Coated Conical, N320, and Short OAL Question

[d3ydx3]

Hey guys,

 

I recently picked up some 125gr Truncated Cone .356 bullets from Falcon Bullets. I've been into reloading for a few months now and have spent most of my time reloading 124gr RN Berrys @ 1.125 OAL w/ 4.0gr of N320. The conical bullets are a bit different to load than I anticipated. Right off the bat, I went with my previous RN OAL of 1.125 and that failed my case gauge, as well as failing the plunk test in my BUL Armory 2011 9mm. Looks like the BUL barrels run pretty tight against the SAAMI specs just like CZ does. I sat out to figure out the max OAL that would pass my case gauge and plunk OK. Looks like I'm going to end up somewhere around 1.07 - probably 1.06 for comfort since I'm working with mixed brass. I'm going to work up loads starting at 3.6 to 3.8, and 4.0 and see where that gets me - ideally, somewhere around 133-135PF. It also looks like that I may be compressing the charge slightly at 4.0. Anything that I should be worried about? Also, does this OAL seem normal for longer 125gr conicals?

 

Another issue that I'm running into as well is the fact that I'm scraping the coating slightly above the lube groove. Is this a big deal? I did some research and adjusted my flare/bell to 0.2 since I normally do 0.1 with my plated RN bullets. That helped a bit, but there is still some scraping during seating especially if the bullet is slightly off center. For reference, I'm using the 4-die 9mm Lee set w/ no U-die (U-die is on its way). I have confirmed that the scraping happens before I use the FCD set to a taper crimp. 

 

Here are some pictures of the bullets for reference, a bullet removed from a case after seating to show the scrape, as well as a test round @ 1.06 OAL. Let me know if you spot anything suspect.

 

https://imgur.com/a/f0UrHEy

 

Thanks!

Edited July 30, 2020 by pealandco

[4n2t0]

The scraping is no bueno (leading), more flare or seat them straighter. A MBF powder funnel or Lyman M die (depending on your setup) usually helps. Some also like the Hornady seater because it guides the bullet. I use Dillon dies on a 650 with a MBF powder funnel and it completely eliminated tip/tilt on my setup, YMMV.

 

Is 3.6gr to 4gr the lead data for N320? If not someone who uses N320 with coated lead should chime in shortly to help out with a charge range.

 

Short OAL's are fine. That's a pretty short OAL for a 125gr bullet but it's all about bullet profile. Only the barrel(s) should be used for determining the OAL of a particular bullet/barrel combo (don't forget the mags, if you're ever long). Check out this thread for more information:

 

 

Edited July 30, 2020 by 4n2t0

[d3ydx3]

28 minutes ago, 4n2t0 said:

The scraping is no bueno, either more flare or seat them straighter. A MBF powder funnel or M die (depending on your setup) usually helps. Some like the Hornady seater because it helps guide the bullet.

 

Short OAL's are fine and testing 3.6gr to 4gr will get the job done.

 

Yeah, that's what I was worried about on the scraping. I just tried a trick on my Lee bullet seater that I read elsewhere. Instead of screwing out 3 times, as Lee suggests in the manual, screw out 5 to 6 times, and it appears to help with the seating. Pulled a bullet and no scrapes! Will give it a few more tries and make sure it isn't a fluke.

[BJB]

1 hour ago, pealandco said:

..... I'm going to work up loads starting at 3.6 to 3.8, and 4.0 and see where that gets me - ideally, somewhere around 133-135PF. It also looks like that I may be compressing the charge slightly at 4.0......

 

If you're looking for a mid-130 power factor then you'll likely need 3.8 to 4.0 gr of N320 with a 125 gr coated depending on your barrel length. 

A little compression at 4.0 gr is no big deal with N320 at these 9mm minor velocities you're looking for.

 

[d3ydx3]

39 minutes ago, 4n2t0 said:

Is 3.6gr to 4gr the lead data for N320? If not someone who uses N320 with coated lead should chime in shortly to help out with a charge range.

 

Short OAL's are fine. That's a pretty short OAL for a 125gr bullet but it's all about bullet profile. Only the barrel(s) should be used for determining the OAL of a particular bullet/barrel combo (don't forget the mags, if you're ever long). Check out this thread for more information:

 

Yeah, 3.6-4 seems to be in the ballpark based on the other threads that I have seen for coated 125 conicals. As far as the OAL goes - yeah, I thought 1.06 was short, as well, which is why I wanted to create this thread. The Falcon Bullet 125 TC profile seems to be very similar to Hornady HAP, which I understand Hornady loads at factory around 1.06-1.07.

[d3ydx3]

As an update, I got to chronograph some loads today with the Falcoat 125gr TCN bullets & N320. This is mixed brass, so very happy with the numbers. I'll probably end up going 3.6 or 3.8 grains based on the data.