7mm/.284 Win: N160 or N165?

[hattori.hanzo]

Hi all,

I have a 28" Heym barrel and would like to shoot Lapua 180 gr Scenar-L 7mm/.284 Win.

According to my calculations Vihtavuori N160 is suitable. However, I also read many posts with recommendations for N165.
The powder doesn’t burn completely - purely mathematically - inside the barrel.

What are your experiences with the two powders?

Best
Uwe

 

[MarkyMark007]

laurie holland says that N160 is a little too fast for 180gr, but maybe he is too harsh on this and will be just fine. people run 180gr in 284win with all kind of powders... but N165 on the other hand, if you have small room in your brass, like in peterson, you may have low velocities with N165, if I understand laurie correctly, because it is very bulky powder and with the lowest energy...
I only tried RS60, N555 and N565 with 180gr in 284win...
if you dont have long freebore to have a lot of room for powder, I would go with N160.

 

[Steel head]

I doubt it won’t burn completely, in fact I’m guessing it’s a burnt well before the end of barrel.
N165 is a nice alternative to H4831 which is a classic 284 powder.
N165 definitely isn’t a speed demon powder.
I use it in my 7 saum successfully as well.

 

[hattori.hanzo]

I doubt it won’t burn completely, in fact I’m guessing it’s a burnt well before the end of barrel.
N165 is a nice alternative to H4831 which is a classic 284 powder.
N165 definitely isn’t a speed demon powder.
I use it in my 7 saum successfully as well.

Thanks for your reply. But is it also for just 28 inch of barrel a good choice?

 

[Steel head]

Thanks for your reply. But is it also for just 28 inch of barrel a good choice?

Yes
I highly recommend you search in the F class forums tons of data on n165 in the 284

 

[hattori.hanzo]

Yes
I highly recommend you search in the F class forums tons of data on n165 in the 284

They are heavily using this but as far as I can see with much longer barrels.

If I put all data into the calculator, I get more speed out of the 28 inch barel with N160. If I would have a longer barrel (around 32 inch), N165 then burns completely in the barrel and will produce more V0 than N160. But this is just math and no real numbers.

 

[Steel head]

30” inches isn’t much longer than 28”
Your overthinking it.

You should easily get 2750-2800ish with reasonable pressures and powder is all burned at about 20”
Uncork pressure is below 9K so extra barrel length is at the point of diminishing returns

Even my much bigger magnum burns all its much slower powder at 30” with considerably more powder.

F class competitiors like N165 because of its excellent fill ratio, stability and cool burning attributes.

 

[hattori.hanzo]

Thanks a lot for your help!