Lehigh 78 grain load success and failures update 3/17, 3/24

[dellet]

I thought it would be good to start a new thread specifically for working on loads for this new bullet. As with everything Blackout potential powders are tough to come by. Lehigh has given us a start of 19 grains of Accurate #9 and I can confirm that cycles and locks back on empty in a 18 inch barrel, velocity could not be confirmed due to darkness. Accuracy was promising, I only shot at 40 yards, but three shots were in a vertical string 1.5 inches high and .5 inches wide canting slightly from 7-1 o'clock.

What I know so far:

Using Remington 300 AAC stamped brass with 19 grains of #9 the bullet resting on the powder give me a COL of 2.260 and loads them as shown to the top of the band below the first groove.

This load is on the hot side, with a flattened primer, but on swipe.

So far what I know worked successfully

18" carbine gas, Carbine buffer, F/A bcg, .092 port, 1/9 twist. Full function cycling and lock back on empty.

Lehigh 78 grain,
Remington brass 1.355 trim
19 Grains AA#9
Col. 2.260
CCI #441
Velocity (will be added when confirmed)


What showed as possible:

Remington Brass 1.355
16.2 grains AA#7
COL 2.225
CCI#41
Velocity avg. 2763

18" Carbine gas, ST2 buffer

This load did not cycle reliably or lock back on empty, I believe in a normally configured carbine or pistol gas system that it would. Accuracy was questionable, 4 inches at 50 yards off hand, I was more interested in function and velocity numbers. I may work on this more as time permits.

Same load as above, 16" AAC micro 7 1/7 twist.

Velocity average 2714.

This seemed to work or show potential. The velocity spread was huge. 150 fps over 5 rounds. the other odd thing was that the first shot was point of aim at 50 yards. The next four were in a 1 1/2 inch group 18 inches high and slightly right. In loads that I have developed for this rifle cold bore shift is less than 1" at 100 yards.

What was a complete failure.

13-13.5 power pistol.

AAC Micro 7

All I can say is I tried. This load had the highest velocity with the best looking primer. Cold bore shot was exact point of aim. Of the next three shots, two are yet to be determined. Target backing was 3'x3' cardboard none hit. This was off a table with a bipod. The last shot, I moved up to 15 yards and punched a square 1/2 inch hole about a foot high and left. Today setting up the chronograph I found one of the three shots I could not account for yesterday. I set it up 10-12 yards in front of where I am shooting from, there is now an inspection hole in one of the tripod legs. The other two shots are still missing

I think this confirms what I thought was happening. The bullets were coming apart. Every shot registered as passing though the chronograph, yet something clearly went through a leg of the tripod. Finding that and the square hole at 15 yards.

I have an email into Lehigh about this and look forward to hearing from them, they have been great about answering questions in the past.

My take on this so far is that using faster powders may be problematic. I got away with it in a slower twist 1/9, but things became very erratic in the 1/7. It might be I just got lucky. I certainly would not even consider running these through a can without a lot of testing.

I look forward to others experiences.

update added

[r.tenorio671]

I thought it would be good to start a new thread specifically for working on loads for this new bullet. As with everything Blackout potential powders are tough to come by. Lehigh has given us a start of 19 grains of Accurate #9 and I can confirm that cycles and locks back on empty in a 18 inch barrel, velocity could not be confirmed due to darkness. Accuracy was promising, I only shot at 40 yards, but three shots were in a vertical string 1.5 inches high and .5 inches wide canting slightly from 7-1 o'clock.

What I know so far:

Using Remington 300 AAC stamped brass with 19 grains of #9 the bullet resting on the powder give me a COL of 2.260 and loads them as shown to the top of the band below the first groove.

This load is on the hot side, with a flattened primer, but on swipe.

So far what I know worked successfully

18" carbine gas, Carbine buffer, F/A bcg, .092 port, 1/9 twist. Full function cycling and lock back on empty.

Lehigh 78 grain,
Remington brass 1.355 trim
19 Grains AA#9
Col. 2.260
CCI #441
Velocity (will be added when confirmed)


What showed as possible:

Remington Brass 1.355
16.2 grains AA#7
COL 2.225
CCI#41
Velocity avg. 2763

18" Carbine gas, ST2 buffer

This load did not cycle reliably or lock back on empty, I believe in a normally configured carbine or pistol gas system that it would. Accuracy was questionable, 4 inches at 50 yards off hand, I was more interested in function and velocity numbers. I may work on this more as time permits.

Same load as above, 16" AAC micro 7 1/7 twist.

Velocity average 2714.

This seemed to work or show potential. The velocity spread was huge. 150 fps over 5 rounds. the other odd thing was that the first shot was point of aim at 50 yards. The next four were in a 1 1/2 inch group 18 inches high and slightly right. In loads that I have developed for this rifle cold bore shift is less than 1" at 100 yards.

What was a complete failure.

13-13.5 power pistol.

AAC Micro 7

All I can say is I tried. This load had the highest velocity with the best looking primer. Cold bore shot was exact point of aim. Of the next three shots, two are yet to be determined. Target backing was 3'x3' cardboard none hit. This was off a table with a bipod. The last shot, I moved up to 15 yards and punched a square 1/2 inch hole about a foot high and left. Today setting up the chronograph I found one of the three shots I could not account for yesterday. I set it up 10-12 yards in front of where I am shooting from, there is now an inspection hole in one of the tripod legs. The other two shots are still missing

I think this confirms what I thought was happening. The bullets were coming apart. Every shot registered as passing though the chronograph, yet something clearly went through a leg of the tripod. Finding that and the square hole at 15 yards.

I have an email into Lehigh about this and look forward to hearing from them, they have been great about answering questions in the past.

My take on this so far is that using faster powders may be problematic. I got away with it in a slower twist 1/9, but things became very erratic in the 1/7. It might be I just got lucky. I certainly would not even consider running these through a can without a lot of testing.

I look forward to others experiences.

..great info, thank you!

...I'm wondering if the "lost" rounds were separating due the 1/7" twist? I look forward to Lehigh's resonse as well as I'm really interested in picking some of these up if 1/7" barrels won't be an issue...

...I'm also hoping someone tests them with the Alliant 410 powder.

[dellet]

I had a short email exchange today with Dave from Lehigh, A great guy with a few suggestions, a few questions and lots of encouragement. He also offers to exchange bullets if I thought it was necessary.

I made one change to the load tested last and went back to the Micro 7 with 1/7 twist, I changed from a CCI#41 to a Remington 7 1/2 primer.

The load as tested:
Lehigh 78 grain CQD
Remington Brass 1.355
19 grains
COL 2.260
Remington 7 1/2
No Chrono due to rain

3 shots @ 10 yards, three round holes at point of aim. No noticeable cold bore shift.
3 shots @ 40 yards, three round holes 4" high. No noticeable cold bore shift.

I have to believe that AA#7 and certainly Power Pistol are just to fast for a 1/7 twist barrel. The loads I tested did not exceed a reasonable velocity 2850 fps, but the bullets came apart. The AA#7 load did not come apart in a 1/9 twist so it may have potential in slower twist barrels.

The only explanation I can think of is that the jacket was compromised because it accelerated faster than both halves could start twisting at the same rate.

I would love to hear other ideas.

For now my opinion is there will be a small window for powders faster than #9 unless the twist is slowed down.

I also wonder how this will play out in a 1/6 barrel.

Anyone else have anything to share?

[rebel]

dellet, I think your assessment is spot on. The rpm's are to fast, I had one 194 ME keyhole at 50 yards while shooting suppressed. I just about crapped myself, but on further inspection realized that it was a partial keyhole and it had an imprint of one of the "Blades" in the target. The bullet had opened in flight at 1020 fps. The other 9 hit in a 2 inch circle offhand. This load was with 11 grains of 1680 and a 9 inch 1 in 8 barrel. I have always believed that the rpms goofed that one round. I can't remember exact speed but it was well within the other 9. Never had it happen since.

[dellet]

dellet, I think your assessment is spot on. The rpm's are to fast, I had one 194 ME keyhole at 50 yards while shooting suppressed. I just about crapped myself, but on further inspection realized that it was a partial keyhole and it had an imprint of one of the "Blades" in the target. The bullet had opened in flight at 1020 fps. The other 9 hit in a 2 inch circle offhand. This load was with 11 grains of 1680 and a 9 inch 1 in 8 barrel. I have always believed that the rpms goofed that one round. I can't remember exact speed but it was well within the other 9. Never had it happen since.

I took a real hard look at the target backing I was using and beside the hole in the chrono tripod and the one square hole in the backing I found yesterday, I found 3 slices about 5/8 inch long. It was scrap cardboard but I was pretty careful to pick one with no holes when I started, so I am pretty sure they were petals passing though

It was also a little humbling to not be able to hit a 3'x3' target at 40-5 yards

[MMA10mm]

I bet dellet! Still, sounds like a fun day. I love trying to figure out complicated ballistic puzzles.

[ronnl001]

I have recently bought several boxes of these for HD use. A member on AR15 took pity on me and sent me about 3/4lb of AA9 so I could get a factory load.

I also have some n105. Anyone with quickload or otherwise have an idea about how it would do? I have emailed Lehigh with this question as well, and will certainly put up their reply.

[dellet]

I have recently bought several boxes of these for HD use. A member on AR15 took pity on me and sent me about 3/4lb of AA9 so I could get a factory load.

I also have some n105. Anyone with quickload or otherwise have an idea about how it would do? I have emailed Lehigh with this question as well, and will certainly put up their reply.

I would be careful with powders faster than AA#9. My experience was not so good. When you look at the burn rate charts, Accurate has VV105 between #9 & #7 and faster. VV has 105 the same as #7, so its a tough call. The loads I worked up with #7 were less pressure and velocity(velocity was less than 2700fps) according to Quickload, than #9, yet the bullets came apart out of the barrel in a 1/7 twist but survived in a 1/9.

I actually found a couple petals about 10' behind and 15' left of where I was shooting a few days later.

Below is more data from Lehigh with other powders. form another thread, close to the bottom of the page.

viewtopic.php?f=151&t=92631&start=80

Accurate and VV burn rate charts.
http://www.accuratepowder.com/wp-conten ... _rates.pdf

http://www.lapua.com/upload/reloading/r ... rt2011.pdf

[drayks]

I finally was able to find a lb of AA#9 this weekend, so will try to put some cartridges together soon to shoot when it warms up a little more. I was unpleasantly surprised to see so much weight variation in the bullets. After weighing a couple hundred and sorting them by weight to ensure a consistent load, I had a low weight of 76.86 grains and a high weight of 78.12 grains. Anyone else have a similar experience? drayks

[dellet]

Tried two loads this weekend, both were interesting. I was more concerned with bullet performance/stabiliy after the previous issues.

The Micro 7was shot off a picnic table and bipod at 50 yards, chronograph at 15.

First load was Lehigh's recommended load. Six shot group, measured 1.12"

19 grns AA#9
LC brass 1.350
Rem. 7 1/2 primer
Col. 2.250

Velocity
2749
2766
2749
2760
2766
2760

avg. 2758
es. 17
sd. 7

After being satisfied with the high end performance, I wanted to see the low end. I put some together for the "Happy Rifle" (makes the boss happy to shoot, no noise or recoil)

Handi Rifle w ACOG

4 grns Trail boss
LC brass 1.350
Rem. 7 1/2 primer
Col. 2.250

Velocity
831
842
827
823
851

avg. 838
es. 34
sd 12

Happy Rifle off a bag, and the wife shot 1.5" group.
The bullets were stabile at 50 yards, passed through 2" wood and were buried about 5" deep in the sand. Recovered with the only blemish being the rifling marks.

Luckily she shot .70" group with 110 Varmageddon's so the Lehigh's won't be her bullet of choice.

When I contacted Lehigh about these, I was told 2350 fps was "minimum operating velocity". From what I experienced at low speeds, these will travel a long way if they do not expand. Be careful with your backstop when shooting these.