Trying to rechamber a botched 30-06 improved

[Paul from Colorado]

As stated above, Cerro cast the chamber (easy to do and not expensive). Figure out ‘what’ it is chambered to.

But seeing the bulge in the brass at the base is a no-go.

Get a new barrel, go the Douglas site, match your barrel profile or call and get a new one then chamber it per your bolt face.

 

[300stw]

use 338-06 brass neck down slowly until the bolt closes firm on the case, load those and fireform, the 338 will give a false ahoulder to headapace on,,,

 

[ImBillT]

Not without setting back the threads and changing the bedding it has. 338-06 air and 30-06ai have the same shoulder and his is deeper than a standard AI.

338-06AI will have the shoulder farther back than a 30-06AI. Also, it would be extremely difficult, if not impossible to set the shoulder back properly on 280AI brass. The shoulder is too sharp to move a substantial distance, and just as the 30-06AI has the shoulder farther forward than the 338-06AI, the 280AI is farther forward than the 30-06AI. This is based on the standard convention of necking up or down before “improving”. If you improved the 30-06 case then necked up or down, the shoulders would all be in the same place.

OP, just buy 338-06, 270Win or 280Rem brass, and size it in your 30-06AI die. First you just adjust your die properly. Take an unfired 30-06 case, and remove the firing pin assembly from your bolt. This is to allow the bolt to close with no resistance. Close it on the empty case(from the magazine so it slips under the extractor). Feel how easily it closes? Next, back out your 30-06AI die a few turns and run the case through. Now try to close the bolt. It should be very difficult or impossible. Don’t try really hard! Adjust your die down an 1/8 turn or less and resize. Try it in the gun again. You will reach a point where it closes with slight resistance. Set your die here, and never change. You will likely need to purchase a tapered expander button for your die if necking up 270 or 280 brass.

Before doing the above, do the test with an unfired 30-06 case. If the case is tight in the chamber, it’s possible that your headspace is correct, but the back of the chamber is fat. That could come from poorly indicating the barrel in during the chamber job.

 

[std7mag]

Wow!
We are jumping ALL over the place on this one!

The reason your getting the "bulge" towards the head is actually due to excess head spacing.
With factory ammo, the case isn't being held against the bolt face.

If you reload, seat the bullet out to seat at the lands. Use a low to mid charge for 30-06 & that bullet weight.

Shoot & measure.

 

[ImBillT]

Wow!
We are jumping ALL over the place on this one!

The reason your getting the "bulge" towards the head is actually due to excess head spacing.
With factory ammo, the case isn't being held against the bolt face.

If you reload, seat the bullet out to seat at the lands. Use a low to mid charge for 30-06 & that bullet weight.

Shoot & measure.

Using the bullet to headspace is semi-doable with EXTREME neck tension. It’s better to form a false shoulder. He can do that by necking up, and then necking back down, or start with a 338-06 and just neck down, or use 270Win or 280Rem, which already have a farther forward shoulder.

 

[jnmullins]

Hi there all I've got a project rifle I'm debating having rechambered if possible. It’s a beautiful sporterized 03 Springfield that someone put an amazing amount of work into the finish and stock work but botched the chamber. According to the barrel stamp its some sort of 30/06 "improved' but doesn't say which one. When I shoot factory 30-06 in it the brass stretches at the base of the case to the point that I'm worried one will rupture someday. I've taken it to 2 gunsmiths. One said not to shoot it and that the only way they could see to make it work would be open the bolt face and rechamber for something like 300wby. It’s a very small light rifle and I doubt the wrist of the stock let alone I could handle that. Another smith said it’s fine and just chuck the brass after I fire it. He also recommended shooting things like 180gr round nose that would reach farther and basically head space off the bullet instead of the case. (have ammo ordered but haven't tried this yet) The rifle is in a mannlicher stock with a belled end to the barrel with front sight base integrated so rebarreling isn't a very feasible option. I'm now thinking about having it rebored to something else. Initial thought was possibly 35 whelen but it looks like the base of the shoulder is at the same place as 30-06 so that knocks that out. Can anyone recommend any other ideas for getting this old girl going on semi readily available ammo? thanks

I have a spare 1903A3 barrel if you decide to rebarrel

 

[Farmerj]

Check with the CMP and see if they have spare barrels as well

 

[Remington92]

New 1903 barrel wouldn’t really be an option unless I found someone to turn it down to match the inletting on the mannlicher stock. I did try the 180gr round nose ammo yesterday and that seems to have resolved most of the case stretching and safety issue from what I can tell. But the accuracy looked like something from a smooth bore musket. Bout 8” at 100

 

[ImBillT]

Places can match that taper.

 

[longrunner]

Here is what I would do- proceed with your own caution/comfort level.

Take standard 30-06 brass (once fired is fine- and not from this gun) and run a .338 and evenn maybe a .358 expander ball through the neck. Slowly neck size the brass with a set of 30-06 (AI?) dies and stop then the bolt will just close on the the brass. Load brass with a reduced load (4895 for a powder would be a good one) and fire form. This should blow the shoulder out to fit the chamber, without stretching the base (as you have seen) since the brass is effectively headspaced (but not completely) on the shoulder. From now on, only neck size this brass. I suspect that some 30-06 AI dies would work best with the steep shoulder as shown in the photos.

 

[Don Fischer]

problem you have is you don't know what it is. I wouldn't fool with it but would re-barrel. Your playing with the unknown!

 

[Remington92]

I was looking at this and thinking a little more. What’s the chances a rechamber and open bolt face to 300h&h would clean it up? Something relatively more available and not much of a recoil step up from 30-06? Also seems like 300h&h would keep with the classy old spirit of the rig

 

[p_ham]

I was looking at this and thinking a little more. What’s the chances a rechamber and open bolt face to 300h&h would clean it up? Something relatively more available and not much of a recoil step up from 30-06? Also seems like 300h&h would keep with the classy old spirit of the rig

300 H&H is too long for the springfield.

 

[antelopedundee]

So dumb question what dies would I use with 280ai brass? The first smith did a chamber cast and said it didn't quite match a 30-06ai

Your first order of business would be to see if an unprimed 280AI case will chamber. It sounds like your chamber is long but maybe not THAT long since a .280 case is about 0.050 longer in the base to shoulder dimension than your other .06 based cases. What shoulder angle is indicated from a fired case, 30 degree or 40 degree or something else? I've found that because of the sharper 40 degree shoulder angle of the AI case that a 6.5-06AI die will NOT set the shoulder of a .280AI case back far enough to chamber in a 6.5-06AI chamber. I had someone looking to make 6.5-06AI cases from .280AI cases because he was trying to avoid the shortening that one gets when one fire forms AI cases from the non AI cases. IF a 280AI case [and you likely will need to trim it about 0.050 shorter first] will NOT chamber in your rifle you might want to consider having it converted to a .30-280AI which will give you comparable or slightly better performance with little change in recoil. Also I'd think that you could use standard .30-06AI dies with a suitably thick washer as a spacer to reload with.