FireFlyFishing
Well-Known Member
Well I guess I need to keep working my load dev…
7RM and 168VLD
- Thread starter overinfinite
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Kmccord
Well-Known Member
It works for me if I follow Berger recommendations, Phil at Berger always states, start with the minimum charge and start working seating depth first. Once you find a seating depth that is the smallest group at 100yds, then run it up the charge ladder. Then I start fine tuning from the load that is as tight as possible. Several ways to skin a cat, just have to find one that works for you. If H1K doesn't work, I would try H4831sc or Retumbo and see if that will work better.
Hahah sorry fire I meant to quote the OP. Seems like your 7mag be dropping dimes!
overinfinite
Well-Known Member
That same load shot 1 other group at 0.836" the same day and then 2 groups over 1.25" and 1 group over 2" the next day.
Feels more like the 0.587" is the lucky anomaly
FireFlyFishing
Well-Known Member
Yes sir. Easy work up too. Got two deer with it this last season!
overinfinite
Well-Known Member
Did bergers seating depth test. Today's temps hung around the 45deg. Did 2 minutes between each shot and 5 minutes between each group. Since I did my ladder test with 0.005"and 0.010" off the lands I bumped up to:
2- 0.040"
4- 0.070"
6- 0.100"
8- 0.130"
The two unmarked groups are a return of the federal berger hybrids only 2 groups of 4 its all i had left. They printed 0.970" and 0.980".
Everything else played the exact same 3 shots in, 2 shots out. No statistical pattern when the 2 Flys either. It definitely did not like 0.100" off the lands. The first shot was up and left.
Best group so far has been with 68.5gr and 0.010" off the lands that same load has printed in the 0.58" and the 1.30" range. I am considering that to be "good enough". But I am also considering that I may put the gun away and see if I need to revisit this with H4831SC in the future.
2- 0.040"
4- 0.070"
6- 0.100"
8- 0.130"
The two unmarked groups are a return of the federal berger hybrids only 2 groups of 4 its all i had left. They printed 0.970" and 0.980".
Everything else played the exact same 3 shots in, 2 shots out. No statistical pattern when the 2 Flys either. It definitely did not like 0.100" off the lands. The first shot was up and left.
Best group so far has been with 68.5gr and 0.010" off the lands that same load has printed in the 0.58" and the 1.30" range. I am considering that to be "good enough". But I am also considering that I may put the gun away and see if I need to revisit this with H4831SC in the future.
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overinfinite
Well-Known Member
I forgot to add- here was my stipulation with building this particular rifle. 24" barreled magnum, shooting medium-heavy VLD bullet to squeeze out about as much potential as I could out of a cartridge in the 68-70gr range.i was considering the 7prc, but I am not a huge fan of the 175-180gr range in the 7s without going up to the 28nosler and all it's recoil. Also, this bergara came up for a good price when I bought it as a factory ridge.
I am a big fan of speed and good BC bullets.. and if this gun needs to run in the 2,700-2,800 fps range with a 168 classic or 2,900fps range with 140-150 bullet, then I could have stepped down to a 6.5prc and done the exact same thing in the 50ish grains of powder.
I am a big fan of speed and good BC bullets.. and if this gun needs to run in the 2,700-2,800 fps range with a 168 classic or 2,900fps range with 140-150 bullet, then I could have stepped down to a 6.5prc and done the exact same thing in the 50ish grains of powder.
FireFlyFishing
Well-Known Member
I would try a different powder or projectile.
I agree. Maybe move on to a different projectile. As much as I hate to admit it I've had to resort to Hornady 175eldx with one 7RM. Just wouldn't take a liking to any bergers. I almost gave up on the barrel and tried 175s and it was immediately acceptable. Terminal performance is still out for debate but at least she's dropping dimes now.
Also, don't chastise me too much but I've seen rifles shoot crazy good at range. Don't ask me how, but they shoot a 2 inch group at 200 yards and a 2 inch group at 600. Seen it with multiple rifles. Maybe send a group at 500 just to see how it holds.
overinfinite
Well-Known Member
After making that post, I dug out some H4831SC, loaded up 5 groups from 63gr to 65gr in 0.5gr increments. Loaded 0.010" off the lands.
Double checked every single powder load, checked BTO length for every load. It looks like a copy and paste from this mornings loads with H1000 and the seating depth chart. 1 group at 1.080" and the rest between 1.25" and 1.5". 3 touching, 2 thrown.
I've tried factory hornady eldx loads and thus thing hated them. But I am wondering if I should try those next or if it would like something more "standard" like a accubond or LRX or even a sierra. I just really wanted something in the higher BC range that would make 65+ gr of powder worth the recoil.
Double checked every single powder load, checked BTO length for every load. It looks like a copy and paste from this mornings loads with H1000 and the seating depth chart. 1 group at 1.080" and the rest between 1.25" and 1.5". 3 touching, 2 thrown.
I've tried factory hornady eldx loads and thus thing hated them. But I am wondering if I should try those next or if it would like something more "standard" like a accubond or LRX or even a sierra. I just really wanted something in the higher BC range that would make 65+ gr of powder worth the recoil.
Kmccord
Well-Known Member
I would take the lowest powder charge listed in the manual you are using and run a seating depth test. I would do .010, .015, .020, .025, .030, .040 and .045 and see if your groups tighten up. Running one seating depth and multiple powders have done nothing but aggravate you. Whichever gives you the best three shot group, repeat again with same charge and depth and see if it is consistent. It should be, then go up the ladder on powder charges. I normally go in 1gr increments until I hit pressure, you should see the three shot groups opening and closing on the ladder. As with the seating test, I pick the smallest and see if it will repeat and if so, I start testing in smaller increments above and below the original charge. That will normally bring me to what I want. Expect to burn through a pound of powder and around 100 rounds of bullets. I also, would not get serious with a load development until I had burn at least 150 rounds down the barrel. This is just my method, like I have said before, there are several ways to skin a cat, this is just what I am custom to using.
I've experienced this phenomenon too. I used to think a .5MOA gun at 50yds will always be a 1MOA at 100yds. That isn't the case. I've seen the same groups at 50yds, 100yds, 500yds, etc. I've even load developed for 1 mile shooting at 50yds and printed sub MOA groups at that distance. One does have to be exact on POI at 50 though. If ballistics solver says with a 100 or 200yd zero the POI at 50 is .3 or .4 inches, or mils, whatever it says, make sure its hitting right there.
