.243 87GR with N550???

Beretta shooter

Well-Known Member
Evening folks, I currently use Sierra 100GR PHs with N550 in my .243 for pretty much everything but I’m thinking about developing a Fox only round for using at night with my drone pro but struggling to find any load data, so I was wondering if anyone has any load data on Hornady 87GR VMax combined with N550?

Many thanks BS
 

Marcher

Well-Known Member
Load data off the internet is not to be trusted without personal verification. BUT you can sometimes get a Lead that saves lots of experimentation.
I don't have the info you need, but do have some info that might lead you in that direction. I have recently started using Vit N 550 because IMR 4350 became unavailable. I load 95 gn Partitions (243) with 41.0 gns N 550 and get 2878 fps, So, what you are looking for, is possible.
 

Beretta shooter

Well-Known Member
Load data off the internet is not to be trusted without personal verification. BUT you can sometimes get a Lead that saves lots of experimentation.
I don't have the info you need, but do have some info that might lead you in that direction. I have recently started using Vit N 550 because IMR 4350 became unavailable. I load 95 gn Partitions (243) with 41.0 gns N 550 and get 2878 fps, So, what you are looking for, is possible.
Hi Marcher,
I’m not so much looking for load data off the internet more if someone has some load data from a manual with n550, min/max loads COAL etc etc . I wouldn’t dream of taking a load that works in someone else’s rifle and trying it in mine as we all know that just because it’s safe in theirs dosnt mean it will be in mine. I’m looking to work up my own load, I’m just looking for a starting place from a manual.

Thanks BS
 

andychas

Well-Known Member
Evening folks, I currently use Sierra 100GR PHs with N550 in my .243 for pretty much everything but I’m thinking about developing a Fox only round for using at night with my drone pro but struggling to find any load data, so I was wondering if anyone has any load data on Hornady 87GR VMax combined with N550?

Many thanks BS
I use the 87gn vmax as a foxing load over 43.5gn of N160, highly accurate trundling along at around 3100, and very emphatic performance. Clearly exact details will be dependent on your rifle but looking at both Lee and Hornady (neither of which list 550 with 87gn vmax specifically) theres an approximate window of between 36 and 41.4gn of 550 with slightly heavier 90gn bullets so start low and work up, you should find a load in there somewhere if you want to use 550. Hornady list their tested COL as 2.640.
 

Beretta shooter

Well-Known Member
Have a look at the Vit website, it’s free
I already did and they don’t list a 87GR bullet, my lee manual dosnt list any Vihtavuori powder for an 87GR bullet either and the Hornady data I have dosnt list any load data for Vihtavuori powder, so......... hence my asking on here.
 

Beretta shooter

Well-Known Member
I have to say that I too use N160 in my 243, very good
I don’t mind buying another tub of powder if it’s going to work better or make life easier, it was more the lack of data for Vihtavuori that was concerning me but I presume people are just using the 90GR data as a starting point?
 

Cottis

Well-Known Member
I don’t mind buying another tub of powder if it’s going to work better or make life easier, it was more the lack of data for Vihtavuori that was concerning me but I presume people are just using the 90GR data as a starting point?
Using the next bullet weight up that most applies to your chosen Vmax (length, surface bearing area etc) would be the way forward.

N550 will work fine. I too use N160 for the heavier bullets in the .243 but if you have N550, you might as well try it. I have not used the 500 series as I worry about premature barrel wear etc but no reason why it shouldn't be fine, especially with a moderate load.

I would be starting around the 38 grain mark if I were using that bullet and powder.
 

Beretta shooter

Well-Known Member
Using the next bullet weight up that most applies to your chosen Vmax (length, surface bearing area etc) would be the way forward.

N550 will work fine. I too use N160 for the heavier bullets in the .243 but if you have N550, you might as well try it. I have not used the 500 series as I worry about premature barrel wear etc but no reason why it shouldn't be fine, especially with a moderate load.

I would be starting around the 38 grain mark if I were using that bullet and powder.
Perfect, thanks for that. I was recommended to give N550 a try with the 100GR pro hunters and to be fair they certainly do the business. Barrel wear dosnt concern me to much if I’m honest as I don’t shoot a huge amount of rounds in a year but if the barrel was to need changed it’s a great excuse for an upgrade ;)
 

Sonicdmb73

Well-Known Member
I have bought N550 as I have run out of H4350 and it seemed the best choice from easily available powders.
The Vihtavuori app shows this for weights above and below. 0A3881E5-73BD-490B-96DE-08C2CABE1E37.pngDA336C04-7198-4585-A042-01B0B8291C5D.png
 

royr

Well-Known Member
Afternoon Beretta Shooter,
This may help?

243-Win. Saami Max @ 60000psi

There are a couple of powders that would be slightly better suited for 87gn V-Max, but overall N550 *C is pretty good choice!

N550 *C, 87gn V-Max. OAL 2.665" (bullet seated to 0.409") Bullet jump to lands (freebore?) approx. 0.030" - 0.035"
Case trim length @ 2.035". Used case capacity estimated @ 54gns

N550 *C = 42.7gns @ 91% case fill; pressure 50400psi @ 99.3% powder burnt in 23inch barrel; predicted MV speed @ 3260fps @ 2064ft pds
N550 *C = 43.7gns @ 93% case fill; pressure 53700psi @ 99.68% powder burnt in 23inch barrel; predicted MV peed @ 3340ps @ 2153ft pds

JB Miller Giroscopic stability is good to 800yards+, with 1-10 twist rate.

Regards
RoyR
 
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Beretta shooter

Well-Known Member
Afternoon Beretta Shooter,
This may help?

243-Win. Saami Max @ 60000psi

There are a couple of powders that would be slightly better suited for 87gn V-Max, but overall N550 *C is pretty good choice!

N550 *C, 87gn V-Max. OAL 2.665" (bullet seated to 0.409") Bullet jump to lands (freebore?) approx. 0.030" - 0.035"
Case trim length @ 2.035". Used case capacity estimated @ 54gns

N550 *C = 42.7gns @ 91% case fill; pressure 50400psi @ 99.3% powder burnt in 23inch barrel; predicted MV speed @ 3260fps @ 2064ft pds
N550 *C = 43.7gns @ 93% case fill; pressure 53700psi @ 99.68% powder burnt in 23inch barrel; predicted MV peed @ 3340ps @ 2153ft pds

JB Miller Giroscopic stability is good to 800yards+, with 1-10 twist rate.

Regards
RoyR
That’s perfect RoyR, many thanks for that it’s very much appreciated!
I’m presuming the official guide lines would be to start at 10% bellow max (43.7GR) at 39.3GR and work my way up checking for pressure signs etc?

Many thanks BS
 

royr

Well-Known Member
Morning Beretta Shooter,
39.3 grains would give a predicted pressure of just 39,700psi, for me that's a bit too low! Too low a pressure can give unreliable results.
41.2grains gives predicted pressure of 45,400psi, that's where I'd be starting. As a "rule of thumb" starting to develop a load I go for an initial predicted pressure of about 3/4 of SAAMI Max.
With 243 @ SAAMI 60,000psi max, then 45,000psi would be my initial starting point. Likewise 223 @ SAAMI 55,000psi max, then 41,500psi would be initial starting point.
If I do not encounter Over Pressure signs, then I stop increasing load when at 10% below max PSI pressure, i.e. 54,000psi and 49,500psi respectively on the above the examples. I believe this 10% buffer gives me a margin of safety that is acceptable; other's opinions may differ.

Maximum bullet velocity FPS, and best down range MOA accuracy are rarely found within one load; usually two slightly different loads are needed, all depends on your personal requirements, hunting or target shooting?

NB. Do not forget about the JB MILLER gyroscopic stability factor - JBM - Calculations - Stability - If a bullet is tumbling there is no consistent accuracy!

Regards
RoyR
 
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Beretta shooter

Well-Known Member
Morning Beretta Shooter,
39.3 grains would give a predicted pressure of just 39,700psi, for me that's a bit too low! Too low a pressure can give unreliable results.
41.2grains gives predicted pressure of 45,400psi, that's where I'd be starting. As a "rule of thumb" starting to develop a load I go for an initial predicted pressure of about 3/4 of SAAMI Max.
With 243 @ SAAMI 60,000psi max, then 45,000psi would be my initial starting point. Likewise 223 @ SAAMI 55,000psi max, then 41,500psi would be initial starting point.
If I do not encounter Over Pressure signs, then I stop increasing load when at 10% below max PSI pressure, i.e. 54,000psi and 49,500psi respectively on the above the examples. I believe this 10% buffer gives me a margin of safety that is acceptable; other's opinions may differ.

Maximum bullet velocity FPS, and best down range MOA accuracy are rarely found within one load; usually two slightly different loads are needed, all depends on your personal requirements, hunting or target shooting?

NB. Do not forget about the JB MILLER gyroscopic stability factor - JBM - Calculations - Stability - If a bullet is tumbling there is no consistent accuracy!

Regards
RoyR
Thanks RoyR
That all makes perfect sense to me and sounds like a perfectly good safety margin to run, I think what I’ll do is load 1 round at 41.2GR , fire it checking for pressure signs and if all good I’ll start working up from there.

Thanks again BS
 

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