Nosler Partition Accuracy

[Tallest]

So... to make a long and overly detailed story short, my brother in law is wanting me to work up and provide a load for his Ruger M77 7mm Rem Mag using nosler partitions. He's providing the hardware, I'm providing the time and "expertise."

I'm posting this here, because this is all for the purposes of hunting. He hunts in Montana, end to end, and some shots are 50 yards, some are 350-400. He wants me to use the 140 grain partitions to get the flattest possible load for said rifle.

My question is about accuracy expectations. I have heard multiple folks say that you lose accuracy using partitions. So, in developing the load, where should I be satisfied. 1 MOA? 2? I like working my own loads up to 3/4 MOA or less if possible. But I've never hunted with partitions past 200 yards, and I have never shot anything past about 120. And those weren't my own loads, they were factory federals. I don't want go through a lot of his money and my shoulder chasing unreasonable expectations.

So for those who hunt with partitions, especially at distance, what accuracy do you expect/consider to be reasonable?

[Oliver Sudden]

I’ve used the 160 grain partition bullet in my 7 mag. and it is very accurate to my longest shot on game. That was 400 yards. At 100 yards it groups from the bench 3/4” for five shots. My powder is Accurate 3100 with CCI primer.

[HiBC]

Well,I used to hunt with partitions in a 7mm Rem mag,long ago when you could still see lathe turn marks on them. I used 160's.I never noticed partitions coming up short on accuracy.
Folks focus on "group size" .Actually,if anything matters,its "group radius",about 1/2 group size. That is the difference between point of aim and point of impact.
I never noticed the partitions failing to give good hunting accuracy.

Bench rest competition or just handloader/shooter group size obsession is one thing,and hunting is another. If we compare a 3/4 MOA group to a 1.5 MOA group,the difference in group radius is 3/8 MOA.

The radius of a 3/4 group at 100 yds is 3/8 in.The radius of a 1.5 MOA group at 100 yds is 3/4 in. The difference is 3/8 in at 100 yds
That's 1 1/2 in difference at 400 yds.,point of aim to point of impact.

In the context of big game hunting,load some,shoot them,see what you get,and decide if its acceptable.

For myself (you do things your way) I might look at a 140 partition as a bit light,and lacking in ballistic co-efficient. I might consider a 150 gr AccuBond as an alternative.
And,I might look at the Nosler IMR4350 data for an idea of a load.

I personally found once I got to 160 and heavier bullets,H-1000 worked pretty well for accuracy and velocity.

With the 150 gr Accubond,you do get a bonded core and jacket,and a little tougher jacket than a ballistic tip.You get a little (10 gr) heavier bullet.And you get the better velocity retention of the higher BC bullet.

But you do things your way!

[Wyosmith]

I used them in my old 7MMs but never a 140 grain. I used 150s,160s and 175s. I got excellent accuracy and the kills were outstanding. So I can't say about the 140s, but I would bet they will be fine.

[jmr40]

Don't overthink this, or let your BIL do so either. The difference in drop at 400 yards between 140's and 175's is only a couple of inches. It's hard to see 2" at 400 yards. I'd be looking at the 160's.

The downside to using a lighter bullet is that MV is going to be around 3200 fps. Most standard bullets don't do so well with impact speeds much over 2800 fps. Many will over expand and give less than adequate penetration.

A 140 doesn't slow down to 2800 fps until 200 yards. The 160's start at about 2900 and are under 2800 at less than 100 yards. And at 400 yards the 140 is only impacting about 20-25 fps faster even with a 300 fps head start.

The Partition does better than most, but I'd be concerned about over expansion at close range with that bullet.

I've used 30 caliber partitions and their accuracy has more than adequate at "normal" hunting ranges. I've shot more accurate bullets, but not enough for it to be an issue.

[reynolds357]

Originally Posted by Tallest

So... to make a long and overly detailed story short, my brother in law is wanting me to work up and provide a load for his Ruger M77 7mm Rem Mag using nosler partitions. He's providing the hardware, I'm providing the time and "expertise."

I'm posting this here, because this is all for the purposes of hunting. He hunts in Montana, end to end, and some shots are 50 yards, some are 350-400. He wants me to use the 140 grain partitions to get the flattest possible load for said rifle.

My question is about accuracy expectations. I have heard multiple folks say that you lose accuracy using partitions. So, in developing the load, where should I be satisfied. 1 MOA? 2? I like working my own loads up to 3/4 MOA or less if possible. But I've never hunted with partitions past 200 yards, and I have never shot anything past about 120. And those weren't my own loads, they were factory federals. I don't want go through a lot of his money and my shoulder chasing unreasonable expectations.

So for those who hunt with partitions, especially at distance, what accuracy do you expect/consider to be reasonable?

The Partition is very accurate. Depending on who made the barrel, the 77 may or may not be.

[reynolds357]

Originally Posted by jmr40

Don't overthink this, or let your BIL do so either. The difference in drop at 400 yards between 140's and 175's is only a couple of inches. It's hard to see 2" at 400 yards. I'd be looking at the 160's.

The downside to using a lighter bullet is that MV is going to be around 3200 fps. Most standard bullets don't do so well with impact speeds much over 2800 fps. Many will over expand and give less than adequate penetration.

A 140 doesn't slow down to 2800 fps until 200 yards. The 160's start at about 2900 and are under 2800 at less than 100 yards. And at 400 yards the 140 is only impacting about 20-25 fps faster even with a 300 fps head start.

The Partition does better than most, but I'd be concerned about over expansion at close range with that bullet.

I've used 30 caliber partitions and their accuracy has more than adequate at "normal" hunting ranges. I've shot more accurate bullets, but not enough for it to be an issue.

You dont have to worry about the Partition at 3200 FPS. Its good for direct shoulder ball strike at that velocity

[Tallest]

Ok...

Given what I'm reading, I'll probably talk him into 150s or 160s.

I had discussed trying a variety of bullets, but part of the long, detailed story is that this is someone of a tribute project. His uncle taught him to shoot and hunt, and it was his uncle who bequeathed the rifle to him before he died. Uncle always swore by partitions, so he wants to keep this true to what his uncle would have shot.

I think if I get an accurate load, he's not going to care too much either way what the bullet weight is.

And as far as the rifle goes, with 150 grain core-lokts it will shoot slightly over 1" groups at 100 yards, and it will shoot right around 3/4" with 154 grain SSTs. So I feel confident the rifle is capable of reasonable accuracy.

[FrankenMauser]

Partitions are the most consistently accurate, dependable hunting bullet I've tested.
Zero reservations.

There's no need to go heavy.

[Tallest]

Originally Posted by FrankenMauser

Partitions are the most consistently accurate, dependable hunting bullet I've tested.
Zero reservations.

There's no need to go heavy.

So you’re saying not to worry about using 140 grain partitions?

[HiBC]

Tallest....You ARE going to get diversity of opinion here. We will drive you nuts if you try to react to each suggestion.

I think consensus answers your question about Nosler Partitions being fine,accurate hunting bullets Use them with confidence.

My opinion is not any better than anyone elses. If I was shooting a 7-08,I might shoot a 140.More likely a 150

It woud not matter if I was shooting prairie dogs with a 7mm Rem Mag,I'd shoot bullets more or less 160 gr weight because IMO,thats best match for 7mm Rem Mag.

A 22 LR shoots a 40 gr bullet. If you cut one in half,its 20 gr. That 20 gr pellet of lead is the difference between a 140 and a 160.
Its not a black and white choice,its a shade of grey,and preference has a lot to do with it.

If your brother in law or whoever likes 140's.let him use them. If anything goes wrong,he owns them.

You talk him into 160 gr bullets,if he hits an unseen tree branch,it will be your fault.

Load em up!

[taylorce1]

I used Partitions on a bear hunt back in 2006. I was shooting a M700 ADL in .30-06 with a Leupold Vari-X III 2.5-8X36 and 200 grain NPT bullets. I found a pretty accurate loads around 52-52.5 grains of H4350, but after the first three shots my shots started to walk to the left. I didn't do anything to this rifle, no trigger job, stock alteration, or bedding. Even though shots four and five walked on me I still had a successful black bear hunt in Petersburg AK.

[Tallest]

Originally Posted by taylorce1

I used Partitions on a bear hunt back in 2006. I was shooting a M700 ADL in .30-06 with a Leupold Vari-X III 2.5-8X36 and 200 grain NPT bullets. I found a pretty accurate loads around 52-52.5 grains of H4350, but after the first three shots my shots started to walk to the left. I didn't do anything to this rifle, no trigger job, stock alteration, or bedding. Even though shots four and five walked on me I still had a successful black bear hunt in Petersburg AK.

And here I was expecting to see pictures of a bear!

[Tallest]

Originally Posted by HiBC

Tallest....You ARE going to get diversity of opinion here. We will drive you nuts if you try to react to each suggestion.

I think consensus answers your question about Nosler Partitions being fine,accurate hunting bullets Use them with confidence.

My opinion is not any better than anyone elses. If I was shooting a 7-08,I might shoot a 140.More likely a 150

It woud not matter if I was shooting prairie dogs with a 7mm Rem Mag,I'd shoot bullets more or less 160 gr weight because IMO,thats best match for 7mm Rem Mag.

A 22 LR shoots a 40 gr bullet. If you cut one in half,its 20 gr. That 20 gr pellet of lead is the difference between a 140 and a 160.
Its not a black and white choice,its a shade of grey,and preference has a lot to do with it.

If your brother in law or whoever likes 140's.let him use them. If anything goes wrong,he owns them.

You talk him into 160 gr bullets,if he hits an unseen tree branch,it will be your fault.

Load em up!

I guess the diversity of opinions exonerates me from finding the right answer. I just need to come up with a right answer.

Thank you for your input!

[FrankenMauser]

Pick a weight that you like and run with it.

My personal preference for most modern cartridges is the "sweet spot" for a given cartridge - where it's most efficient and bullets aren't too heavy or too light. I.e.: 130s/140s in .270 Win, 165s in '06, 265s/275s in .444 Marlin, etc.

But I do tend to go heavy, or even stupid-heavy with some things, when the mood strikes me.
To date, I have not fired a bullet lighter than 154 gr in my 7x57s, or a bullet lighter than 143 gr in my 6.5-284. I've run 220s in 30-30, and up to 440 gr in .444 Marlin.

Run what you think will work, and you'll be fine.

[taylorce1]

Originally Posted by Tallest

And here I was expecting to see pictures of a bear!

Sorry I thought you'd like to see how the bullets shot!

[HiBC]

I guess the diversity of opinions exonerates me from finding the right answer. I just need to come up with a right answer.

What is,IMO,illusion is that there is a right answer.

Hunting presents a whole lot of variables. One bullet may have a theoretical small advantage on one day with one animal at one particular anatomical presentation,and on a different day,the other bullet may have a theoretical advantage.

And on either day,a bullet causing trauma has a mind of its own. Results will vary.

While I tend to prefer heavier bullets,myself,and I tend to use a 160 in the 7mm Rem Mag,I CAN make a reasonable,data based argument in favor of the 140's (and I'll still use 160's)

If I start with the premise that I want an arbitrary impact velocity of 2000 fps to make the bullet perform

And if I consider my load manual shows I can get 3300 fps with a 140 gr bullet and 3000 fps with a 160 gr bullet

The 160 gr bullet has a BC of 475 and the 140 has a BC of 435,

The 160 will shed velocity at a slightly slower rate than the 140. It begins "catching up". But 3300 vs 3000 is a pretty good gap.

I don't want to get too wrapped up in transcribing data,but the 140 will hold above 2000 fps about 100 yds farther. Its approximately 500 yds vs 600 yds,favoring the 140.

I,myself,would not consider shooting at an elk at 500 or 600 yds. Therefore,for myself,those parameters are moot.Still,I DO look at what range a bullet becomes slower than the velocity recommended by the bullet manufacturer for expansion. That max range of bullet performance might be more important on more moderate cartridges,starting out at say,2600 fps.

A 160 might have the edge for reliable penetration if some bone is hit.

But lets not forget we are talking about a 20 gr bit of lead difference.

Its amusing if people get in an impassioned argument over a 165 gr 30-06 bullet vs a 150 or a 180. Its 15 gr of lead! Half a 22 short bullet!!

I don't think its ever going to make the difference between a drop dead kill and a 1/2 mile tracking job.

I forget,is the recipient of these loads your brother in law? Close enough.

If your BIL has a preference,if he likes 140's,lets honor his preference and give him 140's. Neither bullet is the "wrong "choice.

In Life,often there is one "right" path. Sometimes,adverse.

But doggone,we need some venues whee "My Preference" is all the reason you need.

Like the beer you like. You know what hair color gets your attention.

I'm old and slow,so I like a close working French Brittany for a bird dog. I'm not into running 150 yards because a far ranging German Shorthair is on point.

That is not a put down of German Shorthairs.Its a recognition of my own shortcomings.

So,relax,enjoy.

If your BIL places that 140 he will be cutting meat.

[Tallest]

I certainly wanted to see how they shot. That was education. But my inner enthusiast wanted to see the hunt produce!

[Tallest]

"Theoretical Advantage" That should be grounds for objection in the court of these vitriolic caliber debates! "Objection your Honor! Calls for Theoretical Advantage speculation!" (Sorry! I know some of you attorneys are cringing!)

Anyway. What this is coming down to is I'm going to send him velocities and basic drop numbers for all of the 7mm/.284 partition weights. He can make an informed decision, and I can work up a load based on his preference.

[FITASC]

I pulled my 7mm mag out for the first time in 20 years the other day. It is a 40 year old Rem700BDL. One of the loads was a Nosler 175 Partition behind 4831.
3 shot group off the bench at 100 yards was dead center 2" high and measured 3/4"

Not too shabby for a 40 year old gun and 30 year old ammo

The 160 Sierra SPBT and Nosler partitions were equally as good; those loads were fresher though, only 25 years old

[reynolds357]

Originally Posted by FITASC

I pulled my 7mm mag out for the first time in 20 years the other day. It is a 40 year old Rem700BDL. One of the loads was a Nosler 175 Partition behind 4831.
3 shot group off the bench at 100 yards was dead center 2" high and measured 3/4"

Not too shabby for a 40 year old gun and 30 year old ammo

The 160 Sierra SPBT and Nosler partitions were equally as good; those loads were fresher though, only 25 years old

Out of curiosity, what was the intended victim of the 175 partition? Elk?
I have a bdl 35 Whelen built in late 80s or 1990. Its scary accurate. I bet your 7 mag is indeed accurate.

[Rapidrob]

I have shot 6.5 / 7mm/ .30 and 8mm bullets out to 800 yards and they shot very well.

[FITASC]

Out of curiosity, what was the intended victim of the 175 partition? Elk?
I have a bdl 35 Whelen built in late 80s or 1990. Its scary accurate. I bet your 7 mag is indeed accurate.

When that load was developed, you are correct - the quarry was to be elk.........but the Sierra 160, Nosler 160 and Nosler Partition also were screaming accurate

[HiBC]

What can happen with shooters/reloaders

A product,like a bullet,might have had a characteristic 25 years ago. I might still let those observations color my opinion today,25 years later.

In fact,its possible the manufacturer has improved or changed the product over 25 years.

And I mgiht have missed the memo. So I ight be wrong.

Back in the early 1970's,the 7mm Rem was quite the rage. Gun writers were taking them to Africa and Alaska. The 175 gr Nosler Partition at that time was built tough for deep penetration.

The advice was if you planned on shooting through ribs,heart,lungs on deer and elk,the 175 7mm partition might be a bit "hard". Expansion might be disappointing.

I chose 160 gr Partitions .I don't have direct experience with the 175;s

I think today if I was considering the 175 gr partitions I'd call Nosler and ask to talk with a tech rep.
They know the bullets better than anyone. They have an interest in you and I being successful and happy.

I will now comment on the 160 gr Sierra BoatTail 7mm bullet. Once again,this opinion was formed in the 1970's.. Sierra may have "adjusted" the bullet today.

I found the 160 gr Sierra to be a violent,destructive grenade of a game bullet when driven 3000 fps. But it may have been a great 7x57 bullet.

Who knows what it was designed for. In fairness to Sierra today,they may have toughened them up some.I don't know. I would advise against hitting a pronghorn with the 1970's version if you like eating pronghorn. Messy..and scary.

[Nathan]

That bullet is accurate enough. I would do 3 rounds of ocw with Hodgdon extreme powder and call it good.

Round #1 @-0.030”, vary full powder charge range in 5 increments
Round #2 take best from round 1 and vary distance off lands
Round #3 take best of round 2, vary charge weight by 1/2 increments and load up what is best.

If over 1”....rethink your load design.