June 22nd, 2019

Reloading Basics: Neck Tension, Expander Balls, and Bushings

Case Loading Neck Tension Sierra Bullets Paul Box

by Sierra Bullets Ballistic Technician Paul Box
One thing that plays a major role in building an accuracy load is neck tension. I think a lot of reloaders pretty much take this for granted and don’t give that enough thought.

So, how much neck tension is enough?

Thru the years and shooting both a wide variety of calibers and burn rates of powder, I’ve had the best accuracy overall with .002″ of neck tension. Naturally you will run into a rifle now and then that will do its best with something different like .001″ or even .003″, but .002″ has worked very well for me. So how do we control the neck tension? Let’s take a look at that.

First of all, if you’re running a standard sizing die with an expander ball, just pull your decapping rod assembly out of your die and measure the expander ball. What I prefer is to have an expander ball that [can give] you .002″ in neck tension [meaning the inside neck diameter is about .002″ smaller than the bullet diameter after passing the expander through]. If you want to take the expander ball down in diameter, just chuck up your decapping rod assembly in a drill and turn it down with some emery cloth. When you have the diameter you need, polish it with three ought or four ought steel wool. This will give it a mirror finish and less drag coming through your case neck after sizing.

Tips for Dies With Interchangeable Neck Bushings
If you’re using a bushing die, I measure across the neck of eight or ten loaded rounds, then take an average on these and go .003″ under that measurement. There are other methods to determine bushing size, but this system has worked well for me.

Case Loading Neck Tension Sierra Bullets Paul Box

Proper Annealing Can Deliver More Uniform Neck Tension
Another thing I want to mention is annealing. When brass is the correct softness, it will take a “set” coming out of the sizing die far better than brass that has become to hard. When brass has been work hardened to a point, it will be more springy when it comes out of a sizing die and neck tension will vary. Have you ever noticed how some bullets seated harder than others? That is why.

Case Loading Neck Tension Sierra Bullets Paul Box

Paying closer attention to neck tension will give you both better accuracy and more consistent groups.

Permalink Bullets, Brass, Ammo, Reloading, Tech Tip 7 Comments »
April 22nd, 2018

The .220 Swift — History of a Great Varmint Cartridge

Sierra Bullets 220 .220 Swift Cartridge powder loading Hodgdon

A History of the .220 Swift Cartridge

by Sierra Bullets Ballistic Technician Paul Box
Sierra Bullets 220 .220 Swift Cartridge powder loading HodgdonThis cartridge was introduced by Winchester in 1935 in their model 54 rifle. A year later, it was added as a standard cartridge in the model 70. What might not be common knowledge to some reloaders is that the prototype for the Swift was developed in 1934-35 by Grosvenor Wotkyns by necking down the 250 Savage case, but in the end, Winchester chose the 6mm Lee Navy case for the foundation for this cartridge.

This cartridge was far ahead of its time and for that reason it received a lot of bad press. We’ve all read the horror stories through the years. Many of those stories were just simply repeated from previous articles even the wording was just slightly different. So how bad was the Swift? Let’s take a deeper look.

Some of the early Swifts had soft barrel steel and some of the rare ones even had barrels that were .223 in bore size. This stemmed from the fact that the .22 Hornets prior to the end of World War II were .223 in bore size and some of these barrels were chambered in the Swift. It was rumored that the Swift peaked in pressure far too quick. I’ll bet they did with a turkey extra full choke barrel.

Burn rates of powders were limited at that time as well, so the Swift was limited in its true ability due to that. It was almost like building a funny car for drag racing when only kerosene was available.

One of the longest lasting black eyes was that it shot barrels out so fast. If you get the barrel branding iron hot and fail to clean it often this can happen. Common sense will go a long ways here. Keep the barrel as cool as you can and properly clean it every fifteen rounds or less will go a long way to improving accuracy life of a Swift.

Sierra Bullets 220 .220 Swift Cartridge powder loading Hodgdon

So what is the real truth about this cartridge? I’m glad you ask. I’ve been shooting the .220 Swift for over 43 years now. It is one of the best varmint cartridges I’ve ever owned. It is not hard to load for, it doesn’t suddenly peak in pressure and it isn’t the barrel burner that you’ve heard. Hodgdon powders once reported a Remington 40-X with over 3,000 rounds of full power loads averaged .344” for five, 5-shot groups. My findings have been the same. It isn’t as hard on barrels as it has been made out to be.

I’ve also read that down loading it slightly will help in barrel life. This is true, but if you buy a thoroughbred you want him to run. Barrels are threaded on the end for a reason. If you have enough fun to shoot out a Swift barrel, just rebarrel it.

The bottom line is enjoy the .220 Swift for what it was meant to be. The popularity of the Swift has slipped in the last twenty years and few factory rifles are now available in this caliber. There is no reason for this and I know the Swift will always have a strong and loyal following.

Sierra Bullets 220 Swift Cartridge Guide

Permalink Bullets, Brass, Ammo, Hunting/Varminting 3 Comments »
March 26th, 2018

Optimize Neck Tension with Bushings, Expanders, and Annealing

Case Loading Neck Tension Sierra Bullets Paul Box

by Sierra Bullets Ballistic Technician Paul Box
One thing that plays a major role in building an accuracy load is neck tension. I think a lot of reloaders pretty much take this for granted and don’t give that enough thought.

So, how much neck tension is enough?

Thru the years and shooting both a wide variety of calibers and burn rates of powder, I’ve had the best accuracy overall with .002″ of neck tension. Naturally you will run into a rifle now and then that will do its best with something different like .001″ or even .003″, but .002″ has worked very well for me. So how do we control the neck tension? Let’s take a look at that.

First of all, if you’re running a standard sizing die with an expander ball, just pull your decapping rod assembly out of your die and measure the expander ball. What I prefer is to have an expander ball that is .003″ smaller than bullet diameter. So for example in a .224 caliber, run an expander ball of .221″. This allows for .001″ spring back in in your brass after sizing, and still gives you .002″ in neck tension. If you want to take the expander ball down in diameter, just chuck up your decapping rod assembly in a drill and turn it down with some emery cloth. When you have the diameter you need, polish it with three ought or four ought steel wool. This will give it a mirror finish and less drag coming through your case neck after sizing.

Tips for Dies With Interchangeable Neck Bushings
If you’re using a bushing die, I measure across the neck of eight or ten loaded rounds, then take an average on these and go .003″ under that measurement. There are other methods to determine bushing size, but this system has worked well for me.

Case Loading Neck Tension Sierra Bullets Paul Box

Proper Annealing Can Deliver More Uniform Neck Tension
Another thing I want to mention is annealing. When brass is the correct softness, it will take a “set” coming out of the sizing die far better than brass that has become to hard. When brass has been work hardened to a point, it will be more springy when it comes out of a sizing die and neck tension will vary. Have you ever noticed how some bullets seated harder than others? That is why.

Case Loading Neck Tension Sierra Bullets Paul Box

Paying closer attention to neck tension will give you both better accuracy and more consistent groups.

Permalink Bullets, Brass, Ammo, Reloading 9 Comments »
July 24th, 2016

A Short History of the .220 Swift Cartridge

Sierra Bullets 220 .220 Swift Cartridge powder loading Hodgdon

A History of the .220 Swift Cartridge

by Sierra Bullets Ballistic Technician Paul Box
Sierra Bullets 220 .220 Swift Cartridge powder loading HodgdonThis cartridge was introduced by Winchester in 1935 in their model 54 rifle. A year later, it was added as a standard cartridge in the model 70. What might not be common knowledge to some reloaders is that the prototype for the Swift was developed in 1934-35 by Grosvenor Wotkyns by necking down the 250 Savage case, but in the end, Winchester chose the 6mm Lee Navy case for the foundation for this cartridge.

This cartridge was far ahead of its time and for that reason it received a lot of bad press. We’ve all read the horror stories through the years. Many of those stories were just simply repeated from previous articles even the wording was just slightly different. So how bad was the Swift? Let’s take a deeper look.

Some of the early Swifts had soft barrel steel and some of the rare ones even had barrels that were .223 in bore size. This stemmed from the fact that the .22 Hornets prior to the end of World War II were .223 in bore size and some of these barrels were chambered in the Swift. It was rumored that the Swift peaked in pressure far too quick. I’ll bet they did with a turkey extra full choke barrel.

Burn rates of powders were limited at that time as well, so the Swift was limited in its true ability due to that. It was almost like building a funny car for drag racing when only kerosene was available.

One of the longest lasting black eyes was that it shot barrels out so fast. If you get the barrel branding iron hot and fail to clean it often this can happen. Common sense will go a long ways here. Keep the barrel as cool as you can and properly clean it every fifteen rounds or less will go a long way to improving accuracy life of a Swift.

Sierra Bullets 220 .220 Swift Cartridge powder loading Hodgdon

So what is the real truth about this cartridge? I’m glad you ask. I’ve been shooting the .220 Swift for over 43 years now. It is one of the best varmint cartridges I’ve ever owned. It is not hard to load for, it doesn’t suddenly peak in pressure and it isn’t the barrel burner that you’ve heard. Hodgdon powders once reported a Remington 40-X with over 3,000 rounds of full power loads averaged .344” for five, 5-shot groups. My findings have been the same. It isn’t as hard on barrels as it has been made out to be.

I’ve also read that down loading it slightly will help in barrel life. This is true, but if you buy a thoroughbred you want him to run. Barrels are threaded on the end for a reason. If you have enough fun to shoot out a Swift barrel, just rebarrel it.

The bottom line is enjoy the .220 Swift for what it was meant to be. The popularity of the Swift has slipped in the last twenty years and few factory rifles are now available in this caliber. There is no reason for this and I know the Swift will always have a strong and loyal following.

Sierra Bullets 220 Swift Cartridge Guide

Permalink Bullets, Brass, Ammo, Hunting/Varminting 5 Comments »