Just got off the phone with Speer.

[dpete]

I just finished talking with a tech from Speer Bullets about their Hotcor #1855 110 grain Spire SP, and their #2023 150 grain Spitzer SP. The reason for my call was to find out the minimum velocity these bullets will mushroom at. What he told me has me even more interested in these bullets than before. He looked up different reduced loads they have and said both of these bullets will expand down to 1530 fps. He looked up various reduced loads for .308 caliber rifles and said they have loads for 300 Savage tested for reduced recoil for kids and those minimum velocities were listed. Granted, 300 Savage is not 300 Blackout but velocity downrange is velocity no matter what rifle it is fired from.

Now the question is at what distance is the 1530fps reached?
The data of each bullet is:

110 grain Spire SP
Ballistic Coefficient Sectional Density
0.273 0.166

150 grain Spitzer SP
Ballistic Coefficient Sectional Density
0.389 0.226
Can someone run a ballpark estimate of what distance the 1530 fps speed might be reached?

The 110 grain Spire points run perfectly in my Blackout AR using 20 grains of Lil'gun and 2.01 COAL with CCI 400 primers. I don't see any reason why the 150s won't run as well.

[randyrucker]

Assuming a nominal muzzle velocity of 1925 fps, the 150 grain looks good out to about 220 yds.

[dpete]

Thanks Randy! If the 150 is good out to 220yds then I would assume the 110 is good out to at least that far maybe more. I started playing with the 110s as an alternative to Varmageddons for target rounds and now I'm leaning towards the 150s as an alternative to Barnes blacktips for hunting. The northern WI woods around here does not lend itself to shots much over 50 yards most of the time so the 150s should have plenty of punch at the ranges we get shots at. I'm planning on doing some testing as soon as I can get a load worked up for them.

[tallburnedmidget]

Who wants to test those bullets and post results?

rebel I'm looking your way

[dpete]

Ummmm, see the last sentence of my previous post. I've got the bullets and a range nearby that goes out to 300 yards. All I have to do is get some loaded up, and collect enough milk jugs or newspapers/phone books to do some expansion tests. Not scientific but its something.

[rebel]

Science is relative We do with what we got, don't we. I think it would be great if you could push a 150 hard enough to expand. I would try it at 50 and then 100 and compare. If the 100 yard bullet doesn't satisfy you, no need to shoot again.
edit - Check out this chart Dolomite posted a while back. This guy spent a lot of time with this and tested in a similar manner.
http://stevespages.com/jpg/bestbullet.jpg

[dellet]

20 grains of 1680 with a 175 SMK/178 Amax is good for 1900-1950 fps in my 16 inch barrel. So the 1950 is certainly well within reach. It might even allow some short barreled fun out to 100 yards or so.

[tallburnedmidget]

Ummmm, see the last sentence of my previous post. I've got the bullets and a range nearby that goes out to 300 yards. All I have to do is get some loaded up, and collect enough milk jugs or newspapers/phone books to do some expansion tests. Not scientific but its something.

Ahh I took your last sentence as testing for a max speed (and accuracy) using a chrony since randy posted speeds.

I'm looking forward to your finds

[dpete]

20 grains of 1680 with a 175 SMK/178 Amax is good for 1900-1950 fps in my 16 inch barrel. So the 1950 is certainly well within reach. It might even allow some short barreled fun out to 100 yards or so.

Speer also makes a 180 & and 200 grain version. I wonder what their low velocity threshold for mushrooming would be? Might be another phone call coming up to Speer.

[rebel]

Looking at the chart I linked above, 2000 fps seems to be the minimum expansion threshold for the 180.