I need a fresh start at load development. new rifle coming.

[Linko]

The more I read posts from some of the veteran shooters who travel to competitions, the less I seem to know!

I have a new F TR rifle being built (my first 308) the chamber is the US team reamer with .170 FB, 30" 10 twist Bartelin

I plan to start with the 185 Jug Berger's. Lapua Palma brass, Varget, cci450

In the past I loaded up 5 each at .2 increments of powder in the top half of the load manual recommendations. Shoot at 100 yds and find the node with the least vertical. Then shoot that range (maybe 4 powder weights) at 200 . Then adjust seating depths.

Reading lately it seems like I should be using a chronograph (just bought a magnetospeed) and finding the least speed variance and working that node at 200. (Most likely close to the verticle method I have been using)

Please help me save time and money. I need a proven plan and stick to it. (Wish I had both more experience and a mentor at my range) I have been a wear out the barrel load developer!! I am spending too much building a rifle to burn out the barrel..

Thanks

 

[texasbilly]

I think your approach is a good one. I use a technique that is similar in which I load a spread of 3-shot loads for a give bullet with what I consider to be the best powder for that bullet weight. If this is to be a target load, I tend to set the oal to touch the lands (or close); if it is to be a hunting load, I tend to set the OAL back .010-.025" from the lands. Once I note what appears to give the best results, I make 10 copies of that load and shoot two 5 shot groups. If results are satisfactory, I reload and start adjusting OAL till I find (what I consider) to be the optimum combination for that rifle, bullet, and load.

Here's a hint: Use a systematic approach to the development of the optimum load. In the end, this trial and error process is a crap shoot. You may find the bullet is fantastic in your rifle; you may find the bullet is terrible in your rifle. Be patient, and keep trying. That's what the hobby is all about.

 

[Fast14riot]

I try to find my seating depth first, using a known accurate, modest charge. Then, in the now fire formed brass I do a velocity/pressure ladder at distance. I combine the two results and fine tune as needed.

However, shooting a 308, do lots of reading, find what the common load is for your bullet/powder combo. It's a path well travelled, not saying that you should blindly follow internet load recipes, but it can greatly reduce the overall amount of testing by narrowing your window. Some bullets like to jump a certain amount, some like a common velocity window, some powders fall within a half grain for most accurate node, etc. Find these out, then test around it (safely, of course).

 

[jrb572]

I thought this was interesting. I have a 300 win mag I am waiting to get back and going to try and see if I can use this to get me in there or at least close.

http://www.65guys.com/10-round-load-development-ladder-test/

 

[daniel brothers]

Finding the seating depth first....Hmmm.... very interesting thought. How important are the SD and ES numbers? I know that we always want them in the low digits, but many have said that it's not a grantee that it will group well at long range...Hmmm again...

 

[Fast14riot]

I thought this was interesting. I have a 300 win mag I am waiting to get back and going to try and see if I can use this to get me in there or at least close.

http://www.65guys.com/10-round-load-development-ladder-test/

This is the same as doing a vertical dispersion test at 300+, but doesn't even need to be fired on a target. IMO, it misses some data like vertical dispersion, potentially being able to read seating depth too.

 

[Mozella]

Finding the seating depth first....Hmmm.... very interesting thought. How important are the SD and ES numbers? I know that we always want them in the low digits, but many have said that it's not a grantee that it will group well at long range...Hmmm again...

Many who have said that are correct.

Here's how I look at it. If you believe that more powder generally makes for faster muzzle velocities and if you also believe that a faster bullet will fly on a flatter path, then you would have to conclude that a faster round will impact higher on the target, all other things being equal. I think few people would disagree with that, generally speaking.

With that in mind, one would conclude that launching every shot of a 20 round F-Class string, to use one example, at exactly the same velocity would tend to reduce vertical dispersion. That would be a good thing and that's why we are always searching for low ES and SD numbers.

However, launching 20 bullets at exactly the same MV won't guarantee small groups at 600 or 1000 yards if the bullets are shaped differently, or are damaged, or have different meplat shapes, or have different neck tensions, or are out of balance, and so-on. That's why we spend money on expensive bullets and take great care to reload them using best practices.

Furthermore, if you believe that a particular MV or perhaps a particular barrel time will give you smaller groups, then launching all 20 rounds in a match at exactly the same MV won't produce the desired results if that MV is the wrong one; i.e. too fast or too slow for your particular barrel, at that temperature, at that altitude, at that barometric pressure, at that time of day, depending on how you hold your mouth, depending if you're wearing your lucky underwear, depending on the phase of the moon and maybe one or two other factors.

Bottom line: At longer ranges most folks believe that low ES and SD numbers are a good thing, but they're not the only thing.

 

[Toby Bradshaw]

How important are the SD and ES numbers? I know that we always want them in the low digits, but many have said that it's not a grantee that it will group well at long range...Hmmm again...

http://forum.accurateshooter.com/th...-a-long-range-shooter-can-understand.3920005/

 

[bsekf]

I use your method, but would recommend trying several powders. I like the case full.

I don't worry about speed, I would like them all in one hole.

Bill

 

[dcali]

This is how I do it: http://bisonballistics.com/articles/sort-of-scientific-load-development-for-f-class

Note: The number of rounds fired in the above article is more than necessary - it just helps to show the interactions between seating depth, charge weight and group size look like. In practice you don't need to shoot so many groups, especially if you load (or at least seat) at the range.

 

[dsculley]

As has already been said, a systematic approach is best, along with good record keeping. If I were building a new .308 I would go to Dan Newberry's forum (www.practicalrifler.fr.yuku.com) and do a little research. You will find known OCW loads for the .308 there. You can also start a thread there and get very good information. With a .308 you don't need to re-invent the wheel, you can probably find a known load that will work well with or without a bit of tweaking. If the load is on the high end you will need to work up to the load to make sure there are no pressure problems. If you want a mentor for this load development, Dan offers load development consulting. Check out the OCW Consulting page at BangSteel.com for more information.

 

[Fotheringill]

I would also do seating depth first. Go to Berger site for instructions. Take a few manuals and take the average middle of the road load for the powder, then average the two or three loads.
Shoot. Even if not a really good load for your rifle, there will still be a marked difference between the five? groups shot with different depths. THEN do your load tests.

 

[Zero333]

If you have access to a 600 yard range this would help. Do a OCW at 600 yards on a calm day with out chronograph. Preferably twice to correlate/verify the results.

The magnetospeed can change group size when attached. This is why the serious fellas have LabRadar's.

A chronograph is a must when developing long range loads at shorter ranges.