78gn LeHigh Close Quarter Bullet

[JD_H]

im not sure if that was a from the projectile or somethin like a plywood shard. It certainly looked metal, except they say there was 100% bullet retention in the block. Then again there was clearly an exit hole in the block... so how could it have retsined all of the bullet when there was a 5" hole clear thru the block? hahah

[Dolomite_Supafly]

Also, if you look at the plywood you will see a mark from the bullet hitting it and bouncing up into the block. It is typical to see low hits with ARs because the sights are so far above the bore.

You can see a petal fall to the floor on the left side of the screen. It was either the one that never made it into the block or one that passed through. Either way it was not "contained within the block".

[dellet]

1. Flatter trajectories aid accuracy (point-and-shoot/judging distance and night-shooting applications).
2. Lighter/faster will extend the effective range by 50-100M, hopefully to .223 effective distances.
3. Less weight of ammunition to hump around (ever compared a 300rd load-out of Blackout to .223?)
.

In CQB, the flatter advantage of a faster bullet are not taken advantage of. A bullet twice the weight has ample velocity to only make a difference of around an inch at 100 yards depending on zero range. 100 Yards is still real far for "close quarter battle". The advantage of a flatter shooting bullet come in to play around like 250+yds. If the bullet is supposed to be for CQB when why even worry about long distances? Just for giggles I calculated 80gr .223 hornady a-max numbers so we can have a logical conversation instead of just hoping. The .223 with its vastly superior BC delivers twice the energy at 500 yards. The 130gr MK319 bullet was 2nd in energy, and the 78gr with its low BC was lowest. The 78gr bullet falls out of the low range of 2350fps, listed on their site, at around 125yds. 300BLK was never intended, in any bullet weight, to be a 500yd cartridge. Now I realize this is the 300 Blackout forum and everyone wants to shoot 300 Blackout, but what is the goal? To shoot 300 Blackout, or to shoot the most capable cartridge for its intended use? It's kinda like trying to make a 12ga shotgun shoot 500 yards. Without taking into consideration charge weight, 218 110gr bullets would only be a pound heavier than 218 78gr bullets, 134 130gr bullets would be 1pound heavier, and 53 208gr bullets would be one pound heavier.

Your Input Variables - Ballistics Results - 300 blackout MK319 130gr bullet
Ballistic Coefficient .277 Velocity (ft/s) 2200 Weight (grains) 130
Maximum Range (yds) 500 Interval (yds) 50 Drag Function G1
Sight Height (inches) 2.5 Shooting Angle (degrees) 0 Zero Range (yds) 30
Wind Speed (mph) 0 Wind Angle (degrees) 90 Altitude (ft) 0
Pressure (hg) 29.53 Temperature (F) 59 Humidity (%) 0.78
Ballistics Results - 300 blackout mk319
Range (yards) Velocity (fps) Energy (ft.-lb.) Trajectory (in) Come UP in MOA Come UP in Mils Wind Drift (in) Wind Drift in MOA Wind Drift in Mils
Muzzle 2200 1397 -2.5 0 0 0 0 0
50 2057 1221 1.3 -2.4 -0.7 0 0 0
100 1919 1063 2.9 -2.8 -0.8 0 0 0
150 1788 923 2.2 -1.4 -0.4 0 0 0
200 1663 799 -1.2 0.6 0.2 0 0 0
250 1546 690 -7.7 3 0.9 0 0 0
300 1437 596 -17.9 5.7 1.7 0 0 0
350 1337 516 -32.4 8.8 2.6 0 0 0
400 1248 449 -51.6 12.3 3.6 0 0 0
450 1171 396 -76.5 16.2 4.7 0 0 0
500 1108 354 -107.7 20.6 6 0 0 0

Your Input Variables - Ballistics Results - 300blk 78gr Lehigh CQB
Ballistic Coefficient .249 Velocity (ft/s) 2800 Weight (grains) 78
Maximum Range (yds) 500 Interval (yds) 50 Drag Function G1
Sight Height (inches) 2.5 Shooting Angle (degrees) 0 Zero Range (yds) 40
Wind Speed (mph) 0 Wind Angle (degrees) 90 Altitude (ft) 0
Pressure (hg) 29.53 Temperature (F) 59 Humidity (%) 0.78
Ballistics Results - 300blk 78
Range (yards) Velocity (fps) Energy (ft.-lb.) Trajectory (in) Come UP in MOA Come UP in Mils Wind Drift (in) Wind Drift in MOA Wind Drift in Mils
Muzzle 2800 1358 -2.5 0 0 0 0 0
50 2617 1186 0.5 -0.9 -0.3 0 0 0
100 2442 1033 2.2 -2.1 -0.6 0 0 0
150 2274 896 2.4 -1.6 -0.5 0 0 0
200 2112 773 1 -0.5 -0.1 0 0 0
250 1957 664 -2.4 0.9 0.3 0 0 0
300 1810 567 -8.1 2.6 0.7 0 0 0
350 1670 483 -16.4 4.5 1.3 0 0 0
400 1540 411 -27.8 6.6 1.9 0 0 0
450 1420 349 -43 9.1 2.7 0 0 0
500 1311 298 -62.4 11.9 3.5 0 0 0


Your Input Variables - Ballistics Results - .223 80gr A-MAX
Ballistic Coefficient .453 Velocity (ft/s) 2800 Weight (grains) 80
Maximum Range (yds) 500 Interval (yds) 50 Drag Function G1
Sight Height (inches) 2.5 Shooting Angle (degrees) 0 Zero Range (yds) 40
Wind Speed (mph) 0 Wind Angle (degrees) 90 Altitude (ft) 0
Pressure (hg) 29.53 Temperature (F) 59 Humidity (%) 0.78
Ballistics Results - .223 80gr A-MAX
Range (yards) Velocity (fps) Energy (ft.-lb.) Trajectory (in) Come UP in MOA Come UP in Mils Wind Drift (in) Wind Drift in MOA Wind Drift in Mils
Muzzle 2800 1393 -2.5 0 0 0 0 0
50 2699 1294 0.5 -0.9 -0.3 0 0 0
100 2600 1201 2.3 -2.2 -0.6 0 0 0
150 2503 1113 2.8 -1.8 -0.5 0 0 0
200 2409 1031 1.9 -0.9 -0.3 0 0 0
250 2316 953 -0.5 0.2 0.1 0 0 0
300 2225 880 -4.5 1.4 0.4 0 0 0
350 2137 811 -10.3 2.8 0.8 0 0 0
400 2050 747 -17.9 4.3 1.2 0 0 0
450 1966 686 -27.7 5.9 1.7 0 0 0
500 1883 630 -39.7 7.6 2.2 0 0 0

Sadly your numbers are cherry picked. To get that velocity out of the 80gr amax I am pretty sure you will need to load it much longer than 2.26" That bullet and the 75gr were designed for single feed or modified mags like AIS in a bolt action.

Your barrel length should also be taken into consideration, likely a 20-24 inch vs a 16 inch. If you compare say a 125 smk at 2450fps which is easily obtainable in a 20" barrel your energy will be about 500 lbs at 500 yards.

I think if you run the numbers you will be surprised. The energy at 500 will be much closer, the 80gr will certainly have less drop.

As for the 78gr Lehigh, it was never designed to shoot past 100 yards. It would be nice if bullet manufacturers would see the desire to stretch the cartridge out to distance and design a few bullets accordingly.

[Klem]

Klem I haven't shot any yet, will PM when I do and have results, will shoot out of the 10.5" 1/8 twist barrel of my build. Plan to try H110, Lil'Gun, and 2400 powders with a CCI primer and LC cases will start reloading within a few days.

PS Plan to aim for a 2200fps average and also will test one box of the Lehigh CQB ammo as my base line accuracy/speed figures.

Just ran the numbers for those three powders in Quickload and looks like 2400 will give the highest velocity before running out of case space. All three powders end up compressed loads at 105% full and still nowhere near peak SAAMI pressure.

I was using 12gns of AP100 in a 12.5" 1:7 with PLGS. Although 2464fps it was short stroking without ejecting the case. At 101% case capacity it was still 10K lbs below SAAMI and not enough pressure to cycle. I think a slower powder like recommended on LeHigh's website and your post is the go.

[Klem]

from a philosophical standpoint, I would stay away from reloading self defense cartidges. If you ever did have to shoot someone, when you were in court the prosecution would tear you to pieces. They'd say you were at home concocting bullets that were intended on inflicting maximum damage, excessively lethal, and a bunch of other nonsense left wing slandering. We all know a bullet is intended to kill, but in a courtroom they play games with such things. I hand load everything except the cartrides loaded in my weapons at home. Those all have commercial "defense" cartridges in them.

It would seem my first impression of you is correct.

[JD_H]

love tha warm welcome to the forum!

[JD_H]

i mention 223 and get berated

[BlogSarge]

https://www.youtube.com/watch?v=ZGr3tGXOKRI

You can even see a petal bounce off the clay AFTER the bullet hits.

Right there is evidence that these can come apart from centrifugal force.

Good eye Dolomite. The caption says that all bullet material was contained in the clay, but that is obviously incorrect. Still, I don't wanna get hit by one of these rounds!

[dellet]

Klem I haven't shot any yet, will PM when I do and have results, will shoot out of the 10.5" 1/8 twist barrel of my build. Plan to try H110, Lil'Gun, and 2400 powders with a CCI primer and LC cases will start reloading within a few days.

PS Plan to aim for a 2200fps average and also will test one box of the Lehigh CQB ammo as my base line accuracy/speed figures.

Just ran the numbers for those three powders in Quickload and looks like 2400 will give the highest velocity before running out of case space. All three powders end up compressed loads at 105% full and still nowhere near peak SAAMI pressure.

I was using 12gns of AP100 in a 12.5" 1:7 with PLGS. Although 2464fps it was short stroking without ejecting the case. At 101% case capacity it was still 10K lbs below SAAMI and not enough pressure to cycle. I think a slower powder like recommended on LeHigh's website and your post is the go.

I ran these at 2100 using 1680 in a 1/7. I felt the difference in velocity was more likely what kept the bullet intact.

They came apart at 2500fps in the same barrel using Power Pistol, but held together in a 1/9 at a slightly higher velocity using the same load. In my conversations with Lehigh at the time, the thought was if the bullet accelerated too fast it might cause the tip to start pushing back hard enough to start expansion or twisting too fast before the whole bullet entered the rifling.

Using #9 which is the powder used in their loaded ammo at 2800 they came apart in 1/7, but not a 1/9.
My thought was since they survived at higher bullet rpms from slower twists, the problem was more likely happening at the other end of the barrel.

[tXr]

Dellet like you mentioned I think it is the rate of acceleration as the bullet encounters the rifling and starts twisting that is causing the very thin section of the brass body, just under the aluminum tip that isn't precut, to fracture. I have them loaded with a moderate load at 3700fps from the 30RAR, which is a 1:10 twist, and have yet to encounter any issues.