06:00 pm |
|
Thanks, George !
I'll check it out.
(I often wondered - IF black powder burned so fast, then what were all those glowing sparks & stuff flying out of my barrel ? I used to shoot all kinds of muzzleloaders, & it was amazing to see the fireworks that came out of the muzzle at times...)
|
Drew Hause MD
Member
|
Posted: Wed Jun 3rd, 2009 07:08 pm |
|
Pressure curves published by DuPont in the mid-1930s. Bell's results were similar.
Last edited on Wed Jun 3rd, 2009 07:08 pm by Drew Hause MD
____________________
http://www.damascusknowledge.com-a.googlepages.com/home
|
John Mazza
Member
| Joined: | Mon Feb 23rd, 2009 |
| Location: | |
| Posts: | 75 |
| Status: |
Offline
|
|
Posted: Wed Jun 3rd, 2009 07:15 pm |
|
Very interesting !
(I wonder what the pressure peak would have been for 2F black powder ? I was surprised how high the pressure was for the BP load was - until I saw that it was 3 F.)
|
Brian Dillard
Member
| Joined: | Thu Feb 26th, 2009 |
| Location: | Colorado, USA |
| Posts: | 74 |
| Status: |
Offline
|
|
Posted: Wed Jun 3rd, 2009 09:24 pm |
|
Ok... so I bought it. I didn't need it, he really needed to sell it.
It's a 1898 DH with Damascus barrels and a fish tail top lever. However it has a butt stock that I don't think is original, it has the oval initial plate like a DH should have but it's checkering is more like a GH, it has the original skeleton butt plate as a DH would with the correct checkering behind it....what it seems to be missing is the little "tear drop" carved in the wood just infront of the wrist.
My CH came with a DH stock straight from the factory....could a DH have come with a GH stock??? I haven't checked under the trigger guard yet, we're packing for a weekend trip (leaving early as it's rained here 14 out of 17 days now!!).
Will post pics next week.
____________________
"hunt um up girl, find those wiley birds"
|
Bruce Day
PGCA Member
|
Posted: Thu Jun 4th, 2009 07:05 pm |
|
Brian Dillard wrote: ....what it seems to be missing is the little "tear drop" carved in the wood just infront of the wrist.
Brian, I suggest you pull the TG and check for the SN under the tang. On special orders anything is possible, but I have never seen an original DH without drop points.
CH guns were different. Again, they all had drop points, but the grip checkering on some is the same as a D, and sometimes with a little extra embellishment. I have a C with D grip checkering but with the inletted checkered side panel. It letters. The C's were supposed to have that curve or bump in checkering, but not all did.
The TG is removed by taking out the tang screw and lifting the tang out of the stock grip channel. Once lifted, hold up and swing to the right to unscrew at the front stud. On all original stocks you will find the SN and on most D's and above, you should find a grade stamp ( "3") below the SN. Also the stock channel will be machine inletted and without chisel marks because the factory did the stocks on duplicating and inletting fixtures. This simple check usually resolves lots of discussion and speculation about correctness or originality. Its quicker to check than it is to discuss it.
____________________
Bruce Day
|
Bruce Day
PGCA Member
|
Posted: Thu Jun 4th, 2009 07:32 pm |
|
John Mazza, the Sherman Bell tests are an eye opener. Most of us have seen these now for years, and they are wonderful at dispelling theories conceived who knows where.
So, Parker and other makers stated that a ruptured breach could be an overload and anything mid barrel ( about 10" down) and beyond was due to an obstruction. You see that's consistant with the pressure/distance graph, and it didn't matter whether it was smokeless or black, the pressure is significantly reduced after 10".
Now I like the RST fellows also, and they make great cartridges, but my point is that with Parker damascus guns, a person may choose to shoot RST's, but he doesn't have to because his Parker is weak or otherwise not strong enough to take reasonable factory loads.
And Don Kaas is spot on with his statement about shooting steel. These modern shot cups are heavy plastic and the designer of these loads contends that the shot does not touch the bore. If you have a more open choked Parker, or shoot the smaller size steel shot, tungsten shot, whatever you want, it will pass through the chokes without bulging and without bore or choke wear. The key with these shells is the same as with lead....check the pressure and stay within the Parker service limits, which you see are really very liberal.
____________________
Bruce Day
|
Dave Suponski
PGCA Member
| Joined: | Thu Jan 6th, 2005 |
| Location: | Connecticut USA |
| Posts: | 1027 |
| Status: |
Online
|
|
Posted: Thu Jun 4th, 2009 09:26 pm |
|
Bruce, This is just my opinion and I am well aware of Parker factory proof testing of both Damascus and Fluid steel guns.But I think advocating shooting store bought Winchester,STS and other brands of shells in damascus guns is unwise. If for no other reason than the age of the damascus barrels. ALL steel deteriorates with age.That is a well known fact.I also shoot my damascus guns but chose to stay at 6500psi or lower.
You have had good results shooting your damascus guns and so have I but I think it best to err on the side of caution.
____________________
Dave....
|
Bruce Day
PGCA Member
|
Posted: Thu Jun 4th, 2009 09:37 pm |
|
If all steel degrades with age, then fluid steel does too, and a person should shoot light loads in Vulcan, Titanic, etc.
What does the steel do? Recrystallize to martensite? I'm not sure steel does degrade with age, with the age of 80-110 years we are talking about. Didn't we have a big debate about this a couple years ago with metallurgists weighing in on both sides and in the end it was not at all settled?
____________________
Bruce Day
|
Dave Suponski
PGCA Member
| Joined: | Thu Jan 6th, 2005 |
| Location: | Connecticut USA |
| Posts: | 1027 |
| Status: |
Online
|
|
Posted: Thu Jun 4th, 2009 10:28 pm |
|
My mistake...I should have been more specific. I was talking about damascus barreled guns.
Bruce just keep doing what you are doing 
____________________
Dave....
|
Bill Murphy
PGCA Member
| Joined: | Mon Jan 10th, 2005 |
| Location: | Maryland USA |
| Posts: | 5872 |
| Status: |
Offline
|
|
Posted: Fri Jun 5th, 2009 12:11 am |
|
| Y'all can say what you want, but Don and I will continue to fight the good fight with empirical evidence of well used guns of all known makes that started life at .729 and 100 and more years later are still .729. In fact, my evidence includes guns that I have fired tens of thousands of times and the bores are still at the original measurement, and even the forcing cones show no sign of burning or erosion.
|
Bruce Day
PGCA Member
|
Posted: Fri Jun 5th, 2009 12:36 am |
|
What I have found is consistant with those findings. Parker talked about wear but the barrel wear I have seen in old Parkers comes from honing, not shooting.
I don't want to be reckless but I also don't want to limit the usefulness of the gun without some verifiable reason. If someone has some evidence, I'd like to see it; without that I see no reason not to use the gun as Parker made it.
I'm gone for a week bicycling 543 miles across Kansas, starting west of Syracuse at the Colo border tomorrow. Dodge City is supposed to be 99 on Sat, then cooling off into the low to mid 80's the rest of the week. Pleasant scenery, get to check out the pheasant road count, look for hunting locations and eat plenty of homemade pie. Maybe next year we can get about 100 PGCA riders? By the time I get back we should be all changed over to the new website.
Last edited on Fri Jun 5th, 2009 12:58 am by Bruce Day
____________________
Bruce Day
|
Lee R. Moege
Member
| Joined: | Mon Dec 1st, 2008 |
| Location: | |
| Posts: | 7 |
| Status: |
Offline
|
|
Posted: Mon Jun 8th, 2009 04:18 pm |
|
| Have a great road trip Bruce! One of my friends from here in Holton, [Roger Hower] is on the same ride. This whole discussion has been very informative as I have a similar thread going on the Fox Collectors web site. Yes I have two loves!. I have a Fox AE 20 gage with 2 1/2" chambers and Chromox barrels. I just finished running the bore dimensions and IF I were going to lengthen it to 2 3/4" I would have barrel walls at that depth of .080/.081. As it is they are about .120. I think in this case, I'm not uncomfortable with a lower pressure 2 3/4" load at all in a plastic shell as they measure 2 1/4" before unfolding. Fox chambers are somewhat tighter and forcing cones shorter than some others I have seen. The bores are .621 and .623 and choked Imp. Cyl./ Mod. with muzzle wall thicknesses of .032 and .036. However I have a split case of RST #71/2 and #8's coming. Have a GREAT Day [no pun intended] Lee.
|
Current time is 06:52 pm | Page:   1 2 |
|
