Hornady 150gr sst

[plant.one]

I have loaded and shot hornady fmjbt 150gn with 19.7 grains of 1680 with a col of 2.110, with no issues.

no two 150gr bullets (or bullets of any given weight for that matter) are the same - even among the same manufacturer. thats why when you look at the 150gr bullets hornady offers the COAL for 300 blackout can be as short a 1.900 and as long as 2.210. the shape and profile of the bullet directly influence both its length and seating depth.

there's more than just max magazine length going on that determines what is both a safe and acceptable OAL - including but not limited to is bullets contact with the lands point, how far the bullet seats in the case (deeper = more pressure with the same powder charge), minimum seating depth to maintain good contact in the neck, etc.


in your example the fMjBT at 2.110 is actually longer than its recommended OAL of 2.090". so at max charge you'd be UNDER published pressure data, and you could probably exceed published max powder charge before you hit that max pressure if you did so cautiously - not a lot, but some.. vice versa... loading the SST the same OAL puts it way under its recommended 2.210 OAL.

[popper]

Shoot them. Slightly compressed due to dep seating depth is not a problem if powder book loads show C.

[Anthonyasphalt]

My mistake was not measuring the sst bullet and resetting my seating die, I did a few hundred rounds with the fmjbt with 18.7 grains, when I ran out of those I grabbed the sst's and loaded them, I then went wait a minute, the bullets look a little different.
The poly tip on the sst is just a little longer, the cannalure's are at roughly the same spot.
So just got to figure out if the difference is 3 grains or less to be on the safe side or just pull the hundred I loaded and reseat too the 2.210

[Anthonyasphalt]

I guess what I'm asking is, would you fire a round and then check for pressure signs? Or would you just pull all 100 rounds and reseat them?

[wildfowler]

I guess what I'm asking is, would you fire a round and then check for pressure signs? Or would you just pull all 100 rounds and reseat them?

Just try what dellet said and load up a few more cartridges at that overall length but start well below current powder charge, increasing powder charge until you get to where you want to be checking for pressure signs along the way.

I’m looking at page 382 of my Hornaday ninth edition book and they list eight different 150 grain bullets including the 150 SST and the 150 FMJ-BT as having an oal of 2.2”. And using 1680 powder list charge range from 15.4 - 22.0 grains.

These eight Hornaday bullets all have the same load data even though as you discovered the ogive is in a different position for various bullets.

I think you’ll find that there is no issue but you need to be safe and test with the lower powder charge first to be sure. Or else just pull them, resize and start over.

[wildfowler]

Edit: I just checked quick load and without updating anything to make changes to how the program calculates. The difference between 2.210 inches with your powder charge shows a pressure of 54,266 PSI.

Using 2.110 shows 75,306 PSI.


As an alternative to check for pressure you could take the same load seated to the normal overall length and bump it down in say .005” increments checking for pressure along the way.

For what it’s worth, quick load shows the hornady book published maximum charge at the correct overall length as having 104,934 psi.

[dellet]

Edit: I just checked quick load and without updating anything to make changes to how the program calculates. The difference between 2.210 inches with your powder charge shows a pressure of 54,266 PSI.

Using 2.110 shows 75,306 PSI.


As an alternative to check for pressure you could take the same load seated to the normal overall length and bump it down in say .005” increments checking for pressure along the way.

For what it’s worth, quick load shows the hornady book published maximum charge at the correct overall length as having 104,934 psi.

That would be why working up is a good idea, no matter what published load data or Quickload says. And those two are considered more reliable than the internet.

Consider that the 105k psi predicted is a good number, Quickload produces a mid range number and then also lot to lot variations of +/- 10%. Starting at the top of data with a hot batch of powder could be interesting.

[dellet]

I guess what I'm asking is, would you fire a round and then check for pressure signs? Or would you just pull all 100 rounds and reseat them?

There is enough information in this thread for you to make your own decision. No one can tell you if it’s safe or not without having spent some time with your rifle. Ultimately you are responsible for keeping yourself safe. Experience counts.

This might be worth considering when loading hot rounds

At what what pressure?

55,000 psi? (SAAMI pressure)
62,000 psi? (5.56mm NATO pressure)
74,000 psi? (proof round pressure)

I have had 110 grain up to 2600 fps in 20 inch barrels, but it was over SAAMI pressure and I would not suggest it.

WildFowler gave you some interesting numbers to think about, I ran the info through Quickload and came up with different numbers based on my components.

My experience after burning through about 10 pounds of 1680, mostly shooting bullets 150 grains and above, says your load would be safe in all of my rifles. It would probably blow primers and probably require hammering the bolt open in at least one. Rifle won’t come apart, but not suggested practice.

I would not pull them apart without doing a load work up, why pull them apart if you don’t have to?

[plant.one]

The poly tip on the sst is just a little longer, the cannalure's are at roughly the same spot.

ignore cannelure placement. its (mostly) irrelevant to this caliber. those cannelure's are based on typical bullet seating depths in cartridges like the 308, 30-06, etc.... we just happen to be cannibalizing those already designed projectiles for use in the 300 blackout. Thats not to say that proper and/or published seating depths for the blackout WONT hit the cannelure - all i'm saying is that you needant be concerned if you do or dont happen to hit the cannelure based on published data.

as dellet mentioned, once you get some experience under your belt then you can experiment if you want to start fiddling with OAL, but that requires GOOD data on YOUR guns before you can start to do so SAFELY. for now... just work within what is known good info and go from there.

I’m looking at page 382 of my Hornaday ninth edition book and they list eight different 150 grain bullets including the 150 SST and the 150 FMJ-BT as having an oal of 2.2”. And using 1680 powder list charge range from 15.4 - 22.0 grains.

first off - you need to reference the published errata data that hornady has online. if you look there you'll see that the OAL for the 150fmjbt has been Corrected to 2.090" and that the SST is 2.210" for hornady's 9th edition. please follow the following link to get that data to update your manual

https://press.hornady.com/assets/pcthum ... 702177.pdf

i highly suggest that you print that out, stuff it in the front of your book and make notes on the appropriate pages for calibers you reload.

for those using other versions - the full current list of errata is published here

https://www.hornady.com/support/load-da ... ook-errata


the takeaway is this - punishing errors happen. thats one of the very reasons that the rule start at minimum and work up until you see pressure signs. that way even in the event of an incorrect OAL published, you're significantly less likely to hurt yourself. the 2nd takeaway is - dont just automatically follow what you see online for reloading data. if a major publisher can make a typo, *ANYONE* can. try to find *similar* data before you go ahead with stuff, especially those of ya'll out there who are relatively new to reloading. you cant be TOO careful.

These eight Hornaday bullets all have the same load data even though as you discovered the ogive is in a different position for various bullets.

while ogive placement is important to the discussion, i would suspect that the *primary* reason they can share the same load data is that their seating depth - how far the bullet goes into the case and therefore case capacity left for powder - is nearly identical based on the varied recommended OAL. Sadly my selection of 150gr bullets is extremely limited so i cant give a proper comparison, but based on the fact that max load data is based on safe max pressure, and pressure is directly proportional to case capacity/seating depth... logic would tend to support the theory.

The 300 blackout has a relatively generous throat/lead area of the chamber (compared to other calibers), so while jamming a bullet into the lands before exceeding mag length is possible, there arent very many bullets out there that can do so without exceeding mag length. some of the light for caliber bullets will literally be falling out of the case mouth before they can even touch the lands. so bearing that in mind, you can see why for the most part people dont worry about it other than as a benchmark for consistency on our reloads.

so unless you have an out of spec chamber with a short throat, or are loading beyond mag length to try to increase velocity, you should be in pretty good shape of not worrying about a bullet jamming into the lands causing pressure issues as long as you stay with published data below max mag length of 2.260" oal.


hth

[dellet]

The poly tip on the sst is just a little longer, the cannalure's are at roughly the same spot.

ignore cannelure placement. its (mostly) irrelevant to this caliber. those cannelure's are based on typical bullet seating depths in cartridges like the 308, 30-06, etc.... we just happen to be cannibalizing those already designed projectiles for use in the 300 blackout. Thats not to say that proper and/or published seating depths for the blackout WONT hit the cannelure - all i'm saying is that you needant be concerned if you do or dont happen to hit the cannelure based on published data.

as dellet mentioned, once you get some experience under your belt then you can experiment if you want to start fiddling with OAL, but that requires GOOD data on YOUR guns before you can start to do so SAFELY. for now... just work within what is known good info and go from there.

I’m looking at page 382 of my Hornaday ninth edition book and they list eight different 150 grain bullets including the 150 SST and the 150 FMJ-BT as having an oal of 2.2”. And using 1680 powder list charge range from 15.4 - 22.0 grains.

first off - you need to reference the published errata data that hornady has online. if you look there you'll see that the OAL for the 150fmjbt has been Corrected to 2.090" and that the SST is 2.210" for hornady's 9th edition. please follow the following link to get that data to update your manual

https://press.hornady.com/assets/pcthum ... 702177.pdf

i highly suggest that you print that out, stuff it in the front of your book and make notes on the appropriate pages for calibers you reload.

for those using other versions - the full current list of errata is published here

https://www.hornady.com/support/load-da ... ook-errata


the takeaway is this - punishing errors happen. thats one of the very reasons that the rule start at minimum and work up until you see pressure signs. that way even in the event of an incorrect OAL published, you're significantly less likely to hurt yourself. the 2nd takeaway is - dont just automatically follow what you see online for reloading data. if a major publisher can make a typo, *ANYONE* can. try to find *similar* data before you go ahead with stuff, especially those of ya'll out there who are relatively new to reloading. you cant be TOO careful.

These eight Hornaday bullets all have the same load data even though as you discovered the ogive is in a different position for various bullets.

while ogive placement is important to the discussion, i would suspect that the *primary* reason they can share the same load data is that their seating depth - how far the bullet goes into the case and therefore case capacity left for powder - is nearly identical based on the varied recommended OAL. Sadly my selection of 150gr bullets is extremely limited so i cant give a proper comparison, but based on the fact that max load data is based on safe max pressure, and pressure is directly proportional to case capacity/seating depth... logic would tend to support the theory.

The 300 blackout has a relatively generous throat/lead area of the chamber (compared to other calibers), so while jamming a bullet into the lands before exceeding mag length is possible, there arent very many bullets out there that can do so without exceeding mag length. some of the light for caliber bullets will literally be falling out of the case mouth before they can even touch the lands. so bearing that in mind, you can see why for the most part people dont worry about it other than as a benchmark for consistency on our reloads.

so unless you have an out of spec chamber with a short throat, or are loading beyond mag length to try to increase velocity, you should be in pretty good shape of not worrying about a bullet jamming into the lands causing pressure issues as long as you stay with published data below max mag length of 2.260" oal.


hth

The 150 FMJ would jam at the 9th edition COL if the case was bumped back to maximum headspace, set for minimum it was fine. the problem was that no new brass is ever set to minimum. So a tight chamber and a short shoulder headspaced off the bullet.

Even the 110 Vmax will jam before falling out of the case and before 2.260". It's all about profile.