Rifleman Q&A: Shotgun Barrel Regulation

by
posted on April 11, 2016
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
qanda2015_fs.jpg

Q: Is there an industry standard for the regulation of double-barreled shotguns? Out of the box, my side-by-side shoots 2" low and 2" to the left. And, has the American Rifleman staff changed the process for evaluating pattern effectiveness in its “Dope Bag” section?

A: Thank you for your note regarding shotgun patterns. There is an industry standard for double-gun impacts, and it is that the patterns shot from both barrels should overprint each other at 40 yds. (r.) American Rifleman has not changed how it patterns in decades We shoot 10 patterns at 40 yds. (25 yds. for .410), and count all the hits within a 30" circle and a 21.2" inner ring. The rings are bisected vertically and horizontally, resulting in eight quadrants. We will also determine the central thickening—the center of the pattern—and measure how far away it was from the point of aim. We then average all the results and include them in the “Shooting Results” table for each review. We have changed the design of how those results are presented in recent years but not the information itself.

It’s worth noting that there are actually two patterning disciplines. The first covers gun fit or point of impact. The second governs how a particular shotshell/barrel/choke combination affects the downrange dispersion of shot, but space does not permit elaborating on that here.

 So far as determining the point of impact of your shotgun, the industry standard is as follows: Erect a target at approximately eye level or slightly higher. Measure exactly 16 yds. from the target, mount the gun and fire three consecutive aimed shots at the target. Then measure the distance between the marked center/aiming point and the center of the shot impact. For each inch of deviation of the pattern from the point of aim, the stock needs to be adjusted 1/16". 

For example, if the pattern center is 2" low and 2" left, the comb of the stock should be raised 1/8" and the stock cast off 1/8" for a right-handed shooter. It is then recommended that the three-shot series be repeated by first mounting the gun, as in an actual hunting scenario, and three shots again fired. If one is an obvious miss, just shoot another round. If there is a question, keep repeating the series of targets and shots until resolved. Shooting both barrels will indicate the necessary amount of stock adjustment required and whether there is an impact problem. If the impact problem appears to be barrel-related, then shoot from a rest. However, with a production gun, I suspect a 6" deviation at 25 yds. is within the company’s range of acceptability.

 Using this system should give you a better understanding of where your shotgun shoots, and whether remedial action, in terms of an eccentric choke or stock adjustment, is necessary.

—John M. Taylor

Latest

Double Stack 1911 Web Main
Double Stack 1911 Web Main

A Guide To Double-Stack 1911s

The 2011 brings double-stack capacity and modular upgrades to the 1911 platform, but not every wide-body 1911 out there earns that name.

Legislators Enjoy Afternoon Of Clays With Benelli USA, Among Others

A bipartisan group of Maryland state legislators met with firearm industry manufacturers and representatives for a day of clays shooting while also attending discussions on the positive economic impacts of the shooting sports.

2025 Ammunition Product Of The Year: Winchester .21 Sharp

For continuing to innovate, particularly in a corner of the ammo world that has seen very little recently, we named the Winchester .21 Sharp as our Ammunition Product Of The Year.

Rifleman Review: Hammerli Arms Force B1

The Hammerli Arms Force B1 is one of the most versatile rimfire rifles on the market, providing room for accessories, allowing for a personal stock fit and even offering caliber-interchangeability.

New For 2025: CZ Scorpion 3+ Magpul Edition

CZ-USA has enhanced its Scorpion 3+ pistol-caliber carbine yet again with a slate of factory-installed Magpul components and accessories.

Summer Suppressor Deals On Now

Whether it is a BOGO deal from SIG or free tax stamps from Guns.com and Silencer Central, there's plenty of hearing-safe savings to be had this summer.

Interests



Get the best of American Rifleman delivered to your inbox.