Hi all,

I have just bought a Sako 75 synthetic stainless in 7mm Remington Magnum. I have done some load development with mixed results. I have tried the 160 grain Nosler partition and got pretty bad results, from 2" to 3.5" 3 shot groups. So i guess my rifle dislikes this bullet. The only other bullet i have tried is Sellier&Beliiot 140 grain FMJ boat tail and i get under 1" groups with that.
So i need to develop an accurate and efficient load for mixed hunting from small deer to moose and wild boar with the same bullet. I guess Nosler partition is out of the question for me so what bullet would you try next? Or maybe i could try another weight partition? I am also looking for a bullet that will not destroy to much meat as i like to eat what i kill. So then i guess the ballistic tip is out of the question as well.
I have 1-9,5 inch twist. Will that be enough to stabilize heavy bullets such as 175 grains?

Another question while im at it. What seating depth would you start developing with? How much free flight?

Igor,

Check out our website, we have quite a bit of 7mm RM stuff.

I have had great success with the 175 gr. Nosler Partition, it is virtually all I ever use. It has been incredibly accurate for me.

Check out the Hornady interlocks, as they tend to be quite accurate as well.

Hope that helps some.

Joel Slate
Slate & Associates, LLC
www.slatesafaris.com

7mm Rem Mag Page www.slatesafaris.com/7mm.htm

Before you give up on the 160 Partiton,Try a different Powder if not already done so.

Igor,
I would not be afraid to try the 154 or 162 Hornady in either SP or SST. I have shot the 160 Partition from 280 Remingtons and they have done well however I can't complain about the 154 SP or the 139 SST. They both shoot well and I have taken both Elk and Mule Deer with them. John.

The Nosler Partition bullet has a two compartment copper jacket design and many rifles will not shoot them well. The Nosler two compartment bullet design produces a bullet out of balance and moves the bullets weight to far forward. When your rifle does not like Nosler it is not likely a bullet weight change will help. Know your rifles bore twist rate and match the bullet weight to that twist rate. A fast twist will like long sleek bullets and a slow twist will like shorter light weight bullets. I know none of my hunting rifles like the Nosler Partition bullets. I would give the Sierra Game king or Hornaday A-Max a try in your 7MM Mag. I have found seating the bullet to just kiss the lands to start works best. Once you determine the powder your rifle likes best then you can work with the seating depth to improve accuracy. Many rifles like the bullet just touching the lands for best accuracy. Seat the bullet into the case at .005 intervals until best accuracy is achieved. I like to use the Ladder test method when developing loads for my rifles. It saves ammo and only takes twenty rounds or less to find the right powder charge your rifle likes best.

Both the 175 grain Remington core lokt and the Hornady interlok have performed well in a lot of 7 mags for the game you mention. I have owned rifles that just would not shoot the partitions well and they are a bit expensive to do a lot of experimenting with.

I've had good results with RE22 and H4831 in my 7mm RM with the 150 and 160 grain partitions. I would try to work with the 160 some more as I believe it is a good all around bullet for the 7 RM. I've also had good accuracy with the 154 gr Hornady but have not used it on game bigger than Whitetail deer. I've tried the X-bullet but my results were worse than yours with the 160 partition. Took a bull caribou with the 160 grain partition last year at about 75 yards. Bull was quartering away and I hit it behind the front shoulder, the bullet went through the lungs and out the other side in front of the far side shoulder, went about 25 yards and dropped. In big game hunting loads I tend to try and keep the bullets off the lands a bit more than I would in a varmint rig. It is usually the last thing I fiddle with when doing load development as my priority would be reliability over getting that last little bit of accuracy.

Don't give up on that bullet yet. It may be the velocity. It could be the powder. Try loading 3 each in .5 gr increments up to the max load and shoot for group size. If you can find a smaller group try loading some in .2 gr increments around the best group loads. If you have access to chronograph that will help too. When I begin the load development process I seat the bullets .050" off the lands of the barrel. An over all length gauge helps here. Stoney point makes them. That measurement can also be taken by seating a bullet long in an unprimed unloaded case and then chambering that round to push the bullet against the lands of the rifling thus pushing the bullet into the case. Then simply eject the case and measeure the OAL and subtract .050". I don't change the OAL until group size gets smaller. There is a lot of information out there on load development. Good Luck