123gr Hornady SST in 7.62x39

[high country]

I have finally decided to start loading for my Howa mini action in 7.62x39. I have had some Starline brass and the bullets sitting for a while, and just recently managed to pick up some CFE BLK. This was the one rifle round I use but hadn't started loading for because the rifle shoots steel case stuff quite well. But at the end of the day, I have trouble leaving well enough alone and cheap steel case ammo isn't as available as it once was, so here we are...

I prepped some brass and started figuring out where to set seating depth. There is a cannelure on these bullets, crimping into the cannelure would result in an OAL somewhere around 2.2" give or take a hundredth. The challenge I encountered is that the Lee seating die I am using will only set the bullet to 2.225", with the case rim making it just to the bottom of the cannelure. The bullet hits the rifling at an OAL of 2.70", so using my typical approach I would set it back 0.20", for an OAL of 2.50". The magazine will fit up to 2.3" so no issues there.

I am guessing that this bullet has a more secant ogive than the standard bullet that the die was designed around, which is why it won't seat the bullet for a crimp into the cannelure. I don't plan to crimp, so my inclination is to ignore the cannelure and try some at 2.25". It leaves more jump to the lands than I would usually start with, but that might not matter. That will put the base of the bullet all the way through the neck and protruding ~0.10" into the case, but that might not matter either.

Thanks in advance any input from anyone that has used this bullet.

 

[NR53]

I've loaded x39 with CFE BLK and .310 dia 123 grain SST but not in Starline brass. I use the Lee seating die and I have no trouble in seating the bullet to 2.19 OAL.

I think you're on the right track, but I can't figure out the problem with the seating die.

 

[joneb]

For a Ruger American Ranch I load the Nosler 123gr VG#7725 at 2.186" this COL lands the case mouth about center in the cannelure. I think I could seat out another .01-.015" without issues but I use these in a semi-auto as well and this COL works well for both.

 

[Blue68f100]

I have finally decided to start loading for my Howa mini action in 7.62x39. I have had some Starline brass and the bullets sitting for a while, and just recently managed to pick up some CFE BLK. This was the one rifle round I use but hadn't started loading for because the rifle shoots steel case stuff quite well. But at the end of the day, I have trouble leaving well enough alone and cheap steel case ammo isn't as available as it once was, so here we are...

I prepped some brass and started figuring out where to set seating depth. There is a cannelure on these bullets, crimping into the cannelure would result in an OAL somewhere around 2.2" give or take a hundredth. The challenge I encountered is that the Lee seating die I am using will only set the bullet to 2.225", with the case rim making it just to the bottom of the cannelure. The bullet hits the rifling at an OAL of 2.70", so using my typical approach I would set it back 0.20", for an OAL of 2.50". The magazine will fit up to 2.3" so no issues there.

I am guessing that this bullet has a more secant ogive than the standard bullet that the die was designed around, which is why it won't seat the bullet for a crimp into the cannelure. I don't plan to crimp, so my inclination is to ignore the cannelure and try some at 2.25". It leaves more jump to the lands than I would usually start with, but that might not matter. That will put the base of the bullet all the way through the neck and protruding ~0.10" into the case, but that might not matter either.

Thanks in advance any input from anyone that has used this bullet.

Something sounds off. Do you have the body of the seating die backed off too far? Normally you would put a sized case in and run the seating die down till you feel resistance and back it off 1-1.5 turns. If all the brass has been trimmed to the same length you only need to back off 1 turn or less. If you have a bullet seated, back off the seating stem and screw it down further till you feel resistance and back it off just a hare. Now adj your seating stem down to your OAL you want. Once done you can readjust the die to crimp if you want. Just remember to back of the seating stem when you adj for crimp, then run the stem back down. I don't crimp any rifle rounds, hurts accuracy.

 

[Y-T71]

*was thinking of something else*

 

[high country]

I've loaded x39 with CFE BLK and .310 dia 123 grain SST but not in Starline brass. I use the Lee seating die and I have no trouble in seating the bullet to 2.19 OAL.

I think you're on the right track, but I can't figure out the problem with the seating die.

Thanks for all the responses! That is interesting that you are doing pretty much exactly what I am trying to do with the same bullet and die, and it is working the way it should. As Blue68F150 points out, something seems off.

Something sounds off. Do you have the body of the seating die backed off too far? Normally you would put a sized case in and run the seating die down till you feel resistance and back it off 1-1.5 turns. If all the brass has been trimmed to the same length you only need to back off 1 turn or less. If you have a bullet seated, back off the seating stem and screw it down further till you feel resistance and back it off just a hare. Now adj your seating stem down to your OAL you want. Once done you can readjust the die to crimp if you want. Just remember to back of the seating stem when you adj for crimp, then run the stem back down. I don't crimp any rifle rounds, hurts accuracy.

My understanding (from Lee's printed instructions) is that the die they ship in the 3 die rifle sets doesn't crimp, so you set it touching the shell holder. That is where I have it, and the case doesn't make contact to set a crimp. That is fine because I don't want a crimp, there is plenty of neck tension.

I have the seating stem screwed all the way in to get that 2.25" OAL just short of the cannelure. There is still some room between the part of the seating stem that contacts the bullet and the body of the die. I could add a shim above that part inside of the threaded portion of the seating stem to seat up to the cannelure (another 0.010" or so), but it just doesn't seem like I should need to do that especially since NR53 didn't need to using the same bullets and dies. Sorry if that doesn't make sense, it is hard to put that into words.

I dunno, I can usually figure these sorts of things out, but this one has me a little stumped. It is hard to believe that I just happened to get a mis-machined die, but I supposed it is possible. Thanks again for the thoughts and suggestions. I will sleep on it and maybe it will occur to me what I am doing wrong. Otherwise, I will either have to order a different die to try, or just modify this one even though I seems weird that I would need to.

 

[Blue68f100]

May want to contact Lee and check to see if my chance they out the wrong Seating stem in the die.

 

[n2omike]

My go-to for the 7.62x39 is the Sierra 2305 Pro-Hunter. It's a .311 diameter 125 grain flat based pointed soft point. It says 303 cal .311 on the box. These are for the guy wanting to hunt with his SKS, AK, etc that has the larger barrels.
But, it doesn't have the pretty plastic tips of the newer, cooler .308 bullets. lol

 

[Akula69]

My go to load for the Hornady SST is a COL 2.20 (1.748 on the comparator). I use AA 1680 at 22.1 grains.

 

[joneb]

My go to load for the Hornady SST is a COL 2.20 (1.748 on the comparator). I use AA 1680 at 22.1 grains

I've had very good results with a Nosler 123gr VG with LRP AND 27.0gr of Accurate 1680 in a RAR, a 5gr load spread with this powder is petty amazing.

 

[joneb]

My go-to for the 7.62x39 is the Sierra 2305 Pro-Hunter. It's a .311 diameter 125 grain flat based pointed soft point. It says 303 cal .311 on the box

Thanks, I will keep a eye out for that bullet. I would like to try those in my RAR.

 

[high country]

I messed with it a little more over the weekend, and was able to clean up the threaded seating stem a little and get it tightened down to get 2.220" OAL. I loaded up 20 rounds at that length to give a try. That is right at the bottom of the cannelure, so is right where I was planning to get to anyway since I'm not crimping and that puts me about 0.030" of the lands.

It still doesn't seem right so I did send a note to Lee, I'll update if I hear anything helpful back from them in case someone else has this problem down the road and finds this thread

 

[joneb]

I'll update if I hear anything helpful back from them

Let us know and thanks. I am curious.

 

[Casefull]

I have Lee dice for 20 different calibers and have used them for 30 years but they are putting out some real crap nowadays. Somethings off with your die. You should be able to push the bullet much farther in then you would want to unless you are not using the presser right.

 

[high country]

I reached out to Lee on it, and they dropped a different insert for the seating stem in the mail to me, no charge. I don't have it yet, no idea when it will get here given the holiday and weather that is developing across the Midwest. But, when I do get it I will definitely post up with the results.

I'm not sure whether they have a couple of inserts for that die, and just include the one for longer/heavier bullets, or if they put the wrong one in. Either way it appears they are making it right, but I'll report back once I have that part in hand.

 

[high country]

Just a quick update, now that the holidays are over and I got a chance to take a look at that alternate seating stem that Lee sent. It is the stem for the 7mm BR/6.5 Grendel. It is slightly smaller diameter, but the insert centers itself so that shouldn't matter. I now have plenty of travel to seat at whatever depth I want with this bullet without having to bottom the seating stem body all the way out to get to 2.220".

Need to load up a few sets of 5 at various lengths down to 2.190" OAL to compare, see it is sensitive to OAL changes (then find time to get to the range!)

Anyway, hopefully if someone else runs into this problem, they can find this thread through search and save a little time thinking they are crazy/doing something wrong. Just shoot Lee an email asking for the 7mm BR/6.5 Grendel, or if you already load for Grendel, grab the seating stem insert from that die and use it in the 7.62x39 die.

 

[vepr12]

Any range updates yet?