When it comes to a micrometer for reloading, it means a micrometer with a spherical (ball) anvil. This micrometer is meant to measure the cartridge neck wall thickness with higher accuracy. The ball anvil type generates less error because the contact area between the anvil and the wall is small.
People also use caliper in reloading such as in measuring the cartridge length, bullet diameter, etc. It’s fast. But, in the case to measure the neck case wall thickness, it is not a good choice. It has a lower resolution and the jaws have a flat surface. A flat surface can lead to error due to surface variations.
Besides, dial indicator and test indicator are also applied in reloading. But, as we discover on the market, today’s test indicators and dial indicators (look at the table) can only reach a resolution of 0.0001″ for its maximum capability. While micrometers can serve with a resolution down to 0.00005″. When requiring a high degree of accuracy (resolution), the choice is micrometer.
The drawback of using micrometers is speed. Dial indicator and test indicators outperform well in this case. If you prefer speed, make sure to use the proper tool such as this RCBS Case Master Gauging Tool. This is important to reduce the surface contact between the case wall and the indicator contact point.
If you are looking for the best micrometer for reloading, here we’ve successfully collected 10 products we consider the ideal ones for reloading. Note: Enjoy the best view on a desktop browser.
As you could see, there are only two kinds of micrometer listed above: the spherical, and tube type according to its anvils. This case can be easily explained when we understand the reloading itself and the piece of the processing that involves micrometers.
Top 6 Best Micrometers for Reloading 2021
According to the consideration explained above, we can now jump into the core points. Below is the list of the best micrometers for reloading.
1. Mitutoyo 395-363-30 Digital Micrometer [Best Overall]
It’s digital, and surely lets you know the reading easily quickly on the LCD screen. So, it gives you speed which is not provided at the mechanical micrometer.
Compared to the other micrometers, this Mitutoyo 395-363-30 has an extremely greater resolution down to 0.00005″/0.001mm. Moreover, the accuracy is ±0.00015″. For those who are seeking the most accurate one, this is a must. The 0.185″/4.7mm anvil diameter is suitable for many cartridges.
In addition, to protect from dust and water ingress, you don’t need to worry because it comes rated with IP65. This IP rating is decent. That said, this protection lets you use it in any place.
Mitutoyo 395-363-30 is available at a high cost. The last time we checked it, it cost almost as twice as its parent Mitutoyo 295-313 which has an old-fashioned mechanical counter. Despite its price, it deserves to be the best overall due to its spec, model, performance, and features.
- Fast reading due to the digital model
- Great resolution 0.00005″ (0.001mm)
- Small anvil with a diameter of 4.7 mm (0.185039″)
2. iGaging 35-040-T01 Digital Micrometer [Budget Option]
Another option for the best digital reloading micrometer is iGaging 35-040-T01. It comes with a digital display (easy and fast to read the measurement) yet a friendly cost. This is an alternative if you think the Mitutoyo above is not matching with your budget.
The least count is good, like the Mitutoyo above, up to 0.001mm (0.00005″) by 1-inch range measurement which is great for most reloading. Also, the ball diameter is 0.1895″, which is slightly bigger than the competitor the Mitutoyo above but still considered good for reloading.
The accuracy that is claimed by iGaging is ±0.00016″. It means when the reading shows 0.00050″, the real tolerated value ranges from 0.00034″ to 0.00066″ and does not get out of that range.
We recommend a digital model for the purpose of reloading. However, the options are limited. iGaging releases this model and it is good news for you. If you think the digital model is also a critical aspect for you, then iGaging 35-040-T01 can be your choice.
- Digital, gives a fast reading
- Decent accuracy and resolution
- Not as accurate as of the Mitutoyo that provides 0.0001″ resolution
3. Mitutoyo 115-313 Mechanical Micrometer
This is a good option for those who are looking for mechanical reloading micrometers. The brand Mitutoyo is well-known as a brand that generates highly reliable precision instruments. The same as Mitutoyo 115-313, it’s prominent in its consistency and accuracy.
Like Anytime Tools AT206541, it serves you with a resolution of 0.0001″ and a range of 1″. The ball anvil diameter is slightly smaller than Anytime Tools AT206541 which is 0.185″.
It challenges you with its mechanical model and the long reading process. Further, it costs you a high amount of money. However, it’s okay since it represents quality.
4. Anytime Tools AT206541 Mechanical Micrometer
This spherical anvil flat spindle micrometer provides you with resolution down to 0.0001″ and 1″ range which is considerably needed for higher precision. Moreover, the anvil diameter is 0.190″ which is suitable for a wide range of caliber. In addition, its spindle is carbide-tipped which is beneficial to create rigidness surface, increase durability and accuracy. Carbide is a kind of extremely hard material that is commonly used for drilling tools.
If you decide to buy, then you have to get educated for a while because it’s a mechanical model. So, you have to get familiar with the manual reading. It’s also available in imperial (inch) unit which makes you have to convert it to metric manually if needed.
5. Mitutoyo 295-313: Mechanical Counter Micrometer
As you could see, this one comes with a mechanical counter. We actually don’t recommend you to buy this type because of its measurement display. You are better off buying the digital ones instead. However, all is up to you.
It provides you with great accuracy 0.0001″ resolution and comes in an imperial unit system. Even though it has a counter, it’s not like the digital one which can easily switch over from mm to inch or vice versa. For its resistance, similar to the other micrometers listed here, they are carbide tipped.
6. Starrett 569AXP Mechanical Micrometer
Not only the ball anvil, but the tube anvil is also actually able to measure the thickness of the cartridge neck wall. Even it can detect what’s wrong with the alignment of the case wall. But, the flatness of the anvil must be really flat.
Starret 569AXP has a 0.1875″ diameter tube anvil which can insert into the inside case and measure the thickness. It comes with enough resolution 0.001″ and 1″ range. This one is good for U.S. users since the measurement unit is available in imperial (inch).
There are actually other models similar to Starret 569AXP. We’ve put them together on the table above. However, we are not prone to choose them to recommend because it’s tube shape which in some cases has issues.
What is Reloading?
Reloading is the process in which the shells or cases of already fired/used ammunition are assembled again for reuse. The primer, projectile, gunpowder, and case are combined together to form a center-fire round.
It has some components:
- Projectile / Bullet
- Case / Shell
- Gun Powder
Once the center-fire round is fired, an unshaped and hot case is left behind. The rest of the components are used in the firing.
In the reloading process, we reassemble the empty and distorted cases to form a cartridge. The center-fire round can be also referred to the cartridge. First, the assembly includes cleaning the case and trimming the size to match with the required length. After that, we replace the used primer with the new one, pour the gunpowder, and replace the projectile as well.
Measurement Issues in Reloading
There are actually several issues in reloading. To cover up, we put them on the following list.
- Uniformity. The size of one cartridge should be exactly the same as the other cartridges.
- Bullet Concentricity. If the case is not concentric then the assembled bullet will not enter the rifling with harmony. In order to enter the bullets consistently, it is necessary that the bullet is properly aligned.
- Alignment of the Case Walls. The case walls are very important for the assembly of the bullet. The ideal bullet has straight walls but the walls can be damaged after being fired. Hence, the walls must be properly aligned with the axis of the case.
- Difference Thickness in Neck Walls. The neck walls should be properly aligned as well because variations in the thickness can lead to an offset of the bullet in its alignment.
- Correct Length of the Case. The length of the case expands when fired. The case needs to be trimmed to the correct length so the bullet can enter the rifling smoothly.
The Thickness of the Case Neck
Despite micrometers can measure extremely a small distance, the use of micrometers in reloading is not as wide and common as the calipers do. People use calipers instead, and micrometers are optional and for advanced users.
People turn over to micrometers commonly mostly to measure the thickness of the case neck of the cartridge. Each side of the case neck thickness is strongly critical to be uniform. It affects and determines the accuracy of the bullet hitting the target.
Case neck is a part of cartridge case where the bullet sticks into. You could see it on the number 3 of the image beside.
In this case, micrometers can do better than calipers. The calipers come with about 0.02mm resolution, in contrast, the micrometers provide down to about 0.001mm resolution. To check whether it is uniform or not; as some users want the more accurate one, surely micrometers are more reliable.
Aside from that, the micrometers that are especially the ball-flat anvil types, allow the measurement to occur in a single spot only. It lessens the error which typically the flat anvil or the flat jaw on calipers does in general.
Things to Consider Buying A Micrometer for Reloading
After reading the entire explanation above, we now can conclude what to put into consideration. There are some factors to think about when choosing the best micrometer for reloading:
1. The Right Type
Not all micrometers can be used for reloading. The ideal ones are those who have spherical (ball) anvil. A tube anvil can be used but try to get the spherical one to minimize the possible error generated from the surface contact. Moreover, both spherical and tube anvil are considered able to get inserted into the cartridge tube to measure the thickness.
2. Anvil Diameter
Despite the right type, you have to consider the size. If the diameter of the anvil you are using is bigger than the diameter of the cartridge tube, it can’t enter. There are some sizes that can be chosen. Make sure they fit with your need.
3. Accuracy & Resolution
Other major things are the accuracy and resolution of the micrometer. Try to look for the most accurate and consistent ones. Picking out the terrible one can waste your money. In terms of the resolution, try to get at least 0.0005″ resolution. This number is decent. If the resolution is good, then it must be backed up with decent accuracy.
4. Mechanical or Digital
An experienced operator is needed in case there is a chance of human error when using the mechanical ones. So, you have to get used to with. Things come differently when switching over to the digital ones which are better in terms of providing measurement results.
Micrometers could be either expensive or affordable. Keep your budget in mind when you are in search of the best micrometer for reloading. Don’t buy the expensive on while the low priced one can give you a satisfied measuring journey.
6. Weather Resistant
This is optional. Some of the measurements do not have the capacity to survive through harsh weather conditions. You need a micrometer that is durable and that will last you for a long time.
Furthermore, choosing a micrometer for reloading is similar to looking for the best micrometers as usual. The most crucial is the anvil type, the diameter of the anvil, and the resolution. The rest behaves as secondary things.
Whatever your choice, it’s up to you. We only try to help. You could see from the table above, you’ve got a bunch of micrometers that we selected from the market. They are all qualified enough to use for reloading. And you just need to make a more selection based on your need.
However, in case you want us to choose for you, we will say the Mitutoyo 395-363-30. However, if you are on a budget, pick iGaging 35-040-T01. All the advantages of them have been explained in the reviews.