Reaming and re-rifling 25-06

[hawlejr]

My desired result is converting my Ruger M77 in 25-06 to 6.5-06 AI.

Here are my two questions:

First, is there enough steel to ream the rifling lands out of a ".257" barrel (.257 groove diameter and .250 land diameter), and then cut new grooves yielding a .264 groove diameter (with .257 lands)? Rifle lands are typically .0035 higher than the grooves, as I understand it, so theoretically, you could ream the 25-06 lands out which would yield a new base diameter for lands of .257. Then, (also theoretically), you could cut new rifling grooves with a groove diameter of .264 yielding the correct rifling land height of .0035 above the groove.

Next the chamber would simply reamed to yield the sharper shoulder of the AI case.

Second question.... would this be worth it, or is it easier to just buy a new 6.5 AI barrel and replace it.

 

[biednick]

Just get a new barrel. It'll be cheaper, less likely to go wrong, and you'll end up with a barrel that has the standard dimensions instead of an oversized bore.

 

[338 dude]

My desired result is converting my Ruger M77 in 25-06 to 6.5-06 AI.

Here are my two questions:

First, is there enough steel to ream the rifling lands out of a ".257" barrel (.257 groove diameter and .250 land diameter), and then cut new grooves yielding a .264 groove diameter (with .257 lands)? Rifle lands are typically .0035 higher than the grooves, as I understand it, so theoretically, you could ream the 25-06 lands out which would yield a new base diameter for lands of .257. Then, (also theoretically), you could cut new rifling grooves with a groove diameter of .264 yielding the correct rifling land height of .0035 above the groove.

Next the chamber would simply reamed to yield the sharper shoulder of the AI case.

Second question.... would this be worth it, or is it easier to just buy a new 6.5 AI barrel and replace it.

Replace it!!!!!

 

[victor3ranger]

Change barrel would be the best thing

 

[Rich Coyle]

Reboring worked great for me. But I went from 6.5 mm to 8mm.

 

[sable tireur]

Second question.... would this be worth it, or is it easier to just buy a new 6.5 AI barrel and replace it.

Worth is subjective and is a variable for each individual. Of course it's easier to just run out and buy an new barrel, that's common sense.

Next the chamber would simply reamed to yield the sharper shoulder of the AI case.

When creating a new chamber in the AI form, the barrel needs to be set back. Read Ackley's directions.

First, is there enough steel to ream the rifling lands out of a ".257" barrel (.257 groove diameter and .250 land diameter), and then cut new grooves yielding a .264 groove diameter (with .257 lands)? Rifle lands are typically .0035 higher than the grooves, as I understand it, so theoretically, you could ream the 25-06 lands out which would yield a new base diameter for lands of .257. Then, (also theoretically), you could cut new rifling grooves with a groove diameter of .264 yielding the correct rifling land height of .0035 above the groove.

Here's where you can run into trouble when relying on shear numbers alone.

There is a rule of thumb regarding the amount of reaming which is necessary to get down to the best metal when doing a rebore. Normally, the folks who perform this action require 0.015" material removal from the existing barrel. So your math needs to look like:

.257 + .015 = .272" minimum. Be sure to read that term 'minimum'.

One of the many realities of reboring involves what the original steel is, the process used to make that barrel and who the original manufacturer was. Some OEM barrels rebore wonderfully while other processes or formulas can leave less than optimum steel for reboring.

Here's the important aspect:

Call the reboring expert you choose and discuss your project with them. This insures you have the best information with which to make your decision.

Enjoy the process!

 

[Coyote Shadow Tracker]

^^^^^^^^^^^^^

 

[hawlejr]

Worth is subjective and is a variable for each individual. Of course it's easier to just run out and buy an new barrel, that's common sense.



When creating a new chamber in the AI form, the barrel needs to be set back. Read Ackley's directions.



Here's where you can run into trouble when relying on shear numbers alone.

There is a rule of thumb regarding the amount of reaming which is necessary to get down to the best metal when doing a rebore. Normally, the folks who perform this action require 0.015" material removal from the existing barrel. So your math needs to look like:

.257 + .015 = .272" minimum. Be sure to read that term 'minimum'.

One of the many realities of reboring involves what the original steel is, the process used to make that barrel and who the original manufacturer was. Some OEM barrels rebore wonderfully while other processes or formulas can leave less than optimum steel for reboring.

Here's the important aspect:

Call the reboring expert you choose and discuss your project with them. This insures you have the best information with which to make your decision.

Enjoy the process!

Thanks for the time you spent relating some very good knowledge. This is what I was looking for. This is a great site, and folks like you make it that way. I hate to throw away a perfectly good barrel, but I have two 25-06 heavy barrel Old Ruger M77 rifles. I guess I'll keep 'em the way they are and forget about the 6.5 play. I have a Creedmoor too, but I enjoy experimenting, reloading, and improving my collection. A 6.5-06 AI in heavy barrel would be a nice addition, and I could form the brass from 30-06 cases as I do for the 25-06. However, the barrel conversion ain't in the cards. So, again, thanks for sharing your knowledge.