Pre-64 Model 70 in 6.5-06 AI

[redneckclimbing]

So I am going to build a 6.5-06 AI for my daughter. The receiver will be a 1956 Winchester Model 70, as her grandfather was born in '56. The difference being, I'm actually going to shorten the case so that the top of the body doesn't move forward versus blowing the shoulder forward. This will allow more of the bullet to be out of the case aligning itself in the throat with a very minimal, if any, loss in case capacity.

My question is, will this feed with a 40 deg shoulder or should I plan on going to a 35 or even 30 deg shoulder? Attached is the reamer print, if any one is curious. I definitely want a smooth feeding action for her.

If you have built anything similar I would sure love to know how well it feeds.

Thanks,
Travis

 

[Danny1788]

Sounds like a lot of work... why not just do a simple 6.5-280AI? take nosler 280AI brass and neck it down to 6.5 with bushing dies and run it. No fireforming and get the most out of the 06 size case?

 

[hunter67wa]

Look at 6.5 Sherman may be everything you want. Good luck

 

[Edd]

......If you have built anything similar I would sure love to know how well it feeds.

Thanks,
Travis

About 30 years ago, I did something similar with the shoulder. I didn't change the shoulder diameter to an AI but I did change the angle by pushing the neck back.

I had a die made that would push the neck/shoulder junction back leaving the body/shoulder junction in the same place but changing the shoulder angle to 26°.

This was a 6mm-280 Remington. I could also use 270 Winchester cases but the shoulder wouldn't be fully formed by the die.

Making a 6.5, you could probably push the necks back to 30° with ease. I would rather have a 30° shoulder than a 40° and would rather have the standard 06 case taper than the AI taper.

 

[L.Sherm]

I did a 6.5x06AI with 40deg shoulder feeds just fine out of a 700 Rem.

 

[redneckclimbing]

Sounds like a lot of work... why not just do a simple 6.5-280AI? take nosler 280AI brass and neck it down to 6.5 with bushing dies and run it. No fire forming and get the most out of the 06 size case?

The reason for not doing this is, I really want to build on a model 70 from the year my parents were born. Should be a super classy gun when all said and done, with a jeweled extractor and bolt and a AAA Fancy Walnut/Maple stock.

The problem there being, when you seat a longer 6.5 mm bullet out so that only the boat tail is in the case it is too long for the action, thus the shortening. Also, when you shorten the shoulder but blow out the body you really don't loose any case capacity if any. I feel like the case capacity could be slightly larger and be fine but we're getting to the top of the bell curve. So you're not going to gain enough velocity (at the same pressures) with 5 more grains of capacity, to make any difference, especially at long range in your trajectories or killing power.

 

[redneckclimbing]

About 30 years ago, I did something similar with the shoulder. I didn't change the shoulder diameter to an AI but I did change the angle by pushing the neck back.

I had a die made that would push the neck/shoulder junction back leaving the body/shoulder junction in the same place but changing the shoulder angle to 26°.

This was a 6mm-280 Remington. I could also use 270 Winchester cases but the shoulder wouldn't be fully formed by the die.

Making a 6.5, you could probably push the necks back to 30° with ease. I would rather have a 30° shoulder than a 40° and would rather have the standard 06 case taper than the AI taper.

Edd-

Did you build yours on a Model 70? Did you have any feeding issues? My main reason for going with the 40' shoulder is it is ALOT easier to get a standard seating die and cut the back off to length rather than having a custom one made.

 

[L.Sherm]

I wouldn't run that much freebore, the O6 case has a long neck. You will be way past the neck shoulder junction at the boatail bearing surface.
.150-.160 is plenty and you will still be above the neck shoulder junction.

 

[Edd]

Edd-

Did you build yours on a Model 70? Did you have any feeding issues? My main reason for going with the 40' shoulder is it is ALOT easier to get a standard seating die and cut the back off to length rather than having a custom one made.

I didn't use a Model 70. I bought a Model 700 mountain rifle and rebarreled it.

 

[redneckclimbing]

Look at 6.5 Sherman may be everything you want. Good luck

Just did, you may be totally partially right, ! So, the Sherman itself would be too long for a Model 70. However, nothing says you have to run the reamer in all the way. I may look at a shortened Sherman. That would make dies super easy to get as well. You just order Sherman dies and cut the back off to length. I appreciate you pointing that out! I'll have to see what elkaholic thinks!

I was actually thinking a shorter neck as well. I know it will probably cost me some barrel life. However, but I believe the tighter and longer you can run the throat of the chamber the straighter the bullet aligns before firing it. (6.5 Creedmoore, 6.5 PRC, 300 PRC for examples)

I did this once with a 7mm RUM before they came out with the 26 Nosler, basically creating a 28 Nosler, and it was really an easy and inexpensive wildcat project. The history of the 28 will tell you how it performed! It was nice, but I would just do a 28 if I was going to do it again.

 

[Edd]

I wouldn't run that much freebore, the O6 case has a long neck. You will be way past the neck shoulder junction at the boatail bearing surface.
.150-.160 is plenty and you will still be above the neck shoulder junction.

His version has a shorter neck. I think his freebore is good.

 

[L.Sherm]

I see that now.

 

[Edd]

The reason for not doing this is, I really want to build on a model 70 from the year my parents were born. Should be a super classy gun when all said and done, with a jeweled extractor and bolt and a AAA Fancy Walnut/Maple stock.

The problem there being, when you seat a longer 6.5 mm bullet out so that only the boat tail is in the case it is too long for the action, thus the shortening. Also, when you shorten the shoulder but blow out the body you really don't loose any case capacity if any. I feel like the case capacity could be slightly larger and be fine but we're getting to the top of the bell curve. So you're not going to gain enough velocity (at the same pressures) with 5 more grains of capacity, to make any difference, especially at long range in your trajectories or killing power.

Moving the shoulder back decreases the capacity more, about 2.3 times as much on a 6.5-06, than putting some of the bullet into the case. If you can get the length you require without having the bullets bearing surface below the case mouth, there is no point in moving the shoulder back.

 

[hunter67wa]

The sherman will run in i 06 acction. rich can speak to this better. Im having one built off a 270 in 700 as we speak