Acceptable accuracy for Double Rifles

First off if there is an older thread that answers my question please direct me to it. I am helping CAustin get into reloading. One of the firearms he has is a 140 Merkel in 470 N.E. For this rifle what would be an acceptable group size under the following parameters: one shot fired from each barrel, multiple shots from the same barrel and finally multiple shots from both barrels. Are DG double rifles generally regulated for 50 Yds.?

Good questions for @AZDAVE and @cal pappas

My Merkel 140 in 470 shoots 1 from each barrel 1-3/4 inch apart at 50 meters. The groups from each barrel are 1/2 inch, mind you this is only with 2 shots from each barrel. I end up with a 1/2 inch group, then an inch or so to the right another 1/2 inch group. This is with Woodliegh 500 grain bullets at 2140 fps

https://www.africahunting.com/threads/realistic-level-of-accuracy-from-doubles.39997/

https://www.africahunting.com/threads/double-rifle-load-development-shooting-distance.36735/

https://www.africahunting.com/threads/those-thinking-about-buying-a-first-double-rifle.731/

Interesting article


https://www.theexplora.com/regulating-double-rifle-at-westley-richards/

I’m a newbie here and there are others who will provide expert opinions. DRs must be fired standing, usually off of sticks to: A. Protect the rifle from damage. B. In some cases protect the shooter in the case of heavy nitro rifles. C. To mimic the conditions of a hunting shot. These types of shots with heavy recoiling rifles are not easy. The amount of nerve/disipline needed to get an accurate shot/shots is an issue with most people. The shots require precise breathing and trigger control with the shooter, if he does everything right to be surprised when the rifle goes off. The guy hunting with the rifle should be the person shooting for load development/ sighting. With all of this considered precision bench rest rifle groups are not on the table. The important thing is regulation meaning each barrels shots are on the correct side of the paper close together. I would say and inch group per barrel and the 2 groups with in 3 to 4 inches of each other would be a decent result. I shot my .577bpe 10 times in a row with 70lbs of recoil each shot. I was sore for 3 days after. Have a nice bottle of single malt with you for meditation purposes. Good luck. Tom

Good morning.
You have read most of the information in the other posts, so I am sure that you have a good idea of what is acceptable.
Also recommend that you read Graeme Wright's book a couple times.

When you start working up loads for the 470 you will need several sessions as most folks can shoot 8-12 rounds of big bore accurately then it can go down hill from there. also be honest with your self there are days that you are shooting well and others that are not quite as good.

When you change the bullet that is different from the one the rifle is regulated with it will most time require patience when developing loads. I have had one double work up a swift a-frame and northfork solid load in a couple range session and only two different powders to shoot better than factory. where my buddy with the exact same manufacture and model etc took 12 sessions with 5 different powders to get his to shoot as well as factory.

There are so many variables that the best I can offer is that you PM me a phone number and we can have a couple hour long calls to walk through everything.

I have a bit of a different - perhaps optimistic view of doubles. My primary hunting double is a Blaser S2. I have .375 H&H, 500/416 Krieghoff, and 30-06 barrels for it. It is designed to be scoped and all three barrels are. Each barrel in each caliber shoots MOA at one-hundred meters using TSX bullets loaded by Hendershots, and each shoots a 2-inch 4 shot L/RxL/R at 100 meters. I sight-in using the right barrel of each - typically 1.5 inches high at 100 meters and have easy point blank range beyond 200 with all three calibers. The second shot is easily minute of antelope out to that range. No, it is not using the rifle as a "traditional" double - but then again, it isn't a traditional design, and the scope can be instantly dismounted for a close range follow-up. With open sights at fifty meters it shoots a single ragged hole with all three calibers. I have taken buffalo to duiker with the rifle - from 20 yards to 200+.

Encouraged, Lance Hendershot and I worked up loads for my two 9.3x74R rifles. One is a German WWI era SxS, and the other a modern French VC OU. The German rifle shoots MOA with the each barrel. At 100 meters the two groups are separated vertically by two inches. We discovered that the builder designed it that way so that the right barrel was on at 100 and that the second barrel fired to the flip-up leaf at 200 meters. Equipped with claw mounts, the scope is sighted in at 100 meters (right barrel) and the cross hairs are also dead on for the left barrel at 200. Ingenious Teutons. The VC shoots almost as accurately as the Blaser, is equipped with a dismountable scope, and is sighted the same as the Blaser barrels.

I also have a pre-WWI 12-bore Paradox. It fires a 740 grain bullet load designed and loaded by Ross Seyfried. We both decided it is more accurate than we can hold. He can do a three-inch composite 4-shot group at 100 meters - I can do 3 1/2 - 4. That is with open sights.

My point is, most of these rifles are capable of quite a bit better than saucer-sized groups at 50-meters.

My Krieghoff .470 shoots 2" 4-shot 50 yd groups (2 x right & left in quick succession) repeatedly with both Hornady factory DGS / DGX and Federal Premium Sledgehammer and open sights.

Here is a quick 1.5 second right & left at 50 yd off hand: typical 1.75" group center to center. Plenty good for a .470 especially considering I can barely see the front bead anymore ;-)

I am pretty sure that off the sticks and with younger eyes behind it the gun can do much better ;-)



This is 1/4 MOB (minute of buffalo) for all practical purposes...

This feisty one took 1 shot at less than 30 yd; double lungs; went 30 yd; death below in less than 2 minutes; so obviously stone dead that the PH told me not to shoot the proverbial insurance shot...



By the way, the new DGX Bonded worked really well...


I agree with Red Leg, you should get 2" or less at 50 yd for a 4-shot group (2x R&L) off the sticks, and yes, 50 yd is typically the distance where you want a big DG double (.470, .500, etc.) to be regulated and sighted. Double .375 would typically be regulated/sighted for 100 yd.

Thanks for all of your feedback. I now have an idea about what to expect.

Adjustable barrels can make a double as accurate as any other rifle…

HWL , well said.

What diameter hole are those? .411?

crs said:

HWL , well said.

What diameter hole are those? .411?

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You are pretty close…. it's .413 dia.

Not the .405 Win, but the 10,3, aka .450/400 2 3/8" NE.

I do not do this every day, but sometimes, it happens!!!


HWL

One thing I liked about the Heym rifles is that they don't regulate their barrels.
There is no crossing point for the barrels at 50 yards, they simply shoot straight and print an inch apart left to right.

HWL - That is one impressive group.

Reading and learning.

BeeMaa said:

One thing I liked about the Heym rifles is that they don't regulate their barrels.
There is no crossing point for the barrels at 50 yards, they simply shoot straight and print an inch apart left to right.

HWL - That is one impressive group.

Click to expand...

Of course they regulate them, or they wouldn’t be an inch apart at 50 yards. And none of my doubles are “regulated” to shoot a converging group at any distance. The left bullet stays left and the right stays right. No properly regulated double should ever cross regardless of distance.

Red Leg said:

Of course they regulate them, or they wouldn’t be an inch apart at 50 yards. And none of my doubles are “regulated” to shoot a converging group at any distance. The left bullet stays left and the right stays right. No properly regulated double should ever cross regardless of distance.

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I thought (apparently incorrectly) that "regulated" meant that both barrels would shoot to nearly the same POI at a certain distance.
This is why I should stick with bolt guns.

Apologies for my ignorance.

BeeMaa said:

I thought (apparently incorrectly) that "regulated" meant that both barrels would shoot to nearly the same POI at a certain distance.
This is why I should stick with bolt guns.

Apologies for my ignorance.

Click to expand...

No problem! There are some cheap ones and abused ones that cross, but a properly regulated rifle (and a Heym sure should be) fires parallel until the bullets hit dirt.

My Merkel 140 470NE was regulated with Woodleigh 500gr SN, to 80m. I have developed the following load that shoots consistently 1-2 inch groups at 100m with federal cartridges, federal 215 magnum primers and 106gr Norma MRP

Red Leg said:

No problem! There are some cheap ones and abused ones that cross, but a properly regulated rifle (and a Heym sure should be) fires parallel until the bullets hit dirt.

Click to expand...

So then why do I see people post that the barrels are regulated at 25 yards, 50 yards, 80 yards...etc.
If they are regulated at 50 yards, aren't they the same at 100?