62 gr FMJ load

[Stats Shooter]

I am working on a 62 Grain FMJ load. Similar to M855 ball ammo. I managed to get out today and do some testing, and thought I would share.

I am using LC Brass, mixed years, trimmed to 1.7485"
CCI 450's
H335
Hornady 62 gr BTFMJ
The bullet is 0.80" long, with a taper from shank to BT of 0.06" and bt diameter of 0.18" for you Quickload users

OAL of 2.220" (Avg)
And CBTO of 1.8760"
I put a light to med Lee factory crimp on each case...like pictured here. (The ring around the bullet was from me pulling it and reseating as I set my dies up)

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All rounds fired from this gun...20" barrel, 1/8 twist

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CAUTION: The following post includes loading data beyond or not covered by currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assume any liability for any damage or injury resulting from use of this information.

I tested from 23.5 to 25.3 gr H335. 2x4 shot groups. results as follows

23.5 gr
2848 fps
ES 39 fps

23.9 gr
2879 fps
ES 41 fps

24.2 gr
2920 fps
Es 34 fps

24.5 gr
2966 fps
ES 21 fps


24.7 gr
3011 fps
ES 27 FPS

24.9 gr
3036 fps
ES 12 fps

25.1 gr
3051 fps
ES 42 fps

25.3 gr
3069 fps
ES 23 fps

Best groups were between 24.7 gr and 25.1

Here is a pic of the 24.9 gr target

Edit: Forgot to mention, groups were fired at 200 yards off a bench (my personal range)

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The x'd out bullet hole was a barrel warmer with a base 24 gr load so ignore it.

Now, this won't win an IBR competition. But will ring steels all day.

BTW all loaded ammo developed and powder thrown on a RL 550 C. No charges were weighed Except to set up the the powder bar.

CBTO measurements were all either 1.8760 or 1.8770 off the Dillon.

Anyway, my next test, if I get time this weekend, is to shoot the load in my 1/7 twist colt, and 1/9 twist stag model 2T to see how it shoots in carbines.

But, so far, for bulk $0.08/bullet, not too bad.


Also, incidentally, the CBTO on this load is the same as the one I use for 75 gr hornady BTHP 'S in this gun.... strange coincidence that it likes the same jump?

 

[Unclenick]

The trick now will be to compare your velocities and SD's to different degrees of crimp.

When you get to a Dillon 1050, you'll find you can adjust the depth of the primer seating ram on it to hit a particular number of thousandths below flush with the case head each time, assuming matching rim thickness among the cases. Forster uses a ram that extends -0.005" below flush, but after springback you often measure -0.004" instead. Ideally, if you get that where it should be, you may find your SD's are reduced.

On ogive-based length measurements, here are readings from some Sierra Match bullets I did that give you some sense of the variation that can occur among bullets and from different brand comparator inserts that have different hole diameters.

 

[Stats Shooter]

The trick now will be to compare your velocities and SD's to different degrees of crimp.

Yes, that is step 3 after I verify how well it performs in the other common rifle twists. I am also going to borrow my coworkers older Mini 14 with 1/10 twist.

I don't know of anyone nearby with a 1/12 gasser to test it in, and I don't think that they are common anymore anyway.

Quickload lists about 3050 as the max velocity, which is nice since I am near it with this load.

I think since I am in the middle of the crimp potential of the factory crimp die, my next move will be to begin increasing the crimp....if that makes things worse, or pressure begins spiking, I will go back to the middle and begin lightening the crimp.

 

[Stats Shooter]

Update

So I made 250 at what I am calling a medium crimp, which is the crimp I developed the load at. Marked the tool head with a dreammel for that amount of crimp notching the die as well.

I then loaded up 100 with what I am calling a heavy crimp. This level of crimp is where the Lee crimp collet is nealy all the way closed and there is a very pronounced mark on the mouth where the crimp die did it's work. I didn't mark this die setting because it is easily repeatable.

I then loaded up 100 with a "light" crimp. This level of crimp causes the collet to barely close. The mark on the case mouth is very light, but there if you look.

I took 50 of each , light, medium (the benchmark), and heavy out to my backyard range and fired 5x10 shot groups each...prone, bipod, rear bag, but no chronograph obviously.

This test was for accuracy only.

First of all, the heavy crimp isn't worth pursuing any further. The best 10 shot group was 2.5 MOA at 200 yards. I'll just use the rest of them as barrel warmers and bore foulers.

The medium crimp produced avg 10 shot groups of 1.75" at 200 yards. This is a bit worse than the 4 shot groups when I developed the load, but I think it reflects better the true accuracy of the load with cold vs warm chambers fired at the same target. I think this is acceptable for high velocity crimped ball ammo.

The light crimped load shot about as accurately as the medium crimped load with an average 10 shot group size of 1.7" @ 200 yards .

Again these were fired out of my highly accurate varmint AR 1:8 twist. Im waiting on some gas rings coming in the mail for my bolt on one of my carbines before I do the multiple gun test.

However, since the accuracy was about the same for both light and medium crimp, the next test will be a velocity test for consistency. I may try another crimp somewhere between light and medium before the velocity test, but given the results so far I doubt it will have any appreciable impact on accuracy.

If I can get an MOA or better load with a velocity SD in single digits, and with similar results in multiple guns, I'll a very nice M855 clone load for both my own steel slaughtering, and a potential commercial load candidate.

 

[Aguila Blanca]

First of all, the heavy crimp isn't worth pursuing any further. The best 10 shot group was 2.5 MOA at 200 yards. I'll just use the rest of them as barrel warmers and bore foulers.

The medium crimp produced avg 10 shot groups of 1.75" at 200 yards. This is a bit worse than the 4 shot groups when I developed the load, but I think it reflects better the true accuracy of the load with cold vs warm chambers fired at the same target. I think this is acceptable for high velocity crimped ball ammo.

The light crimped load shot about as accurately as the medium crimped load with an average 10 shot group size of 1.7" @ 200 yards .

Did you intentionally mix your units of measurement, or was that a slip? For the heavy crimp, you wrote "MOA," but for the other two you gave us inches at 200 yards. 1 MOA is 1" at 100 yards, so 2.5 MOA would be 5 inches at 200 yards.

Is that what you encountered? Or was it 2.5" -- which would be i.25 MOA?

 

[Stats Shooter]

Did you intentionally mix your units of measurement, or was that a slip? For the heavy crimp, you wrote "MOA," but for the other two you gave us inches at 200 yards. 1 MOA is 1" at 100 yards, so 2.5 MOA would be 5 inches at 200 yards.

Sorry,

Didn't mean to be confusing. I was partially distracted when writing.

The Heavy Crimp load was 5" at 200 yards or 2.5 moa....so not good

 

[brasscollector]

If I can get an MOA or better load with a velocity SD in single digits, and with similar results in multiple guns, I'll a very nice M855 clone load for both my own steel slaughtering, and a potential commercial load candidate.

• I cannot for the life of me get my SD down to what I would consider reasonable levels in my 223 loads. #s in the 30s but it's an MOA load so I don't dwell on it.
• A true M855 clone wouldn't be this accurate (I ran about 100rnds of M855 thru a few of my guns and none would manage better than 4 MOA)

 

[Stats Shooter]

A true M855 clone wouldn't be this accurate (I ran about 100rnds of M855 thru a few of my guns and none would manage better than 4 MOA)

I can give you many examples of a factory load having poor accuracy in a specific gun, only to shoot well in an other.

In fact, the gun I am developing this load in hates 55 gr fmj factory ammo. XM 193 is 2-3 moa at best in my 20" Varmint AR. My hand loaded 55 gr fmj's arnt much better.

But , in my 1:9 twist carbine, xm 193 is 1.5 moa with a red dot optic at 100 yards. It shoots decently in my 1:7 colt too.

On the other hand, with 75-80 gr projectiles, my varmint AR is 1/4-1/2 moa easily.... neither of my carbines have achieved that level of accuracy.

 

[Unclenick]

…And keep in mind the true M855 has a penetrator. The more parts you put in a bullet, the harder it is to keep the mass symmetrical about the axis. The Hornady doesn't have that problem.

The JBM version of Don Miller's calculator says 10.5" twist is nominal for the Hornady (this is at the slow end of 2700 fps; faster will be better) and 12" is marginally stable. 7" is pretty fast for it, so stability will depend on how well Hornady made the bullets.

Primer seating can be key to low SD.

"There is some debate about how deeply primers should be seated. I don’t pretend to have all the answers about this, but I have experimented with seating primers to different depths and seeing what happens on the chronograph and target paper, and so far I’ve obtained my best results seating them hard, pushing them in past the point where the anvil can be felt hitting the bottom of the pocket. Doing this, I can almost always get velocity standard deviations of less than 10 feet per second, even with magnum cartridges and long-bodied standards on the ’06 case, and I haven’t been able to accomplish that seating primers to lesser depths."

Dan Hackett
Precision Shooting Reloading Guide, Precision Shooting Inc., Pub. (R.I.P.), Manchester, CT, 1995, p. 271.​

 

[Stats Shooter]

And keep in mind the true M855 has a penetrator. The more parts you put in a bullet, the harder it is to keep the mass symmetrical about the axis. The Hornady doesn't have that problem.

Yes the SS109. I have 2k of those bullets, new and not pulled. They have no green tip but that's because the green paint is added after loading.

The weight on them is all over the place. 59.5 gr to 63gr+ . And the lengths are just as inconsistent. For those reasons I have yet to waste powder or primers loading them.

The SS109 has a purpose, but that purpose doesn't exist for just about all civilian applications because it is a poor hunting, plinking, target shooting, or self defense bullet unless the guy is wearing class 3 or 4 body armor. And many ranges have banned their use

Therefore, though I have some, I likely won't develop a load with them anytime soon.

 

[hdwhit]

Unclenick wrote:
…And keep in mind the true M855 has a penetrator. The more parts you put in a bullet, the harder it is to keep the mass symmetrical about the axis.

This is a very good point.

Thank you.

Some time ago, I picked up some bulk bullets at a fantastic price. The seller said they had a "dimensional inconsistency". Well, I looked at them and my eyes were pretty sharp back then and I didn't see any inconsistency. In fact the bullets only varied by +/- 0.1 grain.

I patted myself on the back for getting such high quality bullets.

- - And then one rolled off the reloading bench.

- - - And another rolled across it.

I grabbed a mirror, put it flat on the benchtop and set bullet after bullet on it and they would all roll a little bit and then stop. It took me a while to realize the "dimensional inconsistency" was in the jacket meaning the lead core was off to one side. Not much, but enough to make the bullet find the heavy spot on a sheet of glass.

Since I hardly every shoot more than 100 yards, I didn't figure it would make a difference - and it didn't. I could still hit the divot in a milk jug at 100 yards. But, for someone reaching out farther or wanting more than 3-4 MOA, these bullets could have been very frustrating.