Berger seating depth ladder opinions

[codym]

Ok so I'm working up a 215 berger hybrid load in my 300 win mag. Components are virgin norma brass, H1000 and Win Lrg rifle mag primers. I did some quick testing last weekend loaded some .006 off the lands and worked up from 73.5 gns in .5 gn increments to 75.0. My best groups at 100 yards were 75 gns at .6'. My chrono took a **** so decided to stop there, find the right seating depth then push the charge weight when I have a chrono to look at fps, es, and std.


Ok so I decided to try the berger seating ladder this weekend. loaded 7 rounds .010 off, 6 rounds .050, 6 rounds .090 off and 6 .130 off. I started with a clean bore. Fired 4 at .010 off and got my worst group at 3.475, next 3 at .050 group was 1.55, next 3 at .090 was 1.075, next was .130 at 1.109. Then started over, 3 at .010 got 1.32 ( two shots in the same hole and I pulled the 3rd shot), next .050 got 1.00 (again 2 through the same hole and one slightly off, didn't feel like I pulled it), next .090 got 2.435 wind started kicking up, last .130 got 1.145. These were at 200 yards. I think the first group was the product of a clean bore, seems like it shot better with all jumps with some fouling. The group with the most potential was the 2nd group at .010, I really think if I wouldn't have pulled that last shot all 3 would have been touching. The most consistent was .050 off, but I was really surprised how well it shot all the way through the ladder. I'm thinking of doing the same thing next weekend but going from .010 to .050 in .010 increments with a dirty bore. What do you all think?

 

[Barrelnut]

Sounds like a good idea. It is hard for me to do load development starting with a clean bore. I like to have 10 shots down the bore before starting any real testing.

I think you will find something good in that .010~.050 range. I wouldn't even clean the rifle before going to the range next time.

In the end you night have to tweak the load a bit, after all the virgin brass has been fired a couple times and fully expanded. But I bet whatever jump you find that works will still hold true.

 

[WeiserBucks]

I've done load development for three 300 WM rifles using the same components except using CCI 250 primers. All of them shot best using 76.0 grains of H1000 and 215 Hybrids at .020" off the lands. All three shot so well at .020" off that I never bothered with a seating depth test.

Definitely proceed with a fouled bore , a clean bore will certainly effect your testing in a negative manner.

 

[ShtrRdy]

Since Norma has two case weights for 300 Win Mag, how much do your new Norma cases weigh?

 

[FURMAN]

I have done load development on two 300WMs. Neither preferred the same seating depth. Based on what you typed the .130 is the most consistent. I would seat some .110,.120,.140, and .150 and see what you get. I would also see what is at 75.5, 76.0, 76.5 and 77. Pay attention to pressure signs. Both of mine preferred 75-76 depending on the powder lot. Pressure was around 77 grains of h1000. You stated you did a ladder. Ladders are shot at long distance looking for vertical. Despite what some may say you will not see any discrepancies from velocity at 100 yards. Every rifle I have every shot larger than .224 has required around 10 rounds after cleaning to produce good groups with the exception of a trick I may have stumbled on but needs more testing for me to be sold on. I am currently shooting a rifle with HBN so this will not work but the last few times I cleaned my last rifle I used one wet patch of kroil followed by one dry patch and the rifle grouped with the first three shots so I will be trying this again soon with a rifle I am not using HBN in.

 

[livetohunt]

I found my node at 76 grains h 1000 and .04 off lands. It shoots almost the same groups at .020 off also.

I have noticed that the 215 bullets heat my barrel up faster than the 210's. They must cause more friction. That was with the same grain amount of h1000 for each. This causes my poi to wander a lot more in shot strings vs the 210's. But this is a factory rifle.

 

[codym]

Thanks guys, Yea I won't be cleaning again for any subsequent testing, it's the OCD from the marine corp, causes me great anxiety to put a weapon to bed dirty.

You know I measured the brass but didn't weigh them, I will do that.

Rfurman I understand what you mean it's not a ladder I just didn't have anything better to call it. So you would go with the most consistent seating depth and not necessarily the tightest groups? I don't have a chrono right now so I don't really want to waste to many components without being able to measure velocity. My hope is to nail down seating depth then play with charges and primers. I'm gonna have to order some CCI's and also want to try the FED 215 M's. The only thing I could find local was the Win.

 

[codym]

I don't have a temp gauge but took my bow and waited at least 1 min 30 second between shots and 5-10 min between groups. Took my bow and shot between. It's a fluted sendero contour and it never got more than slightly warm to the touch.

 

[FURMAN]

215s have a shorter bearing surface so the heat thing is either an anomaly or not actually happening. codym I would not try another primer until you find this one will not work. If you are looking for a good long range load you are looking for the best vertical(not always found by the smallest groups at 100) and it has to be repeatable. Typically I find the load with the best vertical at 600 plus yards and then play with seating depth at short range but there are many ways to skin a cat.

 

[codym]

Gotcha, thats why I shot these at 200 yards, do you think I would get more useable data if I jump to 300? I've never used the vertical data first, in all honestly this is the first I've played with seating depth to this extent. I grew up reloading but most of these techniques are pretty new to me. We would generally go by book coal and pick a bullet, powder and primer and go from there. Long range shooting for us was 600 yards!

 

[FURMAN]

I would not switch what you are doing with this rifle since it seams as if you are getting decent results. I fully believe the quickest way to an accurate load(over 30 rifles) is with a ladder starting with bullets seated at the lands shooting at at least 600 yards and then doing seating depth testing. The next best is the OCW at 100 yards but you have to be able to read the results and not get hung up on tiny groups. I have found if you start with seating depth first rarely you will find that the seating depth at one powder charge will not work at the best powder charge. I have not seen the reverse. Others swear the seating depth preferred by the rifle does not change but I can show you several rifles that disagree. Like I said before stay on the path you are on and try the different powder charges. You can play with seating depth some more but if it were my rifle I would be looking around the .130 area.

 

[codym]

Thanks brother I appreciate it. When my next rifle is done I think I will bug you a little more and try doing the ladder method.

 

[Rhovee]

There is a different seating depth suggest by Berger for the Hybrid bullet design. They suggest starting at 15 off and working in 15 increaments. Mine shoot best at 35 off. I would be surprised that you wouldn't be able to find a seating depth between 50 and touching. I would suspect you would of jumped over a good depth if your way off around 130 thou. One thing i have done before is tried a seating depth test when i was on a "scatter" node. It's to bad you don't have a chrono, i would find a flat velocity node about 1-2 grains below pressure and then test off that.

 

[codym]

Yea kind of screwed up my plans. Im gonna grab a magneto speed in a couple weeks but I got an archery elk hunt and another rifle being built so funds are a little tight. I will get her there eventually.