Shooting 2.75-inch shells in the 3.5- inch chamber of a 12-gauge shotgun shouldn’t cause any erosion to the chamber, but there will be increased fouling, and it needs to be thoroughly cleaned.
Q: I HAVE A 12-GAUGE PUMP SHOTGUN WITH A 3.5-INCH MAGNUM chamber, and I want to use it on the skeet range. Will shooting 2.75- inch shells in the 3.5-inch chamber cause erosion in the chamber? Will shooting the shorter shells have any negative effect on patterning?
James Parker Via e-mail
A: Shooting 2.75-inch shells in your gun’s 3.5-inch chamber shouldn’t be detrimental to the chamber or the bore, but most likely there will be increased fouling in the chamber area. If left there, that fouling could lead to corrosion, so be sure to do a thorough cleaning after the shooting session. As for patterning, often shooting 2.75-inch ammo in a magnum chamber results in a better pattern, but there are a lot of variables, so that doesn’t hold true in all circumstances.
Compressed Powder Charges?
Q: Are there any downsides to loading compressed charges in rifle cartridges?
Name and Address Withheld by Request
A: Yes and no. By that I mean there can be. When approaching com-pressed-charge loads, I have been advised by propellant ballisticians much smarter than I to follow the following rules:
1.) Always select a propellant/charge weight that provides at least 90 percent load density.
2.) Avoid exceeding 106 percent propellant density, especially when loading single-base cylindrical propellants.
That’s because you may increase the risk of ignition problems, even when using magnum primers. Erratic ignition (i.e., unexpected transient pressures) is surely detrimental to predictable and consistent ballistic performance.
According to Hornady Chief Ballistician Dave Emary, the second consideration is not technically applicable to spherical propellants. Hornady’s now-discontinued Light Magnum rifle ammunition was safely powered by significantly compressed charges of “ball” powder. Hornady’s latest Super- formance propellants achieve the same objective-enhanced external ballistic per- formance—with less powder, resulting in reduced recoil.
Emary emphasized that’s not the case for cylindrical propellants. When you compress a heavy charge of “stick” powder, you can actually hear the crunch of the propellant grains breaking up under the bullet base. In effect, you’re increasing the expected burn rate by haphazardly crushing a portion of the propellant charge. That’s not good! Think about it. For most popular cartridges there are myriad safe and reliable recipes to try that allow you to load enough—but not an excessive amount—of powder to achieve safe and reliable performance from your handloads.
Now that’s not to say I never pour powder slowly into a funnel fitted with a long drop tube to achieve optimal load density. I will also tap the case gently while slowly pouring the powder if necessary to get the charge in. But I do that only if I’m experimenting with a new load, and the velocity and/or accuracy results I’ve achieved so far strongly suggest another few tenths of a grain might further improve performance.
However, when you compress the excessive powder charge while seating the bullet, you’ll likely deform the nose profile. So whatever advantage you hope to gain with more powder, you’ll surely lose by reducing the bullet’s ballistic coefficient, degrading accuracy, and, possibly, its terminal performance.