280AI & 160gr Partitions issues

I like to exhaust the factory options before tinkering with handloads unless I want to achieve a specific velocity.

I’ve had great luck with the factory Federal Terminal Ascents in .280AI. They’re a slightly different bullet than the Trophy Bonded Tipped, but very similar in design and also based off the Trophy Bonded Bear Claws as @shootist~ mentioned
 
Haven’t been here long, but it seems most of y’all go for practical over fancy and latest gadgets. So, with that said, I’m trying to get a load for my daughter in her Weatherby Camilla (ladies) that she can hunt whitetail and nilgai with the same load. The gun has a 9” twist, 24” barrel and a 2” factory muzzle break. Right now she is probable comfortable taking up to 300 yard shot and hopefully with some trigger time on this gun, that actually fits her 5’ frame, she will stretch that out to 400+, especially on the nilgai.

So now for my dilemma. Straight out the box my son and his buddy loaded some 140gr cup and core loads. Play with the new gun loads! IDK what they were, just the cheapest box on the shelf with a middle of the road powder charge as listed in the manual. The thing was sighted in and shot an honest 1” group at 100 yards.

So, they went and loaded three different powders (what they had on the bench but I think it was H1000, 4350 and 4831) at three different charge weights pushing 160gr Partitions and about the best they could do was a 2” or so group. Nothing seemed to work. (The cup and core bullets are generally not recommended for nilgai, but she has a bull on the wall taken with a 90 grain out a 25-06 at 200 yards.)

My questions…..
Are Partitions that bad of accuracy at 100 yards?
Is the twist fast enough? Too fast?
Too heavy a bullet?
Would a bonded bullet (Accubond, Sirocco) be a better choice?
Try a 150gr? I don’t think they make it in a Partition, 140 & 160 only.
Try to conjure up some A-frames?
Is a TTSX or other monolithic a better choice?

All replies are welcome!
Thanks
Tim
With the exception of 175 gr TSX and a few of the heavier Hammer bullets, a 9 twist will stabilize any 175 or 160 gr bullet you run through it.

Scirocco II is a good bullet, but if you're allowed a 280, I wouldn't go lighter than 160 gr, and preferably 175 gr.


A Frame
North Fork SS
Partition
Accubond

I got great groups with 175 gr Partitions in my 280AI, then they became unobtanium for more than a year. They're available now, but I'd already bought North Forks 175 gr, just haven't done any LD with them yet.

I also got great groups with 160 gr A Frames at about 2950 fps. Then they also became unobtanium. North Fork doesn't seem to have the logistics/production issues that Swift and Nosler have had the last 2 or 3 years.

Personally, I wouldn't hunt nilgai with any cartridge that doesn't start with .33 or bigger. It isn't that the smaller ones won't work, it's that south Texas doesn't have nearly the quality of trackers that are ubiquitous in Africa.
 
I've never killed a nilgai, but by reputation they're pretty tough. A .280 AI can certainly kill them, but realize you're already on the light side of "enough gun".

"She is probable comfortable taking up to 300 yard shot...." To me this means you need to stay inside of 200 yards with a rifle/bullet combo that is marginal to start with. The accuracy of your load is 10% of the equation. Shooting accurately and confidently in field situations is 90% of the equation. In reality, 2" accuracy is acceptable for any range you should be realistically shooting at Nilgai. Admittedly, I wouldn't be happy with it, but don't get distracted by stuff that isn't so important.

A good 6mm bullet in the vitals is better than a marginal hit with a .284 or even .338, every day of the week.

That said, I'd avoid a cup/core bullet. On my list would be A-frame, TTSX (or Hammers), or Accubonds in that order. Right now 7mm A-frames are available at Midway.

I've killed plenty of springbok and pronghorn with TTSX. They just die. No worries at all for whitetail.

I've had 2 rifles that just never liked Partitions. Maybe I would have gotten them to shoot with some effort, but sometimes it's just easier to try something else. Good thing there are plenty of other options.
 
I've never killed a nilgai, but by reputation they're pretty tough. A .280 AI can certainly kill them, but realize you're already on the light side of "enough gun".

"She is probable comfortable taking up to 300 yard shot...." To me this means you need to stay inside of 200 yards with a rifle/bullet combo that is marginal to start with. The accuracy of your load is 10% of the equation. Shooting accurately and confidently in field situations is 90% of the equation. In reality, 2" accuracy is acceptable for any range you should be realistically shooting at Nilgai. Admittedly, I wouldn't be happy with it, but don't get distracted by stuff that isn't so important.

A good 6mm bullet in the vitals is better than a marginal hit with a .284 or even .338, every day of the week.

That said, I'd avoid a cup/core bullet. On my list would be A-frame, TTSX (or Hammers), or Accubonds in that order. Right now 7mm A-frames are available at Midway.

I've killed plenty of springbok and pronghorn with TTSX. They just die. No worries at all for whitetail.

I've had 2 rifles that just never liked Partitions. Maybe I would have gotten them to shoot with some effort, but sometimes it's just easier to try something else. Good thing there are plenty of other options.
Well said, all of it
 
Get a copy of Doc Robertson’s book, ‘The Perfect Shot’.
Shoot the heaviest bullet that her rifle will stabilize.
Virtually every African guide I talked to says Barnes x bullets (TSX or TTSX) or a comparable monometal.
They will also tell you not to get excessive with the velocity.
And don’t let anyone tell you that TSXs aren’t good for deer. That’s sheer nonsense!
While I love Nosler Accubond I’d recommend the TTSX over them for Nilgai.
Of course if she is really good and knows her shot placement and won’t take a questionable shot, the Accubond will be quite adequate
I shot all of my African animals with Speer HotCore, but I was shooting a larger caliber at 2725ish.
1754876553171.png
1754876553171.png
 
@Twraska

No you were pretty clear on that point.

The general consensus on this forum, I believe, is to always load for the bigger tougher animal and use that same load for the smaller ones.

As Nathan Foster has mentioned on his site, you may want to break bones [on lighter game] to get better expansion and faster killing.

Trophy Bonded Tiped, the modern version of the excellent TTBC - also known as Federal Terminal Ascent, is another one to consider, although it's probably only available in factory loaded ammo:

Thread 'Any love for the federal terminal ascent?' https://www.africahunting.com/threads/any-love-for-the-federal-terminal-ascent.90950/

And finally - If your daughter is uncomfortable shooting 300+ yards under field conditions, tell her she has lots of company - and is a very wise young lady. :)
She is blessed with her brother’s patience and will pass on a shot rather than take a bad one. Not to say she’s never made a bad shot, just doesn’t push the envelope. She’s never been into rifle hunting (grew up duck hunting) until she got married and started going with her husband so she’s got a lot of catching up to do.
 
Sometimes a gun just doesn’t like a bullet.

I would give the Barnes TTSX a try. Then maybe Accubond and A frames if they are available. Also different powder charges of course. I have one rifle that groups can double in size with a half grain difference in powder.

Were the cup and core and partitions loaded with the same jump to the lands?
To my knowledge yes. But I am not positive as I wasn’t the one loading them.
 
My first accurate rifle was a 280 AI built by Kenny Jarrett over twenty years ago. It came with two loads that shot 1/2” groups with not much help from me. They were both Nosler’s, a 150 BT behind IMR 4831, and a 175 Partition using IMR 7828. I killed everything with that rifle and used the BT in the chamber and the Partitions in the magazine.

I have a feeling that your Wby. has a pencil thin barrel, and on the long side? Which means it’ll take a bit of load development to make it shoot, or with a bit of luck come easy.

BTW, back in the day Kenny never liked the Barnes X bullets, now the Tipped TSX’s are among his favorite to use in his guns.

My current GAP Built 280 AI has a 26” M24/40 carbon Bartlein with a 1:8.7 twist vs the #4 24” on my older Jarrett Rifle which was either a 1:9 or 1:10”? Back when Hornady came out with their ELD’s I never could get them to shoot either.

I did however use a completely new reamer on my Terminus build designed by Dave Manson and a gentleman from NZ Nathan Foster. It came about to help with ease of making just about anything work in these guns and the newer higher BC bullets.

As much as I’d like to say that’s the case just like my older Jarrett the FMR 280 AI did not like any of the LRAB’s, ELD’s, etc. in my experience the NAB tends to take a bit more work than any Ballistic Tip, or Partition IMO. But I have gotten good accuracy with TSX FB bullets out of my older rifle.

Bonded bullets tend to take more effort to shoot vs how easy it is to get a BT, or NPT. Over the last twenty five years I tended to get them to shoot in roughly 25 rounds or less! They typically shoot well at around.020” to .030” off the lands.

I ended up with getting both the 160 BT’s and the 160 NPT’s to shoot to the same POI using the same load, 57.0 H4831sc. H4831sc was also used in my Jarrett with the Barnes TSX FB 160.

I might add that I don’t push them like Kenny loved doing and stuck with the velocity from the Hodgdon manual.

Good luck with your project and don’t be afraid to switch to a different bullet! The barrel will like what you’re using or not, best to just move on.
Yes that Weatherby Carmella is a fairly light gun with a really thin barrel. That lightness on the front is what she liked about it.
 
Thanks for the reply. However, I’m needing a single load for both. I don’t think I made that clear in my OP.

Her hunting opportunities may allow cull whitetail bucks, trophy whitetail or nilgai at any given time during the day at ranges as close as 30 yards on the deer, 50-75 on the nilgai and as long as she feels comfortable taking a shot. I know that’s asking a lot out of a single round, but that’s the reality of the hunt.
@Twraska
The beauty of the partitions is that the Speer hot cor has the same BC.
Personally I would work up a load for the Speer hot core that's accurate THEN you can use the partitions with the same powder charge.
Being the same BC they usually group to the same poi.
That way you can use the cheap hot-cores fore deer and the partitions for other game.
Bob
 
@Twraska
The beauty of the partitions is that the Speer hot cor has the same BC.
Personally I would work up a load for the Speer hot core that's accurate THEN you can use the partitions with the same powder charge.
Being the same BC they usually group to the same poi.
That way you can use the cheap hot-cores fore deer and the partitions for other game.
Bob
May I humbly suggest that you use the term less expensive instead of cheaper for the Speer Hot Core. I believe that their price causes people to think they are inferior and that isn’t so in my experience!
(Granted that I’m a one time safari hunter with limited experience there)
I shot all my plains game with HotCore and was very impressed with the results.(Sable, warthog, Blesbok, Impala and Zebra)
HotCore are not as tough as Aframe, Accubond, etc. but still a very good and accurate bullet!
 
The 145 LRX in my opinion would be ideal. Plus in my experience, quite easy to make shoot well. The benefit will be Barnes legendary retained weight, deep penetration, less recoil and the LRX's ability to expand at lower velocities.
 
Haven’t been here long, but it seems most of y’all go for practical over fancy and latest gadgets. So, with that said, I’m trying to get a load for my daughter in her Weatherby Camilla (ladies) that she can hunt whitetail and nilgai with the same load. The gun has a 9” twist, 24” barrel and a 2” factory muzzle break. Right now she is probable comfortable taking up to 300 yard shot and hopefully with some trigger time on this gun, that actually fits her 5’ frame, she will stretch that out to 400+, especially on the nilgai.

So now for my dilemma. Straight out the box my son and his buddy loaded some 140gr cup and core loads. Play with the new gun loads! IDK what they were, just the cheapest box on the shelf with a middle of the road powder charge as listed in the manual. The thing was sighted in and shot an honest 1” group at 100 yards.

So, they went and loaded three different powders (what they had on the bench but I think it was H1000, 4350 and 4831) at three different charge weights pushing 160gr Partitions and about the best they could do was a 2” or so group. Nothing seemed to work. (The cup and core bullets are generally not recommended for nilgai, but she has a bull on the wall taken with a 90 grain out a 25-06 at 200 yards.)

My questions…..
Are Partitions that bad of accuracy at 100 yards?
Is the twist fast enough? Too fast?
Too heavy a bullet?
Would a bonded bullet (Accubond, Sirocco) be a better choice?
Try a 150gr? I don’t think they make it in a Partition, 140 & 160 only.
Try to conjure up some A-frames?
Is a TTSX or other monolithic a better choice?

All replies are welcome!
Thanks
Tim
Tim, My kimber Mt Extreme shoots the 160 Accubond very well with IMR4350 at 56-57.5 grains and a 210 primer. I turn the necks on them as well, and pick up slightly more consistency. It shoots the Hornady 162 ELDX slightly better but the Accubond is a better hunting bullet imo. Best of luck!
 
A 140 TTSX from a 280 AI will absolutely kill at 400 yards. Especially on a dense medium like the Nilgai.

Not sure what you are on about, do you have much killing experience with mono metals or are you saying what you maybe had heard?

If he’s having accuracy issues with the partition than he should absolutely try TTSX (a better Nilgai bullet even at 400 yards)
I consider it axiomatic that mono metal bullets require high impact velocity, but since the op asks if partitions are known to be inaccurate, it bears mentioning, especially since so many folks are shooting long these days. If your Barnes is hitting fast enough to open at 400 then yeah of course it works, and there’s a feather in your cap. I’m just saying that we as hunters these days should be cautious about pushing the limits of small bullets on big animals and that’s what I’m ‘on about’. I’ve witnessed both success and failure with the mono metal bullets here in Alaska, particularly on moose. I do keep my irons sighted with Barnes for close range backup on bears, as not much else compares in this weight class, but I don’t consider them the all around go to for my purposes. Have a nice day.
 
@Twraska
The beauty of the partitions is that the Speer hot cor has the same BC.
Personally I would work up a load for the Speer hot core that's accurate THEN you can use the partitions with the same powder charge.
Being the same BC they usually group to the same poi.
That way you can use the cheap hot-cores fore deer and the partitions for other game.
Bob
I can swap between Partitions and Ballistic Tips with no chance in poi in the Tikka 6.5. Both have similar accuracy with the BT just a little better.

If having accuracy issues, the first thing to consider is a bedding job, IMO.

Also, if swapping between mono metal and jacketed bullets, it's very important to clean the bore with a good copper remover such as Boretech.
 
I can swap between Partitions and Ballistic Tips with no chance in poi in the Tikka 6.5. Both have similar accuracy with the BT just a little better.

If having accuracy issues, the first thing to consider is a bedding job, IMO.

Also, if swapping between mono metal and jacketed bullets, it's very important to clean the bore with a good copper remover such as Boretech.
Actually we are talking about a lot of good to great bullets here.
I tend to shy away from Partition because of their reputation for shedding the front section to easily. Ask African guides and I’ll give you 3-1 odds that is the first thing they will say. If I’m not shooting mono-mental I’d take the Accubond or Swift Sirocco .
All of these are great bullets and will do well on both species.
Remember that you are saying that she might shoot 300-400 yds. Your bullet needs to be able to maintain minute of angle at that distance. I don’t know anything about southwest US but in Africa it you draw blood you pay for the animal, even if it’s only a scratch. (Ethics aside)
A friend of mine has a #1 in.280AI and he swears by 160 Acubond religiously for everything he hunts from Antelope to Elk.
(1/2 min. moa I’d swear by it too)
 
May I humbly suggest that you use the term less expensive instead of cheaper for the Speer Hot Core. I believe that their price causes people to think they are inferior and that isn’t so in my experience!
(Granted that I’m a one time safari hunter with limited experience there)
I shot all my plains game with HotCore and was very impressed with the results.(Sable, warthog, Blesbok, Impala and Zebra)
HotCore are not as tough as Aframe, Accubond, etc. but still a very good and accurate bullet!
@geopat
Sorry mate.
In Australia Speer hotcore are a cheaper option than most other projectiles available.
In NO WAY am I implying they are an inferior bullet
In actual fact they are a very good game bullet that have proved deadly and very accurate in my rifles.
The 100gn Speer hot core in my 25 at 3,600 fps is absolute dynamite on fallow deer for broadside shots and the 250 gn 35 Cal hotcore is an excellent bullet at 2,700fps is an excellent bullet in the Whelen.
Bob
 
I can swap between Partitions and Ballistic Tips with no chance in poi in the Tikka 6.5. Both have similar accuracy with the BT just a little better.

If having accuracy issues, the first thing to consider is a bedding job, IMO.

Also, if swapping between mono metal and jacketed bullets, it's very important to clean the bore with a good copper remover such as Boretech.
@shootist~
If I have a rifle that isn't shooting properly and the barrel is already free floating the first thing I do is put a few bits of old credit card under the barrel at the friend to put a bit of upward pressure in the barrel. You would be surprised how well this can work
Bob
 
@shootist~
If I have a rifle that isn't shooting properly and the barrel is already free floating the first thing I do is put a few bits of old credit card under the barrel at the friend to put a bit of upward pressure in the barrel. You would be surprised how well this can work
Bob
Bob - On advice of my gunsmith I usd that trick to see if I needed to glass bed a forward pressure point under the barrel of my Sako 338 WM. (I did and it worked.) I've never thought to try it on anything else - so thanks for the tip.
 
Bob - On advice of my gunsmith I usd that trick to see if I needed to glass bed a forward pressure point under the barrel of my Sako 338 WM. (I did and it worked.) I've never thought to try it on anything else - so thanks for the tip.
@shootist~
More than welcome.
Some don't believe it works but it can work wonders.
A person I knew bought a factory rifle with slight upward pressure in the forend and removed it. The rifle then went from a good shooter to a shotgun pattern. He had to replace the pressure pad.
Bob
 

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