The 7mm SAW Chronicles

7mm SAW

Here at PDI our love affair with Clayton Smith’s (#WestTexasOrdnance) extremely versatile 7mm SAW cartridge has already been documented in the tale of Trollhammer. After Trollhammer’s success, we decided that the SAW might be just the ticket for a mid-range (out to 600m) ultralight rifle, so set out to build twin 7mm SAW’s as the platforms from which to test our new Featherweight Gen3 stock.

The only thing we had to wait on were barrels – a pair of 20″ Sendero Light carbon wrapped PROOFs. We waited. And we waited. Then, along came COVID. We waited some more. After after 2 years of waiting, one of the barrels arrived… Oh happy day! The result was “Captain Feathersaw”… the 7mm SAW weighing in at 2.7kg/6lb (bare rifle) and very compact, it’s ready to be carried for days, or if things go really well, weeks! The other barrel did finally turn up and you’ll see that written up as a PROOF vs Bartlein head to head battle of the carbon fibre.

We were going to write this post as a preview 7mm SAW featherweight article and give a full review after ‘the Captain’ had been to New Zealand but… life… COVID… You get the drift. The upside is ‘the Captain’ has actually moved to New Zealand in the interim… So grab a Speights and slip off your jandals for a rifle review with some sweet as high country content. Chur.

7mm SAW
Captain FeatherSAW in their natural habitat

The anatomy of a Feather SAW:

  • Featherweight Gen3 Carbon stock
  • Tikka t3 action
  • MTNGear NZ bolt handle
  • Lumley Arms ‘Long Action’ bolt stop – effectively makes the action length between a tikka ‘Medium’ and ‘Long’, perfect for the SAW
  • TikkaT3 3 shot medium magazine modified for longer COAL
  • TierOne 30mm one piece rings for the 17mm dovetail – lightweight, integrated bubble level, beautifully finished
  • Lumley Arms Tikka T3 Detachable Bottom Metal – 83.5g of delightful machining 
  • Lumley Arms Ultralight Trigger Spring – the already excellent tikka factory trigger now breaks at a clean 1lb every time
  • Proof Research 1 in 8″ twist Sendero Light 20″ carbon wrapped barrel, chambered in #1 the 7mm SAW (short throat)
  • A-tec H2 suppressor, run with 2 out of 3 modules
  • MTNGear NZ mountain bipod
  • Beartooth 2.0 comb raising kit

20″ 7MM SAW Testing and Development

We decided before even building this rifle that it would be shooting the 160gr Sierra Tipped Matchkings. In the 7mm SAW Trollhammer they had proved very accurate, easy to tune and absolutely deadly on deer ranging from small fallow to large Sambar. Being a short barrel and a hunting rifle we decided to try to maximise velocity and start with AR2208 (=Varget) rather than the compressed load of AR2209 (=4350) that Trollhammer favours.

2208 might be a great fit for 140-150gr class hunting projectiles. For the 160gr we found that we hit pressure at about 42gr, which gave us 2700fps out of the 7mm SAW 20″ barrel. We did find decent accuracy at 41.6gr (2663 fps).

So, roll on 2209 (aka old faithful)… This time, case capacity was the limiting factor. Things were getting pretty crunchy at 46gr. Again, velocity was sub optimal (we ran out of case at 47gr, 2700 fps) but we found a load at 46.3gr that shot the lights out (0.33MOA, 5 shot round robin group at 300m) so roll on fire forming our virgin brass.

Trollhammer was built before 7mm SAW brass was available and the result (necked down, neck turned Lapua Palma .308 brass) was excellent. For the mid-range hunting application of FeatherSAW we decided that neck turning was a step too far and we bought some brass made for WTO by Alpha Munitions. From our experience so far, the capacity and pressure profile of the Lapua seems that tad bit friendlier and the extra case prep pays dividends with excellent ESs. That said, the results we’ve seen from the Alpha Munitions/WTO 7mm SAW brass are great and the time saving of having a ready to go case is compelling.

We’ve stayed away from Reloder powders generally in Australia because ADI is a) locally produced, b) easier to get, c) cheaper, and potentially most importantly d) generally has good temperature stability. In NZ some of those relationships change, including generally shooting in lower temperatures. So, with a fair bit of fire formed brass now available and an ADI powder shortage in NZ, a few odds and ends tubs of Alliant powders were sampled (Powerpro 2000, Reloder16 and Reloder17).

Powerpro2000 supposedly burns between 2208 and 2209 (perfect right!?)… But it’s a ball powder and struggles to fill the 7mm SAW case. We haven’t hit pressure limits with it yet but suspect that we will without the case being particularly full and it’s temp sensitivity (according to Dr Google) is substantial. We got up to 43.5gr which was yielding 2629fps and maybe only 2/3 case capacity… We may test further.

Reloder16 supposedly has a very similar burn rate to 2209 and is made for Alliant (by Bofors in Sweden) to have low temperature sensitivity. It could be a great choice for a longer throated 7mm SAW with heavy projectiles but for FeatherSAW, its low density means it fills the case too quickly. We didn’t hit pressure but also didn’t get great velocity: 2560fps with a full case at 45gr (no drop tube used).

Enter Reloder 17 – developed for short magnum cases with a burn rate slightly slower than 2209 but metering well with reasonable density, 17 has developed a reputation as a bit of a speed demon. While its temp credentials may be questionable, in the moderate temperatures of the South Island and with the idea of maximum hunting ranges being ~500m, we felt this powder had some serious potential for FeatherSAW… And we were right.

Three 0.3moa groups were shot at 46.8, 46.9 and 47.0gr with a muzzle velocity of 2720-2760 fps. The little 7mm SAW case is nicely at capacity, giving a ‘kiss’ of crunch when seating the bullet. From a 20″ barrel with a 160gr projectile out of a lightweight hunting rifle, we’re more than pleased. Note – this load is near pressure limits so PLEASE work up to it if you’re interested in replicating it. 

Stubbie 7mm SAW … Eh? Get to the hunting bro!

The compact package in the Bolly Featherweight stock is a joy to carry and shoot, even suppressed, plus with a bipod still comes in at 3.2kg/7lb. DISCLAIMER – that’s with the MTN Gear bipod, which is not your average bipod! Head here (Coming Soon!) for an initial review as we go ultralight with the MTN GEAR Mountain Bipod.

To test its versatility, Brooky topped ‘the Captain’ with the sublime Delta Titanium HD 1.5-9×45 for two very different roar hunts this year – dry open tops in North Canterbury, followed by a trip into the jungles of the deep south. 

Young stag taken at 15m

The 7mm SAW and Delta 1.5-9×45 combo performed beautifully. Maximum magnification and crisp turrets accounted for a hind for meat at 400m in a brief foray to the tops. In contrast, the huge field of view at 1.5x and the magnificent illuminated centre dot reticle were bad news for this young stag at 15m in thick crown fern in the dim light of dawn. 

12 Point Stag taken at 150m

Ironically, the quickest handling required was ultimately required on the dry, open North Canterbury tops – a quick shot off the knees at 150m accounted for this 12 pointer. He had been passed up earlier to grow but unfortunately he prematurely sealed his own fate a few hours later when he stepped out right where we were expecting to see a big, heavy old 10 that we had been sparring with; in fading light and with a limited shot window he was taken ‘by mistake’. It was pretty gutting at the time but it was part of a great hunt and many kilos of sausages are slowly eating the pain away…

Needless to say the 7mm SAW and 160TMK from a 20″ barrel is doing the job nicely, with rapid kills on animals ranging from nanny tahr to red stags! For the full rundown of Captain Feathersword’s maiden Autumn and Winter of hunting in NZ, head to the PDI instagram!

Captain FeatherSAW , aka our first 20″7mm SAW performs just as beautifully hunting in the NZ mountains as Trollhammer did in PRS Australia, NZ Mountain Challenge competitive shoots and in the Sambar woods of Victoria. It packs more than enough punch out to 500m even in a short-barrelled rifle that also handles well in thick bush. For exceptional versatility dropping in and out of the bush-line, the Delta Titanium HD 1.5-9×45 is a simply exceptional pairing and for someone looking for the ultimate ‘precision’ scrub or bush rifle system, Captain FeatherSAW is a mighty contender.