6.5-300 Weatherby for Long Range Shooting

[high country]

I've wasted enough brass going from 308 to 260 to have bought a 7mm die for in between.

[jasnt]

I would think the bushing dies would be your ticket.  I would step them down slowly not in one resizing. You will have more consistent neck thickness by stepping down gradually and even though this will take more time you only do it once.  I would aneal the new brass, step down in 3 or 4 steps and then trim and sort, fire form and aneal again then I always aneal every 5th loading. Brass will last way longer and hopefully you won't have to ream necks

[matt509]

Wow.....there are a couple things in here that really surprise me, and also a couple questions that I have.

1) Why with the temperature differential with US869; is this the only powder being used for these rounds?  With velocity vs. temp variations of over 100 fps....that definitely rules it out for me.  Especially for Long Range Hunting.  I test my powders (well not any more, I know which powders are temp stable, and I stay with those) and stick with them for shooting. 

2) In our experience we haven't found the 6.5 class of bullets to really care for any velocities over 3250-3300 fps.  It seems they have a couple really sweet spots around 2750-2850 and 3100-3200 (In our precision rifle competitions, we are speed capped at 3200 fps). 

3) Barrel life on any overbore cartridge, should not be a concern......It is going to burn up!!  Faster burning powders, at higher velocities = It will burn up quicker.

I literally just went through this.  I have somewhat of a different set of standards to choosing a wildcat.  Long story short, I went 6.5 WSM; and here is why.
a) You can feed these full houses of Retumbo or H1000 (both of which are slower burning powders, minimizing throat erosion & both are extremely temp stable) and get decent velocities.  I plan on pushing the Nosler 130 LR AB exclusively.  I am aware the B.C. projections seem un doubtedly high, but Bryan Litz has done extensive testing on them.  In his testing he found "when the projectile is properly stabilized (over 1.8 on the Miller stability chart) the advertised B.C. is within 2-3%).  My set up, 8 twist barrel with velocities over 3100 fps, I achieve roughly 1.88-1.92 on the Miller stability. 

b) How good of brass can I get?  How big of a pain in the ass is this gonna be to make?  Essentially, the 6.5 WSM is named the 6.5-300 WSM.  You can purchase these dies from Midway, Brownells, Sinclair, etc.  Already made, and you can usually find them in stock.  I went with the Redding Full Length kit, as I am not a fan of the Lee dies.  Now on to the brass.  I looked at the SAAMI specs of the WSM family and started comparing prints.  To my surprise the 300 WSM & 270 WSM are identical, other than neck diameter.  Now, what kind of brass can I get?  A quick Google search showed me that Bullets.com carries Norma 270 WSM brass, at not too bad of a price......Perfect I ordered 50 pieces, as this is a hunting rifle and 50 pieces should last a long time.  Now the 270 actually carries an I.D. of .277", where as my 6.5 carries an I.D. of .264" = -.013" a simple one step neck down, with no neck turning, no donut, etc.
    - Disclaimer-I hate brass prep!!!  I will not turn necks, debur flash holes, anything other than sizing and trimming to length. 

c) Since, I could find factory dies available, I knew there was a reamer out there.  Now to find what gunsmith had it......I called my gunsmith, and alas....he owns one!!!  Jackpot!!!  Box it up, and send it over the mountain to him!!  I should have this build back by the end of March, and have a load developed within a couple weeks.  I will update as necessary.

**This build had a couple requirements for it. 
1. Lightweight - I am going to weigh in at 8 lbs with scope, bipod, and full mag.  I had a Proof Carbon Fiber barrel laying around in 6.5, A Manners carbon fiber elite stock with DBM already inletted, and a Tikka T3 action.  I purchased a Vortex PST 6-24 as it weighed in at 28 oz, the lightest scope with all the features I was looking for.   
2. I wanted a laser beam that maintained over 1000 ft/lbs of kinetic energy at 1000 yards.  I used a 4" circle as my maximum point blank reference.  So I will zero this rifle at 250 yards, which will put me 2" high at 150 yards; zeroed at 250; and fall out of my 4" circle (-2" from zero) at 300 yards.  At 1000 yards, it will drop -187.2"; or 5.2 mils; will deflect 43" (1.2 mils) and still maintain 1083 ft/lbs.

[yorketransport]

Wow.....there are a couple things in here that really surprise me, and also a couple questions that I have.

1) Why with the temperature differential with US869; is this the only powder being used for these rounds?  With velocity vs. temp variations of over 100 fps....that definitely rules it out for me.  Especially for Long Range Hunting.  I test my powders (well not any more, I know which powders are temp stable, and I stay with those) and stick with them for shooting. 

The best answers to that are powder bridging and burn rate. When you burn that much powder in a relatively small bore, wide bodied case you get powder bridging issues which can cause erratic pressures. Think of dumping 95 grains of H1000 into a powder funnel with a .264 diameter hole. All of the powder jams up in the neck and it doesn't flow smooth. Now take a ball powder like US 869, H335 or something like that and do the same thing. The ball powders flow through like water.

US869 is about the slowest burning ball powder that will work in such a large capacity small bore case. Sometime you just have to use what works.

[high country]

Wow.....there are a couple things in here that really surprise me, and also a couple questions that I have.

1) Why with the temperature differential with US869; is this the only powder being used for these rounds?  With velocity vs. temp variations of over 100 fps....that definitely rules it out for me.  Especially for Long Range Hunting.  I test my powders (well not any more, I know which powders are temp stable, and I stay with those) and stick with them for shooting. 

2) In our experience we haven't found the 6.5 class of bullets to really care for any velocities over 3250-3300 fps.  It seems they have a couple really sweet spots around 2750-2850 and 3100-3200 (In our precision rifle competitions, we are speed capped at 3200 fps). 

3) Barrel life on any overbore cartridge, should not be a concern......It is going to burn up!!  Faster burning powders, at higher velocities = It will burn up quicker.

I literally just went through this.  I have somewhat of a different set of standards to choosing a wildcat.  Long story short, I went 6.5 WSM; and here is why.
a) You can feed these full houses of Retumbo or H1000 (both of which are slower burning powders, minimizing throat erosion & both are extremely temp stable) and get decent velocities.  I plan on pushing the Nosler 130 LR AB exclusively.  I am aware the B.C. projections seem un doubtedly high, but Bryan Litz has done extensive testing on them.  In his testing he found "when the projectile is properly stabilized (over 1.8 on the Miller stability chart) the advertised B.C. is within 2-3%).  My set up, 8 twist barrel with velocities over 3100 fps, I achieve roughly 1.88-1.92 on the Miller stability. 

b) How good of brass can I get?  How big of a pain in the ass is this gonna be to make?  Essentially, the 6.5 WSM is named the 6.5-300 WSM.  You can purchase these dies from Midway, Brownells, Sinclair, etc.  Already made, and you can usually find them in stock.  I went with the Redding Full Length kit, as I am not a fan of the Lee dies.  Now on to the brass.  I looked at the SAAMI specs of the WSM family and started comparing prints.  To my surprise the 300 WSM & 270 WSM are identical, other than neck diameter.  Now, what kind of brass can I get?  A quick Google search showed me that Bullets.com carries Norma 270 WSM brass, at not too bad of a price......Perfect I ordered 50 pieces, as this is a hunting rifle and 50 pieces should last a long time.  Now the 270 actually carries an I.D. of .277", where as my 6.5 carries an I.D. of .264" = -.013" a simple one step neck down, with no neck turning, no donut, etc.
    - Disclaimer-I hate brass prep!!!  I will not turn necks, debur flash holes, anything other than sizing and trimming to length. 

c) Since, I could find factory dies available, I knew there was a reamer out there.  Now to find what gunsmith had it......I called my gunsmith, and alas....he owns one!!!  Jackpot!!!  Box it up, and send it over the mountain to him!!  I should have this build back by the end of March, and have a load developed within a couple weeks.  I will update as necessary.

**This build had a couple requirements for it. 
1. Lightweight - I am going to weigh in at 8 lbs with scope, bipod, and full mag.  I had a Proof Carbon Fiber barrel laying around in 6.5, A Manners carbon fiber elite stock with DBM already inletted, and a Tikka T3 action.  I purchased a Vortex PST 6-24 as it weighed in at 28 oz, the lightest scope with all the features I was looking for.   
2. I wanted a laser beam that maintained over 1000 ft/lbs of kinetic energy at 1000 yards.  I used a 4" circle as my maximum point blank reference.  So I will zero this rifle at 250 yards, which will put me 2" high at 150 yards; zeroed at 250; and fall out of my 4" circle (-2" from zero) at 300 yards.  At 1000 yards, it will drop -187.2"; or 5.2 mils; will deflect 43" (1.2 mils) and still maintain 1083 ft/lbs.

It's not just you on the velocity windows. I contacted litz when I started into the 6.5's and he told me to push them around 2800- 2900. I have built several now and they do like it there for sure.

[bearpaw]

Thanks for the comments everyone, I still haven't decided what I'm going to do. I might go ahead and rebarrel my Mark V to a 340 for now and wait a while to get more intel on the 6.5.

[mountainman]

Thanks for the comments everyone, I still haven't decided what I'm going to do. I might go ahead and rebarrel my Mark V to a 340 for now and wait a while to get more intel on the 6.5.

an awesome round in itself my freind!

[2labs]

Wow.....there are a couple things in here that really surprise me, and also a couple questions that I have.

1) Why with the temperature differential with US869; is this the only powder being used for these rounds?  With velocity vs. temp variations of over 100 fps....that definitely rules it out for me.  Especially for Long Range Hunting.  I test my powders (well not any more, I know which powders are temp stable, and I stay with those) and stick with them for shooting. 

2) In our experience we haven't found the 6.5 class of bullets to really care for any velocities over 3250-3300 fps.  It seems they have a couple really sweet spots around 2750-2850 and 3100-3200 (In our precision rifle competitions, we are speed capped at 3200 fps). 

3) Barrel life on any overbore cartridge, should not be a concern......It is going to burn up!!  Faster burning powders, at higher velocities = It will burn up quicker.

I literally just went through this.  I have somewhat of a different set of standards to choosing a wildcat.  Long story short, I went 6.5 WSM; and here is why.
a) You can feed these full houses of Retumbo or H1000 (both of which are slower burning powders, minimizing throat erosion & both are extremely temp stable) and get decent velocities.  I plan on pushing the Nosler 130 LR AB exclusively.  I am aware the B.C. projections seem un doubtedly high, but Bryan Litz has done extensive testing on them.  In his testing he found "when the projectile is properly stabilized (over 1.8 on the Miller stability chart) the advertised B.C. is within 2-3%).  My set up, 8 twist barrel with velocities over 3100 fps, I achieve roughly 1.88-1.92 on the Miller stability. 

b) How good of brass can I get?  How big of a pain in the ass is this gonna be to make?  Essentially, the 6.5 WSM is named the 6.5-300 WSM.  You can purchase these dies from Midway, Brownells, Sinclair, etc.  Already made, and you can usually find them in stock.  I went with the Redding Full Length kit, as I am not a fan of the Lee dies.  Now on to the brass.  I looked at the SAAMI specs of the WSM family and started comparing prints.  To my surprise the 300 WSM & 270 WSM are identical, other than neck diameter.  Now, what kind of brass can I get?  A quick Google search showed me that Bullets.com carries Norma 270 WSM brass, at not too bad of a price......Perfect I ordered 50 pieces, as this is a hunting rifle and 50 pieces should last a long time.  Now the 270 actually carries an I.D. of .277", where as my 6.5 carries an I.D. of .264" = -.013" a simple one step neck down, with no neck turning, no donut, etc.
    - Disclaimer-I hate brass prep!!!  I will not turn necks, debur flash holes, anything other than sizing and trimming to length. 

c) Since, I could find factory dies available, I knew there was a reamer out there.  Now to find what gunsmith had it......I called my gunsmith, and alas....he owns one!!!  Jackpot!!!  Box it up, and send it over the mountain to him!!  I should have this build back by the end of March, and have a load developed within a couple weeks.  I will update as necessary.

**This build had a couple requirements for it. 
1. Lightweight - I am going to weigh in at 8 lbs with scope, bipod, and full mag.  I had a Proof Carbon Fiber barrel laying around in 6.5, A Manners carbon fiber elite stock with DBM already inletted, and a Tikka T3 action.  I purchased a Vortex PST 6-24 as it weighed in at 28 oz, the lightest scope with all the features I was looking for.   
2. I wanted a laser beam that maintained over 1000 ft/lbs of kinetic energy at 1000 yards.  I used a 4" circle as my maximum point blank reference.  So I will zero this rifle at 250 yards, which will put me 2" high at 150 yards; zeroed at 250; and fall out of my 4" circle (-2" from zero) at 300 yards.  At 1000 yards, it will drop -187.2"; or 5.2 mils; will deflect 43" (1.2 mils) and still maintain 1083 ft/lbs.

It's not just you on the velocity windows. I contacted litz when I started into the 6.5's and he told me to push them around 2800- 2900. I have built several now and they do like it there for sure.

This is nice to hear, I'm building a Swede. And thinking pushing the 3k FPS. 2700 -2900 are pretty easy. With the 142 lrab.