Pre-64 Model 70 in 6.5-06 AI

[redneckclimbing]

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.

Edd-
I'm sure you are correct, you will loose more capacity by pushing the neck down vs. seating the bullet deeper. However, capacity is not the end all be all to me. I have seen a ton of cartridges where the more bullet that is sticking out of the cartridge the more accurate it is. I believe it is aligning the bullet in the throat better and it then engages the rifling more concentric to the bore.

Think if you took a cleaning rod that wouldn't bend, and you put it in the muzzle of you barrel about two inches. You would probably be able to move the other end of the rod about 5 degrees in either direction (for example). Now, if you put 20" of the rod in the muzzle, you would only be able to move the other end of the rod about .5 degrees. Your bullets are the same way in the free-bore area of your chamber.

Look at most bench rest cartridges for example. I will say these are almost exclusively "mid-volume" cartridges compared to their bore size, which I believe is the number one factor in knowing whether or not a cartridge will shoot, but also almost exclusively the bullet will be seated out in front of the cartridge very far.

I don't know though, what do you other guys think?

 

[redneckclimbing]

I see that now.

L.Sherm is the Sherman your design? (Just guessing from the name) The free-bore length was basically plagiarized from the 6.5 Creedmoore. I thought it would be a good starting point guess?
Do you still think you would go shorter?

 

[L.Sherm]

No not my design, Rich Sherman is the designer.
Personally if your gonna go shorter you might as well go Creed.

 

[Edd]

Edd-
I'm sure you are correct, you will loose more capacity by pushing the neck down vs. seating the bullet deeper. However, capacity is not the end all be all to me. I have seen a ton of cartridges where the more bullet that is sticking out of the cartridge the more accurate it is. I believe it is aligning the bullet in the throat better and it then engages the rifling more concentric to the bore.........

I share your opinion about capacity and bullet alignment but I was thinking capacity was a priority to you because of your AI design.

 

[FURMAN]

It sounds like you are going to duplicate the 6.5x284 case capacity with a ton more work and money.

 

[Edd]

No not my design, Rich Sherman is the designer.
Personally if your gonna go shorter you might as well go Creed.

I don't think a Creedmoor would be a good option but, if capacity isn't a priority, an improved version of a 6.5x57 might deserve some consideration.

 

[L.Sherm]

Why not, it's for his daughter. You keep getting shorter and your at the Creed velocity's with alot less work.
Just block out the mag box if it doesnt feed in the LA and I bet it would be fine

 

[Edd]

Why not, it's for his daughter. You keep getting shorter and your at the Creed velocity's with alot less work.
Just block out the mag box if it doesnt feed in the LA and I bet it would be fine

That would be a waste of a nice Model 70 Action. It would be similar to buying a 66 Corvette and putting a Pinto engine in it.

 

[L.Sherm]

Same thing as shortening the 6.5x06AI.

 

[Edd]

Same thing as shortening the 6.5x06AI.

If you consider 1.486" and 1.950" to be the same, I guess it is.

 

[Alibiiv]

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

View attachment 160163

From the OP and your replies is appears that you are reinventing the wheel! I did not notice what you are planning to do with the rifle that you are building for your daughter?? There are a number of options around what you are looking to do without designing another "questionable" cartridge to do it with. The Sherman line of cartridges, both long and short, with their longer necks, ought to have a caliber in them to meet your accuracy needs. I have a .270 Ackley Improved with the "40" degree shoulder in a Ruger 77 that was originally a 30-06, never a feeding issue at all. My thoughts are that if you are going to go with the Ackley Improved design, stick with the blown out case and the 40 degree shoulder to get the maximum out of your casing, but again look at the Sherman line of cartridges, you can rent a reamer, good brass is available, and you can get dies already made for them. Good luck with your build.

 

[CliffM]

From the OP and your replies is appears that you are reinventing the wheel! I did not notice what you are planning to do with the rifle that you are building for your daughter?? There are a number of options around what you are looking to do without designing another "questionable" cartridge to do it with. The Sherman line of cartridges, both long and short, with their longer necks, ought to have a caliber in them to meet your accuracy needs. I have a .270 Ackley Improved with the "40" degree shoulder in a Ruger 77 that was originally a 30-06, never a feeding issue at all. My thoughts are that if you are going to go with the Ackley Improved design, stick with the blown out case and the 40 degree shoulder to get the maximum out of your casing, but again look at the Sherman line of cartridges, you can rent a reamer, good brass is available, and you can get dies already made for them. Good luck with your build.

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

View attachment 160163

I rebarreled a pre-64 win to the 6.5 Sherman case, it feeds ok but not a slick as the push feed M70.
I can throttle it down to 6.5 284 territory if needed.

 

[CliffM]

I rebarreled a pre-64 win to the 6.5 Sherman case, it feeds ok but not a slick as the push feed M70.
I can throttle it down to 6.5 284 territory if needed.

Just a thought , maybe don't refer to it as an A.I. unless it actually an Ackley Improved or it is possible you might not get what you want.

 

[GLTaylor]

I have 3 Ackley Improved cartridges. All 40 degree shouldered true Ackleys, all straight walled. All feed fine. 2 in 700 actions, one in a benchrest action. If you call it anAckley, I believe it is supposed to have a 40 degree shoulder?