Max loads

[bboswell]

I consistently see people post about starting at book max charge or very near it. I have recently come upon an extreme example why this is a bad idea. Both rifles are custom rifles in 280AI shooting 150g LRAB's with same powder and primer.

This round has extremely varied load data with the following start/max loads:
Sierra - 53.4-59.4
Nosler - 59-63

Rifle 1 - Brass is Nosler factory brass, Schneider Barrel that measures 2.760 to the lands with OAL gauge. Gun likes 0.040 jump to lands. At 61g bolt lift was way too stiff, obvious primer pressure signs etc

Rifle 2- Lapua 30-06 brass fire formed, Bartlien barrel that measures 2.730 to the lands. Gun likes 0.120 jump to lands.

Rifle 2 has not reached any pressure signs yet while near Nosler max and a couple grains over Sierra max. But at same charge as rifle 1 it was 150 fps slower.

I expected that this meant the Lapua brass had more capacity, nope measured and Lapua has 1.4g less water capacity than Nosler brass.

Had I started rifle 1 near the max listed by Nosler I feel certain it would have locked up.

[WyoBull]

I never start at max when working up a load. I typically start about the middle between min and max and then work from there. Sometimes I work up and sometimes work down as it all depends on accuracy. Max load does not always bring with it more accuracy. It takes time as you know to work up a good load that optimizes accuracy for that specific rifle and they are all different.

[aggieman08]

I consistently see people post about starting at book max charge or very near it. I have recently come upon an extreme example why this is a bad idea. Both rifles are custom rifles in 280AI shooting 150g LRAB's with same powder and primer.

This round has extremely varied load data with the following start/max loads:
Sierra - 53.4-59.4
Nosler - 59-63

Rifle 1 - Brass is Nosler factory brass, Schneider Barrel that measures 2.760 to the lands with OAL gauge. Gun likes 0.040 jump to lands. At 61g bolt lift was way too stiff, obvious primer pressure signs etc

Rifle 2- Lapua 30-06 brass fire formed, Bartlien barrel that measures 2.730 to the lands. Gun likes 0.120 jump to lands.

Rifle 2 has not reached any pressure signs yet while near Nosler max and a couple grains over Sierra max. But at same charge as rifle 1 it was 150 fps slower.

I expected that this meant the Lapua brass had more capacity, nope measured and Lapua has 1.4g less water capacity than Nosler brass.

Had I started rifle 1 near the max listed by Nosler I feel certain it would have locked up.

Good post and thanks for the info. As a sideline item, I don't know how applicable a sierra book is when loading Nosler bullets. I am making the assumption that you are using load data for a 150 sierra bullet out of the sierra book. The potential problem you may run into is the bearing surface maybe different on the Nosler bullets. The bearing surface effects the fiction on the bullet as it goes down the barrel which in turn effects the pressure.

This does not explain why the nosler book is so far off and that's what really has my attention.

It looks like you have a very tight chamber on the first rifle.

Once again good post.

[TXBRASS]

I always start low and work my way up. Doing so gives the performance data on the way up. Some of my "SWEET" loads are mid-range. I prefer accuracy over max FPS and starting low and going up is the only way to find perfection...

[ItsLeo]

I've personally hit an actual max load for my rifle at more than 1 grain under "book" max. The primers were flattening and the bolt was getting stiff to open. If I had started at max I may have had a serious problem. Got a new batch of the same powder and was able to go a little over "book" max changing nothing else.

The lesson I learned there was that powders can vary quite a bit batch to batch. This variance can really bite you when loading cartridges that use lots of powder. I also learned that sometimes "Book" max is not safe.

[Artos]

I would think the quality of the case may be a factor?? I don't get many reloads out of my Nosler brass (yes, I run hot) Maybe the softness & it not reducing back after forming to the chamber is the cause vs capacity??

I do get a little bolt resistance, but simply toss the case if there isn't any resistance when seating the primer...this is my key to toss the case. I don't really even keep count.

I also remove my firing pin & close the bolt on resized cases...if I do not get a free fall & some resistance on the bolt (with the firing pin out) it tells me the elasticity is gone.

[Sterlin8er]

I agree with starting low and working your way up. I also find that the mid range works for me. But I have only been doing my own reloading for about a year now but it still works best for me.

[bboswell]

I would think the quality of the case may be a factor?? I don't get many reloads out of my Nosler brass (yes, I run hot) Maybe the softness & it not reducing back after forming to the chamber is the cause vs capacity??



I do get a little bolt resistance, but simply toss the case if there isn't any resistance when seating the primer...this is my key to toss the case. I don't really even keep count.



I also remove my firing pin & close the bolt on resized cases...if I do not get a free fall & some resistance on the bolt (with the firing pin out) it tells me the elasticity is gone.

Your loads sound like mine.

I was thinking brass as well but concentrating more on internal capacity than actual physical properties, you raise great points.

[bboswell]

I agree with most comments here.

The reason for this post comes more from other sites or groups I follow where I see people start with the "most accurate" charge per a book or load the "max load" per the book and then run into trouble.

I thought that this example might show some newer loaders understand why we all start low and work up.