Here is a build (really product assembly) of a 7 mm STW on a Shilen DGR action. Since the action isn't too common, I thought this would be a good one to post.
It was reading posts from the lunatics
err ... 7mm STW Brotherhoods that swayed me too this cartridge.
: To build an ELR shooter for target and open range hunting. The pluses are putting high bc/high mass bullets down range with high muzzle velocity. The downsides are recoil, cost, and tricky design criteria. Also, short barrel life at 1200 - 1500 rounds? Depending on the bullet and altitude this cartridge will deliver supersonic beyond 2000 yards. Action was chosen because I am a barrel nut person. I like mixing around cartridges and the barrel nut allows me to do this. I did not go with Savage because it would have taken too much work to make this rifle a repeater without compromising the handloads. Shilen offers the ideal action in my opinion for a high quality action made to order for a barrel nut/floating bolt head. The long magazine inlet and side bolt release is ideal for long cartridges.
: DGR long action from Shilen. This is a Rem 700 clone built by Stiller for Shilen. It has an extended magazine box opening (3.950” vs. ca. 3.65”) and side bolt release to accommodate longer cartridges. The design comes with a barrel nut and is threaded to 1 1/16” - 20 (not standard). The bolt head is floating. The recoil lug is thicker than normal at 0.3”. A Shilen trigger, with Rem safety was installed. I installed a full 20 MOA base from Shilen. Shilen offers both short and long versions. The long was in stock when I purchased it, but that might have changed by now. I heard on the net that there is currently a wait for the short.
: HS precision with aluminum block. Required opening up recoil lug space to accommodate larger lug. Harris bipod attached. Taped on some foam to increase LOP and cheek hight. Will modify both later to something more permanent. I installed an extended magazine from Wyatt Outdoors to accept longer COAL cartridges out to 3.825”. Trigger guard/bottom metal, mag spring and follower came from Brownell’s. Currently un-bedded, but will do so in the future.
: It is a 24” barrel contoured to Shilen’s S4 Savage replacement dimensions; it is their select match stainless steel version. Throated to accept 180 gn Berger VLD with COAL of 3.8” (I don’t have the dummies in front of me now). When rifle is used for hunting, I will at least test the new 168 gn Berger classic hunting. These are supposed to be very tolerant to jump while maintaing a high bc. No brake or suppressor at this point.
: March F 3-24x/42 mm with illumination. Mil dot reticle and RMAD turrets. This scope is FFP. Held in place by rings from Badger Ordnance. This scope was taken off of another rifle I own.
: Total unloaded weight w/o bipod: 11.4#. I was looking to hit between 11-12#. Too much lighter would probably require a brake.
: First day out to zero. I used HSM cartridges with 168 gn Berger VLD bullets. Easy conditions of 70 F with light winds. All shooting was done prone off of a Harris bipod with a sock of pinto beans for rear support. All shooting was done at 10x. First impressions at zeroing were that it has an acceptable kick (less kick than I anticipated), but seeing impact at 100 yards was impossible. Midway through zeroing I had to retighten action screws which had rattled loose. Trigger appears to be set to 1.5# as measured with my gauge. I typically set my triggers to 3#. I had a couple ‘surprise fires’, thus haven’t gotten the feel of the lighter trigger, yet. Will probably adjust to 3#. I neglected to measure the COAL of the HSM ammo, but it was easily cycled through the Wyatt magazine.
Collected very quick and dirty dope (limited ammo):
200 yards: +0.1 mil
300 yards: +0.4 mil
385 yards: +0.9 mil
500 yards: +1.5 mil
My chrony jumped in front of a speeding bullet last year and I haven’t replaced it yet. Using JBM ballistics and the observed dope, a rough estimate of MV is around 3300 - 3400 f/s.
I can’t really speak to precision yet. Everything else on this build has met or exceeded my expectations, so if the precision meets expectations then I will be a very happy camper. It was a good day at the range.