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Forum Index > Rifles general discussion > Nosler Partition

Nosler Partition

27 Jul 2014
@ 09:26 pm (GMT)

Ed Stewart

I cant find any .270 cal 150gr SST anywhere and I have no idea when they will be back in stock. So I decided to get some 150gr partitions and try them in the Weatherby since I have run out of SST. I had the SST shooting around 1/2 moa. Backed off my load half a grain to see how the partition would shoot and they shot a four shot group of around 3 inches. I have never had a group that big out of this gun and the partitions are over twice the price of Hornady projectiles so I dont really want to have to start from scratch. Had them seated .020" from the lands. Do I need to back my load off a couple of grains and start from there or try a different seating depth? Didnt expect them to be spot on straight away but I am a bit lost with a group that big.
Load is:

COAL with Hornady bullet comparator is 97.2mm
Federal LR primers
Remington brass
51.5gr AR2209

Cheers, Ed.

Replies

1
27 Jul 2014
@ 10:33 pm (GMT)

Nathan Foster

Re: Nosler Partition
Hi Ed, could you please look over the following, double check (including the COAL) and answer where necessary:

My test projectile length is:

My max COAL is: 97.2mm (??? 87.2mm???)

I seated my loads to a COAL of:

If the base of the bullet is seated flush to the case neck / shoulder junction with my test projectile, the COAL is:

I was using ????? reloading dies

The velocity of my SST load was:

When I backed off a half grain and tested the Partition, velocity was:

I have loaded the SST up to ???? grains 2209 when testing in the past.

has the rifle been accurized in any way.

OK, sorry for all of the questions Ed. Hope we can find a simple solution.

29 Jul 2014
@ 02:24 pm (GMT)

Grant Harris

Re: Nosler Partition
Hi Ed,

If you can get the partitions to shoot you will love them!! Nathan put me on to them earlier this year and love the results.

I've got them shooting quite well in my rifle (Winchester m70) with a coal of around the 85/86mm mark (can't remember exact, written down somewhere) that's 15 though of my lands. Also using 2209 but using 54gr - this is still a mild load.

I'm surprised your group was so large. When I first tried them I loaded up from 52.5gr to 55gr in half grain increments and the worst group was just over an inch and were all quite a similar POI. Maybe your rifle just doesn't seem to like them?

Good luck and hope you get it sorted as I am a Partition fan :)
31 Jul 2014
@ 07:38 am (GMT)

Ed Stewart

Re: Nosler Partition
Hi Nathan,

I have been looking everywhere but I can not find where I wrote the velocities for the 150gr SST in the Weatherby. I have the 130gr SST for the Weatherby in my book and the 130 and 150gr velocities for for our Tikka 270.

To make it worse I never put the partitions through the chronograph since it was late in the day and it doesnt like reading in low light. I was just hoping they would shoot well and I could load a couple for close range shooting in the bush this weekend. Then fine tune the load next week.

So now I am using factory rounds for the weekend and I will load some more partitions next week, put them through the chronograph and go from there.

My max COAL was 97.7mm but that was the reading on my callipers with the bullet comparator fitted to them. Without it my COAL was 86.84mm and I seated the projectiles to 86.34mm

I am using RCBS reloading dies, I did notice that it was hard to get the projectiles sitting square in the case mouth with the flat base on them so maybe thats half my problem.

The rifle has been bedded and stabilised with your compounds, locking lugs lapped and trigger lightened.

From what I remember the SST was near max pressure and velocity at 52.0gr so I never loaded them and faster.

Will let you know when I have the velocity of the partition or if I find where I put my SST data.

Cheers, Ed.
31 Jul 2014
@ 06:48 pm (GMT)

Nathan Foster

Re: Nosler Partition
Hi Ed, 86.34mm is about perfect, the projectile will be seated flush to the case neck shoulder junction. You can also try a full 1mm jump if need be.

It may well be the dies versus the heel of the bullet, resulting in introduced concentricity problems. It would be well worth investing in a set of Lee deluxe collet dies if you can put some money aside. I think this die set is going through a name change now so you will need to double check with Dan at Reloaders Supplies for current details.

The throat on your rifle is the same generous dimensions of old which I prefer. But normally, I do not hit max pressures until I am up around 55 grains or higher. Sweet spots with this throat length are generally found at between 53 and 55 grains ADI 2209 (H4350) with some rifles displaying optimum performance at 55 grains while others display reduced case life which is rectified by stepping down just a half to 1 grain. Sweet spot (accuracy) velocities are generally 2900 to 2950fps though some rifles will want to sit just below 2900fps. A very few will go over 2950fps and display good accuracy and case life (long barreled rifles).

Besides throat length, much depends on the brand of brass used (I generally use Winchester for max capacity and strength). Bore dimensions are yet another factor. Those reading this post are advised to be very careful if attempting to duplicate my loads.

OK, will do my best to help once you get a chance to test loads again. I would like to test concentricity if possible though.
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