Quote:
Originally Posted by southernman
Iclund, I haven't bothered with testing between 12.3 and 12.5grains, I am well inside 1/2 an inch with both rifles, for five shots, and this is with all charges tried, except the max charge of 12.8.
The varmint CZ is likely shooting groups of around .3-.4, and small game here is much bigger, rabbits, hares, cat, opossums all between 5 to 15lbs. So slightly larger target,
Brass used during the intinal testing was Hornardy. With 2-4 firings, full length sized with redding dies, and Winchester small rifle primers,
I have since used, once fired formed Ppu brass, and noticed no obvious difference in accuracy,
Even the fireform Ppu brass,( I drop charge by half a grain )is well inside a one inch group,
I see no point in fiddling any further, with my .17 hornets, for any small accuracy gain, if I want more accuracy, in a varmint rifle, I will take my Sako in .17 fireball and shoot 25gr v-max or Cooper 6x45 and shoot a 65 gr v-max or 80gr Serbia, as both are much less affected by wind, have far greater legs, more energy, and far better scopes.
Great walk about gun, but if I want long distance, I take another rifle.
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Thanks for that information as it will be very helpful to the OP, and others. I only asked if you had tried 12.4 grains because working up in larger increments one can miss an accuracy node with these small cartridges. I stopped fiddling with the 17 Hornet because of the overpressure problems resulting from Hornady's initial loadings and load data that was obviously obtained by the "Safe in My rifle", with disclaimer of course. I have went to the more practical 22LR for close in gophers and my 20 wildcat which is practical for 100 yard to 500 yard shots on these little buggers .
When the 17 H was first introduced I was very excited to try this well designed little 17. I likely had one of the first in Canada and after obtaining this Load Development Information from Hornady I quickly set about using it in a practical way to find a load, in new brass that compared to the factory ammo I had obtained.
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It was in late winter but I went ahead and did this ladder with AA 1680 as it showed 12.4 grains getting 3700 fps in a rifle just like mine using the same components.
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Wow 12.0 grains impressed me so I loaded up a few and wow nearly the same velocity as the factory and to the same POI on two targets!
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Buddy did a ladder with H335 and the 25 V-Max and we thought we had a keeper when we saw the 12.8 grain target which appeared to be a nice full load.
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I went ahead and drew up the cartridge to find what I had and found that the 20 V-Max load only filled 93% of the case below the bullet. I realized that AA 2200 may be a better fit than the 1680.
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Later that spring, as the weather warmed up my measurements , against the Saami Drawing shown earlier and primer protrusion measurements, showed that the pressures developed by both the factory load and my "good" AA 1680 were not
"safe loads".
My drawings helped me determine full loads of AA 2200 under the 20 V-Max and I estimated the velocity I might get, which proved more than a bit off.
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I contacted Western Powders and told them what I suspected which was that the Hornady Data was much too hot with 12.4 gr AA 1680 and the 20 V-Max. I also gave them my findings on AA 2200 and suggested it would get more velocity than the 1680 and about the right pressure from a full case. I asked them if they would provide pressure data. About a month or two later they came out with the data in their online manual which showed 11.2 gr 1680 as max delivering 3498 fps and 49,657 PSI. The AA 2200 Data showed a max load of 13.0gr, exactly as my new brass drawing indicted, developing 3553 fps and 49,768 PSI with more than acceptable accuracy.
Wow a "Good Safe Load" was now possible and later proved practical. It seems strange that Hornady's factory ammo now runs more than 100 fps slower than their original hype indicated
. My methods may seem impractical to some but they do work much better than trial and error.
Later that summer, on a hot day in the gopher patch, my good friend had the misfortune of a blown primer with factory ammunition as shown on previous pictures. Luckily he did not sustain any bodily harm but it was the demise of the 17 H, as far as I was concerned, because my methods were again proven right, in spite of denial by one of the Hornady engineers on this project.
I did work on another 17 Hornet last spring and have reported on that earlier in this thread. I did want to try CFE BLK but we decided to scrap the project in spite of what looked like a very good powder that would make this cartridge what Hornady had originaly reported it to be.