35 Whelen Accurate 360-270CG Load Development

[8uck5nort]

My initial goal was to reach minute of deer at around 2100 to 2200 fps for an all purpose load with both of my current 35 Whelens.

First rifle is a tried and true JES rebored Mossberg Patriot and the second a brand new CVA V2 Scout.

I loaded several different charges of H380 and Accurate 360-270CG GC, PC. WW alloy HT to about 20 bhn. sized .358

I started at 53.0 gr which yielded 2280 fps. Accuracy was meh. The starting velocity surprised me. I was already there.

I progressed up to 54.5 gr which yielded around 2360 fps. Accuracy improved. Not MoA, but I would say deer worthy with 2 inch groups at 60 yards.

I have loaded another ladder starting at 54.5 and will continue up to 55.5 gr.

Can someone with quickload give me a safety check? I am not seeing any obvious pressure signs except the unexpected starting velocity. Maybe my chrony is lying to me?

I am running out of my initial batch of 270 gr so will have to cast more.

I would be interested to know what other powders would be suitable to pursue the above goal. I have some slower burning powders on hand like IMR4350, Superformance and H1000. I also have faster "whelen" approved powders RL15, cfe223,h335, and leverevolution.

I am more interested in accuracy over speed, but the thing that surprised me was there was little if any velocity improvement between my 22 inch mossberg barrel and the 25 inch CVA barrel. Just an observation.

Thank You in advance for your input.

[8uck5nort]

I spent the weekend casting up 200+ more Accurate 36-270CG's. I plan on taking half and Heat treating them and leaving the other half un-heat treated. I also tried a different way of seating the gas checks. I have a Lee sizer so I decided to invert the bullet and run the base through first to seat the GC's. Initial observation seems to indicate the checks actually crimped better. Dunno. When I resize them after PC I will see if I have any "pulled" checks. I will start PC both batches in the next couple of days.

In the meantime I loaded up a test batch of 10 more with H380 to 55.5 gr. I also went ahead and loaded a ladder of IMR 4350 starting at 50 gr. and working up to 51.2 gr.

So as soon as the weather and/or my job gives me a break I will do some shooting and hopefully have some picture proof of groups and chrono displays.

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