Home Forums Reloading Big Game Rifles Reading your targets

Hi,
Can anybody tell me when searching out a handload for a new rifle. If you study old targets. Can you tell when your rifle is starting to responed positively to changes.
Example I have heard vertical stringing is a hot barrel and bad bedding could be horizontal patterns.
What grouping pattern shows up before it's tightest group sizes.
Thanks Jimi

Since I "bed" most of my rifles' actions and float the barrels, I find that as I approach the "sweet spot" as concerns the amount of powder used, the groups start to shrink.

At that point, I begin using incremental powder increases of only one tenth of a grain in the amount of powder I'm using and maintain the 1/10th of a grain incremental increase in powder until the groups begin to "open up" again which indicates that I've gone out the "top" of the "sweet spot".

As an example, my heavy-barreled Sako .222's "sweet spot" with VihtaVouri N130 powder is from 21.5 to 21.8 grains (inclusive) behind a 50 grain Sierra "Blitz" varmint bullet. At 21.9 grains, the MV increased, but the 5-shot groups began to open up again.

My Ruger #1 International's (aka "RSI") "sweet spot" with H4350 powder is from 47.2 grains to 47.6 grains (inclusive) behind a 140 grain Sierra flat-based ProHunter bullet.

When I actually get INTO the rifle's "sweet spot" which may be as little as a few tenths of a grain wide or as much as a half a grain wide, the 5-shot groups quickly get down to "minimum" size and stay there as the velocity increases with each new incremental increase in powder. Then, when just another 1/10th of a grain of powder is added, the group size begins to get larger... and groups get larger & larger as more and more powder is added.

Of course, all of this "accuracy" depends on the shooter being consistent and using good shooting techniques, the rifle being accurate shot-to-shot, the rifle rest being solid and the wind being consistent. Sometimes, this is a VERY hard combination to achieve and keep.

In testing and achieving s rifle's ultimate accuracy, "consistency" in ALL things is "king".


Strength & Honor...

Ron T.

I watch for where "test groups" impact the target in relation to the POA all things else being consistent, and initially don't really care about group size though a smaller group size often correlates with what I'm after.

Several consecutive grain weights impacting in the same location on the target means I've hit a sweet spot. I usually find two sweet spots; one about 2/3's up the ladder, the other just under booked max. That's the one I want.

I then adjust group size via seating depth......

A search of the "ladder" method of load development will save you a lot of time and powder. Basically you select a powder and bullet and load a single round with your beginning load. Then load a second single round with a charge that is 1/2 or 1 grain higher and you continue doing this until you are near max. Mark each cartridge with a magic marker, "1", "2", etc.
Then, on a nice windless day, against a large backstop, you shoot this sequence of loads. Don't change your scope, use the same point of aim and chart the location of each bullet strike on a cheat sheet.
It's best to shoot at a distance greater than 100 yards so the clustering will be more apparent. If you are testing a tight shooting target rifle you may even need to go out to 300 yards. When you pull your target, transpose the cartridge numbers onto the target. You will see some of the numbers tend to cluster while others are more strung out. You, of course, want to concentrate on the powder range where the bullets cluster.
At this point, depending on your findings, you can pick the powder range and start loading groups of three for testing or you can do another ladder. Once you have things close, you can start testing groups of 5 or more.
Three shot groups tell you very little. Five shot groups tell you more. But a single group, even 5 shots, is kinda meaningless.

+1, I slowly learned this awhile back.

I don't trust a load until I've shot it on at least 3 or 4 different days. It takes time but also builds alot of confidence in the rifle/load combo. I also found loads that shoot well at 100 or even 200 yards sometimes shoot like chit further out.
A big target(board) at 400 yards works for me and you know if things shoot well at 400 it's gonna be fine at say 237 yards.

As far as keeping notes/targets, I used to be terrible.
Then I bought a reloading log book from Sinclair. It has helped ALOT and they only cost about what $8?

Thanks for all you responses
I guess it makes sense to start with a bullet weight that is known to function well in that caliber. Like 30-06 usually works
well with 165 grain bullets since were watching Point of Impact.
The rifling is made to stabilize a certain weight projectile.
Is this correct?

A 1:10 '06 will shoot a LOT of stuff well.......

90% of the bullets thru my 30-06s are 165grs. Others swear by 180s.

Generaly speaking a 30-06 should work well with 150 to 180 grain bullets, maybe even heavier - but - it depends on how finicky a given rifle is and also the twist rate/rifling. In a 30-06 don't worry about the twist rate though, they're made to shoot 150gr to 180gr bullets. A very good barrel will shoot many loads and bullet weights well. A more finicky rifle will show a preference for a given weight/load.

A 165 grain bullet is a great place to start - sort of middle of the road.

My 30-06 shows a distinct preference for 165s. A different rifle may like 150s or 180s better. It all depends on ..........

fish head