N160 / N560 in .308 with 155 SMKs

25 Sharps

Well-Known Member
Hello chaps

I have an older .308 target rifle that I bought off of Bewsher, shoots well with 43gr n140 under a 155 but I get pressure signs at 43.5.

I'm just wondering as it has a 32" barrel whether it may benefit from a slower powder such as N160 or N560 (both of which I have here) as I may get lower pressure and make the most of the longer barrel.

Application would be longer range target work, out to 1000y.

What are people's experiences / thoughts?
 
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I asked the same question and Laurie responded with a negative
he has forgotten more about 308 target shooting than I will ever know so I took it at face value

you will struggle to get the volumes in a think
n140 seemed to work well
n550 could be a good test
what bullets are you thinking?
 
I asked the same question and Laurie responded with a negative
he has forgotten more about 308 target shooting than I will ever know so I took it at face value

you will struggle to get the volumes in a think
n140 seemed to work well
n550 could be a good test
what bullets are you thinking?

Great minds think alike hey?

Thinking 155gr SMKs or perhaps A-max as these could be quite humane on fox too!

Thing is it shoots so well, as you know, with the N140 giving 2780fps there's probably not much point in mucking about with it but I've got 3/4 kg of both powders mentioned for the swede and though if it was a known combination I may give it a go, ah well.

Maybe the 123gr a-max from the swede is the answer!
 
168 a-max is almost nicer than the 155, outside UK great on fox, deer and some use it for long range goats.
Quite common in Germany to use N150 in 308 for target.
edi
 
Hello chaps

I have an older .308 target rifle that I bought off of Bewsher, shoots well with 43gr n140 under a 155 but I get pressure signs at 43.5.

I'm just wondering as it has a 32" barrel whether it may benefit from a slower powder such as N160 or N560 (both of which I have here) as I may get lower pressure and make the most of the longer barrel.

Application would be longer range target work, out to 1000y.

What are people's experiences / thoughts?
n160 is prob a bit slow.
However, if you have the longer 155 SMK, rather than the stubby one, you could load it rather long to bung more powder in and make use of your barrel...
As for the pressure signs, what are they?
You could also load longer in the n140 and see how you fare?

I load 44-45gr n140 under a scenar to mag length in a 26"TRG depending on the range.
Primers are moving toward flattening but the CCI's are quite soft so nothing of concern.
 
I'm shooting a shorter barrel (24 inches) and so far have had good results with N140 at 42.1 for SMK 155s loaded to 2.800. Not tested velocities yet but groupings were about 0.4. I'm finding the 155's a bit short for my freebore (50 thou jump with those seated properly) so will be trying 168 A-Max or SMKs and re-working loads using my remaining N140.

The only thing I note about N140 is that for equivalent MVs to alternative powders it seems to be giving higher pressures, so there will be alternatives such as the Swiss RS range, specifically the RS52 powder (seem to be gaining in popularity) that seem to provide good results with lower chamber pressures. However, ready availability of Viht powders and track record with those using the .308 still seem to make it a popular choice.

Lyman's 49th gives a max load of 46.2gr N140 under a 150gr SP resulting in a pressure of 56,700psi for an MV of 2,795 fps. RS52 by comparison gives a max load of 47.1gr under a 150gr SMK for 46,571 psi and 2802fps.

I think I'd be trying some RS52 when the N140 is used up.

I'm also finding CCI BR primers fairly soft and getting pressure signs like flattening of primers when approaching 44gr under a 155 SMK.
 
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