Realoding fine tunning

[czechsonofagun]

For my Winchester 70 I developed a load with reasonable accuracy using IMR4350 and HNDY BTSPS 140 grains. Since I saw a lot of positive feedback on HNDY SST I got a box of 130 grain bullets and I can't get it to group decently. This is how I worked it:

- 4 groups of rounds, 9 rounds each
- groups were 56, 57, 58 and 59 grains of IMR 4350
- shot from rifle shooting rest on a bench 100 yards
- 3 shots 56, 3 shots 57, 3 shots 58 and 3 shots 59 grains
- repeated 3 times and compared results for each weight group
- holes were in 2" circle at the best, 3" circle in the worst case

For the BTSP I used same process and from the same distance and the same shooting rest I get 1/2" groups.

Please, advice, since I lack experience in reloading, where should i go from here? Hornady max load is 60 grains for the bullet, but I don't think maxing it out would make difference. I was thinking about getting a batch of new brass and trying it again, but as I said, I don't have enough experience to decide which way to experiment. What is the most influential component? Powder if the bullet is given?

 

[EarPlug]

Here is a great forum for reloading data

Accurate Reloading

 

[chh]

That is a lot difference between the 140 and 130 grain bullets. What cartridge are we talking about? Are you loading to the same cartridge length over all? Using any crimp?(I do not) Full length sizing or neck sizing the brass? All of those(and more) can cause quite a bit of variation. Your gun's barrel twist may also be more suited for heavier than lighter bullets. My custom 22-250 will make ragged holes with 55 to 70 grain bullets and will shoot about 3" groups with 45 grain bullets. My .308 is not nearly as picky. A 1" or smaller group is easily possible with either 125 or 150 grain bullets(the only 2 loads I have tried).
Personally when I find a load I like I tend to stick to that load. I don't get too wild experimenting. I know that takes a lot of the fun out of it, but I mainly just want a load that works.

 

[toddbailey]

For my Winchester 70 I developed a load with reasonable accuracy using IMR4350 and HNDY BTSPS 140 grains. Since I saw a lot of positive feedback on HNDY SST I got a box of 130 grain bullets and I can't get it to group decently. This is how I worked it:

- 4 groups of rounds, 9 rounds each
- groups were 56, 57, 58 and 59 grains of IMR 4350
- shot from rifle shooting rest on a bench 100 yards
- 3 shots 56, 3 shots 57, 3 shots 58 and 3 shots 59 grains
- repeated 3 times and compared results for each weight group
- holes were in 2" circle at the best, 3" circle in the worst case

For the BTSP I used same process and from the same distance and the same shooting rest I get 1/2" groups.

Please, advice, since I lack experience in reloading, where should i go from here? Hornady max load is 60 grains for the bullet, but I don't think maxing it out would make difference. I was thinking about getting a batch of new brass and trying it again, but as I said, I don't have enough experience to decide which way to experiment. What is the most influential component? Powder if the bullet is given?

the most influential component after bullet is power along with seating depth which can make a lot of difference but takes lots and lots of trial and error which in it self can be fun

but by the sounds of this your rifle does not like the sst stop wasting powder and primers and give the rest of the bullets to someone who can use them and on another note i would recommend nosler accubonds i have had really great success with them both with accuracy and on game performance! or just stick with the btsp

by the way your procedure is basically the same i have been using for the last 15 years some guns just do not like some type/weight of bullets and some will shoot .5" groups with anything you feed them!

sorry for the long winded post

 

[czechsonofagun]

Thank you, gentlemen, appreciate your input

 

[Sigarms]

What is the most influential component?

The man pulling the trigger
The gun & sights
The ammo/load

The fun part is figuring out how one or all them is screwing you up

Buy yourself a decent inexpensive chronograph (you may be amazed).

Also know the wind, temperature, and humidity.

You've got the rest of your life to load. Take your time and don't judge a load by only nine rounds. You may be missing something and not even know it.

 

[whistlepig]

For my Winchester 70 I developed a load with reasonable accuracy using IMR4350 and HNDY BTSPS 140 grains. Since I saw a lot of positive feedback on HNDY SST I got a box of 130 grain bullets and I can't get it to group decently. This is how I worked it:

- 4 groups of rounds, 9 rounds each
- groups were 56, 57, 58 and 59 grains of IMR 4350
- shot from rifle shooting rest on a bench 100 yards
- 3 shots 56, 3 shots 57, 3 shots 58 and 3 shots 59 grains
- repeated 3 times and compared results for each weight group
- holes were in 2" circle at the best, 3" circle in the worst case

For the BTSP I used same process and from the same distance and the same shooting rest I get 1/2" groups.

Please, advice, since I lack experience in reloading, where should i go from here? Hornady max load is 60 grains for the bullet, but I don't think maxing it out would make difference. I was thinking about getting a batch of new brass and trying it again, but as I said, I don't have enough experience to decide which way to experiment. What is the most influential component? Powder if the bullet is given?

You didn't mention a caliber here. In my experience the powder and the bullet is most significant. Brass or primer seems not to be that big a difference for me. Expensive brass reloads longer and is cheaper in the long run. It is very important that every powder charge is weighed with a powder scale. A variance in the powder is the most detrimental to accuracy and a variable that is easiest to eliminate. As far as bullets go that depends on the gun. Guns are very particular about bullets. Two identical guns will not shoot the same bullet as well. That requires expensive trial and error. Nosler is the best that I have ever used but Nosler may not shoot well from your gun. No different than my 22 rim fire. My 22 shoots better with some brands than others.

 

[DieselPower]

For starters what caliber? Can't help to much with component options without knowing what your loading for. It may be as simple as trying a different powder with a slightly different burn rate. How are you seating the bullet, to the book COL or a set distance from the lands? I have seen some guns with chamber dimensions that were fairly far off that wouldn't shoot worth a darn. After checking the chamber dimensions and adjusting the COL to suit they shot quite well.

When I work up a new load I usually use 4 or 5 different powders. The spread in accuracy can be as much as 2+ inch's at 100 yards.

 

[czechsonofagun]

The rifle is chambered in .270 WSM and I tried to eliminate - to some extent - that nut by the trigger using rifle rest. Also every charge is measured on RCBS 5-5 and trickled to the last fracture of a grain.
I believe I know a thing or two about setting and repeating processes and measuring and experiment recording, but I lack the experience - thank you, guys, for sharing your knowledge with me.

 

[Egon]

Prokop, the solution is obvious, some analysis is required. First you must insure the barrel is bedded properly. Then you must measure barrel harmonics for different loads and bullets and adjust the load so that the bullet exits the barrel at a null point rather than a deflection point.