Unconventional Solution to Savage .17 B-Mag accuracy issues? Build-along (sort of)

gabrielguitars

gabrielguitars

CGN Regular
Rating - 100%
234   0   0
Location
Edmonton
So I, like many other B-Mag owners, am not entirely satisfied with the grouping capabilities of my new gopher-obliterator. I bought a nifty new Boyd's stock for it, thinking that the much more stable and rigid platform would help, but I found out that it didn't. Don't get me wrong, when shooting it at game, it still performs well, but the paper seems to tell a different story. So what's a guy with machine tools, little sense, and big balls to do? Let me tell you. I decided to take a page out of the benchrest boys' book and build a barrel block mount for this beast. Typically, these are built on rifles with a parallel huge barrel that weighs lots more than the action, and the block grabs a large section of the barrel. With the B-Mag, there really only is the section of the breach with the turned rings in it that is parallel, so there isn't a lot to grab. What offsets this (I hope!) is the fact that the barrel and action are featherlight. Here is what I did:

This is a pic of a trued-up aluminum block just a little over 3/4" thick, that I have bored a hole in for the 0.860" breach section of the barrel, with a 0.005" relief to allow for fully seating.

The next step was drilling for the 5/16" NC socket caps I was going to use for the clamping job, and counter-sinking the heads.

Here you see the bolts in. I made the heads to be exactly flush with the top of the block. The block has been cut in half, the holes tapped, and the edges dressed. It's starting to come together!


In these next two pics you see my next stage. I drilled and tapped a hole for a piece of 7/16" ready-rod underneath the barrel. The idea behind this is to have the ready-rod set into an epoxy-filled groove milled in the forend, adding lots of strength and stability to the clamp itself, as well as the forend. As the balance point of the entire gun is forward of the area where I am clamping the barrel, it will want to tip forward, so this supporting 'leg' out front makes lots of sense.
 
Last edited:
Continuing on, you will now see the milling I had to do in my Boyd's stock to accomodate this contraption:

I ended up having to cut the ready-rod shorter than I really wanted to, just due to the limitations of my milling machine. I am sure there will still be plenty of strength in this anyway, and the shorter piece of ready-rod will not add quite so much extra weight to the forend. Next you will see the completed appliance sitting in it's spot in the stock:

At this point, I am almost ready for the epoxy. The only issue to solve at this point is to make some way of being aware of the orientation of the clamp when it sits in the stock during the curing process. I quickly made up a piece of aluminum the same diameter as the barrel shank, with a 3/8" hole in the centre to put my 18" drill bit into. Clamping this into the block, I can use the drill bit to determine how the block is sitting in the stock.


So, today I finally anted-up and epoxied it into the stock. Here is what my workbench looks like today:

The tape on the sides is holding some extra epoxy to the sides to try and dress-up the sides a little. It was unfortunate that I had to cut so far into the sides to accomodate the block, even moreso that I went a little farther than needed! Hopefully I can dress it up a little, but this project is more a proof-of-concept project anyway, not so much a showpiece. I will be taking it out on May long weekend to test out. I will post some pics in a couple of days or so when I get the gun into the stock (block???).
 
So it has been more than 48 hours since I epoxied the 'appliance' into the stock. I mounted the rifle in the block/stock tonight, and everything looks really spanky! The orientation of the barreled action is perfect, so I am over the moon so far. The only real drawback so far is that the light skim of bedding on the right side of the block cracked when I tightened the bolts. It is really only superficial, but unfortunate. The general feel of the gun now when in the block is rock solid, totally different than the way it felt before with just stock bolts. Tomorrow I will try and clean up the bedding around the sides of the block, mount the scope, and post some pics. For now, here are two to give you an idea of what it will look like, and so you can see the orientation of the barrel in the forend. Oh, BTW, I think I will be installing two bolts from underneath the stock into the clamp block for added torque resistance when tightening/loosening the clamp.

 
Nice! I love it!

I had been very interested in the B-Mag, until I actually picked one up and noticed that the barrel is literally thinner than my pinky finger at muzzle. If this works for you, you will have a really sweet little gun on your hands!

NOW, Mr. "I have a milling machine", lets see what you can do with that abortion of a bolt handle...
 
I don't mind the bolt handle, really. Anyway, I finally was able to test fire the barrel-blocked-B-mag, and the results are good. Not great, but good. I was having quite a bit of trouble before the mods with vertical stringing. After the modifications, the vertical stringing has been completely removed. The problem is, it still isn't what I would call 'accurate.'. I found that my benching technique (bipod prone) needs improvement, as I could see the crosshairs wavering side to side a lot, and this is exactly how the groups turned out. I also need to try the 25 grain load, as that seems to work better for many. I would consider it a qualified success - I would have liked better.
 
Wow, great work and thanks for sharing all the photos Certainly thinking outside the box trying improve accuracy. I feel like the accuracy limitations with this cartridge has a lot to do with who is producing the ammo. If another manufacturer apart from Winchester starts producing some better quality stuff it could solve the issue.
 
A suggestion? Try opening up the channel on your boyds up. That barrel has some significant harmonics, and it's possible it is still touching the stock of the forestock. I am taking mine out to a 3/4" channel for the bull barrel and my old one is doing amazingly well in the poly stock the ss one came in. My only explanation of that is the new stock is shorter and has a huge 3/4" channel.
 
You must log in or register to reply here.
Back
Top Bottom