Getting Ready to load 7mm SAW? Thinking about building one, but wondering what barrel length you should run? Here are some common questions and answers regarding loading and performance of this great little round.
General Loading FAQ’s
What is the trim length for 7mm SAW? The max case length is 2.010″, same as the parent .308 Winchester cartridge. Factory new WTO brass typically measures 2.000-2.003″ right out of the box. When loading for our personal SAW’s, we keep our brass around 2.006-2.008″.
What powders work best for this cartridge? Our favorite powders for 7mm SAW use are Hodgdon Varget, Hodgdon H4350, Reloder 16, Vihtavuori N540, and Vihtavuori N550. We have also used Winchester Staball 6.5, CFE223, and Ramshot TAC. As a rule of thumb, any powder that is suitable for use in the 6.5×47 Lapua or 6.5 Creedmoor cartridges is a viable option for the 7mm SAW as well.
How much should I bump the shoulder back when re-sizing? We recommend bumping headspace .003-.004″ from your fired case headspace measurement. SAW headspace is measured at the .375″ datum point of the shoulder. Nominal GO dimension is 1.627″ at .375″ datum, and NO-GO is 1.632″.
How long will WTO 7mm SAW brass last? This is a very subjective question, and it obviously depends on multiple factors such as loading pressures, annealing, and re-sizing practices. That being said, the short answer is if you take good care of your brass, it will last a long time! We are still actively shooting SAW brass with over 10 firings without loose primer pockets, case head separations, or any split cases. As a matter of fact, to date we have never observed a split case in this cartridge. During the pre-production testing of the Alpha Munitions 7mm SAW brass, we did a little experiment to check case longevity. We pulled a single case at random and loaded a relatively stiff but not maximum charge of H4350(45.8gr) under a 162gr Hornady ELD-M bullet. We continued to load and fire this combination on that single case without annealing for 27 firings. There was still no significant loosening of the primer pocket or other damage to make the case unusable on the 27th firing.
Which reloading die set should I buy? This is a matter of your own brand preference, although there are a few differences that you may need to consider. Both our Hornady and Redding die sets are match grade dies that feature a full length bushing resizer for interchangeable neck bushing. Both sets also feature a micrometer adjustable bullet seating die. The Hornady seating die design sits significantly higher in the reloading press however, so this may need to be considered if you are loading long bullets and using a press with an over-the-top handle design like the Forster Co-Ax. On a bottom handle press such as RCBS, Hornady Lock-N-Load, etc., die height is not a concern. Another difference to consider is adaptability. If you plan to own other cartridges in the SAW family such as the .25 or .27 cal variants, The expander/decapping assembly components for those calibers are available from multiple sources for the Redding die, making it easily configurable to accommodate the other cartridges in the family. This is not the case for the Hornady die. Both die sets can produce very straight, concentric, and accurate handloads.
Performance and Longevity
How long will my barrel last? This is another highly subjective question that depends greatly upon ambient temperature, barrel temperature, firing schedules, and chamber pressure, as well as the types of powder used for loading. In our experience, a typical 7mm SAW barrel under normal shooting conditions will last well over 3500 rounds. We’ve seen some competition barrel for PRS/NRL style use that died closer to 3000 rounds, and were shot hard and hot for the entire lifespan. When considering a typical hunting rifle or even an NRL hunter style competition build, those barrels will go quite a bit longer.
I’m trying to decide on the right barrel length for my rifle. What kind of velocities should I expect? Below is a simple chart that gives the average velocities we see with known safe loads for different barrel lengths and bullet weights. Every barrel is different so there are outliers on both sides of these numbers, but after building a multitude of rifles in this caliber we’ve gotten a good feel for the average speeds you can expect.
|Bullet weight||Avg. MV||Avg. MV||Avg. MV||Avg. MV||Avg. MV|