My 9.3x74R was regulated with norma 285 ORYX. It shoots as per the target with open sights. I put a 1x4 leupold on and it shot about 5" apart at 50 yards. I have hornady and norma brass and 285 privi bullets. Any suggestions on loads with the IMR powders?Min and Max if possible.

Mine works well with 65 grns of IMR 4831 and a LR primer.

Are they crossing or shooting apart? If they are crossing, you have slowed down the recoil cycle by adding the weight of the scope, thereby causing the bullets to exit the muzzle before the muzzles jump farther into their respective arcs, which, without the scope, they would reach the zenith of the jump arc sooner and the bullets would exit so they would not cross. Solution; slow the bullets down. If they are shooting apart, my theory is all wet and you should just try different loads until you find one it likes.

What kind of scope? How heavy? DPCD is on to something here.

It is shooting apart. I have a leupold 1x4 scope and the rings and bases that are for the gun. The scope is short and light. I would not bother with the scope the the eye is not as it was. I only have IMR powders. Is the 65 grns of IMR 4831 a max load?

Is it still shooting appart with the Factory ammo it was regulated with? The shape (bearing surface) of the Oryx and PRVI bullets are very different. Put them side by side and you will see what I mean. I expect you will need to adjust the loads for this bullet.

I had the same issue with mine. It took 16 load combos to sort out. TSXs crossed and CEBs shot apart. All shot fine with irons. Turned out to be some issue with the dynamics caused by load density. At least that is the only thing I can figure.

The load that worked for me was the CEB solids and Non-Cons with 53grs of IMR4064 and a small amount of filler. Give that one a try. It took me the better part of 4 months to work out thAt load. I hope that helps

Todd

I shot my little Chapuis yesterday. I am amazed at how well it shoots. My load with Reloder 15 shoots much better than the factory target. My advice, take the scope off and shoot it with irons. If you want a scope, buy a bolt gun in 9,3X63.

Ontario, The load I gave you is the load that regulates in my rifle. I don't ever rum maximum in my stuff. That load works well with Privis!
Maximum is determined by your rifle with flattened primers ect.

Mine wears a 1.75 x 6 Leupold and shoots well with the scope.

I have to comment on the max load issue; yes, 65 grains of IMR4831 is listed a max load and flings a 286 grain at 2360 fps (nosler), however, that is all you can get into the case anyway and even that is compressed. Consider that the 9.3 only operates at 42000 cup anyway (about 45000 psi), which is sometimes not enough to flatten primers or cause hard extraction; at least not like we are used to in a 54000 cup (over 60000 psi) bolt gun. The above posts are right, something in the load dynamics, velocity is usually the main factor, but there are others, are throwing the regulation off and you will just have to play with it. BTW, the 53/4064 load mentioned above is a minimum load producing only 35000 cup, so that might be the direction to head.

Ontario

I know its not the same class rifle, but my Valmet in 9.3 does the same thing. I have not been able to find a load that shoots good with the scope, so I just use iron sights.

quote:

Originally posted by ontario:
My 9.3x74R was regulated with norma 285 ORYX. It shoots as per the target with open sights. I put a 1x4 leupold on and it shot about 5" apart at 50 yards. I have hornady and norma brass and 285 privi bullets. Any suggestions on loads with the IMR powders?Min and Max if possible.

quote:

Originally posted by dpcd:
Are they crossing or shooting apart? If they are crossing, you have slowed down the recoil cycle by adding the weight of the scope, thereby causing the bullets to exit the muzzle before the muzzles jump farther into their respective arcs, which, without the scope, they would reach the zenith of the jump arc sooner and the bullets would exit so they would not cross. Solution; slow the bullets down. If they are shooting apart, my theory is all wet and you should just try different loads until you find one it likes.

quote:

Originally posted by Todd Williams:
I had the same issue with mine. It took 16 load combos to sort out. TSXs crossed and CEBs shot apart. All shot fine with irons. Turned out to be some issue with the dynamics caused by load density. At least that is the only thing I can figure.

The load that worked for me was the CEB solids and Non-Cons with 53grs of IMR4064 and a small amount of filler. Give that one a try. It took me the better part of 4 months to work out that load. I hope that helps

Todd

As you can see Ontario, your problem is not unique to your Chapuis rifle, when mounting a scope on a double rifle that shoots very well with irons, but goes crazy when a scope is added.
This is common to double rifles in general, but far more common in double rifles that are chambered for light calibers that are faster barrel time, and in very light weight rifles like the Chapuis. This is not as common in rifles that have a slower barrel time, and the rifles its self being heavier. The larger bore rifles being heavier, the weight of the scope and mounting hardware is a much smaller, percentage wise, of the total weight of the rifle, than it is with the same scope and mounting hardware on a rifle that is far lighter, with a faster barrel time.

The draw back is that the light rifle is not as versatile with being able to switch back and fourth from scope to irons, and back without having to have two separate loads, one for irons, and another for the scope. With a heavy rifle the weight of the scope and hardware makes far less change in the muzzle flip, and impact on the target because of the slower reaction to flip because if the weight of the barrels, and slower barrel (longer) barrel time.

Todd can help with this, as as he said he fought this problem for some time before he found something that would shoot with the scope. I haven’t talked to him since he found it, and I don’t know if the load he finally found will shoot with the irons as well. I hope they will but I have my fingers crossed!

……………………………………….Good luck guys!

quote:

Originally posted by dpcd:
I have to comment on the max load issue; yes, 65 grains of IMR4831 is listed a max load and flings a 286 grain at 2360 fps (nosler), however, that is all you can get into the case anyway and even that is compressed. Consider that the 9.3 only operates at 42000 cup anyway (about 45000 psi), which is sometimes not enough to flatten primers or cause hard extraction; at least not like we are used to in a 54000 cup (over 60000 psi) bolt gun. The above posts are right, something in the load dynamics, velocity is usually the main factor, but there are others, are throwing the regulation off and you will just have to play with it. BTW, the 53/4064 load mentioned above is a minimum load producing only 35000 cup, so that might be the direction to head.

Careful here. With a 286gr bullet, 53grs of IMR4064 is MAX LOAD producing 2355fps in my rifle. The Barnes #4 manual shows 53.5grns as Max. It is NOT a minimum load.

Mac, this load is actually shooting great in my Chapius both with and without the scope. When I went to the CEBs, the 53grains of IMR 4064 was crossing. 67grns of IMR 4831 was shooting apart. So with the same bullet, but different powders, the results were just the opposite. This gave me the idea that something was definitely possible to get it corrected. I revisited the 4064 and noticed that the case was about 85% full, while the 4831 was compressed. I tried just a pinch of filler and that solved the problem nicely.

Nosler data from loaddata.com shows 56.5 of IMR4064 as being max. A Square shows 53 as min and 57 as max for 4064. Two other examples; A square shows RL-15 at 61 grains max; Barnes shows 54.5. Nosler shows 55.5 of N140 as max, Barnes shows 54. That shows that there are differences in data from various sources. I am always careful and so should everyone else be. PS; my Barnes #4 shows 53 of IMR 4064 as max, not 53.5 as yours does. I believe the rate of acceleration of the bullet caused by faster vs slower powders has an impact on regulation on these relatively HV and light rifle, calibers.

quote:

Originally posted by Todd Williams:

quote:

Originally posted by dpcd:
I have to comment on the max load issue; yes, 65 grains of IMR4831 is listed a max load and flings a 286 grain at 2360 fps (nosler), however, that is all you can get into the case anyway and even that is compressed. Consider that the 9.3 only operates at 42000 cup anyway (about 45000 psi), which is sometimes not enough to flatten primers or cause hard extraction; at least not like we are used to in a 54000 cup (over 60000 psi) bolt gun. The above posts are right, something in the load dynamics, velocity is usually the main factor, but there are others, are throwing the regulation off and you will just have to play with it. BTW, the 53/4064 load mentioned above is a minimum load producing only 35000 cup, so that might be the direction to head.

Careful here. With a 286gr bullet, 53grs of IMR4064 is MAX LOAD producing 2355fps in my rifle. The Barnes #4 manual shows 53.5grns as Max. It is NOT a minimum load.

Mac, this load is actually shooting great in my Chapius both with and without the scope. When I went to the CEBs, the 53grains of IMR 4064 was crossing. 67grns of IMR 4831 was shooting apart. So with the same bullet, but different powders, the results were just the opposite. This gave me the idea that something was definitely possible to get it corrected. I revisited the 4064 and noticed that the case was about 85% full, while the 4831 was compressed. I tried just a pinch of filler and that solved the problem nicely.

That's good, however my load for the 9.3X74R regulates perfectly in my Merkel 140E is 56.0 grs of 4064 but the bullet is a 286 gr Nosler Partition, and that is .5 grs under max with that bullet, no filler. That rifle weighs in at 8.3 pounds, and useing a different bullet. That rifle is not scoped though.

Thanks to everyone. I have written down all the loads and will try them as soon as it warms up. I am hoping that I can find a load that will shoot with and without the scope.I am going to start with IMR 4831 as it appears to have a large span from 58 to 65 Grns. I hope to use the same load in a Ruger # 1.

You might have to have the gun re-regulated if all else fails! Double rifles can be a pain in the ass.