faster than N160 but slower than N140......

bewsher500

Well-Known Member
having just returned from a range day I am informed that my .270 is breathing fire.....
(of course it is! Its a real man's calibre and comes with the visual entertainment expected!)

but, I am considering the fact that it is not perhaps utilising the full powder colum
rifle is a JD Parker Hale standard barrel (24"? maybe 22"..)

135gr SMK or 130gr SP Interlocks over 4.0cc or 54.5gr of N160
Norma Brass and CCI BR primers

shoots well and I use the N160 in the .243 as well

do i faff finding another powder or continue using the fire breathing beast as is!?
if the former what are my options?

have 2.5kg of N160 for sale if that is the case!
 
thanks
on a serious note i can count below 160

although is 560 not slower?
guess i was interested in 270 users with history of faster powders
 
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Hello. I have used N160, IMR-4350 and Hodgdon H-4831 (both long and short) in my twenty-four inch barrel Parker-Hale.

I have been unable to locate any data for N150 in 270 Winchester calibre! Odd but there it is!

I only use 150 grain bullets now, so my experience may not be entirely useful to you, but after wasting £90 on two tubs of IMR-4350 over about eight month period I went back to using Hodgdon H-4831.

I also was searching for something just a littel bit faster in burn rate. But the reality is that H-4831 is the No1 USA choice in that calibre for good reason.

I don't experience any fire breathing but have never gone beyond 55.0 grains which, with a Hornady 150 grain "Interlock" gave me an honest and chronographed velocity over 2,800fps at the muzzle.

Currently loading 54.7 grains with a Speer Hot Cor 150 grain but working up to 55.0 grains.

My loading notebook isn't in handy reach but I can post details tomorrow or Tuesday. It also has notes on 140 grain Hornady "Interlock" with the fastest load averaging 2,905fps with no more that ten or twenty or so fps variation.

To be honest whilst I got good accuracy with the IMR-4350 I just was filling more of the case and getting a better balanced load with the H-4831 so as not to persist with the IMR-4350.

Reality is that THE powder for the 270 Winchester and a twenty-four inch barrel is Hodgdon H-4831 and all the others are behind it.
 
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Not surprised by the fire breather Ed, N160 in 22" burns ~92% so expect a little flame!
Here is a couple of charts of burn rates to help you, I have upped the charge a little in the second chart to see how burn rate improves from what you were using.


Eds load (sort by velocity); (Prop.Burnt column)
Eds270_zps603eab5c.jpg
 
This chart sorted by prop. burnt I cropped @ <94%

270win_zpsec625b94.jpg


Use only for an idea of what is going on, I do not have Ed's case data, seating depth etc...

BTW assumed 22" barrel.
 
That is very interesting.

I started on N165 and quickly moved to N160 and stuck with it since (2yrs or so)

majority of my loads are 130gr Interlocks
I have lots of others made up (including some 140gr Nosler, Swift 140gr, 150gr Partition Gold, down to some 100 and 90gr Hollow points!)
but not had a chance to use them in anger!

I only just got some SMK's for a range day and as I was in a bit of a hurry I used the 130gr charge level with the 135gr SMK's (it is still way off max of 56.5gr, which is incidentally less than VV's data last year!, the max for 130gr is 62gr)

I have checked and it is a 24" barrel (actually 600mm/23.75" quoted in several places)

Load details are as above
OAL is 84mm to the meplat on the 135gr SMK (that measures to be seated 12mm)
Case length 64.25mm

Products - Lapua

if 54.5gr is burning 92% in a 22"
then I wonder what the max load of 56.5gr is doing in the stated 24.5" barrel that VV quote above? or worse 62gr of N160 under a 130gr!

some of their numbers don't stack up
 
That is very interesting.

I started on N165 and quickly moved to N160 and stuck with it since (2yrs or so)

majority of my loads are 130gr Interlocks
I have lots of others made up (including some 140gr Nosler, Swift 140gr, 150gr Partition Gold, down to some 100 and 90gr Hollow points!)
but not had a chance to use them in anger!

I only just got some SMK's for a range day and as I was in a bit of a hurry I used the 130gr charge level with the 135gr SMK's (it is still way off max of 56.5gr, which is incidentally less than VV's data last year!, the max for 130gr is 62gr)

I have checked and it is a 24" barrel (actually 600mm/23.75" quoted in several places)

Load details are as above
OAL is 84mm to the meplat on the 135gr SMK (that measures to be seated 12mm)
Case length 64.25mm

Products - Lapua

if 54.5gr is burning 92% in a 22"
then I wonder what the max load of 56.5gr is doing in the stated 24.5" barrel that VV quote above? or worse 62gr of N160 under a 130gr!

some of their numbers don't stack up

Bung a cleaning rod down the barrel to the bolt face and mark the rod at the muzzle, measure this and then there is no question!
There is other info needed but do not want to discuss that on an open forum!
 
Bewsher500

[h=3]N500 series[/h]The N500 series powders are impregnated extruded rifle powders with Nitroglycerol added as extra energy component. If higher loading densities and more energy are needed, N500 series powders are competent alternatives for the N100 series powders. N500 series High Energy powders are available in five different burning rates

Hope this helps
 
Here's my results with my old BRNO ZKK600 in 270 Winchester, 23.50" long barrel, shot about three or four years ago over a chronograph:

140 grain Hornady INTERLOCK BTSP
52.4 gns VIHTAVOURI N160 = 2,858 fps

140 grain Hornady INTERLOCK BTSP
55.4 gns HODGDON H-4831 = 2,856 fps
56.0 gns HODGDON H-4831 = 2,867 fps
56.5 gns HODGDON H-4831 = 2,892 fps
56.8 gns HODGDON H-4831 = 2,905 fps

I also chronographed Hornady factory ammunition with 140 grain INTERLOCK BTSP (product code #8505) and got a velocity of 2,952 fps average.
 
interesting that 1.5gr of powder made next to no difference in velocity

irritatingly VV dont have data for 140gr and N160!
I would love to know what the actual velocity figure for 54.5gr and 130gr Interlocks is
According to VV 62gr is 3090fps
yet 52.5gr give 2900fps
 
interesting that 1.5gr of powder made next to no difference in velocity

irritatingly VV dont have data for 140gr and N160!
I would love to know what the actual velocity figure for 54.5gr and 130gr Interlocks is
According to VV 62gr is 3090fps
yet 52.5gr give 2900fps


Happy to oblige (almost). I don't think hypothetical results from Quickload help much btw.


31/3/2001 Heym SR20N .270 (60cm) Hornady 130gr SP - Norma cases - CCI 200 primers

VIT N160

52.0 2766

53.0 2795

54.0 2822 2824 2830 2836 2844


19/5/2001 Heym SR20N .270 (60cm) Hornady 130gr SP - Norma cases - WIN WLR primers

VIT N160

55.0 2812 2820 2830


You can see the different results just by changing primers. Substituting heavier & thicker RWS cases usually increases the MV by 30 - 40 fps.

Another difference is that the Heym has a long throat so my OAL was much longer @ 88.0mm, so only the results with one rifle can be predicted. For the record, results from my current Tikka .270 (only 57cm) with other powders are quite a bit faster than the Heym above.
 
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