Another 300 Win. Mag.

[NYDAN]

My neighbor bought a used Sako A7 Big Game with the Rough Tech stock. He plans to use it for Whitetail Deer in NY this and Elk & Mule Deer in Montana next year. I volunteered to work on a load for him. This is what I came up with.

EDIT: I copied the neck tension wrong. The correct neck tension is 0.002" NOT 0.0025" - 0.003".





I suspect he will be happy with a 0.27" group size.
Dan

 

[DrMike]

It appears that you have performed an admirable piece of work, Dan. Excellent in every way. He should be thrilled with what you have given him.

 

[desertcj]

Great work. The .281" jump is interesting....that's a long ways from the lands!

 

[DrMike]

Great work. The .281" jump is interesting....that's a long ways from the lands!

I have worked with rifles that required that amount of jump just to get the accuracy required. It is unusual, but certainly not unheard of.

 

[NYDAN]

Great work. The .281" jump is interesting....that's a long ways from the lands!

This rifle has a detachable box magazine. That is as long as I dared load them. It appeared that a cartridge 3.34" long would bind up.

I couldn't go shorter either. The ogive of the bullet was already in the short neck (the bullet dia. in front of the neck was at 0.306"). I tried combinations of three different bullets and two different powders. The 180 BT and RL-23 appeared to offer the most promise. Then I refined the powder charge.

Dan

 

[TXbaldhunter]

I have a Sako A7 Long Range with the 26" heavy fluted barrel.I never could get it to shoot that good seated deep.In fact,in order for it to function in the short magazine box,it has to be seated less than 3.300.The 180gr Nosler Ballistic Tips were seated so deep in the case,I could push the bullet in by hand because the short necked 300 Win Mag case didn't have enough neck tension to hold the bullet since the bullet ogive was starting to get in the neck already.I could crimp them and probably hold the bullet in place,but I didn't want to go there.I figured if there was a cartridge in the magazine,the recoil would probably drive the bullet deeper in the case and risk the chance of poor accuracy or worst case the bullet being pushed into the case from the recoil and dumping powder into the magazine.I had some ammo loaded for my other 300 Win Mag that has a longer mag box so the bullets can be seated out farther.Nearly every 300 Win Mag I've checked is about 3.500-3.570 to the lands.I've been able to get good accuracy with and OAL of 3.490.My Sako liked it at that depth.He was my results.I guess I'll just shoot it as a single shot.You only need one well placed 300 Win Mag shot anyway.

 

[Guy Miner]

Outstanding guys! Great accuracy with game-taking bullets from a powerhouse cartridge.

*Look at those wonderful SD & ES numbers! Wow! That indicates a high quality handload to me.

Something to consider for the 300 Win Mag and shorter magazines... Nosler came up with a specific 180 grain Partition bullet just for that application decades ago and it's still in the lineup!

30 Caliber 180gr PPT Partition (50ct)

30 Caliber 180gr PPT Partition®

www.nosler.com

Ya, it's not the highest BC. Wah. It will work just peachy.

Regards, Guy

 

[TXbaldhunter]

Outstanding guys! Great accuracy with game-taking bullets from a powerhouse cartridge.

*Look at those wonderful SD & ES numbers! Wow! That indicates a high quality handload to me.

Something to consider for the 300 Win Mag and shorter magazines... Nosler came up with a specific 180 grain Partition bullet just for that application decades ago and it's still in the lineup!

30 Caliber 180gr PPT Partition (50ct)

30 Caliber 180gr PPT Partition®

www.nosler.com

Ya, it's not the highest BC. Wah. It will work just peachy.

Regards, Guy

I have some of those Protected Point Partitions.Yes,they were made for the 300 Win Mags with short mag boxes.A lot of those mag boxes are around 3.400.I think a lot of short mag boxed rifles were chambered for the 300 Win Mag because Saami specs. are 3.340 for the cartridge,so in theory it should be a non-issue.They really should have been made with a mag box min. of 3.500 for this cartridge to take full advantage of the different 30 cal bullets available for it. I still say SAAMI specs for the 300 Win Mag is way off.The OAL length of 3.340 is way too short.The 300 Win Mags I have are around 3.550 to the lands.To give you and example as to why I think this is an error,take a look at the case length of the 300 Win Mag and the 308 Norma Mag.The Winchester case is 2.620 and the Norma case is 2.559.OAL for the Winchester is 3.340 and the OAL for the Norma is 3.347.I ran into an issue with a Sako A7 300 Win Mag.It is built on their M action instead of the L action and the rifle magazine is too short for this cartridge to feed and shoot accurately because I would have to load the cartridge under 3.300 for it to feed in the magazine.In doing so,the short neck Winchester case is already getting on the bullet ogive with the Ballistic Tip or AccuBond and with so little neck tension on the bullet,I could push the bullet in by hand.

 

[NYDAN]

Outstanding guys! Great accuracy with game-taking bullets from a powerhouse cartridge.

*Look at those wonderful SD & ES numbers! Wow! That indicates a high quality handload to me.

Something to consider for the 300 Win Mag and shorter magazines... Nosler came up with a specific 180 grain Partition bullet just for that application decades ago and it's still in the lineup!

30 Caliber 180gr PPT Partition (50ct)

30 Caliber 180gr PPT Partition®

www.nosler.com

Ya, it's not the highest BC. Wah. It will work just peachy.

Regards, Guy

Guy, that is a great suggestion. Thank you. I will be on the look-out for those bullets. Dan

 

[TackDriver284]

Excellent shooting and that is a great load you worked up.

 

[NYDAN]

I have a Sako A7 Long Range with the 26" heavy fluted barrel.I never could get it to shoot that good seated deep.In fact,in order for it to function in the short magazine box,it has to be seated less than 3.300.The 180gr Nosler Ballistic Tips were seated so deep in the case,I could push the bullet in by hand because the short necked 300 Win Mag case didn't have enough neck tension to hold the bullet since the bullet ogive was starting to get in the neck already.I could crimp them and probably hold the bullet in place,but I didn't want to go there.I figured if there was a cartridge in the magazine,the recoil would probably drive the bullet deeper in the case and risk the chance of poor accuracy or worst case the bullet being pushed into the case from the recoil and dumping powder into the magazine.I had some ammo loaded for my other 300 Win Mag that has a longer mag box so the bullets can be seated out farther.Nearly every 300 Win Mag I've checked is about 3.500-3.570 to the lands.I've been able to get good accuracy with and OAL of 3.490.My Sako liked it at that depth.He was my results.I guess I'll just shoot it as a single shot.You only need one well placed 300 Win Mag shot anyway.

TX, I can appreciate just what you are saying, having just worked up loads for two 300 Win. Mags. I have come to the conclusion that if a person was going to re-barrel or set-back a barrel for a 300 Win. Mag. the thing to do is buy a custom reamer with a shorter throat.

I am going just that for a 300 WSM that I am having built. Dan

 

[xphunter]

Excellent!

 

[JD338]

Excellent load development and shooting.
Nicely done Dan.

JD338

 

[ShadeTree]

Very good all the way around! Great shooting and load work.

 

[RL338]

My neighbor bought a used Sako A7 Big Game with the Rough Tech stock. He plans to use it for Whitetail Deer in NY this and Elk & Mule Deer in Montana next year. I volunteered to work on a load for him. This is what I came up with.

EDIT: I copied the neck tension wrong. The correct neck tension is 0.002" NOT 0.0025" - 0.003".

View attachment 17843

View attachment 17844

I suspect he will be happy with a 0.27" group size.
Dan

Now that will make him happy , good job

 

[diverdown]

I have a Christensen Arms Ridgeline in .300 Mag. I had a similar problem with OAL. The rifle has a hidden magazine which is plenty long enough but the distance to the lands wouldn't allow me to go over 3.330. I eliminated that problem with a throating job. Now I'm at 3.600 with the Federal Bullets and they do indeed shoot quite well.

 

[Alaska]

I have some of those Protected Point Partitions.Yes,they were made for the 300 Win Mags with short mag boxes.A lot of those mag boxes are around 3.400.I think a lot of short mag boxed rifles were chambered for the 300 Win Mag because Saami specs. are 3.340 for the cartridge,so in theory it should be a non-issue.They really should have been made with a mag box min. of 3.500 for this cartridge to take full advantage of the different 30 cal bullets available for it. I still say SAAMI specs for the 300 Win Mag is way off.The OAL length of 3.340 is way too short.The 300 Win Mags I have are around 3.550 to the lands.To give you and example as to why I think this is an error,take a look at the case length of the 300 Win Mag and the 308 Norma Mag.The Winchester case is 2.620 and the Norma case is 2.559.OAL for the Winchester is 3.340 and the OAL for the Norma is 3.347.I ran into an issue with a Sako A7 300 Win Mag.It is built on their M action instead of the L action and the rifle magazine is too short for this cartridge to feed and shoot accurately because I would have to load the cartridge under 3.300 for it to feed in the magazine.In doing so,the short neck Winchester case is already getting on the bullet ogive with the Ballistic Tip or AccuBond and with so little neck tension on the bullet,I could push the bullet in by hand.

Those Nosler PP we’re specifically for the German Weatherby with 1/12 twist the shorter bullet would stabilize in the 300 Wby barrel back in the 60’s better than the Part Spitzers . At that time all the Weatherby factory Tiger box ammo was loaded with the PP Part.

 

[flyingagg]

Those Nosler PP we’re specifically for the German Weatherby with 1/12 twist the shorter bullet would stabilize in the 300 Wby barrel back in the 60’s better than the Part Spitzers . At that time all the Weatherby factory Tiger box ammo was loaded with the PP Part.

That’s interesting because the 180 nosler BT, AB, and PT stabiles very well in my German 12 twist Weatherby 300. 1/2” at 100 yard

 

[TXbaldhunter]

I was looking at some other bullets I have that might actually work even better than the Nosler Protected Point for short mag boxes like the Sako A7.Even though the Protected Point is shorter at the tip,it still has the issue of the ogive of the bullet getting into the short neck of the 300 Win Mag case.It's not as much as the Ballistic Tip or AccuBond,but it's still there.I would never trust a bullet with the ogive seated into the short neck of the 300Win Mag case,to have enough neck tension to keep the bullets in the magazine in place.I've seen how exposed lead tip bullets in the rifles magazine will start to flatten out after the rifle is fired.In the case of a plastic tipped bullet,you won't see a flattened tip,but you could see the bullet going deeper into the case.The Speer Grand Slam,Deep Curl and Federal Fusion bullets I have can be seated below the 3.300 length without getting the ogive into the case,but you still have that .250 or so jump before you get to the lands to deal with.Getting any rifle to shoot well with that much jump can be a crap shoot.You can burn up a lot of time,primers,bullets and powder in doing so.That's why I decided to just shoot mine as a single shot with the same load that will work in my other 300 Win Mags.In the case of the Sako A7,lengthening the mag box in this rifle is out of the question too,because the rifle is built on a medium action,which won't allow it to go longer.Nice rifle,but it's a shame Sako didn't consider this when they chambered it for the 300 Win Mag.Maybe the issues with the rifle design was the reason they quit making the A7.

 

[Alaska]

That’s interesting because the 180 nosler BT, AB, and PT stabiles very well in my German 12 twist Weatherby 300. 1/2” at 100 yard

Also the German Weatherby did not have the cutout in the action to allow for longer cartridge length .