Hello from Scotland~

I've been playing with N133 in my .444 Marlin with 300 grain plus cast gas checks bullets. It became apparent that N133 is listed in the "WRONG" place on burn rate charts many listing it close to IMR 4198
Experince has shown it to be much slower.......

I have recently bought a .218 Bee and N133 while accurate is too bulky for this small case and lack of space meaning it is simply not possible to get enough in to produce good velocities.

I've been looking at N120 as a possible alterative......BUT as ive learnt burn rate charts cant be trusted and i think N120 may be slighty faster than i require.

N130 is now being looked at........

Out of interest 45 gn of N133 with the Lee 310 gn cast bullet produces 1840 f.p.s with very little variation and is very clean.

Im looking for the "N" powder closest to IMR 4198 any thoughts from you V V powder uses ?? Im looking for "experince" NOT burn rate chart info !

Englander

I tried N-120 and N-130 in my 444. I wound up buying the big jug of N-130 because the difference between them seemed negligible and the N-130 had more uses in the stuff I reload. HTH

Tom

I've just about finished an 8-pound jug of N120. It appears to be equivalent burn rate to IMR 4227 in 30-06 (.303 Brit, 8x57, and few other 30's) with cast boolits. I've burned ALOT of 4227 over the years. Can't comment on N130, never used it. sundog

Depends on bullet weight.

In my 222rem N120 was superlative with 40gr but N133 was better with 55gr.

In the powder burn rate chart I compiled http://stevespages.com/powderrates.html
I have:

N-120 listed as 107
IMR-4198 listed as 112
N-133 listed as 126

(Slower to faster)

As for "relative burn rates", everything is a factor! The variation in "relative burning rates" varies not only by manufacturer, year and which way the wind is blowing, but also by the capacity of the case you are loading that powder in, the type of primer you are using, and the weight of bullet which is sitting on top of that primer and powder.

Not only that, but it also depends on how much powder you are loading.

Now add all that togther, and then confuse the matter even more because each lot number of the same powder, from the same manufacturer, will have a different burning rate!