39 gr. SBKs, just a statement.

Sask Boy · Post by **Sask Boy** » Sun May 20, 2007 9:02 am

On Friday I went to our local dealer to pick up some bullets and was advised that they are out again.
It is going to take another week to 10 days to get in more, I do not know about the rest of you but it sure seems that 39 gr. Sbks have grown in popularity???

glenn asher · Post by **glenn asher** » Sun May 20, 2007 9:27 am

The word has been out for a while now, since they were introduced, anyway. 40 VMs have been "iffy" in accuracy from the git-go, they were the "next closest thing" and have proven themselves to be very accurate, and less fussy to get shooting well in most rifles. With the high BC rating Sierra gives them, it was a given that they'd be popular. Last year, I did a poll that had them #1 over all the other bullets combined, which says a lot about them. It's no secret that they are fine bullets, and their popularity is bumped up by the poor showing from the 40 V Max and the NBT 40, which is also a bit "iffy" in most rifles. If one bullet is showing itself to be accurate in the majority of rifles, it follows that demand will also lean that direction. It's one heckuva coup for Sierra, since Hornady is the main developer of the Twenty Caliber amongst the big makers.

acloco · Post by **acloco** » Sun May 20, 2007 6:57 pm

Have you seen the pics I have posted lately? Nothing wrong with the 40 VMax's in the splat factor.

Of note, my rifle keyholes the 39 grain Sierra's....too long of bearing surface for my Savage 12FV.

Of another note, the 32 grain Sierra's vaporize about 6 feet from the muzzle when pushed to the 4050 range.............

gunsaregood · Post by **gunsaregood** » Sun May 20, 2007 10:22 pm

Interesting the personalities of different rifles. Like acloco, I too have a Savage 12FV. But in mine, the 40Vmax is not very good for accuracy (ok for splat), yet, like acloco, a 32 Sierra will not work over 3800.

Bergcrane2 · Post by **Bergcrane2** » Mon May 21, 2007 7:28 am

Yeah, the words out. My VSSF II loves em. I couldn't get the 32 or 40 Hornadys to pattern at all. If fact it was so bad, I thought the gun was the problem. I like Sierras so much, I'm loading the in my 30-06 and my 300WSM too.

janneuf · Post by **janneuf** » Mon May 21, 2007 3:59 pm

My Savage 12 FV loves the 39 grain Sierra BK. I've shot .25" groups with them.

Vaporizing bullets? I'd love to see that.

majcl5 · Post by **majcl5** » Mon May 21, 2007 5:37 pm

I love the 40 grain v-max in my .204 but my 22-250 has not shot the 50gr v-max very consistantly does anybody like the 50 gr sbk in the 22-250

Guy M · Post by **Guy M** » Tue May 22, 2007 3:38 am

"Vaporizing bullets? I'd love to see that."

Fairly common when fragile bullets are pushed hard, from a fast-twist barrel. See it now and again at long-range prone matches, where the guys have their rifles set up with fast-twist barrels to stabilize long bullets.

Just a little puff of smoke a few feet or a few yards in front of the rifle - and no hole in the target downrange...

By the way - this can also happen when a fellow loads .25 cal pistol bullets in a .257 Weatherby mag case. Makes the most interesting "birdshot" type patterns on targets only 10 yards in front of the rifle...

skipper · Post by **skipper** » Tue May 22, 2007 7:30 pm

Guy M

Sounds like you have some personal experience with vaporizing bullets. Got any pictures of those targets??? I'd love to see them.

Guy M · Post by **Guy M** » Sat May 26, 2007 6:46 pm

Those .257 Wby targets were long ago in my mis-spent youth. About the same time we had to use a 4' cheater bar to open the bolt on the same Weatherby with heavier loads.

I survived, and so did the rifle, but sorry, no photos of any of it back then...

Seriously though - a fragile bullet - like many "varmint" bullets - driven hard from a fast twist barrel will often fail only a few feet from the muzzle. Interesting "puff" then it's all over...

Regards, Guy

aulrich · Post by **aulrich** » Wed May 30, 2007 10:41 am

It happend to a buddy of mine he was shooting 50 grain blitz in a 223 and when the weather warmed up there would be a puff 10 feet in front of the barrel, drove him nutz till we figured them out. We had used older data which was hotter than the new stuff so as the temps warmed up we pushed past the design limit.

Rodbolt · Post by **Rodbolt** » Wed May 30, 2007 12:01 pm

acloco wrote:Have you seen the pics I have posted lately? Nothing wrong with the 40 VMax's in the splat factor.

Of note, my rifle keyholes the 39 grain Sierra's....too long of bearing surface for my Savage 12FV.

Of another note, the 32 grain Sierra's vaporize about 6 feet from the muzzle when pushed to the 4050 range.............

If bullets "vaporize" it's because they are overstressed. Too many rpm due to fast twist/high velocity but more likely due to rough bore just ahead of the leade. I shoot eight different 204R's and all of them shoot the 39gr BK very well, some will shoot the 40 V-max and some will not. All shoot the 32Vmax, 32 BK and 39BK as well. I have a 20 BR that will push the 39 BK to over 4200fps with great accuracy. The only downside is at this velocity (under 300 yrds.) it severs a prairedog in to various pieces rather imparting the flips or long air time...

The Sierra BlitzKing do have very thin jackets, which is makes them great, explosive bullets for small varmints and less ricoshets. Berger bullets have a heavier jacket for that may still shoot if you get heat cracking in your barrel throat.

gunsaregood · Post by **gunsaregood** » Wed May 30, 2007 4:27 pm

What's the twist on the 20BR you have that pushes a 39BK over 4200?

I just found a load with my Savage 12fv, 1 in 12, that will vaporize a 39BK around 3950.

Robert harrel · Post by **Robert harrel** » Wed May 30, 2007 6:39 pm

i have a 20 br with 9 twist bbl and with 39 bk see about 4175 with h335 when they start vaporizing but have pushed them to 4250 with benchmark without any problems

Rodbolt · Post by **Rodbolt** » Wed May 30, 2007 10:08 pm

My 20BR has a Bartlein cut rifle barrel in 1-12" twist, finished at 28". Can't say enough good about this barrel, I've order more (long wait) and I've got a second identical barrel that I will put on an old Shilen PPC action/rifle this week. I started modifying the BR brass in the lathe tonight to fit the PPC bolt as I don't want to modify the Shilen bolt.

I shoot the sleeved Remington 20BR at 4060-4070fps, the 4200 plus loads were hot in my gun but did shoot very accurately. I'm now using a slower powder and I'm hoping for extra barrel life with the slower load.

My only Savage 20 cal is a LRPV in 204R. It shoots real well but the barrel is one of the worst to clean of all my modern rifles. The powder fouling can really be felt on a patch after soaking with Wipeout. A button rifled barrel can be rough and this one is. I don't have too many rounds down the barrel so I'm hoping it will improve...............doubt that it will ever be what I want though.

39 gr. SBKs, just a statement.

39 gr. SBKs, just a statement.

39 Sierra BK in Savage 12FV