Is this math sound? (.223).

[BigMacMI]

I have worked a load for .223 that I like.

55g FMJ Winchester standard bullet
2.225" OAL
24grains H335
No chrono data.

I was gifted 400x Nosler 55g HP Varmint rounds.
HP rounds are 0.050" shorter (visually appears to just be cut off at the tip. Makes sense)

I could not find this load in my book. Nosler web site wasn't particularly helpful. (seem to all be tipped projectiles)

So, given my OAL was longer than min specified in lee manual (2.200) for my powder onthe FMJ (loaded to 2.225), I loaded the HP Nosler 0.050 shorter at 2.175".

Admittedly this is a bit shorter than many of the recommended lengths by Lee, but they do not list a HP in same bullet weight. I calculated that this would put the base of the bullet in the same orientation to the powder charge, giving same internal case volume as the FMJ round. I have loaded 10 of them to test. Plan to do a load test of 23, 23.5, 24, 24.5 as I did with my FMJ.

I am getting comfortable with loading/testing things i can easily find (read, common loads) to cross-reference and work from there. This is the first that is not 'by the book', so wanted to check my logic

 

[Walkalong]

So, given my OAL was longer than min specified in lee manual (2.200) for my powder onthe FMJ (loaded to 2.225), I loaded the HP Nosler 0.050 shorter at 2.175".

Admittedly this is a bit shorter than many of the recommended lengths by Lee, but they do not list a HP in same bullet weight. I calculated that this would put the base of the bullet in the same orientation to the powder charge, giving same internal case volume as the FMJ round. I have loaded 10 of them to test. Plan to do a load test of 23, 23.5, 24, 24.5 as I did with my FMJ

You'll be fine, and you are right to work it up again, although I wouldn't be surprised if you end up at the same charge weight for these.

 

[jmr40]

Starting load according to http://www.hodgdonreloading.com/data/rifle is 23 gr @ 3018fps. Max load is 25.3 gr @ 3203. You're right in the middle and should be fine and get around 3100 fps from a 24" barrel.

 

[rg1]

You should be ok with that very short oal but I'd say it's much too short. Your powder charges are in line with 55 gr. bullets in .223 Rem. A tip would be to set your bullet seater the same as your Win 55 gr. bullets then seat the Nosler HP. Measure the overall length. That should put the ogive of the HP bullet at the same point as the Win bullet. Just for info, Nosler tested all their 55 grain bullets, even the 55 HP at 2.260" which may be too long for your chamber. I wouldn't seat any 55 grain bullet, Spire Point, Hollow Point, or FMJ less than 2.200". For a bolt action rifle I think it's a good practice to find the maximum length of your chamber and what oal touches the rifling. Then back off .025-.050". Less maybe for a bench target rifle. For AR-15's the maximum that will fit in a magazine is 2.260" but I seat my longest bullets 2.250" maximum. Just my method. Try seating the Nosler with the seating die set the same for the 55 Win bullet.

 

[horsey300]

I have worked a load for .223 that I like.

55g FMJ Winchester standard bullet
2.225" OAL
24grains H335
No chrono data.

I was gifted 400x Nosler 55g HP Varmint rounds.
HP rounds are 0.050" shorter (visually appears to just be cut off at the tip. Makes sense)

I could not find this load in my book. Nosler web site wasn't particularly helpful. (seem to all be tipped projectiles)

So, given my OAL was longer than min specified in lee manual (2.200) for my powder onthe FMJ (loaded to 2.225), I loaded the HP Nosler 0.050 shorter at 2.175".

Admittedly this is a bit shorter than many of the recommended lengths by Lee, but they do not list a HP in same bullet weight. I calculated that this would put the base of the bullet in the same orientation to the powder charge, giving same internal case volume as the FMJ round. I have loaded 10 of them to test. Plan to do a load test of 23, 23.5, 24, 24.5 as I did with my FMJ.

I am getting comfortable with loading/testing things i can easily find (read, common loads) to cross-reference and work from there. This is the first that is not 'by the book', so wanted to check my logic

Nosler says to seat that puppy to 2.26 https://load-data.nosler.com/load-data/223-remington/ so I'd start there, as someone said above me^^^ and yes working up is smart too, I would also add that I use a nosler length and the powder manufacturers charge data most of the time (95%) and provides some VERY nice results, so another vote for the longer c.o.a.l.

 

[Blue68f100]

I don't know what chamber you have in your gun but I always check to find the MAX OAL with any bullet I used. Just yesterday I was loading a Hornady 52gr BTHP-M bullet. Hornady recommends a 2.250" length. I'm into the rifling at 2.230", so that's not going to work. So I had to adj the OAL and start the workup with the 2 powders I want to try. If you have a 5.56 chamber gun your probably fine. My match gun has a min spec 223R which is tight. Does make it easy reaching the lands though.

 

[Sunray]

You can have 25 thou OAL difference by fiddling with the off-the-lands distance. 25 thou isn't very much. Like horsey300 says, Nosler shows a much longer OAL than .2.225" too. Mind you, it's the same OAL for all types of bullet. Your's should be too.
Anyway, load for the bullet weight and don't worry about the construction. It doesn't matter. Like Walkalong says, you'll probably find that 55 grain is 55 grains.

 

[BigMacMI]

I appreciate all of your insights!!! I guess i was concerning myself more with the internal volume being the same between 2 similar weight bullets. I also see now that the shorter bullet would just be allowing more internal volume for the case, which would in turn allow it to run a lower pressure.

I have not yet calculated the distance to my lands. I will load a few more tonight and test the 2 lengths against each other. As long as both run well, i will go back to the length I have been loading my FMJ loads to.

I will also start looking at loading to 2.250 vs my 2.225 as it sounds like most people like to go to the longer load. I will test my preferred load against the longer load as well (for the FMJ load). However, i imagine 0.025" isn't going to change velocity terribly much, more the difference in the jump to the lands (doubtful it will make anything worse).

I appreciate the discussion here on THR. I enjoy the process and hope to have good knowledge to share with people in the future as well!

 

[witchhunter]

Just make sure they fit the magazine and aren't touching the lands. Start low and work up, you will be fine. Most of us will use the data by bullet weight, but be careful when using an all copper or all lead bullet as then it could be a little different. Good luck!

 

[Bart B.]

Nosler says to seat that puppy to 2.26 https://load-data.nosler.com/load-data/223-remington/ so I'd start there

The fine print on Nosler's data says it's just SAAMI spec. Seat them wherever you want.