Tightening up my long range reloads.

[MagnumManiac]

@MagnumManiac I am talking specifically for a long range build out to 1600-2000 yards not 300 yards. An ES of 100 fps will change your point of impact by 22 inches at 1000 yards so I would take a 1" group at 100 yards with an ES of 2.6 over my 0.3" group at 100 with an ES of 40. Just hoping I can get the 1" group down to ½" by messing with brass and seating depth.

Brass prep will make diddly squat difference at the yardages you describe. My earlier post regarding 100fps ES had zero to do with your circumstances, the point is that great groups may NOT have great ES/SD numbers…
You are also talking about groups at 100, sorry, but this is simply meaningless if you intend running those at 2000yrds.
I shoot competitively at 2000 metres, 1600 metres and 1000 metres, my testing is done at 300 metres, then moved to 600 metres for verification. Nothing at 100 tells you anything statistically…

Cheers.

 

[Laguna Freak]

I've got a powder charge with a great ES and SD but it was only a 1-1.25" grouping at 100 yards. My ES was 6.9 and SD 2.6 over 4 shots (Garmin Xero) with 59gr H1000 and 140gr ELD-M bullets right at the lands flying 3060 fps. What's the best way to tighten the grouping? I was thinking I'll make sure all my brass are proper lengths and anneal then back them off the lands in 0.015" increments until I get a good grouping? And if that doesn't work maybe try a different brand of 140gr bullets?

I currently shoot a 123gr ELD-M load with 57gr H1000. ES of 38 and SD of 11.8 only pushing 2970fps which isn't great but it puts 5 shots in one hole at 100 and hit 4/4 shots on 12"x16" steel at 880 yards. I would love to find a good grouping with the 140's since the node is at a higher velocity and the higher ballistic coefficient so all around should be a better long range load when I start pushing the distance out towards a mile.

Shooting a L/H Tikka T3 CTR in 6.5 PRC

IMO, seating depth testing is your next step. I would not be immediately concerned with the higher velocity node that you have ID'd at the current seating depth. If chasing velocity is your priority, you may not achieve the repeatable PoI you say you are seeking. I'll gladly give up 100+ fps from 3,000+ to get 0.5 MOA groups if I need to.

If I were in your shoes, I would test starting at 0.020" off the lands with 3 rounds, then seat deeper with 3 rounds at 0.010" increments all the way out to 0.120" off the lands if required. I doubt you'll have to go that far. IMO 0.010" increments is more thorough than 0.015" because it is easy to skip over a node(s) at 0.015" increments. I would also reduce my powder charge to avoid an over pressure load as I seat deeper.

Once you have ID'd a seating depth range that may be 0.010" to 0.020" wide, you can continue working the charge and seating in that range to determine the optimum charge at the optimum seating depth.

 

[Maxoutmaze]

IMO, seating depth testing is your next step. I would not be immediately concerned with the higher velocity node that you have ID'd at the current seating depth. If chasing velocity is your priority, you may not achieve the repeatable PoI you say you are seeking. I'll gladly give up 100+ fps from 3,000+ to get 0.5 MOA groups if I need to.

If I were in your shoes, I would test starting at 0.020" off the lands with 3 rounds, then seat deeper with 3 rounds at 0.010" increments all the way out to 0.120" off the lands if required. I doubt you'll have to go that far. IMO 0.010" increments is more thorough than 0.015" because it is easy to skip over a node(s) at 0.015" increments. I would also reduce my powder charge to avoid an over pressure load as I seat deeper.

Once you have ID'd a seating depth range that may be 0.010" to 0.020" wide, you can continue working the charge and seating in that range to determine the optimum charge at the optimum seating depth.

@Laguna Freak I don't think I need to be worried about pressure as they're seated right at the lands now so it should be less pressure if they're back from the lands, no?

 

[Laguna Freak]

@Laguna Freak I don't think I need to be worried about pressure as they're seated right at the lands now so it should be less pressure if they're back from the lands, no?

Not necessarily. You are correct that at the lands safe pressure is likely safe at slightly deeper seating depths but as the bullet is seated deeper in the case, the pressure curve changes. Your safe at the lands, may not be safe at 0.070" deeper seating.

 

[mtbullet1]

I use lee factory crimp die as last operation, it helps "uniform" es/sd for me

 

[Maxoutmaze]

I got lucky today and found a tight group real quick. 0.035" off the lands shot 0.75" at 200 yards. 3028fps average, 1.9 SD and 4.5 ES over 4 shots (Garmin Xero). 140gr ELD-M, 59gr H1000, 24" 1-8" twist. Will load up some more and make sure I can replicate it again. Perfect day for shooting, 20 degree Celsius and almost no wind.

 

[K.E.C.]

I got lucky today and found a tight group real quick. 0.035" off the lands shot 0.75" at 200 yards. 3028fps average, 1.9 SD and 4.5 ES over 4 shots (Garmin Xero). 140gr ELD-M, 59gr H1000, 24" 1-8" twist. Will load up some more and make sure I can replicate it again. Perfect day for shooting, 20 degree Celsius and almost no wind.

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