Ladder loads
 

I have two calibers I need to work a load for. Thanks to Mike I have a bunch of SS109 bullets and am going to work towards an XM855 clone. I am going to go up in .5 grain increments from 25gr up to 27 gr. Looking towards the best accuracy for my PSA M4 forgery.

The other ladder load is for .41 Special. Looking to keep that load as mild as possible without affecting accuracy out to 15 yards.

My Caldwell chronograph should arrive on Friday. Thinking about a ranger tip next weekend. Any advice on how I should set up and what to look for?

What powder do you plan to use for the 5.56 load?

Winchester 748 for the 5.56 and Unique for the .41 Special.

I also have H335, 231, and Bullseye available.

did you read the links I posted the other day?? in the one from 24 hour campfire "RJM" lists 8, 41spl loads using Unique and a variety of cast and Jacketed bullets.

Yes I did thanks! They we're mostly talking about 7-8 grains of Unique so I used 7 as a max load. Remember I am working that load to be easy on my grandfathers hands, 92 years old and even the standard .41 Special loads can hurt. He wants a very mild Special load so I am starting at 5 grains and working up from there. I am looking to see if there is much of a point of impact shift so the sights will be as close as possible with no adjustment.

First, be aware that chronographs often raise more questions than they answer. Especially when you get drastically different readings on different days with the same load.

Make sure the chronograph is always the same distance from the muzzle. Make sure it's not too close to the muzzle or the muzzle blast can screw with the readings.

Using windscreens on a clear day can sometimes have a different reading than not using them on a cloudy day.

What you are mainly looking for is correlating variances in velocity with different points of impact. Those flyers might possibly be due to velocity. If so, it could expose flaws in your loading technique. Or it could just be a squirrely load that is far away from a sweet spot. If it's not due to velocity difference, then it is the shooter, or the bedding of the rifle, or a dirty barrel, or a damaged crown, etcetera, etcetera, etcetera.

When you find a load where the point of impact is not sensitive to changes in velocity (within reason), and the velocity is not very sensitive to small changes in the powder charge, then you have found a sweet spot.

Always record the temperature!

http://www.cotep.org/forum/picture.p...pictureid=1046

I've had a pound of 748 for a few years.....don't remember why I bought it. I should use it for some 5.56 if it tends to work well. My standard 5.56 powder is Varget.