300 prc load development

[Nmbowhunter06]

I've been doing load development for my bergara 300 prc. I started out with a ladder test at 600 yards. The results I got were 75.5-77.0 grains had little to no vertical in them. So I loaded up 3 shot groups 75.5,76.0,76.5,77 grains and went and shot this morning. The results were every group was pretty much the same size about 100 thous difference when measured with my calipers and poi on the targets at 100 yards were all indentical So right now I don't know which to pick to start playing with seating depth? FYI I haven't shot any through my chronograph yet because it took a dump
On me

 

[Wide Glide]

Without having a chronograph I only see 3 options to distinguish if they all seem the same.

Option one shoot further

option 2 shoot more rounds per group

Option 3 shoot more rounds per group at a longer range

 

[MagnumManiac]

What distance were those groups shot at?
They do not look that impressive to me.
I like to test seating depth prior to shooting for group. I pick a middle load with the powder I want to test, then load 3 rounds of each @ .005", .010", .020", .030" then if none of those work, I use Brian Litz's seating depth test.
The governing factor with all of this is the mag length, of course. If you are restricted to a short length mag box, say 3.4" then you need to load from max mag length back to about .050" and no more in the same .005" increments.

Cheers.

 

[Nmbowhunter06]

Magnum maniac I haven't done any seating test yet just finished my ladder the other day and picked charges that had only 1" vertical dispersion and shot groups at 100 with them and this was the result exact same group size and poi so My question is do I pick right in the middle of this and perform seating depth test?

 

[Tiny Tim]

I believe seating depth should be done outside of your accuracy powder node. This will show the truest result of the seating test and be more readily apparent than right in the middle of the powder node. I think this is what Magnum Maniac was getting at. Once this is established, the load is tuned with the powder charge.

 

[Nmbowhunter06]

I believe seating depth should be done outside of your accuracy powder node. This will show the truest result of the seating test and be more readily apparent than right in the middle of the powder node. I think this is what Magnum Maniac was getting at. Once this is established, the load is tuned with the powder charge.

Hey appreciate the response no I understood what he meant I was always told to just to do seating after you look for a powder charge and is what I've been doing. Just I did a ladder and then shot groups at 100 with what I think is my node and all the groups are exactly the same size and same poi so I'm having a hard time picking which powder charge to go with to start testing seating depth. I was told by a friend of mine to scrap this whole combo and move on but I'm not ready to give up.

 

[Highvoltage]

Shoot closer to see what those groups look like. I shoot at 200 to start. This is where groups begin to show their face in an accurate rifle. I start with powder charge. Then I'll take the best 2/3 and move out to 325 ( farthest I have to shoot). Usually 1 will show the most promise. I'll retest this then move onto seating. Now that I know my powder charge I shoot my seating at 325, and again 1 will outshine the rest, then I finish by retesting my refined powder and seating together. At 100 everything is close to or sub moa in an accurate rifle and it makes it a challenge to distinguish much for me. Best wishes.

Ps I've blown through a lot of components trying new combos it's part of the fun!

 

[Nmbowhunter06]

Shoot closer to see what those groups look like. I shoot at 200 to start. This is where groups begin to show their face in an accurate rifle. I start with powder charge. Then I'll take the best 2/3 and move out to 325 ( farthest I have to shoot). Usually 1 will show the most promise. I'll retest this then move onto seating. Now that I know my powder charge I shoot my seating at 325, and again 1 will outshine the rest, then I finish by retesting my refined powder and seating together. At 100 everything is close to or sub moa in an accurate rifle and it makes it a challenge to distinguish much for me. Best wishes.

Ps I've blown through a lot of components trying new combos it's part of the fun!

Hey appreciate the input for sure. Yeah I've never seen 4 different powder charges shoot almost exactly the same same and poi. But those charges on a 600 yard ladder had almost no vertical spread at all.

 

[Tiny Tim]

Could you test them at a longer range. W/o a chronograph, its difficult to know. If you could test @ 600 as before, it may be revealing.

 

[Nmbowhunter06]

Could you test them at a longer range. W/o a chronograph, its difficult to know. If you could test @ 600 as before, it may be revealing.

That's actually what I was debating on doing this evening or tomorrow morning shooting them at either 400 or 600 to see what they do

 

[Tiny Tim]

If 400 is an option, it may be better than 600. Less wind drift. You already know they group well @ 100. Maybe do five shot groups rather than 3. Should give you a good basis for your final decision.

 

[Nmbowhunter06]

Yeah that's the plan. Thefatal mistake I made in my reloading is I measured wrong on the oal I was suppose to use to perform the ladder test so I'm thinking that is the reason for the groups being over an 1". I think I'm actually .100 thou seated deeper than where I wanted to be. I based the seating depth off the factory ammo hornady match ammo that shot decent. Those were 225eldm and that's what I'm loading.

 

[Steve gavette]

Yeah that's the plan. Thefatal mistake I made in my reloading is I measured wrong on the oal I was suppose to use to perform the ladder test so I'm thinking that is the reason for the groups being over an 1". I think I'm actually .100 thou seated deeper than where I wanted to be. I based the seating depth off the factory ammo hornady match ammo that shot decent. Those were 225eldm and that's what I'm loading.

The ELD-M factory Hornady was .040 off in my chamber.

 

[Nmbowhunter06]

The ELD-M factory Hornady was .040 off in my chamber.

I haven't actually measured my chamber with the oal gauge I was trying to cut a corner and use the factory coal but I messed up. I think the measured at 3.7 if I'm not mistaken and I think ended up seating them 3.558. Sorry I'm not at the house to check the measurements. I know off the ogive it was 2.900 and that's where I seated them.