Sierra 150 grain 6.5 Matchking

[FrankG]

I got the o.k. from Hornady. From all the testing and data they have in different calibers etc...as they pushed velocity up or increased the twist rate, that as bullet rpm went up (or a combination of both twist and velocity) that the 5R rifling helped fight bullet failure vs an even groove barrel.

 

[Longrange57]

I got the o.k. from Hornady. From all the testing and data they have in different calibers etc...as they pushed velocity up or increased the twist rate, that as bullet rpm went up (or a combination of both twist and velocity) that the 5R rifling helped fight bullet failure vs and even groove barrel.

I have Bartlein 5R, 1:7 tw 223, 1:12tw 223, 1:10 tw 308, and 6.5 x 47 1:8 tw that are all phenomenally good shooters. Never had a bad 5R barrel. All my bullet blowups years ago were factory fast tw and light 223 bullets at very high rpm.

 

[sremmell]

Would a 7 twist be too fast for a 150 at 3050? That’s 313k Rpm. I see guys saying they’re blowing up the 150’s but I talked to Sierra this week and they said that’s news to them. They claim to have not heard of a single blow up. Looking at a Bartlein 5r 1:7

 

[Bulletman]

I work at Sierra and can assure you that we are aware that these bullets can be blown up in certain circumstances. Whomever you spoke with may be out of the loop however.

 

[sremmell]

I work at Sierra and can assure you that we are aware that these bullets can be blown up in certain circumstances. Whomever you spoke with may be out of the loop however.

So do you think too fast of a twist is what is making them blow up?

 

[Bulletman]

Twist is a factor but not a standalone cause, bore diameter, rifling type and condition, as well as land and groove numbers are all contributors.

 

[sremmell]

Twist is a factor but not a standalone cause, bore diameter, rifling type and condition, as well as land and groove numbers are all contributors.

Hmm. I can either get a 1-7 5r or a 1-7.5 5r. May just go for the 7.5

 

[whatwind?]

4 R and 2900+ FPS are the two factors I believe so far

I don’t think there has been any blow ups with 5R

 

[sremmell]

View attachment 1097148 4 R and 2900+ FPS are the two factors I believe so far

I don’t think there has been any blow ups with 5R

I guess I’ll try the 7.5 5r and see what happens. I have plenty of 147 eld’s as a back up plan

 

[FrankG]

Go back and read some of my earlier posts.

In 6.5CM my barrel is a 1-6.75 twist. Honest 2700fps out of a 23” barrel. Bullet rpm is 288K.

I’ve had no failures and have shot 150smk, 147 Hornady’s and box 140amax ammo.

My 6.5PRC F class barrel is a 7.25 twist. Will be shooting it shortly once weather breaks more.

Later, Frank

 

[sremmell]

Go back and read some of my earlier posts.

In 6.5CM my barrel is a 1-6.75 twist. Honest 2700fps out of a 23” barrel. Bullet rpm is 288K.

I’ve had no failures and have shot 150smk, 147 Hornady’s and box 140amax ammo.

My 6.5PRC F class barrel is a 7.25 twist. Will be shooting it shortly once weather breaks more.

Later, Frank

Very good info. thank you. What length are you doing your f class and what kind of velocity are you expecting?

 

[FrankG]

Very good info. thank you. What length are you doing your f class and what kind of velocity are you expecting?

Right now the barrel is installed at 32” finish length.

With 147 and 150gr. Bullets I’m thinking 3100-3200fps.

Todd at work has a 6.5PRC hunting rifle. 24” barrel I believe it is at and box ammo is running right at 2990-3000fps. His barrel is a 7.5 twist.

 

[wboggs]

I shot 10 shots at about 3206 in a 6.5 prc in a Bartlein 7.5 5r to see if they would blow up. They did not. Have used about 65 in the same rifle at 2900-3120 with no failures.

 

[sremmell]

Right now the barrel is installed at 32” finish length.

With 147 and 150gr. Bullets I’m thinking 3100-3200fps.

Todd at work has a 6.5PRC hunting rifle. 24” barrel I believe it is at and box ammo is running right at 2990-3000fps. His barrel is a 7.5 twist.

Yea I’m looking to run a 27 inch on a prc. I think I can get about 3050 with the 150’s.

 

[wboggs]

Yea I’m looking to run a 27 inch on a prc. I think I can get about 3050 with the 150’s.

I think that is a very realistic goal. My barrel is 30" and I am below max using H1000. I would like a load 3050-3100 for my rifle but the 3120 shoots so well I hate to use barrel life looking for perfect.
You can get higher velocity with RL26 and I used it for the 3206 load. Accuracy was not there.
Will follow your progress.
Bill

 

[sremmell]

I think that is a very realistic goal. My barrel is 30" and I am below max using H1000. I would like a load 3050-3100 for my rifle but the 3120 shoots so well I hate to use barrel life looking for perfect.
You can get higher velocity with RL26 and I used it for the 3206 load. Accuracy was not there.
Will follow your progress.
Bill

I plan to use h1000. I have xm action that I can load them out to 3.250 and fit in the mag but from what I’ve seen they’ll end up around 3.050 about .020 off the lands. I plan to use it for the steel competition at my range and they have a 3100 speed limit so no need to push it to the limit

 

[wboggs]

Very close to my oal. 0.015 off shoots best for me. I use a 5r and whatever you have, keep it clean and smooth
My best wishes for your success. It craters steel pretty well.

 

[sremmell]

Very close to my oal. 0.015 off shoots best for me. I use a 5r and whatever you have, keep it clean and smooth
My best wishes for your success. It craters steel pretty well.

Thank you. Yes I definitely plan to run 5r based on everything I’ve read here

 

[sremmell]

I went ahead and bought a Bartlein 7 twist 5r. After looking at stability numbers I would be 1.51 on the colder days here and one of the place I shoot is right at sea level. This also give me options if anyone comes out with any heavier bullets that need a tighter twist

 

[Steveb]

Matrix Ballistics produces a 162 grain VLD with an estimated BC of approx. .750 according to shooting results.