Help with load data for 17 MachIV & W748

[piper235b]

Hi,
Just wondering if someone can help me with min -max powder load range for a 17M4 using Berger 25 grn Varmint HP's, a 22" 1:10 twist barrel, Fed 205 Primers and Win 748 powder?

Thanks
Piper

[BRUCEK]

748 which I found too slow. If that's all the powder you have you may want to pick up a pound of BENCHMARK. I've tried many powders and found it to be the most accurtate with decent velocity. My current load is 18.5 grains which is moerate in my gun but would suggest you start a grain lower. I'm using 7 1/2 primers and 25 grain V Max bullets.

This info won't help if you must use 748 but based on my experience...

Bruce

[piper235b]

Thanks,
I have tried faster powders with good results. The previous owner had a pet load using W748, which I thought would be too slow, and disregarded them.

However I was playing around with some 748 loads last Saturday (I've never learned to leave things alone!!) and found them very accurate, I didn't check speeds.

I went up to 19.9 grains OK, but don't want to go further until I know what the max load should be, or what other people have found.

Regards
Piper

[A17Shooter]

Piper,

Back in '92 I tried 20 gr of 748 in a 16.25" Bullberry barrel chambered for the Mach IV. The load was a Remington 25 gr, over 20 gr of 748 and a Rem 7 1/2 primer. The velocity was 3436 and the accuracy was pitiful. Course those Remington bullets weren't very good.

[Ackman]

Originally Posted by piper235b

Hi,
Just wondering if someone can help me with min -max powder load range for a 17M4 using Berger 25 grn Varmint HP's, a 22" 1:10 twist barrel, Fed 205 Primers and Win 748 powder?

Thanks
Piper

Don't even mess with 748 in a MIV, it's too slow. In my guns the best - fastest and most accurate - powders are AA2230 and VV133. In that cartridge I shoot only 25gr bullets.....accurate velocity range is 3880 to about 4050 depending on which powder-bullet-primer......10" twist, .195" neck.

[Dean2]

I agree with the other posters. You can get slow powder to shoot good groups, but the speed is not good and they tend to be dirty. If it is the only powder you can get, that is one thing but there are far better choices, including Benchmark, for the 25 grain bullets. 748 has a burn rate slightly faster than 4895, slower than 322 and faster than 335, both of which Hogdon lists loads for under the Fireball. In my experience, 8208, 4895 etc are too slow, works with the 30s, but too slow for the 25s. Pick the powder that gives the highest velocity, and lowest pressure and you have about the perfect burn rate for that load.

If you want to use it keep going up .2 grains at a time measuring web expansion and watching primer condition.