.308 not stabilizing 150 gr Speer btsp

[Namhunter]

Hi all, I've recently bought some 150 gr Speer soft points (btsp) because I couldn't find any 150 sst or 150 accubonds at my local gun stores.

That being said,the 150 sst and 150 accubonds shoot 0.746 - 0.789" groups all the time in my 308 SAKO.
As the heading states,the 150 gr Speer does not even stabilize,nevermind grouping.

I've tried all velocities from 2300 to 2800 and none of them come close to stabilizing.

Loads go from 38.9 to 44.5.
I use Varget powder,Sako brass and cci200 primers.

Any of you guys had this problem before or may have some advice?
That would be very much appreciated.

 

[troy fairweather]

Did you measure them to be sure there not undersized some how, some pictures of the group's would be nice are they tumbling or just not grouping. What's your coal some of the speers have a pretty long ojive.

 

[Namhunter]

The speer is slightly shorter than the sst.
Speer measures 1.071" and sst 1.198"
Circumference of the bullets are exactly the same at .309
Unfortunately threw away the speer targets but they definitely keyhole the paper. Like I said,not even expecting a group if they tumble like that.
Also,the shorter bullet I think is the problem due to its weight vs length. I have shot 120 grain bullets with great results too.

My coal on the sst is 2.800 and on the speer 2.700, although I started if with the speer at 2.800 and got the same crappy keyhole results.

 

[stringnut]

The 150 gr btsp was out go to bullet for years. Accurate and devastating on whitetail. Loaded it in 5 30/06 and 3 308. Never had an issue.

The bullet being shorter is not an issue unless you a custom barrel with some crazy fast twist. Even then it is unlikely to be a problem. In the old days bullets were of less quality and were often out of balance. Spinning them faster than necessary to stabilize magnified this and caused groups to open up. If a factory twist you should be able to shoot 110gr to 180 gr with no issues. Something else is amiss here IMHO.

The longer bullets actually require more stabilization than the short one. That is why you had good luck with the 120 gr. There could be something fundamentally wrong with the bullets, but, I don’t think it is length. I have seen bullets of the same weight not shoot as well. However I have never seen them keyhole.

 

[Namhunter]

Yeah I don't understand this at all,on paper and through experience with other 150 grain bullets these speer bullets should perform decent to say the least...any other bullet that I have shot through this rifle did great..its a standard 1:12 twist 22" barrel.
I don't know if the bullets are faulty or what the problem could be.


I thought it was my barrel but shooting factory 150 grain hornady soft points proved that my barrel was still good.

 

[troy fairweather]

Have you shot any other bullets since the 150 speers maybe something is up with the gun all of a sudden. Heavy carbon or copper possible, somehow the crown got nicked. Did you weigh a bunch of the speers, or cut one open to see if anything is funny inside.

 

[Namhunter]

Tested to see if my barrel was maybe burnt out by using factory hornady ammo. Also 150 gr softpoints. I weighed them one by one. They aren't exactly 150 gr but close enough. Haven't cut one open but I wouldn't know what to look for if I did.

 

[Hugger-4641]

Even on burned out barrels, groups usually open up before you see keyhole. Either the bullet is slipping, not staying engaged in the rifling, or the cg of the bullet core is way off.

 

[wanderinwalker]

Tested to see if my barrel was maybe burnt out by using factory hornady ammo. Also 150 gr softpoints. I weighed them one by one. They aren't exactly 150 gr but close enough. Haven't cut one open but I wouldn't know what to look for if I did.

Based on the information you've given so far, the issue HAS to be with the specific box of bullets you're working with. Like troy said, sectioning one of the bullets will probably provide the most useful information since everything else has checked out. You're looking for air pockets in the lead core, the core not being centered in the jacket, the jacket material having inconsistent thickness around its circumference. It feels like a real long shot, but it's the only explanation left.

Is there any chance you can grab a box of some other kind of 150 grain .308" bullets to try out? That would probably be my first stop before sectioning a bullet, just to make sure you're not going to start chasing your tail trying to track down the issue.

 

[Namhunter]

That's my thoughts too,that this specific box or even the shipment is faulty...I tested 155 berger vld's to check,they don't shoot to good out of my rifle but they don't keyhole at all. And like I said,hornady factory 150 gr also shoot good. It's just these speer 150 gr that keyhole. At first I thought that maybe I'm over stabilizing them at 2780 fps,but even bringing the speed down systematically failed to yield any good results.

 

[243winxb]

Your gun doesnt like the low cost Speer bullet. Should be stable https://bergerbullets.com/twist-rate-calculator/

My 243 prints larger groups using Speer., but ok for plinking or hunting

My key holes were from a bad barrel, with larger then normal groove diameter. The exposed lead tip would melt, leaving a gray lead smear on a white target @ 100 yards. Sierra bullets.

The full key holes were with a 243, 70gr Remington match bullet.

 

[Charlie98]

There could be something fundamentally wrong with the bullets

I used to load the Speer 170grn HotCor bullet in the .30-30, on a fluke I switched to the Winchester SilverTip component bullet... and my groups shrunk about 1". The Speers weren't bad, but every other bullet I've tried since has been better... including quality cast bullets, and that in the dreaded MicroGroove Marlin. Because of that... while I'm a big fan of Speer handgun bullets, I don't buy Speer rifle bullets any longer.

I thought it was my barrel but shooting factory 150 grain hornady soft points proved that my barrel was still good.

Then, all else being equal, it's the bullets.

 

[stringnut]

That's my thoughts too,that this specific box or even the shipment is faulty...I tested 155 berger vld's to check,they don't shoot to good out of my rifle but they don't keyhole at all. And like I said,hornady factory 150 gr also shoot good. It's just these speer 150 gr that keyhole. At first I thought that maybe I'm over stabilizing them at 2780 fps,but even bringing the speed down systematically failed to yield any good results.

Really can’t see them being overstabilized as we run them at around that speed in every 308 we ever had. My brother used to push them to 3020 fps, chronographed, from his 30/06 with no problems. If one bullet is keyholing you should be seeing poor accuracy from others. Have you tried weighing the bullets? If they’re significant variations there is your answer.

Poked around in my loading components and do not have any of that bullet left. Will check with my brother and he may have a few I could send you. Have a few loaded in 30/06 , but, that doesn’t help you any.

 

[Namhunter]

Yeah I don't think that a 150 could be over stabilizing at 2700 fps..I shoot the 150 SST's at around 2800 fps and they work great.

The speer bullets vary in weight slightly but not something to be concerned about. 149.3-149.7 gr over 80 bullets.

Starting to think my gun might just be a little picky on what I feed her.

 

[GeoDudeFlorida]

Yeah I don't think that a 150 could be over stabilizing at 2700 fps..I shoot the 150 SST's at around 2800 fps and they work great.

The speer bullets vary in weight slightly but not something to be concerned about. 149.3-149.7 gr over 80 bullets.

Starting to think my gun might just be a little picky on what I feed her.

Did you ever contact Speer about it? They may swap out the box for fresh.

 

[JDeere]

Is 1:12 twist correct? To slow maybe? I just have never seen a .308 in 1:12. Mine have always been ateast 1:10. Just a question for my own information?

 

[Namhunter]

Problem is, I'm from Namibia and here we really struggle to get ammunition from out gunshops. That's why I switched to speer bullets due to not getting any other 150 grain bullets.

 

[Namhunter]

Is 1:12 twist correct? To slow maybe? I just have never seen a .308 in 1:12. Mine have always been ateast 1:10. Just a question for my own information?

Yes, measured by myself and a gunsmith. 1:12 twist from factory

 

[AJC1]

Problem is, I'm from Namibia and here we really struggle to get ammunition from out gunshops. That's why I switched to speer bullets due to not getting any other 150 grain bullets.

Asking because I don't know, is lead readily available and easy to get. Might make a good case for shooting cast bullets.

 

[Namhunter]

Asking because I don't know, is lead readily available and easy to get. Might make a good case for shooting cast bullets.

I don't know how accurate cast bullets are though? Lead is available yes,but like I said, accuracy.

Hunting distances range between 150-300 yds. So I need some accurate bullets lol

 

[Random 8]

Your rifle should stabilize that bullet all day long at a wider velocity range than possible in your. 308. I suspect a problem with your specific batch of bullets. Externally, the boat tail could be asymmetrical. Internally the core could be off center or poorly swaged with air voids. Also check the crown of your barrel for damage and check the bore for uneven deposits of jacket fouling.

I would try the Hornady or Speer flat based and see what happens.

 

[AJC1]

I don't know how accurate cast bullets are though? Lead is available yes,but like I said, accuracy.

Hunting distances range between 150-300 yds. So I need some accurate bullets lol

Accurate lead bullets are a function of knowledge and skill. There will be an investment of time to learn, the tradeoff is once your good, if the resource is plentiful and cheap your good forever.

 

[Namhunter]

Your rifle should stabilize that bullet all day long at a wider velocity range than possible in your. 308. I suspect a problem with your specific batch of bullets. Externally, the boat tail could be asymmetrical. Internally the core could be off center or poorly swaged with air voids. Also check the crown of your barrel for damage and check the bore for uneven deposits of jacket fouling.

I would try the Hornady or Speer flat based and see what happens.

Exactly my point. It should stabilize the bullet,does so with very good results with the Hornady 150's. Rifle shoots good with factory 150 grains that I've tested after shooting the speer bullets. So barrel and crown still good. I have a suppressor fitted but also doesn't have an effect on the factory hornady ammo

 

[FLIGHT762]

Is 1:12 twist correct? To slow maybe? I just have never seen a .308 in 1:12. Mine have always been ateast 1:10. Just a question for my own information?

1-12" twist in 308 Win. was very common. Two of my precision bolt 308's are 1-12". They have both have been shot out to 1000 yds with bullet weights from 155 to 178 with very good accuracy. No issue with bullet stability with bullets up to 178 Grs. Around 20 years ago, there was a move to using 308 barrels in 1-11.25" and 1-10" for target rifle barrels for using 175+ grain bullets. These twists are now common in target 308 Win. Rifles.

My two 308 gas guns, a SR-25 and GAP 10 both have 11.25" twist barrels. Winchester still uses a 1-12" twist in their Mod. 70 hunting Rifles in 308 Win.