Need help with a drilling!

[frog stealer]

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.

 

[Red Leg]

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.

MOA three-round groups is more typical of a drilling than what you are experiencing (I have owned at least a dozen over the last fifty years and currently have four). That said, because three different barrels are working against each other, it is sometimes necessary to allow the rifle barrel to cool longer between shots than is usual with a bolt action or single shot. That will typically stop stringing.

Also, German 6.5x57's "R" or rebated prefer heavy for caliber loads.

If that doesn't improve the group, I would suggest taking it down. With the forend removed hold the barrels by a string at the forend latching point. Then tap them with a wooden rod of some sort. An old school hammer handle is perfect. If they ring like a bell, they will eventually shoot with the right load. If you hear a "clunk" you have a solder issue which was unfortunately a problem with some East German SxS's and drillings.

 

[frog stealer]

MOA three-round groups is more typical of a drilling than what you are experiencing (I have owned at least a dozen over the last fifty years and currently have four). That said, because three different barrels are working against each other, it is sometimes necessary to allow the rifle barrel to cool longer between shots than is usual with a bolt action or single shot. That will typically stop stringing.

Also, German 6.5x57's "R" or rebated prefer heavy for caliber loads.

If that doesn't improve the group, I would suggest taking it down. With the forend removed hold the barrels by a string at the forend latching point. Then tap them with a wooden rod of some sort. An old school hammer handle is perfect. If they ring like a bell, they will eventually shoot with the right load. If you hear a "clunk" you have a solder issue which was unfortunately a problem with some East German SxS's and drillings.

Thanks for your recommendations…I will try extended cooling sessions and will check to see if the barrels ring true during my next range session.

 

[ActionBob]

Thanks for your recommendations…I will try extended cooling sessions and will check to see if the barrels ring true during my next range session.

If the barrels ring true. Definitely try heavy for caliber bullets. And running them a tad slow may be worth a try.

 

[Mekaniks]

Have you tried cleaning the bore with a copper remover?

I had a single shot Thompson barrel that did the same thing and cleaning the copper out fixed it.

 

[Dirtdart]

In most cases the "R" designates the rimmed version of a particular cartridge as opposed to the rimless version.

 

[Excessexpress]

Shoot two rounds, cool completely - like half an hour or more.


More often than that and you will find the shots climbing.

 

[Longwalker]

In the German shooting ranges I have visited, it is common to have a flexible air hose to place in the bore of the rifle between shots to cool it. The compressed air flowing through the bore ensures a cool barrel and shot to shot repeatability. Drillings are generally designed for shooting one precise shot, not “groups” so shooting quickly almost guarantees a vertical string unless measures are taken to mitigate the heat of barrel expansion.

 

[frog stealer]

Thanks to all for the comments…some really good stuff here! The comments recommending 2 shots and then a lengthy wait make sense, as most of my groups were vertical with two shots almost touching, and the third way high!

I will be trying some heavier 140 and 160 grain bullets, as well as much longer cooling times during my next range session, thanks again to all!

 

[Dirtdart]

I have to do the majority of my load development during the summer in Florida. All of the advice given on cooling time between shots is spot on but it can be a lesson in patience especially when you are heating up faster than the barrel is cooling.
To decrease time between shots I use the barrel cooling fan by MagnetoSpeed for the bore and a battery operated (pick your brand) fan for the exterior. Trust me on this one.

 

[frog stealer]

I have to do the majority of my load development during the summer in Florida. All of the advice given on cooling time between shots is spot on but it can be a lesson in patience especially when you are heating up faster than the barrel is cooling.
To decrease time between shots I use the barrel cooling fan by MagnetoSpeed for the bore and a battery operated (pick your brand) fan for the exterior. Trust me on this one.

Haha, while probably not quite as hot as Florida, my last range session was in Southern Michigan with temps in the low 90s and high humidity!

Thanks for the lead on the barrel cooling equipment, I will definitely check this out! Using the equipment, how long do you typically wait between shots?

 

[steve white]

Maybe not so much for influencing groups, but test for a difference in first shot placement between resting the fore end on your hand and in using a sand bag, etc. Most of mine shoot a field reproducible zero off the palm of my hand, and shoot high off a rest of any kind. Not enough for a miss in any case.
I even want to know where the first CLEAN shot will go vs one from a dirtied bore, cold, of course.

 

[F. Vaccaro]

Not to drift the thread, I have a couple of rifles that shoot much better groups hand holding the forearm rather than resting it on sandbags.

frog stealer, I am very interested in the idiosyncrasy of your rifle. Please keep us informed.

 

[Dirtdart]

Haha, while probably not quite as hot as Florida, my last range session was in Southern Michigan with temps in the low 90s and high humidity!

Thanks for the lead on the barrel cooling equipment, I will definitely check this out! Using the equipment, how long do you typically wait between shots?

I have never taken it to the level of using a clock but get a fair idea from what the barrel feels like to the touch on the back of my hand from past experience. Not very scientific I know. My guesstimate would be 15 minutes between shot 2 and 3. Generally a full stock rifle takes a little more time than a half stock. I didn't have these cooling fans with the last drilling I worked up but will pay more attention if I ever get around to having a scope mounted on my Sauer 3000.

When things are going well and the first couple of shots give me that warm fuzzy feeling I have to really chill out to keep from rushing the next shot or three. That is a character flaw of mine that I hope you don't have. I am the only one using this range so I have to provide my own distractions between shots.

 

[Peter Larsson]

It is normal for a drilling to rise 5-7cm per shot.
They are one shot rifles.
Wait 15min between the shots or shoot one shot per day when shooting
your other rifles.
I use to do that. 6,5x57R shoots light for caliber bullets normally.
Around 130gr.

 

[forshoes]

I've taken to using a Harbor Freight non-contact infrared laser thermometer to track barrel temperature. At this point, I have not had it long enough to draw conclusions, but it will track the temperature increase for progressive rounds and at multiple locations on the barrel.

 

[F. Vaccaro]

A very interesting thread on a type of rifle I have no experience with. I’m going to follow & learn!

 

[Rubberhead]

Thin barrels heat up quick and distort quicker than the heavy (bull) barrels of the super accurate rifles.

 

[Kraut]

Advice from my very experienced gun dealer for test shooting drillings:
Load all barrels, let the gun cool down after each shot (roundabout15 mins), rest the forearm circa a hand's width in front of the trigger guard.
Hope you enjoy your classic!

 

[frog stealer]

Thanks again to all that posted…I will take all that I learned from this post and will apply it to my next range session! I will be sure to post results once I get some time to actually go shooting.