TargetTalk

Not sure if it makes a difference or not but if you lessen the weight of the projectile do you have to change the powder input as well, up or down? I was using 98 gr HBWC with 1.5 of powder, trying out 80gr HBWC. Thx.

I think you would need to increase the powder charge slightly. Who makes and sells 80gr .32 HBWC. I wouldn't mind trying some.

Leon wrote:I think you would need to increase the powder charge slightly.

My insinct says you would need to reduce the charge, but I stand to be corrected.

My reloading data suggest a higher starting load with a lighter bullet. Maximum load hardly increases.

FWIIW: http://www.lapua.com/en/products/reload ... odata/6/35

Suggest you check with your powder/ bullet reloading data.

Greetings Hans.

J.Hoes wrote:My reloading data suggest a higher starting load with a lighter bullet.

That's certainly what it says.

Can anyone explain the logic please.

David Levene wrote:

J.Hoes wrote:My reloading data suggest a higher starting load with a lighter bullet.

That's certainly what it says.

Can anyone explain the logic please.

A lighter projectile will need higher velocity to generate equal energy to cycle the action?

A lighter bullet needs more speed to fly stable. Don't know about the theoretical physics, but my experience with light H&N and Lapua bullets supports this theory, I always give them 0.1 - 0.2 grs more powder.

Thanks guys.

My instinct was that, given the same driving energy, a lighter bullet would accelerate and fly faster. I must be wrong.

I think that a lighter bullet will start to move earlier than a heavier bullet and the pressure behind the bullet will not be the same as with a heavy bullet. You might even use a faster powder.

I think we should all wait until David Moore chimes in. He probably knows more about loading for .32 than anyone else on this board.

If you reduce the bullet weight on our C/fire auto's you will need to increase the bullet velocity for both pistol function and bullet stability.
The lighter bullet will accelerate faster down the barrel, increasing the internal combustion volume of the chamber quicker thus reducing the peak combustion pressure and temperature.
To counter this you either increase the burn rate of the powder or increase the volume of powder or both.

The Lapua table shows a good example of the difference between a 83g and a 98g projectile. Missing from this table are the CUP pressure figures but I will bet they are nearly identical for the maximum load data.

You do not say what powder you are using, but if you are using 1.5g of Bullseye powder on a 98g pill, then a 80g pill will need about 1.8g.

Start with 1.6g and work up using a chronograph, aim for 800-830 fps but take extreme care as you exceed about 2.2-2.5g.

Reinhamre wrote:I think that a lighter bullet will start to move earlier than a heavier bullet and the pressure behind the bullet will not be the same as with a heavy bullet. You might even use a faster powder.

With a lighter projectile the available case volume is bigger, it will accelerate faster - possibly too fast for the optimum pressure curve of the powder - due to less mass and friction.
To say it another way there isn't enough back pressure on the powder for it to burn optimally, or as much time for the powder to burn.
Target loads tend to be right at the lower end of the ideal pressure to begin with.

In my experience with a lighter projectile you either need more powder, or use a faster powder, or to seat the bullet deeper.

Staying on the topic of the .32............. I see Berrys Bullets produce a 83gr plated HBWC. Has anyone tried their bullets? I normally shoot Speers due to availability. The Berrys are listed as a .312 compared to the .314 of the Speer/Lapua/HN. Does the plating change the need for oversizing the bullet? My Pardini slugs at .313.

JamesH wrote: With a lighter projectile the available case volume is bigger, it will accelerate faster - possibly too fast for the optimum pressure curve of the powder - due to less mass and friction.
To say it another way there isn't enough back pressure on the powder for it to burn optimally, or as much time for the powder to burn.
Target loads tend to be right at the lower end of the ideal pressure to begin with.

In my experience with a lighter projectile you either need more powder, or use a faster powder, or to seat the bullet deeper.

A light bullet does not say everything about the volume, WC vs. RN or SWC!

Read what David M wrote, just what I tried to say in the first place.......

Thanks all for the helpfull input. Will put into practice what you have said.
Cheers.

Coastwatcher wrote:Staying on the topic of the .32............. I see Berrys Bullets produce a 83gr plated HBWC. Has anyone tried their bullets? I normally shoot Speers due to availability. The Berrys are listed as a .312 compared to the .314 of the Speer/Lapua/HN. Does the plating change the need for oversizing the bullet? My Pardini slugs at .313.

I have used the Berry 83 gr plated...they function very well in my Hammerli 280 with 1.7 grains of W231

Thanks palooka, I am going to give them a try.

JamesH has it exactly right.

Another thing you might want to try is to experiment with several brands of magnum primers to try to get the pressure up so the powder burns better.

I know this goes against the grain for many shooters, but give it a try. What could it hurt? Primers sometimes have surprising effect on accuracy. In my own experience, I've had group sizes shrink by half with a primer change.

I use Berry's 83 gr HBWC plated with 1.5 gr of VV N310 in my GSP Expert and my SP20 RRS.

Very accurate and no bullet tumbling at 50 yards.