5.7x28 fun...

[CubCouper]

Picked up a 5.7x28 reamer this winter and a 700 bolt that had been reworked the little cartridge. A 14-twist Shilen tube found its way to the lathe, and eventually an action and a stock from the spare parts bin came together to form the new Noisy Cricket. Using some known-good Hornet loads for guidance, what I ended up with was a very pleasant surprise.... it shoots very well! 10.7 grains of Lil'Gun pushed the 40 gr Vmax's to just over 3000fps, but 10.6 at 2870-2900 seems to be where it is happy.

Hand-feeding the tiny rounds into a 700 action is an exercise in dexterity, as is extracting the spent cases which almost stand up inside the short action lug area. Still, I expect that some prairie dogs will soon learn to fear this monster.

Rod

 

[Johnny_V]

Now how cool is that. Great job. Could you be so kind as to post some pictures of the rifle? I would very much like to see the finished product. Savage used to make the Model 25, Walking varminter in the 5.7, although I have never seen one. Always wondered why none of the major manufacturers picked up on this cartridge and made either a single shot or bolt gun. Also, could you elaborate on the difficulties you encountered during the build process?

Again great job and thanks for sharing.

 

[CubCouper]

No real difficulties for me. The interesting work was done by someone else -- bushing the bolt face and cutting in the extractor. The rest is just a standard Rem 700 SA build with a stock trigger. The fly met his demise with it mounted in an SPS Varminter stock. I moved it to this B&C stock for some more load development. I've got a handful of stocks around the shop, and things move around quite a bit as I borrow parts to try out ideas. This may find a home in an old Hunter-Class BR stock since it is a dedicated single shot and its ultimate purpose is to annoy prairie dogs.

The 700 action is way too big for the 5.7 cartridge, but an idea was morphing to chamber one barrel in as many calibers as possible without changing anything other than the bolt. Progress from 5.7x28 up through the Fireball, Waldog, Deuce, 22BR, 22-250, ...? More likely, I will just move on to another project and enjoy this oddity as is. I'm not sure that kind of test would really reveal any useful information anyway.

The 5.7 (and the Hornet) responded really well to Lil'Gun powder, but the stuff is very charge-sensitive. A tenth of a grain is a big change when the whole charge is only 10.6 grains. I'm lighting it with Federal 100 small pistol primers. I've got 1800 pieces of one-fired brass that came with bolt. The stuff is likely off some govt practice range and the first 50 pieces or so show a +/- 4gr difference in weight -- cheap and definitely not the Lapua-esque quality I like to work with, but workable. Down in the shop today building a dedicated trimmer -- the straight walled body doesn't grip in the Wilson-style case holder I made, and there's too many cases to do to fight with it.

The rest was standard BR load development - pick a powder, try a range of charges and seating depths and watch how the the groups take shape. Tweak it up take out the vertical and down to take out the flyers and -voila- dots appear.

I just picked up a Remington 799 (Mini-Mauser) that would be a much better fit for the cartridge and make a sweet little walking rifle.... maybe next winter.

 

[linebaugh]

Very neat.

 

[rickiesrevenge]

I've always thought that was a neat little case. Might consider removing the ejector so the case stays on the bolt until you pluck it off.

Aaron

 

[Johnny_V]

I've always thought that was a neat little case. Might consider removing the ejector so the case stays on the bolt until you pluck it off.

Aaron

I do that with all my bench guns. With such a short cartridge you might consider cycling the bolt faster so the case doesn't get trapped in the receiver.

Quick question. Since there isn't any appreciable shoulder setback with a bolt gun, is the polymer coating really necessary? I know the coating is needed for the PS90 and the FiveSeven pistol, but not sure on a bolt gun.

 

[matthias]

In bolt action Rifles the coating can be removed . I use stainless pins in a tumbler wet .

Lots of fun

 

[Johnny_V]

I kinda figured the coating was nonessential. I may delve a bit further into a build like this.

 

[ChuckinJax]

That is cool, is that brass common?

 

[Johnny_V]

That is cool, is that brass common?

Fairly common, but highly sensitive for handloading.

 

[matthias]

Sensitive yes.
Careful loading required? Yes
Load data is available. It isn't that hard to load.

 

[CubCouper]

I've been working on it a bit -- since the recoil is so brutal on a monster like this, I decided it needed a muzzle brake. In fact, one brake wasn't enough, so I added a second one over the top of the first one. Calmed it down Still shoots flies!!

 

[rickiesrevenge]

Interesting brake.

Aaron