Velocity and powder conundrum

[Modoc]

Always a good idea. I got no pressure signs, but I also know that can be deceiving with an AR.

This was in a Howa 1500 Mini. I was loading middle of the charge window plus 10% of the window for practice ammo. This has worked very well before resulting in several MOA or smaller loads in various rifles, just this time the two data were significantly different. Nosler Max is 27.5gr and Hodgdon is 38.0gr 28.0gr

[sundowner]

The brass is Starline and the Ogive is 1.169" and I never load above the manufactures Max load , either bullet or powder max . 28.7 has been hodgdon's for many years . Also thir listed PSI is 49,800 and 2508fps .

[sundowner]

Sundowner, not to be jerk, but Hornady Ten says that max load using 123 SST and H335 is 26.4gr with velocity of 2300fps. Also Quickload shows that 28.7gr of H335 pushing a 123gr SST has velocity of 2553, with pressure of 58,585psi. Your velocity agrees well with the Quickload numbers. I am well aware that QL is only an estimation, but it seems that you have really hot load at 28.7gr. QL gives a velocity of 2365 fps sat the Hornady max load of 26.4,with pressure of 44,759psi using standard QL parameters for temp and elevation. I have used 25.5gr H335 and 123 SSTs with an 18 inch Grendel Hunter upper and have chrono'ed about 2250fps.

I use the powder manufactures load info and that load that you are talking about has changed over the years and additions , it has gone down , their load is below the fps listed on their ammo box .

[VASCAR2]

Part of velocity discrepancies in listed sources is barrel length used for testing. Hornady has used 14.5”, 18” barrels and possibly other lengths depending on the particular reference manual. Western/Ramshot/Accurate used 20” barrels where Speer, Sierra, Nosler and Hodgdon use 24” barrels for testing.

[NDSwede]

Very good discussion, I've appreciated reading it. Here's a couple thoughts for future consideration.
1. Your current load doesn't really have enough velocity or energy to shoot 400 yards. You need about 2550 fps mv to have 1000 fpe at 400 yards. Also 1900+ fps is required on target to initiate expansion.
2. As has been stated Leverevolution gives the highest velocity of any powder I know. It is temp sensitive though.
3. Metal magazines like the AR Stoner allow you to load out to a COAL of 3.100".

[Harpoon1]

Hodgdon shows 28.7gr for max load of H335 on their reloading data page. That's with a Sierra 123 gr bullet.

So Hodgdon uses a 24” 1/9 twist barrel and the Hornady data is out of 18” 1/8 barrel.

If you subtract 150 fps, for the differences in barrel length. Say around 25 fps per inch! You’re basically only 50 FPS apart for additional 2.3 grains of powder! Something’s off, somewhere!

The only other thing I can see, the SST has cannelure and the Sierra doesn’t. So one is crimped, should have a lot higher neck tension than the other that isn’t!

Edited: just checked the Sierra data and they show 28.2 grns/2490 fps as their max, with 123 BTHP and 24” 1/8.

[trubulator]

Very good discussion, I've appreciated reading it. Here's a couple thoughts for future consideration.
1. Your current load doesn't really have enough velocity or energy to shoot 400 yards. You need about 2550 fps mv to have 1000 fpe at 400 yards. Also 1900+ fps is required on target to initiate expansion.
2. As has been stated Leverevolution gives the highest velocity of any powder I know. It is temp sensitive though.
3. Metal magazines like the AR Stoner allow you to load out to a COAL of 3.100".

So there is another question I have been wondering about. My usual MO as a hunter is to be a sneaky bugger and get right on top of my quarry for a close in shot. We do a muzzleloader hunt every fall and I take deer well within 100 yards. Last fall I shot a pronghorn within 75 yards by using the terrain and being extremely sneaky. So my experience of shooting game at 300+ yards is nil. I am trying to stack the deck in my favor for the first attempt, so I have deliberately chosen to work with SSTs, which Hornady says expand starting at 1600 FPS. When I plug my particulars into a ballistic calculator, I get 936 foot pounds and 1851 FPS at 400 yards. Maybe I am missing something, but I am assuming that being 250 FPS over minimum expansion velocity as disclosed by the manufacturer and darn close to 1000 ft pounds should drop a whitetail doe, no? Since I have no terminal experience, I would be interested in what others' have seen.

Ideally, I will be a lot closer when (heh, if) I shoot. That said, I have hunted this property for years and much of it has very little cover for me to be sneaky in, so a long shot is a definite possibility based on past experience. I hope to be luck and make it a close shot, but I would rather be prepared to take the long shot if that is all that is offered.

[PA_Allen]

Trubulator,
Don’t sweat it. If you fire a 123gr SST at 2400 fps and place your shot, you will cleanly kill any deer on that property. I shot that combo for years out of my 16” Grendel (123 SST, 2400 fps) and killed dozens of deer from 20 to 350+ yds. Go hunt with confidence and have fun.
- PA

[trubulator]

Trubulator,
Don’t sweat it. If you fire a 123gr SST at 2400 fps and place your shot, you will cleanly kill any deer on that property. I shot that combo for years out of my 16” Grendel (123 SST, 2400 fps) and killed dozens of deer from 20 to 350+ yds. Go hunt with confidence and have fun.
- PA

Thanks. I am looking forward to the chase. If this combo works, I will use if for pronghorn next year when I expect to get another tag.

I am planning to hunt bear in September with a 35 Rem. If it turns out that likely shots will be longer than 150 yards, I may switch to the Grendel.

[NDSwede]

Here’s a very interesting video on the subject of velocity required for expansion. His bullet should be hitting at about 1780 fps. As he shows there is no expansion at that velocity.
My ballistic calculator shows your bullet should also hit at about 1780.
Personally I’d call your load a 300 yard gun. It should hit at 1925 fps and 1010 ft pounds of energy.

https://youtu.be/XiEx_JQCfbg

[trubulator]

Here’s a very interesting video on the subject of velocity required for expansion. His bullet should be hitting at about 1780 fps. As he shows there is no expansion at that velocity.
My ballistic calculator shows your bullet should also hit at about 1780.
Personally I’d call your load a 300 yard gun. It should hit at 1925 fps and 1010 ft pounds of energy.

https://youtu.be/XiEx_JQCfbg

Hmmm, when I plug my particulars into a calculator I get 1915 FPS and 1002 FPS at 350 yards. Part of it is that I am correcting for elevation and atmospheric conditions, which probably gives me a bit more range (4350' elevation, low humidity, basically high plains/desert). At 400 yards I get 1851FPS and 936 FPE. I'd probably be happiest to keep this to 350 yards.

[VASCAR2]

Here are velocities I got for factory Hornady 123 grain SST at 70 degrees using a Magnettospeed chronograph with AR-15’s. Just for reference a Friend used his 24” 6.5 Grendel AR-15 to take a buck antelope at 500+ yards at 7200’ ASL in Wyoming. My Friend was using a Max load of A-2520 with a 120 grain Nosler hunting Ballistic Tip. He had used this load to take numerous antelope, some with his 18” 6.5 Grendel and some with his 24” AA 6.5 Grendel.


123 Grain SST Hornady

12” 2277 (chrono by forum member with lab radar)

16" 2430

18" 2493

20" 2511

24" 2583

Just for comparison here is a hand load using 31.0 grains CFE 223 and 123 grain Nosler CC I chronographed on the same day. LeveRevolution will give very similar velocities to CFE223. I got basically the same velocities using 123 grain A-Max as Nosler CC.


Hand Load 123 Grain Nosler CC, 31.0 grains CFE223, CCI 450

16" 2449

18" 2471

20" 2526

24" 2619

[NDSwede]

Wow, I reread my previous post regarding COAL. Max COAL is not 3.100”. On my Ar Stoner mag it’s 2.310”. That makes a lot more sense. ????

[trubulator]

I am seeing CFE 223 available. Is the temp sensitivity enough of an issue to really make me want to avoid it for a hunting load powder?

[NDSwede]

Vascar2, I get very similar velocities using LeverEvolution as you do with CFE223. I’ve got a 20” barrel Ar. I’m getting 2557 fps from 31.4 grs of Lever.
All the usual precautions, etc, etc.

[DIANEB]

I started loading Grendel this summer. I am working with factory starline brass and 123 grain SSTs fired out of a 20" BCA upper. I have been working with the powders I could get, namely TAC and H335. My goal is a 350 to 400 yard load for deer on a piece of land where there is little cover and shots might be quite long (could not get closer than 400 yards last year with a rifle that was good for 200). I have been loading to a couple thousandths over the Hornady book min of 2.245" and ran through a couple rounds of ladders to arrive at a couple of good loads. The best TAC load was 27.0 grains with ES of 21 and SD of 8 and average velocity of 2358. The best H335 load was 27.4 grains with ES of 30, SD of 14 and average velocity of 2401. I am running out of time to do load testing, so I decided that the H335 load would have to do and loaded up 3 boxes for the Fall. So at least for now, I am going to run with what I have.

My question is where do I go from here? Hornady Black chrono'd at 2525 FPS out of my rifle and is very accurate, so I imagine that I could do better velocity wise with the SSTs. I also would ideally like good temp stability from whatever powder I use, as the place I hunt can be below freezing or 90F in the Fall. Should I simply be looking for a more suitable powder? Based on what I have read on the boards, it sounds like 8208 or perhaps Accurate 2520 would fit the bill, assuming I can find them. Seat longer? I imagine I need to stay within the 2.26" for magazine purposes. Something else?

Has anyone tried the Hornady 120 grain CX bullet yet? Seems like a candidate for my application as well.

If you can find A2520 give 28.5 grains a try with 120 ELD and the 123 SST both shoot great out of my BCA 18" velocity should be about 2450 fps...
Also 26.5 grains of Benchmark shoots great too...

[trubulator]

If you can find A2520 give 28.5 grains a try with 120 ELD and the 123 SST both shoot great out of my BCA 18" velocity should be about 2450 fps...
Also 26.5 grains of Benchmark shoots great too...

You'd figure two and a half or 3 years into the shortage things would be getting better. Maybe, but excruciatingly slowly. My bad luck to be chasing a new cartridge due to banged up shoulders. I will probably pick up a pound of CFE223 while it is around and keep an eye open for 2520. Some day 8208 might finally be available.

I liked TAC pretty well, but it didn't have the necessary velocity. Maybe I will burn the rest of the pound up in target loads. Seems like it would also work in 223 or 35 Rem.

[DIANEB]

You'd figure two and a half or 3 years into the shortage things would be getting better. Maybe, but excruciatingly slowly. My bad luck to be chasing a new cartridge due to banged up shoulders. I will probably pick up a pound of CFE223 while it is around and keep an eye open for 2520. Some day 8208 might finally be available.

I liked TAC pretty well, but it didn't have the necessary velocity. Maybe I will burn the rest of the pound up in target loads. Seems like it would also work in 223 or 35 Rem.

You'd think things would be getting better by now but I still think the government has something to do with the shortage...

[trubulator]

You'd think things would be getting better by now but I still think the government has something to do with the shortage...

And CFE 223 is gone locally. I can fine 2520 online, but I don't want an 8 pounder. Guess I will be patient and watch for 8208 and 2520, with cfe 223 as a possibility.

Is there published data for leverevolution, or is this wildcat stuff?

[NDSwede]

Kind of wildcat. If you look at BFT’s list of favorite loads you will see several loads.