brainstorm with this data

[curtiscd]

Just for the extra info., would you mind sharing the caliber/ bullet specifics? I'm assuming 7 RM w/ 180 Bergers?

 

[DUSTY NOGGIN]

thanks for all the help, i will post results next weekend , or sooner if possible

 

[DUSTY NOGGIN]

Just for the extra info., would you mind sharing the caliber/ bullet specifics? I'm assuming 7 RM w/ 180 Bergers?

yes exactly , target vlds

my goal for this gun is 1500 - 1700 ... if i do the lower node i barely stay supersonic at the 1700 , so i hope this higher node works out

 

[curtiscd]

Considering that you are shooting steel w/ a target bullet you may also consider backing your charge wt. down for your seat depth test so you can include a little jam as well. I know a lot of the hunting and target VLD's prefer to kiss the lands a little. Just be sure to back the charge down as you'll probably see a jump in pressures by doing so.

 

[dsculley]

Fwiw, my 7rm likes the Berger's at 0.070" jump,

 

[DUSTY NOGGIN]

i ended up with the 68.8 charge weight and found a better seating depth .040 away from first seating attempt --

but i am wondering what might be suggested , regarding another powder choice -- the retumbo was the most plentiful powder i had and also gave best velocity per hodgon data -

so i have a few other options that fit this combination & i think i should at least check another powder --

i have h1000 h4831 imr 7828ssc hybrid v & h4350

since 1000 is so close to retumbo i would , like to try at least one powder a little faster -- keep in mind i really need to keep this bullet moving 2900 or better to meet the goals of this rifle

• Hodgdon

Retumbo
.284"
3.290"
64.4
2,638
46,400 PSI
70.8C
2,914
59,600 PSI

• Hodgdon

H1000
.284"
3.290"
63.2
2,605
46,000 PSI
69.5C
2,884
60,000 PSI

• IMR

IMR 7828
.284"
3.290"
59.6
2,570
45,300 PSI
65.5
2,874
58,900 PSI

• Hodgdon

H4831
.284"
3.290"
58.6
2,652
51,800 PSI
64.5
2,830
60,200 PSI

• Hodgdon

Hybrid 100V
.284"
3.290"
53.6
2,594
48,800 PSI
59.0
2,810
59,700 PSI

• IMR

IMR 4831
.284"
3.290"
56.4
2,608
48,900 PSI
62.0
2,841
59,500 PSI

• Hodgdon

H4350
.284"
3.290"
52.0
2,553
48,000 PSI
56.0
2,752
59,000 PSI

let me know what you think ???

 

[Canhunter35]

If you're not running out of capacity with retumbo and getting the desired velocity, I would shoot and see how you do at 1k, and if the hits stay close vertically, indicating you have a tight es. If you do, there's no reason to try other powders. If your es isn't as good, try h1000. But if you leave your velocity node you will open up your es. So best case would be to try a different powder at the same velocity and compare your es