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Vhitavuori N-120
Posted: Sun Sep 01, 2024 12:34 pm
by drone
I bought a Kg of this as it seems to be similar (in burn rate) to Rl7 which is all but unobtainable.
I intended it for use in cast loads for both 30/30 and 308 but some advice I've been given says it gives significantly higher pressures than Rl7.
I have a whole range of cast boolits going from 120 rrn gc, 150 grain powder coated, 165 grain gc and 175 grain gc and wonder if anyone has any experience, good or bad to top up the blanks in my memory.
Re: Vhitavuori N-120
Posted: Sun Sep 01, 2024 12:42 pm
by drone
FWIW I have some lapua123 grn fmj which Vhita give a load for but I have some N-133 coming for that bullet and also have significantly more n-140 and n-150 amongst others that will give reasonable velocity without worrying me unduly but I have planned other uses for them. I'm also not a speed freak as most of my plinking is at 100 yards and less.
Re: Vhitavuori N-120
Posted: Sun Sep 01, 2024 2:35 pm
by dromia
Re: Vhitavuori N-120
Posted: Sun Sep 01, 2024 2:41 pm
by dromia
Pressure depends on the load regardless of powder.
You cannot use data for one powder with another powder no matter how close they may appear in burning rate charts.
However burning rate comparison can be helpful in giving a starting point for working up a safe load.
A read of this should be helpful in working up loads safely.
https://www.full-bore.co.uk/viewtopic.php?t=8480
Re: Vhitavuori N-120
Posted: Sun Sep 01, 2024 4:33 pm
by Mauserbill
Hello
Thanks Dromia, excellent information, keep it coming shooters, just had an outing with Schmidt Rubin K31 147grn FMJ at 100m starting point using N110. All good very accurate cases/primers showing no over pressure signs a very pleasant loading in fact. "Vit N110 was a very clean burning powder" seems to be very similar to 2400 in its characteristics.
Re: Vhitavuori N-120
Posted: Sun Sep 01, 2024 9:23 pm
by drone
Dromia, many thanks for that, I used Harris's article as a base for my experimentation with cast and low velocity loads in both my 308 and 30/30 without any issues until I got magtech LR primers then the shtf and they started top hatting which had a fairly high pucker factor I switched back to S&B lr and there was no issue .
When I looked at the 308 brass, they were GGG match 7.62 with a circular crimps that I'd probably (like definitely) removed too much brass and giving the primer cup somewhere to flow. 30/30 were a mix but not so badly affected ie visible with a magnifying glass but not, as the 308s, to the naked eye.
I subsequently found that magtech would deform with light loads of regular powders and jacketed or mono bullets in these cases but not in my other cases eg Federal and GSL. I bought a 100 308 peterson srp cases and they are now fine and I've sorted all my cases and retained the GSL and Peterson brass but scrapped the rest, some because they had multiple loads through them and the GGG so that I don't have to worry about them. I've upgraded my 30/30 brass all to either winchester, hornady or federal ( I had quite a cache of factory ammo and got gifted 100 winchester new brass)
Back to the original point I was raising re n-120. I noticed one of your posts referred to the length of time that you'd used both n110 and n120 for cast loads in military calibers and this piqued my interest.
I'm looking to get between 1800 and 2000 fps as all the boolits are about 20 - 22 BHN with gas checks except the 150s which are powder coated.
If, after next weekend, I still have my eyes and fingers I'll post up how things went.
FWIW, I didn't dump the 30/30 brass, I just annealed them and necked them down to 22 savage for my model 1899.
Re: Vhitavuori N-120
Posted: Mon Sep 02, 2024 4:02 am
by dromia
Please give your pressure tested printed data sources for these loads.
Self developed loads without data are not allowed, what works for you may not work for someone else.
https://www.full-bore.co.uk/viewtopic.php?t=39540
Re: Vhitavuori N-120
Posted: Tue Sep 03, 2024 8:52 am
by dromia
drone wrote: ↑Sun Sep 01, 2024 9:23 pm
Dromia, many thanks for that, I used Harris's article as a base for my experimentation with cast and low velocity loads in both my 308 and 30/30 without any issues until I got magtech LR primers then the shtf and they started top hatting which had a fairly high pucker factor I switched back to S&B lr and there was no issue .
When I looked at the 308 brass, they were GGG match 7.62 with a circular crimps that I'd probably (like definitely) removed too much brass and giving the primer cup somewhere to flow. 30/30 were a mix but not so badly affected ie visible with a magnifying glass but not, as the 308s, to the naked eye.
I subsequently found that magtech would deform with light loads of regular powders and jacketed or mono bullets in these cases but not in my other cases eg Federal and GSL. I bought a 100 308 peterson srp cases and they are now fine and I've sorted all my cases and retained the GSL and Peterson brass but scrapped the rest, some because they had multiple loads through them and the GGG so that I don't have to worry about them. I've upgraded my 30/30 brass all to either winchester, hornady or federal ( I had quite a cache of factory ammo and got gifted 100 winchester new brass)
Back to the original point I was raising re n-110. I noticed one of your posts referred to the length of time that you'd used both n110 and n120 for cast loads in military calibers and this piqued my interest.
I'm looking to get between 1800 and 2000 fps as all the boolits are about 20 - 22 BHN with gas checks except the 150s which are powder coated.
If, after next weekend, I still have my eyes and fingers I'll post up how things went.
FWIW, I didn't dump the 30/30 brass, I just annealed them and necked them down to 22 savage for my model 1899.
Firstly Those loads (removed as no printed pressure tested data source provided) seems very high from my experience, I have never gone so high and especially with N110.
I would not rely on pressure predictors especially with the to be honest nigh on over the top loads you are proposing.
Secondly 20-22 BHN is far to hard and brittle for cast bullets unless you have perfect bullet fit, also I find gas checks unnecessary for such middling velocities.
Re: Vhitavuori N-120
Posted: Tue Sep 03, 2024 9:56 am
by drone
Thanks for the heads up, I have to be honest, I'm having a rethink as I have a large number of 308 cal bullets that I'll use up before going back down this rabbit hole.The only problem is that they are all various, couple of 100 tsx, 100 or so 180 sp and about 100 smks in 168 grn.
I have enough n140 and n150 to load all those and the old vhitavuori website also has some published loads for 30/30 using 130 and 150 grn bullets using the n120 so I can use that there.
Thanks to all for interest and comments.
FWIW I use
https://www.p-max.uk/ a free predictor and I post it with the following caveat, measure the powder space accurately FOR EACH BULLET you load also for each brand of case, using the methodology highlighted in the instructions. I have found that such data matches Vhitavuori's data within 1% of the velocity in my experience.
As my magnetospeed rarely coincides with Vhit data by anything up to 4 or 5% I assess the outcome as a very good approximation. but it is just that, an approximation.