Maximum twist rate for Nosler Partition?

270WSMXBolt

270WSMXBolt

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I have tried to find reloading data for 160 grain Nosler Partition in a 6.8 Western. None of the published data lists the bullet. So I was looking at it's general construction and I started thinking maybe it's not capable of staying together in fast twist barrels. Is there somewhere that lists maximum twist rates? I have looked and can't find the info. Cheers
 
remington jim said:
I ve Shot 160 gr partitions from my 8 Twist 7 PRC at 3150 to 300 yards and they were find . 🤷‍♂️
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This is 1 in 7. It's just weird that they list it for the 270 WSM at 1 in 10 and when I did a giggle search Rockslide had a thread that mentioned them self destructing at high twist. Thanks RJ I may try a couple for giggles but I don't want to mess with some overpressure thing... I have no starting point so I'm trying to be safe and maybe fake being smart too. Cheers
sorry correction.. 1-7.5"
 
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The 160 partition is a semi-spitzer. It's closer to a round nose than other partitions, I can only assume this is to ensure the bullet stabilizes in the 1:10 twist 270wins it was designed for many years ago.

The 150gr partition has a better BC than the 160. IMO there's no point in using the 160 in a fast twist barrel where other bullets with higher BCs can be stabilized. Plus partitions are freaking expensive these days! If you've got some already might as well give em a try, but I wouldn't go buy some to put in a 6.8W.
 
I have about 70 bullets that I just want to use up for fire forming some ADG brass. No other use for them. I originally purchased them as a bear hunting bullet but have since found others more effective by way of accuracy. I just don't want to make some stupid mistake doing up an unpublished load. I know what I think would be safe. But assumptions can crown the king of stupid.. Cheers
 
OK if you've already got the bullets I would just find any data for a 160gr soft point bullet. Starting load should be plenty to fire form. If you can't find anything for a 160, interpolate something from data that's around it - for example, Sierra has data for 150gr and 175gr with a couple of powders listed for both. Eg. H1000 data for 150gr is 58.8-64.8, and for 175gr is 56-61.1.

Given that info, I'd probably start with 57-58gr of h1000 for a 160 partition (after cross referencing with another source of data to ensure there's nothing amiss with Sierras data)
 
It comes down to RPM.

I think there is also some variance based on the specific barrel(minor factor).

~300k RPM is what I have found with some match bullets. But it really depends on the bullet.

You are likely fine, but obviously you still need to test for load dev anyways...
 
todbartell said:
I highly doubt the Partition would not make it to the target from a 7.5t 6.8W
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Your right.... even if it did deform from spin it would undoubtedly make the distance... That's one of the reasons this has my Spidey Senses tingling... The Partition bullet construction is unique so the reason to exclude it from data must have a reason?.... Right?
 
If there’s data for 270WSM I’d just use the starting load. If you want to be more precise, compare the case volumes and or data for each cartridge using the same bullet and powder. Should be able to calculate a percentage to work with. Or sell the 160’s and use a way cheaper known bullet with data. The Partitions are over $2 each in store now!
 
270WSMXBolt said:
Your right.... even if it did deform from spin it would undoubtedly make the distance... That's one of the reasons this has my Spidey Senses tingling... The Partition bullet construction is unique so the reason to exclude it from data must have a reason?.... Right?
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Bullets don’t deform from spin. Either they make it or they disintegrate in flight.

More likely the reason the Partition wasn’t included in the initial data is that it’s aero form doesn’t really fit the anticipated end user. The 6.8 was pushed as more of a long range hunting cartridge.

Not exactly exposed lead tip bullet territory.
 
KodiakHntr said:
Bullets don’t deform from spin. Either they make it or they disintegrate in flight.

More likely the reason the Partition wasn’t included in the initial data is that it’s aero form doesn’t really fit the anticipated end user. The 6.8 was pushed as more of a long range hunting cartridge.

Not exactly exposed lead tip bullet territory.
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That's about right. There isn't much data for the partition bullet in 6.8 Western for the same reason there isnt much data for 30-30 flat nose bullets in a 300 winmag.
 
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Yeah the 6.8 is about sleek and slippery like ABLR, Berger, TGK, LRX etc - so most manufacturers aren't going to devote resources to test specific blunt projectiles even though the 6.8 would make them work as good or better than a 270WCF
 
todbartell said:
Yeah the 6.8 is about sleek and slippery like ABLR, Berger, TGK, LRX etc - so most manufacturers aren't going to devote resources to test specific blunt projectiles even though the 6.8 would make them work as good or better than a 270WCF
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I agree.. My current hunting load is with 160 grain Hammer Hunter tipped bullets for the 6.8wstrn. They are very sleek and slippery. Typically at least a 100fps faster than similar weight and powder charge. My dilemma is the cost and availability of them. Hell even the 165 ABLR's have gotten ridiculous cost wise so I'm trying to save the really good stuff. Don't get me wrong I'm not poo pooing the quality of a Partition but the two 6.8's I have don't need to burn expensive rounds if I've got old stock that I didn't pay big bucks for. Just trying to safely fireform brass. It would be nice to keep smacking the 300 steel too while fireforming the cases though and do it safely. That's all I'm trying to do. Cheers
 
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You can fireform with COW loads... you aren't going to have problems with the 160 PT's at starting loads.
 
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