Rifle inaccuracy. Photo by Ron James/Sporting SHooter
An unacceptable group! What can you do about it?

Reloading the second time around

Having carried out the process of load development on your new rifle or barrel it is entirely possible that the results are not what you expected to achieve. 

Where do you go from here? What can you do to improve the situation, if anything? 

A common problem is the use of more modern, usually larger, projectiles in older cartridges. 

As an example, the 220 Swift cartridge has enough case capacity to usefully use projectiles in the 60-70gn range at reasonable velocities but commercial barrels are usually 1:14” to 1:15” twists, which are simply not fast enough for the bigger projectiles. 

If this is not the problem, how do you proceed? What is the group on the target telling us? 

If the shots are vertical, extra powder may be required — but only if you have not already reached the maximum load, which should not be exceeded. 

When shots are horizontal the most common claim is that wind or a straight sighting problem has caused the horizontal stringing. When such shots appear on the target on a windless day and the rifle is shot off sandbags, I would suggest there are other causes.

Rifle accuracy with hand-loaded ammunition. Photo by Ron James/Sporting Shooter
Convention suggests that this load needs more powder

Personally, the first issue I would look at is changing the powder. 

I prefer to start with a powder in the middle of the range, which allows some flexibility to change in either direction. 

Logic may say that for a heavier projectile, the next slowest powder may be best but this is not carved in granite. I’ve often found that the next fastest powder provides a better accuracy solution. 

Change primers is a simple solution that it appears to work in some situations. I think benchrest primers appear to provide a flatter pressure curve.

Rifle powders and projectiles. Photo by Ron James/Sporting Shooter
Changing powder and/or projectiles is an option

The next issue revolves around the seating depth of the projectile. Flat-based projectiles in the main seem to be unfussed about the issue but their boat-tailed cousins are just the opposite. 

I do not know why this is so but it is a fact, you might have to try several depths to arrive at a satisfactory answer. Some projectiles appear to have very shallow boat-tails; perhaps ‘bevel’ would be a more accurate description. I have not had a seating depth issue with such items.  

The other issues with cases revolve around the neck and the amount of tension or grip on the projectile. I believe that this is a complicated issue overall and there is still a lot of experimenting taking place to see exactly which particular issues are worthwhile. 

Also in this area is the subject of case neck turning and the eventual thickness of the case neck, a whole can of proverbial worms. 

Who said the answers were easy?

Rifle bullets. Photo by Ron James/Sporting Shooter
A variety of projectiles in the same calibre

Finally, when all else fails perhaps it is time to change the projectile, even to one of the same weight. They might look the same but I am willing to bet there will be dimensional differences, often quite small.

These small differences often affect the bearing surface on the bore and perhaps more importantly the difference between the base of the projectile and the ogive of the said projectile. 

All of these little differences can add up and produce a less-than-acceptable group. 

A common problem occurs with those who ignore an over-length case, which almost invariably causes flyers. 

Another common problem is loose screws involving the telescopic sight. You simply cannot shoot tight groups with them loose. Guess who got caught! 

Many potential problems can be overcome in the first instance by adequate research of the products to be used. It can save a lot of time and energy!




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Ron James