Test Data Opinions - 44 Mag w/ 240 XTP


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Asherdan
November 12, 2007, 01:40 PM
I was trying a new bullet/powder combo out on the range last weekend and I'd like opinions on the data.

Marlin 1894, 44 Mag, W-W Brass, 2400 powder, CCI300 primer, 1.6 OAL, Lee FCD heavy crimp.

19.5g
1582 fps avg. ES 26 - SD 9.18

20g
1665 fps avg. ES 25 - SD 8.66

20.5g
1762 fps avg. ES 22 - SD 7.34

Hornady sent me a copy of the load data (http://i192.photobucket.com/albums/z120/Asherdan93/Hornady240XTP_265XTP44Mag.jpg) for the 240g XTP bullet that lists powder charge with a velocity range. Start is 17.3g for ~1400 and max is 21.5g for ~1700. I'm looking for an accurate load in the 1600 fps range so I backed off 2 grains and laddered up in .5 grain increments. The data is from 10 shot strings fired for grouping 5 at 50 and 5 at 100 yards. The 20 and the 20.5 grain loads were very accurate, with a slight but noticeable edge to the 20.5g load. The 19.5g load was a little smoky around the case mouth, otherwise brass and primer appearance was normal for all loads. No unusual report or recoil with any load. In short all appeared fine.

My main question is, what do I go by as my cutoff here? I'm 1 grain below max charge but the velocity is exceeding the data listing. Should I back off that 20.5g load a little and use velocity as my cutoff, or powder charge?

If I remember the recommendation is to stop when you hit either, whichever comes first, but I'd like opinions.

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Steve C
November 12, 2007, 04:14 PM
Higher velocity doesn't necessarily indicate higher pressure as there is enough difference in the guns themselves to give you the difference in velocity you are seeing. In addition velocity will increase at higher elevations and greater temperature due to thinner atmosphere. You can take the same load and put them through 3 different guns, with the same barrel length, shoot them on the same day and get 3 different average velocities by a couple hundred fps.

As long as you are not seeing obvious pressure signs like flattened or cratered primers, etc. I wouldn't worry. Use the load that shoots the best for you.

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