I have copied the pertinent information dealing with the construction of N-SSA approved barrels. I was unable to copy the drawings that went with this. The website that has all the information is
http://www.n-ssa.org/NATIONAL/RULES/Rules013108.pdf Hope this helps.
SECTION 10: ARTILLERY MATCHES (CANNON)
IMPORTANT NOTICE
In this, and in all other sections and sub-sections of these Skirmish Rules, the term “approved” by the N-SSA or its designated representative(s) shall mean that the item in question has been found to meet the dimension, configuration, mechanical function, and authenticity criteria of the N-SSA. It does not in any way imply, or infer, or guarantee the safety or the integrity of any particular item.10.1 PARTICIPATION
Member and Probationary Organizations may fire Artillery pieces in a Skirmish as prescribed in the Skirmish program, Skirmish Rules, and special regulations of the Inspector General of the N-SSA, Inc. and/or the Artillery Ordnance Officer; however, refer to rule 2.11 for participation of skirmish staff.
10.2 ELIGIBILITY
Actual or exact scale replicas of Civil War artillery pieces may be fired. The term “Civil War” applies to any artillery piece whose model antedates April 26, 1865. Replicas of artillery pieces must duplicate original pieces. All reproduction barrels must be made of iron, steel or bronze. All reproduction barrels and those original barrels failing inspection must be lined with a bore liner of extruded seamless steel tubing of a minimum ANSI standard and of a minimum 3/8-inch wall thickness.
Figure 10.1
The liner must be closed at the breech end with a steel plug, sweat-fitted into the liner and welded. The breech plug must have a radius of at least 25 percent of the bore radius and be at least 1 inch thick at its thinnest point. (See figure 10.1). All reproduction barrels manufactured after March 1, 1986 must have pictures of the liner and breech plug before and after welding. No reproduction barrel shall be approved after March 1, 1986, that does not have one caliber’s thickness of metal surrounding the bore at the breech. (See figure 10.2 for example.) Liner may be affixed by casting barrel around the liner or by other approved methods such as bonding with high strength adhesives. The method of locking the liner in the barrel shall be approved by the Artillery Ordnance Officer. The gun and its crew must pass the inspection specified in Section 18. A gun crew shall consist of a minimum of four members of the organization. Effective 1 February 1996, all artillery pieces must be originals or full-size, exact replicas to be approved.
a. Scale replicas currently having N-SSA approval, except those with tank-type rifling, may be sold or transferred to N-SSA members or organizations and continue to be used as long as they pass the inspection at the time of transfer. If a scale replica fails to pass inspection, or is not currently inspected, it shall be disqualified from further N-SSA competition.
b. A cannon with a reduced bore is considered a scale replica gun, and is, therefore, not allowed, unless already in N-SSA use as of February 1, 1996.
c. A reproduction of rifled cannon must be rifled, unless already in N-SSA use as of February 1, 1996.
