VV N310 question (2)

I need to replace Bullseye powder with N310 for my .45ACP pet loads.
 
I just can't find reloading data listing both powders with comparable velocities, so I don't know where to start.
 
For example, my long line load is 3.8 gr Bullseye with a 200 gr HiTek SWC bevel base bullet. I chrono'd those around 740 fps.
Starting loads for a lead bullet (is a lead bullet the closest match to a HiTek coated bullet in reloading data?) in Lee's Modern Reloading is 4.0 grains Bullseye (720 fps in the book) / 3.7 gr N310 (827 fps).
 
My second load is for the short line : 4.2 gr Bullseye with a 160 gr HiTek BNSWC flat base bullet (clocked around 810 fps).
 
Could you please help me with suggestions on what amounts of N310 should be on par with my Bullseye loads ?

I don’t shoot the same Bullets but one is close
My long line is 185 Zero JHP and 4.5 I was told this is the AMU load. I didn’t know that when I worked it up. I tried several different loads and in fact 4.5 was hands down the best. Holds X in my 1911 at 50
My short line in 200 Zero SWC and 3.8. This holds a big one hole at 25

Speed with 185 is 791 10 shot Avg 
Speed with 200 is 702 10 shot Avg

I use a 17lbs main spring and a 14 lbs recoil

It has been my experience that bullseye loads can’t be found in a book

Some will chime in and say N310 and lead are not the best partners but with the loads I use I do not get any leading whatsoever and I only clean my 1911 a couple of times a year

If I were you I'd try 3.7-4.0 gr N310 under the 200 gr SWC.  That Lee velocity info looks a little whacked.

Go direct to the source

https://www.vihtavuori.com/reloading-data/handgun-reloading/?cartridge=52

From the looks of it 3.9 is a good starting load with a 200 grain.  IIRC N310 will “down load“ without issue so you could try 3.7 as well as 3.9.

185 JHP with a load of 4.1gn n310 or 3.8gn of Bullseye shot similar speeds in some testing I did a while back. 

I tested some other loads as well with different crimps and OAL, but in general I found that in this 3.5-4.5gn range, about 8-10% higher load of n310 will get you close to Bullseye.

I trust the “by the book” charts very little, as everyone kinda makes their own bullet so they will all be a bit different.  So without an actual test, how do you know?  Even our chronographs will not agree.  

I do trust shooting my bullets, from my gun, through my chrono, at the same testing session.  The results may not match yours, but at least my own results will all be relative to each other!  

4.0 gr of N-310 with a 200 gr SWC is giving me 770 FPS from a 5” PII.

Link to Vihtavuori smart phone app— https://www.vihtavuori.com/resources/vihtavuori-reload-app/

apipeguy wrote:4.0 gr of N-310 with a 200 gr SWC is giving me 770 FPS from a 5” PII.

Link to Vihtavuori smart phone app— https://www.vihtavuori.com/resources/vihtavuori-reload-app/

I have and am shooting this load and I have chrono’d it multiple times always 700-710 FPS?? Wonder why yours is so much higher

Thank you gentlemen, that helps a lot !

James Hensler wrote:

apipeguy wrote:4.0 gr of N-310 with a 200 gr SWC is giving me 770 FPS from a 5” PII.

Link to Vihtavuori smart phone app— https://www.vihtavuori.com/resources/vihtavuori-reload-app/

I have and am shooting this load and I have chrono’d it multiple times always 700-710 FPS?? Wonder why yours is so much higher

I have no idea. Shooting Precision coated 200gr SWC using a LabRadar to chrono and my last test was shooting indoors in about 68 degrees with a 20 shot test. Not sure when I can get out again to retest the load. The Vihtavuori app shows 4.0 gr with a 200 SWC @ 823.

I have and am shooting this load and I have chrono’d it multiple times always 700-710 FPS?? Wonder why yours is so much higher

VV310 is a fast powder and very sensitive to case capacity after the bullet is seated (and sensitive to crimp some as well).  So any shorter overall length (more bullet base in case) or longer overall length (less bullet base in the case) will increase or decrease the velocity respectively.  Bullet caster use different moulds and there can be differences is the base length versus the nose length and nose diameters for SWC .45 bullets. 

For example I use 200 gr Oregon Trail SWC for long line and 180 gr Oregon Trail SWC for the short line.  The different bullets are seated exactly the same on the shoulder of the bullet and the overall length is very close to the same for both loads. The 200 gr load is faster than the 180 gr with the same powder charge since the 180 takes up less case space.

CR

Here's a test that the Marine Corps did with BE and N310.  From what I see, using about 10% less N310 as you would for BE gets you close to the same velocity.

https://servimg.com/view/19296309/48

As you can see, both jacketed and lead 185 gr. Zero bullets were used.

Asking the right people makes things so much easier!
Thanks a lot gentlemen.

I use 4.2g N310 with a 200g LSWC at 50yds; when checked on a ransom rest it put 8/10 bullets in 1".  I use Titegroup for short line.
My rule of thumb lately is Titegroup and Bullseye are roughly the same grains to push the same bullet mostly the same speed so if you see TG in a chart you can cross over.
The charts at the end of this article back up the 10% figure (3.9 grains N310 push a 185g bullet same as 4.2g of Titegroup or Bullseye, about 700fps).
https://www.shootingtimes.com/editorial/loads-for-the-bullseye-shooter/99418