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GG375
.333 member


Reged: 27/02/04
Posts: 347
Loc: Brisbane
What is causing this - any ideas?
      #58448 - 07/06/06 02:32 PM


Hi Guys

Finally got to play with my new to me Krieghoff classic double. It is a 9.3 and is scoped with a S&B 1.5-4x scope in an ERA swing mount. The rifle was factory regulated for Romey ammo using 286 gn Woodleighs, however I decided to try developing a load for the 270 gn Speer first off.

Anyway at 50m the first group of 4 was about a 2.5" group. Subsequent groups of 1 gn extra (ie 1 group each of 56, 57, 58 and 59 gn of RL15) shrank the groups down to about 1 inch which I am very happy with. What puzzles me tho is that the opposite to normal is happening as the powder charge increases. The first group of 2.5 inches had the barrels crossing - the bullets from the right barrel hitting to the left of the bullets of the left barrel. As the powder charge got heavier the group shrank down to the 1" but the barrels are still crossing - not that it is a problem now that the group is down to 1 inch but I am curious to know whats happening - any one else ever had this occur?

Thanks and Cheers.

GG

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JPK
.375 member


Reged: 31/08/04
Posts: 734
Loc: Chevy Chase, MD
Re: What is causing this - any ideas? [Re: GG375]
      #58470 - 08/06/06 12:00 AM

In Graeme Wright's book he discusses how a double can come together at a velocity below that for which it was regulated, then divirge and come together again at the correct velocity.

It happens in my rifle with very light loads with full weight bullets. I suspect that, at least for my rifle, there isn't enough recoil to "uncross" the barrels. I beleive that my theory is supported by the fact that the rifle shoots low with these light loads as well, indicating the there also isn't enough recoil to create sufficient muzzle rise. Faster loads with more recoil conform "to the rules" and more velocity brings the barrels together, vertical change doesn't seem to be much of an issue past a certain velocity and recoil level. But I haven't taken a bullet and powder selection through the whole progression that Wright describes.

JPK

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Bwanaclark
.224 member


Reged: 20/05/06
Posts: 24
Re: What is causing this - any ideas? [Re: GG375]
      #58478 - 08/06/06 02:08 AM

You might try it off hand if you haven't already, off sticks if you can. If shooting from the bench, try a different hold and posture as well. This makes a big difference for my rifle and some loads that cross a bit from the seated bench don't offhand. I'd be very interested to hear if you see the same thing.

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Sunshine
.224 member


Reged: 06/02/04
Posts: 48
Loc: Cape Town, South Africa
Re: What is causing this - any ideas? [Re: GG375]
      #58492 - 08/06/06 05:47 AM

Hi GG,

how do you like the gun, any pictures for us? How are the engravings? Is it a new gun or second hand?

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foxfire
.375 member


Reged: 25/11/04
Posts: 511
Loc: Long Island N.Y.,
Re: What is causing this - any ideas? [Re: GG375]
      #58494 - 08/06/06 06:19 AM

Why play around with it. Find the group that shoots the tightest and if they cross adjust the barrels so they don't.
My 9.3x74R set of barrels crossed @ 100 yards very little mind you but they crossed. I found the load that shot the tightest. I turned the barrel adjusting screw 1/4 of a turn and voila! problem solved.
My 7x65R set of barrels shot lousy with all factory loads even after adjusting the barrels to keep them from crossing. We developed a load using a heavier bullet. The pattern tightened up considerably and I adjusted the barrels at 100 yards to where I wanted them to shoot.

--------------------
No good deed goes unpunished

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400NitroExpress
.400 member


Reged: 26/11/03
Posts: 1154
Loc: Lone Star State
Re: What is causing this - any ideas? [Re: GG375]
      #58501 - 08/06/06 08:20 AM

Without chronograph data, it's impossible to say.
---------------------------------------------------------------------------

--------------------
"Serious rifles have two barrels, everything else just burns gunpowder."

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bulldog563
.400 member


Reged: 21/10/05
Posts: 1153
Loc: California
Re: What is causing this - any ideas? [Re: foxfire]
      #58504 - 08/06/06 10:13 AM

I wasn't aware you could manually adjust the regulation on Krieghoff DR's. Is it like that for all of them?

--------------------
Join the National Rifle Association:
https://membership.nrahq.org/forms/signup.asp

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foxfire
.375 member


Reged: 25/11/04
Posts: 511
Loc: Long Island N.Y.,
Re: What is causing this - any ideas? [Re: bulldog563]
      #58512 - 08/06/06 01:43 PM

Yes you can, on any caliber set of barrels up to and including the 375H&H.

--------------------
No good deed goes unpunished

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GG375
.333 member


Reged: 27/02/04
Posts: 347
Loc: Brisbane
Re: What is causing this - any ideas? [Re: foxfire]
      #58521 - 08/06/06 07:19 PM


OK fellas thanks for that.

It sounds as if my loads may not be going fast enough and that I should probably chrony them and see whats what. Regarding the adjustment screw - I am going to leave that as a last resort and continue to work on loads in the hope that I'll achieve my goal. I have a good feeling about this rifle - will try Woodleighs next.

Sunshine, this is a second hand rifle but is as new. Will get some photos organised when I have a moment. She is a lovely little rig although a tad heavy with that bloody great illuminated S&B scope on top. I'm thinking about getting some 1" rings and whacking a VX111 1.5 - 5x on it. No engraving, blued action and lovely piece of walnut.

Cheers.

GG

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k80
.333 member


Reged: 07/05/04
Posts: 314
Loc: San Antonio ,Texas, U.S.A.
Re: What is causing this - any ideas? [Re: GG375]
      #58552 - 09/06/06 10:02 AM

There is a tremendous amount of
adjustment with the Kreighoff. I
know first hand. I adjusted mine
the wrong way.

--------------------
Ken
San Antonio

Welcome to South Texas

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GG375
.333 member


Reged: 27/02/04
Posts: 347
Loc: Brisbane
Re: What is causing this - any ideas? [Re: k80]
      #58555 - 09/06/06 10:35 AM


K80 and Foxfire

Would you mind outlining the method for using the adjustable wedge? Which way does what? Common sense tells me that screwing the grub screw IN would spread the barrels apart (and hence the groups) but I have never been known for my over abundance of common sense! No instructions came with the rifle for re-regulating - so anything at all you can tell me will be very much appreciated. Many thanks.

Cheers.

GG

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foxfire
.375 member


Reged: 25/11/04
Posts: 511
Loc: Long Island N.Y.,
Re: What is causing this - any ideas? [Re: GG375]
      #58560 - 09/06/06 01:27 PM

GG375,
Here's the link to your new owners manual.
Krieghoff's Classic Double rifle owners manual

If you look at page 8 & 9 it says, turning the set screw on the front sight between the barrels "COUNTER CLOCKWISE" will spead the barrels and separate your shots.
If you look down the barrels as you turn the screw 1/4 turn you will see the barrels separating.

Hope this helps I really like my Krieghoff and getting used to the cocking mechanism was easy.

--------------------
No good deed goes unpunished

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BlainSmipy
.375 member


Reged: 24/11/05
Posts: 558
Loc: Washington, USA
Re: What is causing this - any ideas? [Re: GG375]
      #58576 - 10/06/06 02:34 AM

*

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GG375
.333 member


Reged: 27/02/04
Posts: 347
Loc: Brisbane
Re: What is causing this - any ideas? [Re: foxfire]
      #58600 - 10/06/06 04:00 PM

Thanks for the link foxfire. Here are some photos - these were the ones the seller sent to me when I was considering the purchase - haven't taken any of my own yet.
[image][/image]
[image]http://[/image]
[image][/image]

Cheers.

GG

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foxfire
.375 member


Reged: 25/11/04
Posts: 511
Loc: Long Island N.Y.,
Re: What is causing this - any ideas? [Re: GG375]
      #58610 - 11/06/06 12:33 AM

GG375,
Your gun has a beautiful piece of wood and I think I like your blued receiver better than mine. Here's the only picture I have of mine.
Silver receiver, Left handed and a plain piece of wood. But I like it a lot.



--------------------
No good deed goes unpunished

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DUGABOY1
.400 member


Reged: 02/02/03
Posts: 1340
Loc: TEXAS USA
Re: What is causing this - any ideas? [Re: GG375]
      #58614 - 11/06/06 04:03 AM

In reply to:

What puzzles me tho is that the opposite to normal is happening as the powder charge increases. The first group of 2.5 inches had the barrels crossing - the bullets from the right barrel hitting to the left of the bullets of the left barrel. As the powder charge got heavier the group shrank down to the 1" but the barrels are still crossing - not that it is a problem now that the group is down to 1 inch but I am curious to know whats happening - any one else ever had this occur?




GG375, you have no worries! What is happening is what is supossed to happen. you are just about perfect, but if you speed it up just a little more till the individule barrel groups trade places, you will have a perfectly regulated rifle. When perfect, in the 1" composit group the two shots from the right barrel will hit on the right, and the two from the left will hit on the left, all still in the 1" composit group.

place the barrels in a vice, with the sights on the target Aim point. take two emty cases with no primers and chamber them. Now look through the primer flash holes at the target. You will see the RIGHT barrel will be pointing at a spot that is low, and on the LEFT of the aiming point. The LEFT barrel will be pointing to a spot that is low and on the RIGHT of point of aim on the target. This is line of sight through the bore, but not line of bullet flight when fired.

When the RIGHT barrel is fired, it will rise, up, and to the RIGHT , and vice-versa for the left barrel. The time it takes the bullet to get to the point where it exits the muzzle, is called barrel time, and this speed, and recoil arch determens where the bullet hits the target! If slow, it will print high, and WIDE, if fast it will print low, and cross (left on the right, and right on the left) the shooting wide is proper, if both barrels are hitting close enough to form a tight composit group, without crossing! You need to speed up just a little to have it perfect!

What you are experiencing is proper. As the speed goes up, the bullets leave the barrels sooner in the recoil arch, so if the right is hitting on the left, and the left is hitting on the right, the speed needs to go UP till they don't not cross, but each barrel shoot it's own group right beside the other barrel, with the right on the right, and the left on the left on the target. But still close enough together to make a tight composit group. Then the rifle will shoot paralel till it comes to Earth, and never cross! It is a falicy that all double rifles cross at some point! They don't if they are loaded with loads that match the regulation.

--------------------
..........Mac >>>===(x)===>
DUGABOY1, and MacD37 founding member of DRSS www.doublerifleshooterssociety.com
"If I die today, I have had a life well spent, for I've been to see the Elephant, and smelled the smoke of Africa!"

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k80
.333 member


Reged: 07/05/04
Posts: 314
Loc: San Antonio ,Texas, U.S.A.
Re: What is causing this - any ideas? [Re: DUGABOY1]
      #58632 - 11/06/06 10:43 AM

What put me in trouble was I changed optics
and load at the same time. I just "screwed"
up. I will try not to do that again.

--------------------
Ken
San Antonio

Welcome to South Texas

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GG375
.333 member


Reged: 27/02/04
Posts: 347
Loc: Brisbane
Re: What is causing this - any ideas? [Re: k80]
      #58662 - 12/06/06 02:51 AM


Foxfire

A rose between two thorns if ever I saw one. What calibre is yours in? I like your scope mount better than mine - it looks like a claw mount where as mine is a swing or pivot mount. The wood on mine is not standard. I think the seller said it is a 4x upgrade. I also like the blued action. Apparently my rifle is built on the big 5 platform as the previous owner thought he might get a set of 500/416 barrels for it one day. The stock is fairly straight.

Dugaboy1

Thank you for your in depth analysis of the situation with my rifle. I will load some more at 1/2 gr increments and see if I can get the right barrels to impact on the right etc. Will then move the target out to 100m - will let you all know how I go.

Cheers.

GG

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foxfire
.375 member


Reged: 25/11/04
Posts: 511
Loc: Long Island N.Y.,
Re: What is causing this - any ideas? [Re: GG375]
      #58664 - 12/06/06 04:28 AM

GG375,
Mine was also bought used. It was built with 470NE and 9.3x74R barrels as they have the same serial number as the receiver. The previous owner added a set of 7x65R barrels which you see in the picture between my sons gun and my future son in laws gun.
All three sets of barrels came with Ziess diavari 1.5x6 scopes. The 7x65R and the 9.3x74R both have claw mounts and the 470 had the scope added later and has a pivot mount.
After I bought it i had it restocked left handed.
I'm thinking of adding a set of shotgun barrels and have a one gun set for any animal, anytime, anywhere.


--------------------
No good deed goes unpunished

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unspellable
.300 member


Reged: 06/03/04
Posts: 187
Loc: Iowa
Re: What is causing this - any ideas? [Re: foxfire]
      #58930 - 17/06/06 07:13 AM

I'm slightly confused on what you are seeing, but the classic case when close to the right load is for a tad more powder to move things in the cross eyed direction and a tad less to move things in the wall eyed direction, ther change in barrel dwell time having a greater effect than the change in impulse due to slightly more or less powder.

This is why some doubles will regulate with a very light load, the impulse is way down but the dwell time is way up and there's a second sweet spot.

But when it's all said and done the rifle will do as it damn well pleases. This due to the barrel vibrational patterns which are not predictable.

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