Possible to Interchange RN for RNFP?

[Scarlett Pistol]

Firearm
? My CZ pistol/rifle model is: CZ 75 Compact, SP-01, CZ 75 Compact w Rail (SP-01 Compact)
? The caliber of my CZ is:  9x19 Luger
? My CZ has the following changes:  Comptetition Hammers, CGW Internals, Lighter recoil springs when using lighter loads. The list will get long, and these don't seem to impact this question.
? I use this CZ in the following ways:  All, but in relation to this question the ammo is for practice and USPSA
? I want ammo accurate at:  When loaded up like I have in the components its for USPSA minor PF and accurate at any distance withing USPSA realms.

Components
? I've been reloading for months/years:  Casually for since 2011ish, Seriously since 2015
? Fully describe the maker, weight, and type bullet: Berry's Plated 124 gr RN and H&S coated 125 gr RNFP
? Powder (brand name and load range):  Alliant BE-86 between 5.6 gr and 5.7 gr
? Primer: S&B Small Pistol
? My Cartridge Over-All Length is:  aiming at 1.120", with results from 1.118 to 1.123


Reloading Equipment
? Press brand and type: Hornady AP
? Dies:  Hornady 9mm 3 die set
? Scale:  Franklin Armory digital scale
? Powder Measure: Hornady Case Activated Powder Drop
? Do you have access to a chronograph ?  No

Question Area
    I have been shooting Berry's 124 gr plated bullets at the load data listed above (which I got from the Alliant load data site, used the 125 gr Lead RN data). I am planning on purchasing some coated 125 gr RNFP bullets from a local company (H&S Bullets). There's no data for BE-86 for this exact bullet design. I was wondering if I can use RN data for RNFP?
    If possible, do I need to do some measurements of the RNFP to make sure the base of the bullet is seating at the same depth as the RN (creating the same case capacity)?
    For my own understanding, what is the point of RNFP VS RN designs? Does this change the shape so that bullets are shorter for the same weight, thereby changing the point where the taper to the nose starts? Does that mean RNFP can be seated deeper (within limits of the case design). Are they more accurate? Or is this the opposite benefit, and the RNFP allows the bullet to leave more case capacity when it is loaded with a longer OAL (within limits of plunk test or max OAL for 9mm luger)? Thereby allowing more velocity, or more of slower powders, sooner contact with the rifling? I may be asking stupid questions, but you all have so much knowledge and I want to understand every aspect of this I possibly can.

Here's the H&S bullets for a visual:
http://hsbullets.com/products/9mm-125gr-rn-356-diameter-1000-count
   

[painter]

You can use the data, but you'll need to adjust the OAL for the differing bullet lengths. Use the bullet length thread to calculate the difference.

The equation you'll be using is case length+ bullet length - OAL = seating depth. Similar seating depths with equal weight bullets will result in similar pressures and velocities.

[Scarlett Pistol]

You can use the data, but you'll need to adjust the OAL for the differing bullet lengths. Use the bullet length thread to calculate the difference.

The equation you'll be using is case length+ bullet length - OAL = seating depth. Similar seating depths with equal weight bullets will result in similar pressures and velocities.

Thanks Painter! On Alliant's site it just says 125 gr Lead RN. There isn't mention of the brand of bullet... Thereby I can't get the bullet length for the equation you shared. Should I call Alliant or what would be the recommended procedure for dealing with this lack of information?
http://www.alliantpowder.com/reloaders/powderlist.aspx?page=/reloaders/powderlist.aspx&type=1&powderid=38&cartridge=23

[painter]

You can use the data, but you'll need to adjust the OAL for the differing bullet lengths. Use the bullet length thread to calculate the difference.

The equation you'll be using is case length+ bullet length - OAL = seating depth. Similar seating depths with equal weight bullets will result in similar pressures and velocities.

Thanks Painter! On Alliant's site it just says 125 gr Lead RN. There isn't mention of the brand of bullet... Thereby I can't get the bullet length for the equation you shared. Should I call Alliant or what would be the recommended procedure for dealing with this lack of information?
http://www.alliantpowder.com/reloaders/powderlist.aspx?page=/reloaders/powderlist.aspx&type=1&powderid=38&cartridge=23

Without all the info...

between a RN and Flat Point...

I'd subtract .050 from the OAL, based on the info in this thread and start at starting load using my chrono to see where I was at.

[1SOW]

What is the diameter of the coated bullet,  .356, .357 or ?
If the diameters are are about the same as the BRY plated and the seating depth is the same,  then starting again at the low end and work up is a reliably safe method.  Using lead load data may be needed if the new bullet diameter is greater.
All this is just my opinion.

[Scarlett Pistol]

What is the diameter of the coated bullet,  .356, .357 or ?
If the diameters are are about the same as the BRY plated and the seating depth is the same,  then starting again at the low end and work up is a reliably safe method.  Using lead load data may be needed if the new bullet diameter is greater.
All this is just my opinion.

Diameter is .356 so I'll use the lead data for sure.

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[copemech]

That ogive looks odd to me. Start over, do your push test, calculate your seating depth.

[Scarlett Pistol]

In the hodgedon online load data for 700X the lead bullets don't have what companies manufactured the bullets. It simply shows LCN for the lead conical nose or LRN. In the list we have on our forum there seems to be a decent amount of variance in bullet lengths for the coated round nose bullets. All this variance in lengths and shapes makes this difficult without knowing the bullet manufacturers or bullet lengths in lead load data. Why are the load data for lead bullets like this? Should I just find a more normal looking round nose coated bullet or is this easier to deal with than it appears?

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[Wobbly]

? What started my whole trip into the world of CZ pistol chambers, fitting new types of bullets, and indeed the Push Test as we now practice it was a RNFP from Zero. That particular bullet, due to it's blunter ogive, gave me a Max OAL of something like 0.990 using the Push Test. [Less than the magic minimum of 1.000" !!] They looked like this...



Even though the H&S don't look to be as blunt, I would say that the first thing to do is NOT to buy any of these bullets, but to get 3 or 5 samples sent to you for measurement. I ended up trading ~985 of the Zero bullets at a substantial loss, simply due to their unworkable shape.

? Once you had the bullet in-hand, you could use the length and proposed OAL to determine a bullet seating depth. Bullet seating depth may limit your brass selection. For mixed brass don't go over 0.200" in depth.

? Yes, you could use any published 124gr load data for LEAD, that correlated to the same or deeper seating depth. When no specific bullet is stated in the data, then cast around for alternate load data. Failing that, strictly adhere to the Starting Load along with using a chrono.


As an aside... New reloaders will find it interesting to note that the Berry 124gr pictured above will allow a full 1.169" OAL , while the Zero 124gr loads at a Max OAL of 0.990". Study the two ogives and see exactly how little change it takes to be forced from a maximum length to a minimum length. This is why we suggest the Push Test to be done on every new bullet. A photo on a web page is not always enough to discern a viable reloading candidate for the CZ pistol.


Whether you could use the bullet or not, it would end up being a very educational exercise for you as a reloader. Go for it, with the caveat mentioned.

 

[Scarlett Pistol]

Thanks everyone! I'll go pick some up to test out and see what happens. I'll also try giving Alliant a call and see if they have the bullet length for their LRN they used.

[IDescribe]

With jacketed and plated bullets, it's common for RN bullets to load out to 1.169 in even a CZ and end up with a seating depth of .170-.190.  Then with jacketed or plated HP or FP, they often push test to something much shorter in a CZ -- 1.07-1.09, and then end up seated much deeper -- maybe .230-.260.  So when you are dealing with jacketed and plated, and you are forced to use load data for a bullet of the same weight but a different profile, it's wise to account for anticipated differences in seating depth as best you can.

With lead, it seems to be a little different.  Lead RN profiles are usually a little squatter than jacketed and plated RN profiles.  I can check my data later, but in my head, most of my lead bullets, plunk tested in a CZ for maximum OAL, tend to fall into the same seating depth range of .230-260, regardless of profile, even the lead RN.  With lead, I would verify that my depth weren't extraordinarily deep, but as long as seating depth was typical, I'd use LRN data for an LRNFP, and trust starting load to cover me.

I'll check data later and make sure I'm not misleading you.

[IDescribe]

Here are four 124/125gr lead bullets plunked in my CZ, listed at their working OAL, which is maximum minus .007 - .018, depending on bullet:

Blue 125gr RN | OAL 1.10 | SeatDepth .220
Bayou 124gr TCG | OAL 1.07 | SeatDepth .240
BBI  125gr RN | OAL 1.10 | SeatDepth .246
ACME 125gr RN | OAL 1.06 | SeatDepth .258


The odd one  out here is the Blue RN, which is unusually shallow, but also noteworthy is the Bayou TCG, which is really a truncated cone flat point, and it seats shallower than two of the RN, though they are all in the same ballpark.

So again, as long as my seating depth with a new RNFP were in the same range as the rest, I would feel comfortable trusting starting load for whatever 124gr lead profile.

I think, as Wobbly suggested, the first thing you need to figure out is how deep this seats at your max plunk.

[Scarlett Pistol]

Picked up a test pack of 100 for $7 during lunch. I'll have time tomorrow to do some plunk testing, measuring, and reloading. I'll post some pics comparing to Berry's once I'm working on it.

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[Wobbly]

Picked up a test pack of 100 for $7 during lunch. I'll have time tomorrow to do some plunk testing, measuring, and reloading. I'll post some pics comparing to Berry's once I'm working on it.

Be sure and report the bullet data to 1SOW for his data collection.

[Scarlett Pistol]

Picked up a test pack of 100 for $7 during lunch. I'll have time tomorrow to do some plunk testing, measuring, and reloading. I'll post some pics comparing to Berry's once I'm working on it.

Be sure and report the bullet data to 1SOW for his data collection.

I definitely will!

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