The new .17WSM rimfire caliber from Winchester is currently only available in the Savage B-Mag rifle. It appears to be a new design from Savage, and the cartridge is an honest performer downrange, far surpassing the .17HMR.
The new rimfire is based on a .27 caliber nail gun blank made by Winchester for driving cement nails. The case is much bigger than a .17HMR, and it was significantly beefed up from a blank case to achieve the performance found in the .17WSM.
This chart was generated by the ballistic software on the Winchester ammo website. It shows the dramatic difference between the .17HMR and the .17WSM at 200 yards. The data sheets are below.
This Savage B-Mag is a very different rimfire. If you click to make the picture bigger you’ll see that it uses a standard round firing pin that is offset to activate the rim of the cartridge.
The biggest quirk of the gun is that it cocks on closing, like an Enfield. Our test gun was a bit stiff. Note that it comes with the scope mounts.
The new rotary magazine from Savage holds 8 rounds. Ours worked flawlessly because we didn’t take it apart to see how it works.
If you click to make this bigger you will see groups running from .65 to 1.66 on the same paper. At 100 yards, the ammo seemed to just be inconsistent, though not an overall bad performer by any means.
This rifle does come with the patented Savage Accutrigger system. It is adjustable and shipped from the factory at about 3 lbs.
The barrel is free floated in the stock, and for about 4 of these dead presidents you can buy both the gun and the Leapers SWAT Scope mounted on top.
Thjis is the .17WSM ballistics chart for the 20 grain load. At 200 yards it only drops 3.5”, which means you can shoot almost point blank at normal game distances.
This is the .17HMR chart with a Hornady 17 grain bullet, the only one Winchester makes in that caliber. It is still an impressive rimfire, but in a different class.
The amazing new rimfire we have all been gushing about since January’s SHOT Show has finally come to fruition. Winchester Ammunition, teamed up with Savage Arms, has introduced a new .17 caliber cartridge called the .17 Winchester Super Magnum that is capable of firing a 20 grain bullet at just better than 3,000 feet per second. That makes it the fastest rimfire ever created, and puts it in a class pretty much by itself for long range rimfire competition and varmint hunting. The problem until now has been that the only reviews out there were from print writers who all shot the exact same prototype rifle that was made for a print writers roundup, so it had very little relationship to the actual gun that you would later find in a store. Add to that the fact that the ammo was simply not available, period. Savage sent us this test rifle over two months ago, but we had no ammo, so like everyone else, we waited. Finally, as you can see from these tests, the ammo has started to trickle out. Several of our dealers have reported that they have gotten 40 box orders in (and quickly out) the door, and this ammo you see here was purchased retail at Bass Pro in Hollywood, Florida. We were only able to get the 2600fps. 25 grain load, but it is still a rip roaring monster for a rimfire, and the accuracy is acceptable, (though not fabulous for a Savage). The Savage “B-Mag” rifle is currently the only gun for the cartridge, and it carries an MSRP of $349. As a first effort on a new and revolutionary rimfire, the B-Mag performed well, and the cartridge looks to have great potential.
The .17WSM is not just a hotter .17HMR. It is a different, and much larger case entirely. Winchester based it on a .27 caliber blank made for industrial nail guns used for cement nails. They make a ton of these blanks, so in their attempt to develop the next hottest cartridge out there, the engineers settled on tooling that they already owned and used. It required substantial modification. They beefed up the case by doubling the wall thickness and added extra meat to the top. This supposedly results in a rimfire case that runs at 33,000 psi, though we have not been able to test the actual ammo in the gun as to the pressure. What we were able to test though was the actual velocity of the 25 grain round, and it clocked at over 50 fps over the box velocity of 2600fps, with a 22” barrel. That is impressive, and judging by the interest we have received on the original article from January, there are going to be a lot of very unhappy prairie dogs, coyotes and grey squirrels from this new and exciting powerhouse of a rimfire.
Using Winchester’s ballistic calculator (also a phone app), we were able to see the broad brush differences between the 17 HMR and the new .17WSM (as well as the .22WMR). If you find it strange that Winchester didn’t call it the .17WMR, you aren’t alone. The “WSM” connotation has been used for “Winchester Short Magnum” for years in centerfire, and it is odd that they used that abbreviation for the new rimfire, but it was probably done to help the cartridge stand alone, which ballistically it does among rimfires. Using Winchester’s only .17HMR in the calculator, which is a .17 grain bullet, the 20 grain.17WSM is already doubling the.17HMR in energy at 100 yards, 278 ft.lbs/sec. vs. 138 ft.lbs/sec. And though their drop is equal at .3 inches, in a 10 mph crosswind the .17WSM has ½ the wind drift, 1.6”, versus. 3.1” for the .17HMR. At 200 yards, the wind drift and energy are similar in relation to each other, but the bullet drop has increased on the .17HMR to almost 3 times that of the .17WSM, 8.9” vs. 3.5” respectively. Winchester actually uses a Hornady 17 VMAX bullet for that cartridge, so it isn’t as though they intentionally sandbagged the round. The numbers on the .20 grain .17WSM are really impressive, but that wasn’t the one we were able to shoot unfortunately. Every gun shop we have spoken with has gotten the 25 grain bullet, and the numbers on that, while still much better than the .17HMR, are not as much of a standout.
Currently the only gun for this caliber is the Savage “B-Mag,” and it appears to be a completely new rifle. If you look at the cartridge head and bolt face picture, you’ll see that it doesn’t fire with a standard rimfire firing pin. It is instead an offset centerfire’ish pin, and the indent on the case is a standard certerfire’ish, indent. The gun also cocks on closing the bolt, which is my only peeve on an otherwise very comfortable and well made rifle. You have to really practice throwing the bolt, because otherwise it is very easy to short stroke it and think you are closing the bolt when you really aren’t. The bolt handle actually quasi-closes about a ½ inch behind the real closing point, so in the field this could lead to a missed follow-up shot if you aren’t careful. Limp’ly running the bolt doesn’t work so good either. The cartridges are held at a steep angle, ready to be pushed in, and if you don’t do it quickly and with some force, they occasionally get sideways on you. We ran 200 rounds through this gun and it isn’t a serious problem. Once you get used to that hard downforce on bolt close, and the length of the throw, it won’t fail to strip and chamber a round even once.
There is also a new rotary 8 round magazine for the B-Mag, and though it is odd, ours worked flawless. Instead of each cartridge following the previous, the way it does in pre-war Savage Model 1899, the magazine has actual slots that you feed the case into as it turns around. It isn’t the easiest magazine to load, but it works as it should out of the box and doesn’t fail. I didn’t open up the mag to see what is inside and how it works, but I have read other reviewers who claimed that they were “gunsmiths,” and, strangely, had magazine problems with the B-Mag. There are two very inviting screws on the front of the magazine, but unless you get something in there that needs to be cleaned out, I would leave the magazine well enough alone and it will work great. Every gun company customer service department will tell you that the biggest problem they have are guys who feel like they have to take apart a brand new gun before they shoot it. I have owned, shot and cleaned guns for decades without ever taking down for cleaning more than a simple field strip, and they work and last just fine. This is a $300 rifle. Don’t take the little pieces apart unless you have to, on any gun for that matter.
Our accuracy testing will have to remain incomplete for the time being because we were not able to get either rendition of the 20 grain Winchester ammo. The 25 grain load was inconsistent, with some 100 yard 5 shot groups coming in at .5” in dispersal, and others 1.5”. That isn’t too bad even with our worst results, and well within varmint tolerances out to 300 yards, but you couldn’t help asking yourself what the rifle was really capable of delivering. Could it be that the .17WSM is just an untamable beast running at too high a pressure through a small action? Probably not, and the evidence is in Savage’s decision to not make a .300 Blackout a couple years back. They were unable to get that cartridge to perform in a bolt gun as well as it has demonstrated in a semi-auto, so they just didn’t make it. There is no way that Savage would make this gun if thought it would only deliver inconsistent performance, which leads us to answer #2: the ammo itself. Other reviewers who shot that prototype gun reported that the 20 grain load performed much better than the 25 grain load, yet we haven’t seen any in the market that I can tell. That usually means that the test ammo was made by hand, not on automated machinery. The 25 grain is what you are seeing in he stores, and this load is unique to the .17WSM because the .17HMR can’t handle bullets that heavy. Most coyote hunters will want the 25 grain, and coyote hunters buy a lot of guns, so the 25 grain is the one that Winchester tooled up the machinery for first. The new ammo just isn’t that consistent yet, and we have all been spoiled on Hornady .17HMR that will shoot into .5 inches reliably in any Savage you put it in. This Savage B-Mag is almost definitely capable of delivering that same consistent tack driving performance, given ammo that is consistent.
The price of shooting the .17WSM will be about 3 bucks per box of 50 more than shooting the same 50 rounds of.17HMR. This is understandable because it has much more brass and powder, but when you are up in the range of $16-18 for a non-reloadable rimfire, the rimfire cost advantage quickly evaporates in a couple prairie dog towns. The 3600 fps. .17 Hornet centerfire cartridge we recently reviewed is a tack driver, and at $18 per box of 25, if you reload them twice you have already saved yourself significant money over the course of hundreds of rounds. It is also easier to stock up on bullets, powder and primers than boxes of ammo should another artificial shortage cut off the ammo supply again. I don’t think the question is, should I get a .17HMR or a .17WSM? Of course you should get a .17HMR for heaven’s sake! The real question is, if I am going to invest in a new experimental .17, should it be the .17WSM or the .17 Hornet? If you handload, it would be the latter. If you do not, probably the former. If Hornady ends up making a .17WSM cartridge, all bets are off. Get your but to a gunshop that day and get a .17WSM before Oprah tells her minions to buy one and they end up backordered for two years. These Savage B-Mags in .17WSM are currently available, and any gun dealer worth her or his salt is squirreling away some ammo when they have the guns to sell, so just ask your local dealer or big box store and you’ll be out shooting the worlds fastest rimfire in no time flat.