150 SMKs and the 6.5 x 284 ***UPDATE***

[wboggs]

Now that is good news and very bad news at the same time! The good news is, is that it is apparent that the bullets WILL shoot well. The bad news, obviously, is that under the stress of long shot strings, even at modest velocities, they don't seem to hold together! Sooner or later, Sierra will either have to fix that problem or go to a different design altogether. I will keep you posted once I get my barrel, hopefully in a a couple of weeks.

I am in the process of testing them out of my 7.5t 5r Bartlein at the 3100fps range but I'm not going to stres test them with long shot strings since I'm a little more interested in barrel life.
ShootDots may have identified that as their weakness but I think a few more shooters will have to test them under those conditions with different twists, 4g, 5r barrels, and velocity to see the complete picture.
Obviously, they must perform under match conditions to be successful. I wonder if the jacket is different than the 142 smk which have been used under match conditions in many different calibers and barrels.
Bill

 

[ShootDots]

I am in the process of testing them out of my 7.5t 5r Bartlein at the 3100fps range but I'm not going to stres test them with long shot strings since I'm a little more interested in barrel life.
ShootDots may have identified that as their weakness but I think a few more shooters will have to test them under those conditions with different twists, 4g, 5r barrels, and velocity to see the complete picture.
Obviously, they must perform under match conditions to be successful. I wonder if the jacket is different than the 142 smk which have been used under match conditions in many different calibers and barrels.
Bill

I am not sure if it's the jacket or the design. It would seem to me that that the jackets would be the same as the 142, ergo the design is suspect to me..

 

[wboggs]

I am not sure if it's the jacket or the design. It would seem to me that that the jackets would be the same as the 142, ergo the design is suspect to me..

All of the extra length is forward of the ogive. You can use almost the same seating settings for the 142 and 150.
Bill

 

[ShootDots]

All of the extra length is forward of the ogive. You can use almost the same seating settings for the 142 and 150.
Bill

You are exactly right! The 150s, as far as I can see, are the exact same bullet, only the nose is, for lack of better terminology, 8 grains in weight longer! Additionally, the nose has the shape of a long VLD. How that would translate into a bullet that has a propensity to blow up, I am at a loss as to explain. But the base to ogive is right on the money with the 142, only the shape and the length of the nose is longer.

 

[rardoin]

I have two matches under the belt (20 x 3 + sighters) at 600 and 1000yds running them in an 8tw 5r Bartlein at 2920avg FPS. No blow ups during testing or at matches. One match in Shreveport was over 95 F by string #2. I have about 350rds down that barrel with the 150's and all is good. Caveat- I have bronze brushes and am not afraid to use them...LOL. I clean down to BARE metal after every 80-90rds using the bronze brush and Iosso/nylon brush every two matches. Bore condition post clean confirmed with a Hawkeye.

 

[1shot]

It seems like the bullets behave properly in 5 groove barrels but are prone to blowing up sooner or later in a 4 groove. As always, this is my observation from both reading other shooters posts, and coupled with my success using a 5 groove canted land 7.5 twist from Bartlein.
I hope this helps,

Lloyd

 

[wboggs]

It seems like the bullets behave properly in 5 groove barrels but are prone to blowing up sooner or later in a 4 groove. As always, this is my observation from both reading other shooters posts, and coupled with my success using a 5 groove canted land 7.5 twist from Bartlein.
I hope this helps,

Lloyd

Does anyone have more experience than rardoin using them in matches?

 

[Mulligan]

Does anyone have more experience than rardoin using them in matches?

@bbarber25
Are you tuning these out of your 6.5 x47?
CW

 

[bbarber25]

Does anyone have more experience than rardoin using them in matches?

I’ve been running them with good results in my 6.5x47, it’s a 4 groove Brux 1-8” twist. I’ve ran them up to 2,800 but run them at 2,745fps, there is a nice node there for me. Used them in 600 and 1,000 yard matches here in CO and Wyo, never had a bullet not make it to the target or key hole. All these targets were at 600

 

[wboggs]

I’ve been running them with good results in my 6.5x47, it’s a 4 groove Brux 1-8” twist. I’ve ran them up to 2,800 but run them at 2,745fps, there is a nice node there for me. Used them in 600 and 1,000 yard matches here in CO and Wyo, never had a bullet not make it to the target or key hole. All these targets were at 600

How many matches have you used them in?

 

[bbarber25]

How many matches have you used them in?

Around 6-8, have fired around 700 of them total.

 

[rardoin]

I will be testing them in a 4 groove Brux, 7tw in a week or two. I may be shooting them in the F-Class Nats in Raton next month. I will run them through two Bart. 5-r 8tw barrels and the Brux 7tw and load for the best barrel....unless the 142 SMK decidedly holds the x-ring better or unless I start getting blow-ups with the 150's.

 

[TZaun]

I should've added that my barrel was clean going into the match yesterday, as I do any other match. I brush with bronze brushes too. After I cleaned it, I confirmed it with my Hawkeye borescope. There was no sign of carbon or copper in it. The bore looked very good, in my opinion. Had to look real hard to see just a little fire-cracking. Match temps were around 98* when I fired my last string.

 

[rardoin]

I should've added that my barrel was clean going into the match yesterday, as I do any other match. I brush with bronze brushes too. After I cleaned it, I confirmed it with my Hawkeye borescope. There was no sign of carbon or copper in it. The bore looked very good, in my opinion. Had to look real hard to see just a little fire-cracking. Match temps were around 98* when I fired my last string.

Hmm...I hope it stays on the cool side in Raton if I shoot the 150....going to be four days of shooting on a mid time barrel unless one of the new barrels is a standout. The throat should be fairly firecracked on my current barrel by the end of the Nats. I have very little firecracking on the barrel I have been shooting the 150's out of.

 

[wboggs]

Hmm...I hope it stays on the cool side in Raton if I shoot the 150....going to be four days of shooting on a mid time barrel unless one of the new barrels is a standout. The throat should be fairly firecracked on my current barrel by the end of the Nats. I have very little firecracking on the barrel I have been shooting the 150's out of.

Sounds to me like we will have much more data on the 150's in the near future. Maybe enough to answer some basic questions. The members on this site are invaluable and freely volunteer their time and knowledge. My hat is off to them and I want to thank all who are contributing to this thread. You are doing the research Sierra should have done.
Bill

 

[Longrange57]

Hmm...I hope it stays on the cool side in Raton if I shoot the 150....going to be four days of shooting on a mid time barrel unless one of the new barrels is a standout. The throat should be fairly firecracked on my current barrel by the end of the Nats. I have very little firecracking on the barrel I have been shooting the 150's out of.

I have shot about 8-900 of these bullets during the past year. They were shot at lower velocities in 8tw 4 groove barrels. Normally the 2730-2840 range as I have already indicated. The difference in our matches which are 530 yards is 5 shot strings with about 15 min in between strings. At 1,000 we run 2 15 shot strings and I've only run them at 1,000 once. I shot them at 4.. 530 yard matches. Just my 2 cents....it appears that there is a possible problem at higher velocities, higher shot volume, additional heat, and possibly type of rifling. It probably doesn't count for much, but I have had absolutely no problems at all. I guess you can send anything over the edge!

 

[rardoin]

The Brux barrel just chambered does not have canted lands like the Bart barrel I have been using. I'll see if that is the difference soon enough.

 

[NV_Dmax]

Thanks everyone for your responses. I have a 7.5twist Brux waiting to get chambered up for the 150 so I have been watching closely. Might end up with a Bartlein if I can find one.

 

[muleystalker]

I have a shooting buddy that has about 6-8 matches with the 150's without any problems.He is running them in the hi 2700's I believe. He is either shooting a 5r barrel or a x-caliber 1;7 6 groove, I will find out. He has been shooting F-class 3 20rnd strings 22min each and sighters, temps are pretty warm here 90's+. Its shooting real good.

 

[Longrange57]

I have a shooting buddy that has about 6-8 matches with the 150's without any problems.He is running them in the hi 2700's I believe. He is either shooting a 5r barrel or a x-caliber 1;7 6 groove, I will find out. He has been shooting F-class 3 20rnd strings 22min each and sighters, temps are pretty warm here 90's+. Its shooting real good.

Keeping with the theme of blowing up bullets...After many years of shooting I have blown up a few bullets! 223/223AI, 6PPC, etc...shooting light bullets with fast twist as we all know it can happen. 50-55 gr ...60-65 gr...all at 3400-3600 and fast twist (1:7), my friends and I have blown up many. The consensus amongst us became bullet spin rate. With the calculation of velocity x 720 divided by twist rate...we all decided that once rpm is above 300,000 it starts to become anybody's guess. I've also seen lightweight 308 bullets blown up with fast twist. This may not be the reason here and very well could be rifling. Rardoin will probably confirm that for us. With what can be gathered from these posts...allow me to put together this compulation.
In getting the info out to us ShootDots has plenty of reason for concern...look at the rpm from these shooters.
ShootDots...blew up....2930...7.5 tw...281,000 rpm
Park Ranger..............2780...7.5 tw...267,000 rpm
SWD....coated bullets..2800...7.0 tw...288,000 rpm
Longrange57.............2940....8.0 tw...265,000 rpm
Rardoin....................2950...8.0 tw...266,000 rpm
1shot.......................2960...7.5..tw..284,000 rpm
2980....7.5.tw...286,000 rpm
3100...7.5 tw...298,000 rpm
wboggs...................3100...7.5 tw...298,000 rpm
tzaun......blew up.....2845...7.25 tw...283,000 rpm
bbarber25...............2745...8.0 tw....247,000 rpm
If I missed something or made a mistake...please forgive! With the fast twist barrels, we are closing in on that magic 300,000 range where anything can happen with excess heat and maybe a barrel thats tighter than another one. It very well could be barrel and rifling, but I would have to conclude that we are also closing in on the spin rate threshold for this bullet. Some may handle 300-320,000, others may not! To the contrary I've also seen some very small calibers shoot at 340,000 with no known problems....but probably not in competition! This thing has got us all scratching our heads because the last thing I want to do is have it happen in a match....especially on the very last shot! That would make me ill!