I put this thread together to help out with reloading for the 6.8 SPC. Hopefully this will answer some of the most common asked questions.
Note: Even though this will be geared for the 6.8 SPC, most of this info can also be used for other calibers.
There are three manufacturers of 6.8 SPC Brass. SSA, Hornady, and Remington. SSA and Hornady use the Small Rifle Primers Pockets, while Remington uses the Large Rifle Primers Pockets.
NOTE: SSA has recently made batches of SSA Brass with Large Rifle Primer Pockets.
The SSA brass generally lasts 10-15 reloads and holds the most powder.
The Hornady brass is very similar to the SSA brass, but generally holds 1 less GR.
The Remington bras is generally a little softer than the SSA brass, so they don't last as long, but you should still be able to get at least 5-8 reloads.
There are 4 basic types of primers: Regular, Magnum, Benchrest, and Military.
These are the standard primers. Generally, they are great for plinking. They will produce decent velocities and good accuracy. When the primer pockets start to loosen up, the standard primers are real loose and may pop out, especially when you have a hot load.
Magnum primers will produce more velocity, but they also produce more pressure and a higher SD. They are good for bulky powders. Generally, magnum primers can produce as much as 40 FPS more over the Standard Primers, which is equivalent to 1/2 GR powder.
Known for their consistency. Great for accuracy, but they are generally more expensive.
Military Primers (CCI #41 and CCI #34):
Similar to the Magnum primers in that they are Magnum Primers, but they have thicker cups and they are a little thicker, which is great for when the primer pockets start loosening up.
Small rifle = 400
Small rifle magnum = 450
Small rifle match = BR4
Small rifle Military = 41
Large rifle = 200
Large rifle magnum = 250
Large rifle match = BR2
Large rifle Military = 34
Small rifle = 205
Small rifle match = 205M
Large rifle = 210
Large rifle match = 210M
Large rifle magnum = 215
Large rifle magnum match = 215M
Small rifle = 6 1/2
Small rifle bench = 7 1/2
Large rifle = 9 1/2
Large rifle magnum = 9 1/2M
Small rifle = WSR
Large rifle = WLR
Large rifle magnum = WLRM
Small rifle = QQQSR
Small rifle = QQSR223
Small rifle magnum = QQQSRM
Large rifle = QQQLR
Large rifle magnum = QQQLRM
There are several different dies available from Hornady, RCBS, Lyman, and Redding.
One of the biggest questions going around is whether to get the Regular Full-length Sizing Dies or the Small Base Sizing Dies. For auto loaders, such as the AR-15, the Small base dies were designed for reliability in auto loaders. Although many people have used the regular full-length sizing dies for years with no issues, the small base dies are just an extra security.
The RCBS dies and the Hornady Seating dies are both very affordable dies that work very well. The Hornady has a sleeve that assists with aligning the bullet. With the Hornady Seating Die, you can also later get the Micro Seating Adapter, which makes it easy to adjust.
Although, crimping the bullets is not necessary, it is highly recommended to crimp the bullets, to prevent bullet set-back. A very affordable crimp die for the 6.8 SPC is the LEE FCD. It is easy to set up and works with or without cannelures on the bullets. In testing that I conducted, the LEE FCD produced a slight (10 FPS) increase and a slight increase in accuracy.
Another highly recommended tool is a Cannelure Tool. Although you can crimp a non-cannelured bullet using the Lee FCD, placing a light cannelure on the bullet will give it the extra grip for the Lee FCD, without sacrificing too much accuracy. If the bullets don't come with cannelures, you can roll your own.
An example of a cannelure tool is the Corbin Cannelure Tool
HEADSPACE GAUGE TOOLS:
For anyone that reloads, the Hornady Headspace Gauge Kit and the Wilson Case Gauge are two highly recommended tools. They both do the same thing, but they are slightly different. These tools measure the amount that the shoulder is bumped back, which is very important because if the shoulder is not bumped back far enough when re-sizing, you will get brass stuck in your chamber. If the shoulder is bumped back too far, you will have excess headspace and your brass life will decrease.
Wilson Case Gauge:
Very basic tool that allows you to check to see if the brass was re-sized properly. The Wilson Case Gauge is caliber specific, so you have to get one for each caliber.
Hornady Headspace Gauge Kit:
The Hornady Headspace Gauge Kit is a little more complicated to use, but with the supplied bushings, you can use it with pretty much any caliber. (The 6.8 SPC uses the "B" Bushing.).
How to use the Hornady Headspace Gauge:
As already mentioned before, the Hornady Headspace Gauge measure how much you have bumped the shoulder back when you re-size your brass. Along with the tool, you will also need a set of calibers. The tool actually attaches to the calibers. Here are the steps:
1. Measure several fired pieces of FIRED brass and record the readings, but use the lowest reading. Generally, the reading is going to be around 3.355"-3.360". (The factory brass is generally 3.350").
2. Lube your brass, re-size your brass, and measure it using the Hornady Headspace Gauge. Ideally, you want to bump the shoulder back .004". Let's say your fired brass is generally 3.355". When you re-size them, you want to bump the shoulder back to at least 3.351".
If you have more than one 6.8 SPC AR, unless you want to keep the brass separate, which is a pain in the ass and not worth it, I would measure a couple of pieces of fired brass from each barrel and take the lowest reading and bump the shoulder back .004" to ensure reliability in all of the barrels.
NOTE: For other calibers, such as the 5.56, I like to bump the shoulder back to the original brass specs to ensure that the ammo feeds reliably in all ARs. I've been to the range with my 5.56 and I tried shooting my ammo in another AR and it had issues because the ammo was set up for my AR. Now, I just re-size the brass back to the factory brass specs. Just something to consider.