Savage B.Mag 17 Winchester Super Mag Teardown

[oregonreloader]

Ricky...that pretty much looks like my stock. You can see the bow in yours, though. Can't see any in mine. I did notice that with the "old" stock, I could use just moderate pressure between my thumb and forefinger to get the forward lip of the forend to bend upward and touch the barrel. (I was concerned that just resting the forend on the lead sled, the weight of the barrel could reduce the gap.) With the new stock, I can't do that with just moderate pressure; it takes pretty much as much as I can apply to the forend to get to bend upward to the barrel. I'm an old fart and I might not have as much finger pressure as others, but there is a noticeable difference between the old and new.

 

[Ricky177]

Thanks for the info... I feel better you can see the difference. As far as your old fingers go, i'm right there with you!!! Still don't think a young set should be able to make it touch. Cant wait to get it back now (approx. 21 days).... i spoke to my guy at the gun shop where i bought it. he's sending it back for me as well as the 10 more he has in his 2 stores. i told him to come to this site and read up on whats going on on here with the B-mags and he spoke to his friend who's a higher up at Savage (their long time friends from what i got out of it) and he told him that he's gonna take back all of his B-Mags and replace them with the newer updated model... i'll let everyone know how this all ends up....

 

[417sparky]

Hi guys, glad I found this site! Lots of good info out there. I slapped a Redfield Revolution 3-9x40 on my Bmag after taking the die grinder to the terrible factory stock. I can know run a dollar bill all the way back with no obstructions. I had the same problem everyone else was having. Never shot it before but I could tell it wasn't right. Now though, the stock is flimsier than before if you can believe that! I had no interest in sending the gun back so I figured I'd give it a try. Going to be ordering a Boyd's soon. Good thing is I was shooting a decent group off the bench with the 20 grain bullets at 100 yards. It was a very windy day shooting with a bi-pod and the stock flexes so bad that I'm getting contact on the side of the barrel near the sling swivel. I'm happy with the initial outing all things considered and think on a lead sled AND with a better stock it would improve. Still nowhere near the accuracy I got out of my Ruger American in 243. Good news is my local Walmart is flush with both 20 and 25 gr. ammo and I must be the only guy shooting this caliber so I'm all in on the Bmag now! The pic that I took wasn't the best group but is an indicator of my average on the first outing today.
(Stock makes contact because of pressure exerted from bipod, otherwise, when just holding the gun it seems to be "floating")

 

[Ricky177]

nice poto sparky.... when you say windy, was the wind coming from 90deg. of the range (cross wind)? also if it was were you compensating for it? thats a solid 2" grouping... i can prob get that grouping out of my .22 long at 100 yards..... i believe you should get a better grouping from that gun if you were indoors and the gun was on a good rest. if it was a 90deg. cross wind and you're shooting off that bi-pod i would be happy as well with that turnout.... also, do you know the back order date as to when you might see that
Boyed's stock? I'm also interested in buying one.

Thanks for the input.....

 

[417sparky]

Funny thing actually, the picture actually is rotated wrong! The shots were all high not left! Winds were coming in from my 5 o'clock. I also messed up and turned the adjustment knob the wrong way so my trigger is heavier than when I got it. Shouldn't tell on myself but I figure I'm not the first! Gonna try to head back out tonight if the winds die. I haven't ordered the stock yet but plan to in the next month or so. Going to take the bmag this weekend on a coyote tournament so hopefully I can scratch a kill or two.

 

[Ricky177]

i too have a coyote turni that i wanted to use mine in.... looks like that aint happening.... good luck on yours though.... with groupings like that your sure to kill whatever you put the crosshairs on...

 

[gsperaz]

Thanks for the info... I feel better you can see the difference. As far as your old fingers go, i'm right there with you!!! Still don't think a young set should be able to make it touch. Cant wait to get it back now (approx. 21 days).... i spoke to my guy at the gun shop where i bought it. he's sending it back for me as well as the 10 more he has in his 2 stores. i told him to come to this site and read up on whats going on on here with the B-mags and he spoke to his friend who's a higher up at Savage (their long time friends from what i got out of it) and he told him that he's gonna take back all of his B-Mags and replace them with the newer updated model... i'll let everyone know how this all ends up....

If your gun is shooting 6'' groups at 100yds ill bet its more then your stock. I had the same issues and savage replaced my gun. The stock, barrel and head spacing was out of spec on mine. Run a cleaning patch down the barrel and see if it gets tight or loose any where all the way. My second Bmag was better but still required stock work and weighing the ammo to improve the accuracy. Ammo consistency is also an issue. I did a test on two 25 grain shells. One weighed 66 grains they other 68. They shot over an inch different at 50yds, and they came out of the same box.
Good Luck

 

[gsperaz]

Funny thing actually, the picture actually is rotated wrong! The shots were all high not left! Winds were coming in from my 5 o'clock. I also messed up and turned the adjustment knob the wrong way so my trigger is heavier than when I got it. Shouldn't tell on myself but I figure I'm not the first! Gonna try to head back out tonight if the winds die. I haven't ordered the stock yet but plan to in the next month or so. Going to take the bmag this weekend on a coyote tournament so hopefully I can scratch a kill or two.

FYI, Savage told me they qualify the Bmags with the 25 grain ammo.
Spec is 1.5" groups at 100yds. They said it was more accurate then the 20gr.
I have had fewer flyers with the 25's over the 20's.

 

[Ricky177]

Ok... The B-mag is on it's way back to it's Birth place... Let see if they can fix it's birth defects....... I spoke with a nice guy over at Savage and he explained to me the issue with the stock hitting the barrel. What happens is picture the barrel is like a tuning fork, when you hit the fork it rings. If you put your finger on it while it ringing it stops and goes flat. Well it the same deal with the barrel hitting the stock. It changes the harmonics of the gun and seriously effects grouping to the sum of 5 to 6 inches.... just like mine! bad thing is he said ill get it back in 5 to 6 weeks..... I'll let you guys know the deal when i see it again.

 

[oregonreloader]

I have about 380 B.MAG 20gn cartridges on hand. Having read that there was considerable variation in cartridge weight, I weighed each of the cartridges using my digital powder scale and recording each cartridge to the nearest 0.1 grain. The weights ranged from 62.5gn to 63.6gn, distributed as follows:

62.5: 1
62.6: 1
62.7: 2
62.8: 21
62.9: 53
63.0: 111
63.1: 63
63.2: 76
63.3: 34
63.4: 13
63.5: 2
63.6: 2

I've sorted the cartridges by weight and at my next opportunity I'll shoot groups by weight, after zeroing using the 63gn cartridge. To the extent the weight variance is a contributing factor to the B.MAG's accuracy (or lack thereof), I should see that in the data. I'll report after shooting.

 

[varmintH8R]

Thanks for posting.

Just looking at that data and doing head math, (at which I admittedly suck) it sure looks alarmingly consistent. Normal looking bell curve and 95% of the data (maybe all of it) is within .1% of mean.

I would be shocked if shooting results correlate to these minor weight differentials. Let us know!

Glad to see some promising info on the 17WSM.

 

[oregonreloader]

varminter...I agree with you. I, too, would be very surprised if there is any statistically significant accuracy difference with this variance in cartridge weight.

However, there seems to be no end of poor-accuracy B.MAG stories and this is just one check mark on the way to eliminate potential causes. The 25gn vs 20gn comparison is another, the "old stock" versus "new stock" is another, and the Savage stock versus Boyd's stock may be yet another. The more things we eliminate as error contributors, the easier it will be to tune this rifle to obtain best performance. Given the rifle and ammo I have, this is the only contribution I can make at this time.

 

[varmintH8R]

varminter...I agree with you. I, too, would be very surprised if there is any statistically significant accuracy difference with this variance in cartridge weight.

However, there seems to be no end of poor-accuracy B.MAG stories and this is just one check mark on the way to eliminate potential causes. The 25gn vs 20gn comparison is another, the "old stock" versus "new stock" is another, and the Savage stock versus Boyd's stock may be yet another. The more things we eliminate as error contributors, the easier it will be to tune this rifle to obtain best performance. Given the rifle and ammo I have, this is the only contribution I can make at this time.

Hope my comment came across correctly - not being critical at all. I think taking the time to weigh the cartridges and record variance is useful in and of itself. Regardless of how your shooting data correlates, I think it puts more (not less) of the overall performance on the rifle (eliminates a variable in your testing),

I think I might some 17HMR sitting around from a lot that is a known performer in my Savage 93 BTVS. If I get a minute I will weigh it and post variance just as a benchmark for your 17 WSM data.

Brandon

 

[gsperaz]

When I started weighing ammo, I just wanted to understand all the variables that could contribute to the accuracy issues I was experiencing. Shooting ammo of the same weight will not fix a Bmag shooting 3" groups at 50 yds. What it will do is help reduce those flyers we get when shooting and help determine accuracy issues. If your gun is already a good shooter, say 1/2" at 50yds then you can expect improvements by shooting ammo of the same weight. One thing to remember is that the powder charge is only one of the variable components, primer, cases and bullets all vary.
In a nut shell it took a combination of stock work, bedding, barrel O-rings and ammo weighing to get my bmag to consistently shoot accurately. I can shoot .25"-.40" groups at 50yds every-time I shoot it. Not the case when I took it out of the box.
And I still get an occasional flyer.....lol. but know its only 1" out instead of 3".

I weighed a box of 50 Hornady HMR 17gr ammo and there was only a .6 grain variation for the box. I was surprised to see such consistency for rimfire ammo. Could be why my savage 93 BTVS shoots .75" at 100yds all day long.