.260 scenar 'ladder' - Can I really tell at 100 yd

[SRSDriver]

I'm new to reloading, and working on a load for my .260, benchmark barrel. I only have access to a 100yard range during the week.

I worked up a ladder of

Lapua Brass
139g scenar
cci BR2
39-42g H4350 in 0.3grain increments

I shot this at my local 100 yard range, and while the higher loads did move up the target a tiny bit, virtually every round is touching each other, so I have a funny ragged hole with a couple just on the periphery, but all fit within a 1" square...

I guess I'm not going to see 'nodes', but my rounds for 2/3/4 and 8/9/10 (near the bottom and top of this ladder) were all very close...

Is trying to work up a load at 100yd pointless? I'm thinking about taking the middle of my 8/9/10 group, loading 15-20 of those, and shooting to see how they hold to each other, and chronoing. If that works, I'll take that when I can get access to a longer range.

Suggestions for a new guy?

 

[244]

Re: .260 scenar 'ladder' - Can I really tell at 100 yd

I am by no means an expert, but have you looked into this?

 

[Ouch!!]

Re: .260 scenar 'ladder' - Can I really tell at 100 yd

You usually wont be able to tell using the ladder test until you are out 3-400yds

 

[Goldbeachman]

Re: .260 scenar 'ladder' - Can I really tell at 100 yd

Working up a load at 100 yards can be done but unfortunately you will be left with a load that is only "worked up" for that fairly short distance and one that may or may not perform at distance.

Using a chronograph will help somewhat in determining what charge weights are developing the lowest standard deviations in velocity, but again, this alone won't arrive at a precision load that is reliably accurate at distance, for that gun. The problem is that shooing groups at 100 yards covers up a myriad of sins, both from the shooter as well as the gun.

The point of ladder testing at distance, for me, is determining what charge spreads (nodes) will result in the barrel being/pointing in the same place, shot to shot, even with a slight variance in velocity because of this, that, or the other reason. You can't see that at 100 yards. At 400 and beyond, it is often obvious.

I've worked up loads that shoot one hole at 100 yards but fall apart after 500 yards or so. However, loads worked up at 400 yards or farther and are well subminute will typically be strong performers at 100 as well (but not always!)

But you gotta work with what you got. Sometimes I've even got lucky picking an educated guess at charge weight, seating depth, neck tension, only to confirm that that load in fact was optimal when I was able to do thorough load development.

Ultimately it depends on what you are going to do with the gun. If its that your shooting is going to be 500 yards and in, doing load dev at 100 yards is better than not doing it at all. Myself, I would probably do it the "old fashioned" way of testing multiple charges and shooting multiple 5 round groups to see if I can see the trending. After settling on a charge, I'd move to seating depth variations and neck tension differences to perfect the load.

You didn't tell us what gun, barrel, etc. you are doing this for. There is some common loads that people find success with for 260 and 139 scenars. Myself, I use 43 g H4350 in a AW with a 24" Bartlein. I have a 22" Pacnor in 260 that likes 43.4 grains and my GAP with a 24" Obermeyer likes 41.5 grains H4350. I note you stopped at 43 grains and it is possible that the gun likes a little bit more. Only testing will let you know and whether you are getting close to max pressures.

P.S. Oh and by the way, work up some rounds again for a ladder test from 41 to say 45, and run a ladder at distance (400-500) when you can get to it. Load 5 or 10 rounds at the 41 weight so you can be sure to start on paper with the lowest weight (that often will save you some headaches!) When getting past 43 examine each spent case for pressure signs, watch for sticky bolt lift, etc. Don't push it too far.

Good luck!

 

[SRSDriver]

Re: .260 scenar 'ladder' - Can I really tell at 100 yd

Thanks for the help!

Being somewhat new to reloading, I figured I'd stop at 42 for the first string playing around, but I didn't see any pressure signs at 42g - It's a DTA SRS with a benchmark barrel.

I think I will need to play hooky and make the drive to the open lands...

 

[Jerry m]

Re: .260 scenar 'ladder' - Can I really tell at 100 yd

My 100 yard hold load where touching at that range could not hold the ten-ring on an F class target at 600 yards. I vote no, go out longer.

Good luck

Jerry

 

[vman]

Re: .260 scenar 'ladder' - Can I really tell at 100 yd

To sum up my answer for your convenience...

NO

Go out to 400 as a minimum

 

[Goldbeachman]

Re: .260 scenar 'ladder' - Can I really tell at 100 yd


Well, we all can't just run out to past 1000 and confirm load development, like uh, this one from this afternoon at 1035 yards: