doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Would you buy your dream gun if barrels were .019

Sure I would, with the following caveats:
1. My "dream gun" concept has changed a bunch of times in the last 30 years.
2. Your dream may well already be in the safe, with just a bit of gunsmithing.
3. Recognizing that even modern barrels are very rarely perfectly concentric, I would want to personally measure the wall thickness, carefully rotating the tube to identify thin spots. I have confidence in my equipment and the reproducibility of my numbers.
4. If the .019" was past 18" - 20" from the breech, with adequate wall thicknesses to that point.
Scroll down toward the bottom here and you'll see the pressure at 18 - 20" using Black, Bulk, Dense, or Progressive Burning powders is about 1000 psi or less. Some of the curves are pressure/time and others are pressure/distance.
https://docs.google.com/document/d/1F2sQuPm05IE4VWYYnCkvuXmYEzQoWd_SQgaAfUOZEFU/preview?pli=1
5. And I'd still use low pressure loads

No.

Too thin.

If it was a British gun, and it was in proof, yes, I would buy it.

What constitutes a "dream gun"??? If a dream gun is one that I would shoot better than all the rest, then likely yes. If not, then probably no.

OK for a gun used quite a bit with low expectation for remaining value.
Not OK for a brand name gun (Boss, Purdey, etc) which high value is likely to stay over time.
I think twice before buying anything below 25mils, and probably not at all if at 20 or below.
It's always possible to dent barrels, and low wall thickness makes the denting probabilities higher as well as the consequences more dire. Not to mention the safety part that should be OK as long as the thin spot is much ahead of the fore-end.
Something not to forget is that corrosion can be nasty under the ribs, and that it is not possible to measure thickness there.
The thinner the tubes, the scarier that becomes.
Best regards,
WC-

So is it original or does it have .019" barrels or both?

Drew;
I have scrolled down to the page in your link which compares pressures for 32 grs ballistite vs 42 grs Schutz, both with 1 1/8 oz shot. The Ballistite load gives 1232 fps @ 2.9 tons (8624PSI) while the Schultz gives 1220fps @ 1.69 tons (4558PSI). However at the 18" & 24" points the ballistite load has .33 tons & .21 tons while the Schultz load has .55 tons & .32 tons.
Now lets assume I have a sound gun in good condition with adequate wall thickness in that important area at the chamber & first 2/3 of the barrel but am concerned because it is thin from 20" on to the muzzle. Is there really any valid reason I should chose the Schultz with its considerably lower breech pressure over the Ballistite load with its noticeably lower Muzzle pressure. With the nearness of the ballistics of the loads both are going to be very close to each other in overall pressure, it's just distributed differently.
Again I feel the entire picture needs to be looked at, not "JUST" the maximum breech pressure.

I think you've made a valid observation Miller. The pressure/distance curve:



Ballistite, Cannonite and Walsrode were dense smokeless; Schultz bulk smokeless. The choice of 32 grains of Ballistite is confusing, as 24 grains is the published load for a 3 Dram equivalent; 26 grains for 3 1/4 Dram.
Alfred Nobel's 'Ballistite' was introduced in 1887, patented in 1888, then �Sporting Ballistite� (for shotgun shells) was patented in 1889, but not released to the trade by Nobel�s Explosive Co. until 1895. The published summary of the Trial states �Ballistite� rather than �Sporting Ballistite�.

PLEASE NOTE that all the curves essentially meet at 6"

The issue of shotgun barrel strength and wall thickness is complicated, and tensile strength is only a part of the equation for estimating bursting pressure.

Barlow's formula P=2 S t / D
P=Bursting pressure in psi.
S=Tensile strength of material in tube wall.
t=Wall thickness in inches.
D=Outside diameter in inches.

Barlow�s refers to a pipe capped at both ends with a static pressure (a pressure cylinder). Shotgun barrels are not designed to be pressure vessels as one end is open and the pressure rises and falls quickly (milliseconds). I've discussed this issue with both a mechanical and metallurgical engineer and neither is aware of a good bursting pressure equation for shotgun barrels.

Burrard used the Alger Burst Formula:
Burst pressure = Ultimate tensile strength x 3(OD � ID) / OD + 2xID

Lame Formula:
Burst pressure psi = Ultimate Tensile strength x (OD squared � ID squared) / OD squared + ID squared

American Standard:
http://www.smt.sandvik.com/en-us/materia...rican-standard/

Ignoring the effects of repeated high stress has a long history of disaster .

The thinner those barrels, the higher the stress. Cycling metal near its yield limit puts you in the range of a possible low cycle fatigue failure.

While a discussion about ultimate strength is relavent too, if you are firing one shot, I would be more concerned with knowing if the stresses were high enough to look at a low cycle fatigue failure. That's a much lower stress.

So, an old relic was shot to pieces, neglected until pitted, rubba-dubbed to make it sparkle,then reamed out to extract some salvage value from it, and it's still someone's "dream gun"?
I'd say that it was definitely not their (the seller's) dream gun. At least not anymore it wasn't.

The "name", model, or description might be a dream gun, but not this actual gun itself.

"Buy the gun, not the name."