28 Nosler Load Development

[chav0_12]

Can someone help me make sense of this data that I acquired yesterday at the range with my 28 Nosler with 195gr Bergers, with Retumbo. I was getting pretty good SDs and ESs once I got to a point. I just can't make too much sense of all of this data. Before I had a chronograph I would make all of my decisions based off of group size. While that may work, I also want to be able to take this rifle out to longer distances and I know how important extreme spreads can be at those longer ranges. If I remember correctly, my best group was at 79gr and then 79.5 also have a respectable groups size but it wasn't as small. I also realized, when I got home, that I was starting to get extractor marks over the 80gr charge. Even going up to 82.5 the marks were light enough that I needed to maneuver the case perfectly in the light to see the marks. There was never any heavy bolt lift or any other pressure signs, well maybe a little flattened primers, but not bad. Should I work in the 78.5-79.5gr range and see what I can get. I am sort of limited by magazine length at 3.605" but I can also get a 3.715" magazine for this rifle. See the charts and data acquired below.

 

[Dmagna]

What bullet? How many shots down the barrel?

 

[chav0_12]

What bullet? How many shots down the barrel?

Edited to add, the bullet. It's a Berger 195gr EOL, I'm using Retumbo. It's a 1:8 twist. I'm close to 200 rounds down the barrel. A little more than 50 of some Nosler factory ammo with 175s. A pressure ladder with virgin Nosler brass and 195s and 177gr Hammer Hunters, maybe 20 rounds there. Then yesterdays 36 rounds plus 50 rounds of fire forming this brass before this test. Might be some I'm missing too.

 

[WapitiBob]

Lance K has done dozens of those 28's, 195's and hammers. He can point you in the right direction.

 

[2buffalo]

I have developed a couple loads for my 28 Nosler. I would put away the chronograph and do either a ladder or OCW to find a node. I don't use a chronograph until the load is fully developed. I am sure others do it differently but this has worked for me. I can say that if you are starting to flatten primers your brass won't last long. I also used Retumbo in my 28 and I can say you are probably pretty hot at 82.5 grains with a 195 grain bullet.

 

[PddPdd]

You may benefit from doing seating depth testing first between velocity nodes that appear to be at 78.7 & 81.1 = 79.9 (if I'm correlating the right data points to the corresponding charge weights). Then follow up with charge weight tuning.

 

[wasskeet]

FWIW, Here with 80gr of Retumbo behind a 180 hybrid in new Nosler brass, I got a few flattened primers and the repriming of said brass went in very easy. Starting over on ADG and see what happens.

 

[chav0_12]

FWIW, Here with 80gr of Retumbo behind a 180 hybrid in new Nosler brass, I got a few flattened primers and the repriming of said brass went in very easy. Starting over on ADG and see what happens.

I'm using ADG now. I'll have to see how these pockets held up.

 

[chav0_12]

You may benefit from doing seating depth testing first between velocity nodes that appear to be at 78.7 & 81.1 = 79.9 (if I'm correlating the right data points to the corresponding charge weights). Then follow up with charge weight tuning.

The problem I have with that is that I just don't have much room to move the bullet. I can move it in, but I'm at mag length now and can't get any longer. The way the computer spit out the graph isn't ideal with the loads, but I wanted to plot the points.

What are you seeing to say that is a velocity node? I didn't see any consecutively flat spots like I was hoping to find. The only ones were the 78.5-79.0.

 

[chav0_12]

I have developed a couple loads for my 28 Nosler. I would put away the chronograph and do either a ladder or OCW to find a node. I don't use a chronograph until the load is fully developed. I am sure others do it differently but this has worked for me. I can say that if you are starting to flatten primers your brass won't last long. I also used Retumbo in my 28 and I can say you are probably pretty hot at 82.5 grains with a 195 grain bullet.

I agree that 82.5 was pretty hot and I didn't plan to go any higher but as far as I could tell at the time it wasn't showing much for pressure signs. I was about to stop at the 79gr load since it did give me a good group and had low ES and SD but I wanted to see if the next one was going to be better.

What do you do after the load development using a ladder or OCW if you have high ESs? I usually had always just done an OCW, looking at groups. I was doing the same here, but I was also chonographing to get data at the same time. That 79gr load produced a nice small group, two shot touching and then I accidentally shot at the wrong point on the third but it landed close to where the others would've been if at the same POA.

 

[L.Sherm]

2buffalo is 100% correct, put the chrono away if you are gonna try and use that to find a " flat spot or velocity node"
TARGET IS THE ONLY THING THAT COUNTS!!!
Watch Alex and Erics new video.

 

[chav0_12]

2buffalo is 100% correct, put the chrono away if you are gonna try and use that to find a " flat spot or velocity node"
TARGET IS THE ONLY THING THAT COUNTS!!!
Watch Alex and Erics new video.

I agree and I will watch what the target tells me but I also want to end up with other data too? Can we not gather data more than one way? group size and velocity node? I'm not saying anybody is wrong but group size at 100 yards is one thing, a bad load can print small groups at close range, but will string vertically at longer ranges. No? So both things can matter. I wasn't just shooting over the chronograph and only gathering that data, I was shooting groups too.

 

[L.Sherm]

Like I said watch the Video Alex and Eric talk about E.S. and there 100% correct.
If E.S has anything to do with Vertical why would 3 shots at 100 be in a straight line vertical. at 100 at 1.5 that all have the exact same FPS

 

[2buffalo]

I agree that 82.5 was pretty hot and I didn't plan to go any higher but as far as I could tell at the time it wasn't showing much for pressure signs. I was about to stop at the 79gr load since it did give me a good group and had low ES and SD but I wanted to see if the next one was going to be better.

What do you do after the load development using a ladder or OCW if you have high ESs? I usually had always just done an OCW, looking at groups. I was doing the same here, but I was also chonographing to get data at the same time. That 79gr load produced a nice small group, two shot touching and then I accidentally shot at the wrong point on the third but it landed close to where the others would've been if at the same POA.

You are just looking at POI elevation flat spot. Group size does not matter to me when I am shooting an OCW. I tune after with seating depth, neck interference, and try different primers if needed. A high relatively high ES does not mean your load is bad as a low ES doesn't mean your load is good. The only way to tell for sure in my experience is to shoot at distance. I only use the chronograph to give me a start in figuring dope with velocities. I am by no means saying this is the only way to get to where you want to be. There is always multiple ways to skin a cat. This is just the most efficient way I have tried.

Like LSherm said let the target tell you because in the end that's what matters.