Hello all, I recently purchased a Simson drilling made in the late 70’s. It is chambered for 12 gauge 2-3/4” on top and 6.5x57R on bottom.

During the past few range sessions, I’m getting groups that vertically string about 2 to 3 inches (shot at 50 yds) with several different powder and bullet weight combinations. For optics, I’m using a new Leupold mk3 mounted with EAW swing mounts.

Have any of you guys had this issue while shooting drillings? I’m wondering if this is just the accuracy I can expect from a drilling, or maybe I’m shooting to fast and the heat is causing the stringing? Any incite on this issue would be greatly appreciated.

In my experience it could very well be not waiting long enough between shots--though newer drillings that don't have the barrels soldered together don't necessarily need such a "cool down."

Does yours have soldered-together barrels?

Yes, mine has traditionally soldered barrels. I also remember many of the groups, while still vertically stacked, often had two impacts very close to each other, and the third 2 to 3 inches straight up or down.

Most traditional soldered barrel drillings walk up and to one side or the other as they warm up. A few seem to just walk up. The rifle barrel "bellies" as it warms, while being held in place on the rifle barrel top side by the shotgun barrels.

I take the barrels off the gun and forend off, then I spray them with starting fluid to cool them if I have to get things done in a hurry. Two closely timed shots can warm up the barrels enough to walk a third shot 1 1/2" to 3". Taking the gun apart to let the barrels cool enough is the secret of finding out a drilling's true accuracy.

I sometimes shoot two shots each on successive mornings. But, one shot from a completely cooled gun five times is the acid test, IMO.

Thanks for your insight, I will definitely try taking the gun apart for cooling during my next range session! How do you determine if the barrels are completely cool? Do you go by elapsed time, or just touch?

I go by touch. I usually take a few rifles with me and shoot the drilling once then play with the others and then go back to the drilling. When your hunting with a drilling the only shot that counts is the first one.

They can be quite accurate.

Wow, that’s some great accuracy! Thanks for sharing!

Going by touch works pretty well.

erich's group above would be a Classic drilling group if the first shot is the low one, second the middle, and third the top. He knows his drillings and loads for them properly.

The three most intelligent people (Mule Deer, luv2safari, and erich) on this subject have already chimed in, they have forgotten more about drillings than most people will ever know. I have learned much about my BBF (20 gauge over 6.5x52r/25-35win) from them and my experience is the same as yours. The lower rifle barrel heats up after 3 quick shots and impact rises.