Aa 1680

[Pahoghunter]

I sent ACCURATE ARMS a message on using AA 1680 in the 17 AH and was surprised at the reply, they don't really recomend 1680 and if you do use it the load with a 20 gr. bullet is a starting load of 10.1 grs and 11.3 max.
A-1680 will be on the fast end of the burn rate spectrum for the 17AH.
Although it can be used it will not be the ideal powder and we estimate your loads to be on the high end vs the typical <43000Psi limit.
Also this kind of caliber will not allways show the pressure signs.
Since the pressure spec is very low, most people doing development work without means to determine the pressure are usually way above that limit.
Good quality weapons will also handle higher pressures and the normal signs will not allways appear at the low pressure and will only manifest at much higher levels.
Since this is such an extremely sensitive caliber its hard to predict or calculate a load.
Did you measure the velocity during your current tests?

We usually recommend slower burning powders for this caliber.
We recently brought back a powder that fits in-between A-1680 and A-2230 called A-2200, which will be the first choice.
We usually recommend the following.
Caliber: .17 Ackley Hornet.

Barrel length: 22-24”

Powder: Accurate -- 1680®. 3rd Choice.

Bullet weight: 20grains.

Start load: 10.1 grains (2900 - 3000 Fps)

Maximum load: 11.3 grains (3300 – 3400 Fps)

Bullet weight: 25grains.

Start load: 9.7grains (2775 – 2875 Fps)

Maximum load: 10.8 grains (3050 – 3100 Fps) LD ca 87%

Powder: Accurate -- 2200®. 1st Choice

Bullet weight: 20grains.

Start load: 10.7 grains (2900 - 3000 Fps)

Maximum load: 11.9 grains (3300 – 3400 Fps) LD ca 98%

Bullet weight: 25grains.

Start load: 10.4 grains (2775 – 2875 Fps)

Maximum load: 11.5 grains (3050 – 3100 Fps) LD ca 96%

Powder: Accurate -- 2230®. 2nd Choice

Bullet weight: 20grains.

Start load: 11.7 grains (2900 - 3000 Fps)

Maximum load: 13.0 grains (3300 – 3400 Fps) LD Ca 104%

Bullet weight: 25grains.

Start load: 11.2 grains (2700 -2800 Fps)

Maximum load: 12.5 grains (3050 – 3150 Fps) LD ca 104%

NOTES:

It’ important to note that SAFETY is our prime concern therefore we strongly recommend.

1. TO ALWAYS BEGIN LOADING AT THE RECOMMENDED MINIMUM “START” LOAD and develop loads in 2% increments towards the MAXIMUM load.

2. If at all possible, measure the velocity and correlate with our data.




Regards

Johan Loubser

Ballistician

Ramshot.Accurate Powders

Tel: 406.234.0422 email: johan@ramshot.com

[Easy_E]

Thanks for sharing this info. I need to start over with my .17 AH last year I was getting stuck cases this makes me wonder if I was a little hot ?

[Ackman]

Hard to figure why they don't recommend 1680. It's become pretty much a standard powder for the 17AH. An awful lot of people use it. My fireform load is 11.0gr/1680 and a 20gr bullet. Formed cases use 11.6gr, 20 Berger or VMax, BR4 primer. I've shot several thousand of them in all kinds of temperatures.....a couple thou. fireforming and a thousands more with formed brass. Even the Contender has been hot enough several times to need cooldown. Those loads are completely safe in my gun. I know others who use the same or hotter loads with that powder.

[Pahoghunter]

My fire forming loads are 12 grs of 1680 and the loads I've started using in th fire formed cases are 12.3 grs, which I thought were still mild?

[TinMan]

I have used the older AA2200 in a standard Hornet, trying to get a lower velocity, quieter load. A full case, roughly 12.5gr gives 2100fps with a 40 or 45 gr bullet, and has a very dull, deep, quieter report. The 17AH must be a very different animal......don't have one yet, but will some day. By the way, this load was around 0.5MOA and had single digit SD.

[Mulerider]

It's all about the 22 Hornet pressure limit being set at 43k (CUP or psi?), and that carrying over to the 17AH. Sometimes the historical firearms cause the issue, sometimes it could be the case...which would have to be the culprit this time, considering the firearms being used.
The corporate positions will err on the conservative side, even if it doesn't translate to some valid real world experience (most of the 17AH shooters in existence!).

It would be great to see pressure reports for a often typical load of 20Vmax over 12.3 -12.5gr of 1680. No doubt high for a "Hornet", but within the range of other typical cartridges?

[RebelSquirrel]

I used 12.4gr of 1680 (compressed), 400 CCI primer for fireform loads with 20gr v-max in my 17AH. Just slight primer cratering and 3800fps. Wasn't an accurate load for me although it did an excellent job of forming brass. Stretched the case necks out just a few thousandths, doing all my trimming after fireform.

[Daryl]

I also use 12.3gr. 1680 as a normal load for 25gr. Vmax and HP's, with 12.6gr. being my 20gr. load with that powder.

They are being ultra-conservative & holding to 1920 Hornet pressure limits which does not compute for our modern bolt actions rifles today- especially with minium taper wildcated rounds on that case.

Their proposed ballistics are inferior to the .17 Squirrel.

[Bighornbob]

At least you guys have a 17 AH to reload for!! I don't know how much longer I can hold out! Cooper is taking their sweet time building it. OK it has only been 2 1/2 months, I just checked my check book. I'll chill out. Sending donor rifle tomorrow to have converted to a 17 Shrew. I really want a 17 AH. Bob

[Ladobe]

I agree 100% with Ackman. It's what I shot in 2 of my 3 17AH's with no problems at all, and I live on the desert where temperature extremes even during a single day can be quite wide from dawn to mid-late afternoon. The last years I was using WC680 MilSurp from an 8# jug as it was so much cheaper than AA1680 (in fact still have unopened #1 bottles of AA1680 and Lil'Gun that were never used after I bought the WC680).

FWIW