N160 for .243

otisthedog

Well-Known Member
#1
Am about to start reloading for .243, using 100gr bullets (probably Sierra Prohunter or Gameking) and N160 powder.
I am struggling to find load data; Viht manuals vary wildly with the latest giving 39.8gr as max load and an older manual 46.9gr, both for 100gr bullets. The Sierra data and Hornady manual I have don't list it for 100gr. Most loads I see posted online mention around 42gr, so currently thinking of starting at 38gr and working up, but I wondered if anyone could share any other min-max data for the above? Thanks in advance.
 
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Woodsmoke

Well-Known Member
#3
The Sierra data and Hornady manual I have don't list it for 100gr. Most loads I see posted online mention around 42gr, so currently thinking of starting at 38gr and working up, but I wondered if anyone could share any other min-max data for the above? Thanks in advance.
Lee gives 37.2gr of N-160 as a starting load for a 90 grain jacketed bullet, and 'Never Exceed' is 42.6gr if that helps at all?

I'm no expert (in fact, I haven't even reloaded a single round yet!), but that's straight from the Lee manual
 

otisthedog

Well-Known Member
#4
Thanks Muir, and as in my post above, I had done this.
Excuse my lack of reloading knowledge, but why revise this data - has the powder 'recipe' changed?
 

Muir

Well-Known Member
#5
Yes. Each LOT of powder produced has slightly different characteristics and each is tested before market. Hence the revisions and why your buddy's favorite Vhit load he's been shooting for the last 15 year is not necessarily applicable to this year's LOT of the same powder.
This is why when you get powder of a different LOT number, you should back off the charge and work back up.
Basic Reloading 101.
You need to do some reading, Amigo! ;) ~Muir
 

Dalua

Well-Known Member
#7
Yes. Each LOT of powder produced has slightly different characteristics and each is tested before market. Hence the revisions and why your buddy's favorite Vhit load he's been shooting for the last 15 year is not necessarily applicable to this year's LOT of the same powder.
Are you suggesting that the powder-makers make a heap of powder to last a year and then test it before publishing that year's manual?

I take the point about bit assuming that one batch-number of the same powder will not necessarily be the same as another - but I'd be surprised if the tolerances for those potential changes explained 7grain drops in max load, such as that described by the OP.
 

Muir

Well-Known Member
#8
Are you suggesting that the powder-makers make a heap of powder to last a year and then test it before publishing that year's manual?

I take the point about bit assuming that one batch-number of the same powder will not necessarily be the same as another - but I'd be surprised if the tolerances for those potential changes explained 7grain drops in max load, such as that described by the OP.
No. Not necessarily, but each LOT -and these are often measured in the X's of tons- is tested to make sure it falls within their parameters. It usually does. Often either the LOT changes or the testing becomes more refined. Hodgdon, IMR, Alliant, Accurate Arms data have all changed over the decades. It's not an uncommon thing. This is why they tell you that all data in a manual supersedes any previous data.

As to the LOT to LOT variations, frankly, I load middle weight charges so I don't do much more than cast a discerning eye on the first cases fired with a new LOT. If it's new IMR4350, I figure it to be the same as the last can of new IMR4350 I bought; or close enough.~Muir
 

Dalua

Well-Known Member
#9
I wonder whether two things are being confounded here.

No batch to batch (or lot to lot, if you prefer) variation should ever account for a 7-grain drop in maximum for a 40-odd grain load. So I suspect that inter-batch variation does not account alone for that change.

Perhaps a wholesale recipe-change, and/or corporate risk-aversion is involved?
 

JMS906

Well-Known Member
#10
Am about to start reloading for .243, using 100gr bullets (probably Sierra Prohunter or Gameking) and N160 powder.
I am struggling to find load data; Viht manuals vary wildly with the latest giving 39.8gr as max load and an older manual 46.9gr, both for 100gr bullets. The Sierra data and Hornady manual I have don't list it for 100gr. Most loads I see posted online mention around 42gr, so currently thinking of starting at 38gr and working up, but I wondered if anyone could share any other min-max data for the above? Thanks in advance.
I recently (this month) used in my .243 Ruger No 1:

Hornady #2450 100gr BTSP Interlock
N160 44.0 gr
Rem 9 1/2 primer

QuickLoad indicates 2850 fps (1805 ft-lbs). It shot well enough, putting three rounds under an inch in a very trying crosswind. This is the first handload I've tried with this rifle.

I've used the following in my .243 Sako 75:

Lapua GB543 90gr Scenar HPBT
N160 45.0 gr
Prvi LR primer

QuickLoad indicates 2900 fps (not used on game, just target). This load proved exceptionally accurate, a little over 1 MOA at 600 yards.

In another life, I'd used the following in my .243 Winchester model 70:

Nosler 95gr Ballistic Tip
N160 43.7 gr
Fed 210 primer

Measured velocity 2925 fps (1803 ft-lbs). This was exceptionally accurate and accounted for numerous foxes, deer and half a dozen pronghorn antelope.

In the same rifle, I also used:

Speer 100 gr BTSP
N160 42.5 gr
Fed 210 primer

Estimated velocity 2900 fps.

Hope this helps.

-JMS
 

otisthedog

Well-Known Member
#11
If it helps..!

From 2008 Viht manual:
100gr Lapua Mega, max load N160, col 2.650in : 43gr
100gr Hornady SPBT, max load N160, col 2.689in : 46.9gr

from 2014 Viht manual:
100gr Speer Grand Slam, max load N160, col 2.689in : 39.8gr
 

deeangeo

Well-Known Member
#12
Unable to share any min/max data, but I've been using Vit N160 for well over 20 years for my .243Win utilising the Nosler 95gn Ballistic Tip bullet.
The load I use is and has been since 1997 44.5gn Vit N160. There has been no noticeable difference between each kg purchase used for my reloading in terms of how the cartridge shoots and the downrange results.
Cannot say more than that....but caution how you work up your loads. ATB
 

Laurie

Well-Known Member
#14
Recent Viht loads data for modern cartridges are ludicrously cautious in many instances. Run them through QuickLOAD and you get PMax values in the low 40,000 psi ranges. Running this one through the program at the standard 2.710" COAL with the 100gn Speer Grand Slam as used in Viht's online data says 39,111 psi (really! :eek::???:) for 2,607 fps MV (v 2,864 fps quoted).

The answer is that Viht has obviously decided that there is a serious risk of people handloading for rifles built on 19th century vintage and clapped out Swedish M1896 actions and Russian M1891 Mosins! Seriously, I cannot think of a single good reason for the scale of the reductions produced. I've not noticed any change in recent N140 or N160 batches from those of say five years ago, and I've not heard of anybody else seeing a large change in characteristics.

QuickLOAD suggests max charges ~43gn are appropriate. Unfortunaely not that many loading manuals list this powder with 100gn bullets, Speer not including it with its Grand Slam and other 100s. Berger does list it for its 95gn Target and Hunting VLDs (Max 43.9gn), and a quartet of 105s (Max 43.0gn). Running QuickLOAD at Berger's 43.0gn with the 105gn Target VLD, the program predicts 54,569 psi (not exactly 'hot' against 60,190 psi SAAMI allowed MAP) for 2,844 fps MV from a 24-inch barrel (Berger data quote 2,849 fps, so a close match.)

With the two 100gn Sierras, QuickLOAD predicts 47,692 psi / 2,791 fps and 47,153 psi / 2,786 fps for the Pro-Hunter and GameKing respectively, both leaving lots of latitude for things that might ramp pressures up over the model. So your idea of starting at ~38.0gn and working up to 42gn looks pretty safe, and you should be able to go somewhat higher if needed without any problems.
 
#16
I too have used N160 for several years. I no longer use 100 grain bullets in my .243 but I have just looked up some records from 2006.
In a Sako Hunter with 22 inch barrel, 42 grains of N160 with a Sierra 100 grain Prohunter bullet, gave 2,868 fps muzzle velocity (1,826 ft.lbs muzzle energy) and was very consistent.
I currently use 44.5 grains of N160 with an 85 grain Speer bullet. This load is well in excess of the current Viht. maximum but functions perfectly in my current Finnlight and my old Sako Hunter. It gives 3,100 fps from a 20 inch barrel and since I started crimping, a maximum spread of 15 fps. Bagged a 130 yd Roe Doe with one yesterday morning.
 

pablo.222

Well-Known Member
#18
N160 is gd powder for heavier range of bullets for .243. Had great success with 44.5grn with 95grn nosler. Just swapped over last month too 100grn sierra pro hunter(half the price of nosler) and they are extremely accurate also.
 

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