Vihtavouri N340 for 40 S&W, please help with load data

[Damon Larsen]

Hey guys, can anybody here help me out with what data Vihtavouri is giving for 40 S&W? Using N340 powder.

My main thing is, I’m using RMR 180gr. FMJ’s. The closest thing I can find to that listed on Vihtavouri’s load data is “Fiocchi LTC“. Other than that, there is Speer HP, but not using hollow points obviously.

Should I go off the Fiocchi LTC data???

Thank you all in advance

 

[Dudedog]

Looks like you have the data from VV already,
This may just muddy the waters but
Lyman 50 shows
Sierra 180 JHP VV N340 1.115 OAL
Start 5.4gr 904 FPS 20800 CUP
MAX 6.0gr 1015 FPS 23100 CUP

For a 175 Jacketed Silvertip @ 1.125 Lyman shows
Start 5.4 gr 891 fps 20600 CUP
MAX 6.0gr 1004fps 23000 CUP

VV data shows 4.6 to 5.2 so lower than Lyman, VVs MAX with the LTC is lower than Lymans start charge with the Sierra..
I am scratching my head looking at the Lyman numbers as they show the same charge range 5.4 to 6 for N350 with the Sierra 180

For a lead 175 Lyman shows
N340
Start 4.8, MAX 5.4 closer in line to VVs numbers
I don't load .40 but since VVs data looks lower I would be temped to use it and work up carefully.

Hopefully someone has loaded the RMR 180 with N340 and will reply.

 

[Blue68f100]

Looks like your comparing Lead (LTC) to a Jacketed bullet. The load data is going to be lighter charge. The Sierra data posted should get you close. Start low and work up.

 

[Dudedog]

Ah VV does not say what LTC is but if Lead truncated cone then VVs data is in line with Lymans lead data.
(didn't think about VVs data being for a lead bullet)

 

[Damon Larsen]

Looks like you have the data from VV already,
This may just muddy the waters but
Lyman 50 shows
Sierra 180 JHP VV N340 1.115 OAL
Start 5.4gr 904 FPS 20800 CUP
MAX 6.0gr 1015 FPS 23100 CUP

For a 175 Jacketed Silvertip @ 1.125 Lyman shows
Start 5.4 gr 891 fps 20600 CUP
MAX 6.0gr 1004fps 23000 CUP

VV data shows 4.6 to 5.2 so lower than Lyman, VVs MAX with the LTC is lower than Lymans start charge with the Sierra..
I am scratching my head looking at the Lyman numbers as they show the same charge range 5.4 to 6 for N350 with the Sierra 180

For a lead 175 Lyman shows
N340
Start 4.8, MAX 5.4 closer in line to VVs numbers
I don't load .40 but since VVs data looks lower I would be temped to use it and work up carefully.

Hopefully someone has loaded the RMR 180 with N340 and will reply.

Thank you very much! I’ll look in to this!

 

[Damon Larsen]

Looks like your comparing Lead (LTC) to a Jacketed bullet. The load data is going to be lighter charge. The Sierra data posted should get you close. Start low and work up.

Ok, so a lead bullet is going to have less, or more of a charge than a FMJ?

 

[Damon Larsen]

Ah VV does not say what LTC is but if Lead truncated cone then VVs data is in line with Lymans lead data.
(didn't think about VVs data being for a lead bullet)

I looked up Fiocchi LTC’s...they almost look like a plated bullet. I don’t know..

 

[Dudedog]

Lead pistol bullets tend to have lower charges than jacketed, not a hard and fast rule.but yes in general.

 

[Damon Larsen]

Lead pistol bullets tend to have lower charges than jacketed, not a hard and fast rule.but yes in general.

Good to know, thank you. I’m fairly new to reloading, so it’s much appreciated

 

[LiveLife]

LTC is Lead Truncated Cone and you shouldn't have much issue referencing lead load data for your jacketed bullet - https://www.vihtavuori.com/reloading-data/handgun-reloading/?cartridge=44

• 40S&W 180 gr Fiocchi LTC N340 COL 1.126" Start 4.6 gr (948 fps) - Max 5.2 gr (1034 fps)

We can also reference load data for slightly heavier bullet. VihtaVuori load data lists 200 gr Speer TMJ which is a thick plated bullet that can be driven to jacketed load data.

• 40S&W 200 gr Speer TMJ N340 COL 1.126" Start 4.6 gr (876 fps) - Max 4.9 gr (910 fps)

VV data shows 4.6 to 5.2 so lower than Lyman, VVs MAX with the LTC is lower than Lymans start charge with the Sierra.

I am scratching my head looking at the Lyman numbers as they show the same charge range 5.4 to 6 for N350 with the Sierra 180

I wondered the same as Lyman start charge is also Hodgdon max charge but found out that may be due to Lyman using .401" groove test barrel instead of more typical .400".

OP, after cross referencing Lyman load data Dudedog posted, I would reference VihtaVuori LTC load data for your powder work up with FMJ bullet.

Keep in mind that Lyman used larger .401" groove diameter test barrel for their testing instead of more typical .400" and tend to have higher start/max charges than other published load data from powder manufacturers like Hodgdon/VihtaVuori who likely used more typical .400" test barrels - https://www.thehighroad.org/index.php?threads/powder-recommendations-for-40s-w.869086/#post-11516903

So slug your barrel and if groove diameter is .401", consider using Lyman data but if your groove diameter is .400", I would reference more conservative load data.

 

[Damon Larsen]

LTC is Lead Truncated Cone and you shouldn't have much issue referencing lead load data for your jacketed bullet - https://www.vihtavuori.com/reloading-data/handgun-reloading/?cartridge=44

• 40S&W 180 gr Fiocchi LTC N340 COL 1.126" Start 4.6 gr (948 fps) - Max 5.2 gr (1034 fps)

We can also reference load data for slightly heavier bullet. VihtaVuori load data lists 200 gr Speer TMJ which is a thick plated bullet that can be driven to jacketed load data.

• 40S&W 200 gr Speer TMJ N340 COL 1.126" Start 4.6 gr (876 fps) - Max 4.9 gr (910 fps)

I wondered the same as Lyman start charge is also Hodgdon max charge but found out that may be due to Lyman using .401" groove test barrel instead of more typical .400".

OP, after cross referencing Lyman load data Dudedog posted, I would reference VihtaVuori LTC load data for your powder work up with FMJ bullet.

Keep in mind that Lyman used larger .401" groove diameter test barrel for their testing instead of more typical .400" and tend to have higher start/max charges than other published load data from powder manufacturers like Hodgdon/VihtaVuori who likely used more typical .400" test barrels - https://www.thehighroad.org/index.php?threads/powder-recommendations-for-40s-w.869086/#post-11516903

So slug your barrel and if groove diameter is .401", consider using Lyman data but if your groove diameter is .400", I would reference more conservative load data.

Sorry for the late reply, but I ended up starting with the max load of N340 at 5.2 gr. since the only data was for lead or LTC and I’m running 180 FMJ. It was exact to a factory load that I fired before running my test loads. Burned perfectly, nice and clean!! Got lucky on the first try, and that rarely happens with me. Lol!! Really appreciate your reply, and wanted to give you some feedback.

 

[fxvr5]

I wondered the same as Lyman start charge is also Hodgdon max charge but found out that may be due to Lyman using .401" groove test barrel instead of more typical .400".

OP, after cross referencing Lyman load data Dudedog posted, I would reference VihtaVuori LTC load data for your powder work up with FMJ bullet.

Keep in mind that Lyman used larger .401" groove diameter test barrel for their testing instead of more typical .400" and tend to have higher start/max charges than other published load data from powder manufacturers like Hodgdon/VihtaVuori who likely used more typical .400" test barrels - https://www.thehighroad.org/index.php?threads/powder-recommendations-for-40s-w.869086/#post-11516903

So slug your barrel and if groove diameter is .401", consider using Lyman data but if your groove diameter is .400", I would reference more conservative load data.

What data do you have that either velocity or pressure is affected by a difference of 0.001" in barrel diameter?