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View Full Version : Question about resizing .270 Win. to 26-06



Crockett
08-29-2013, 07:57 PM
Iím in the market to buy a 25-06 and with our shortages, Iím trying to find 25-06 cases and having trouble finding them. I do have quite a few .270 Winchester cases.

Therefore I have two questions about resizing the .270 cases to 25-06.

My concern is with:

1- I believe the headspace is the same on .270 and 25-06 Ė so -- can I just run the .270 cases into a 25-06 full length resizing die and except for trimming to length -- be good to go?

2- Do I need to trim the neck thickness once I resize to 25-06?

Thanks,
Crockett

Dick Grosbier
08-29-2013, 08:43 PM
2- Do I need to trim the neck thickness once I resize to 25-06?


This is a valid concern. It is going to depend on both the cases and the chamber, but most factory chambers have relatively loose neck dimensions. Since you are smart enough to realize it is a potential problem I am sure you will be aware if you have problems with the neck being too tight. That being said, I seriously doubt you will need to turn the necks.
Dick

Charles E
08-29-2013, 10:18 PM
Well, Ken Howell in his book Designing and Forming Custom Cartridges, under making .25/06 cases, says "...Or resize .270 Winchester brass full-length in the 25-06 sizer die, trim to length, and deburr...

So yes, with the possible exception of neck diameter, you should be fine. As Dick points out though, most factory chambers assume a largish neck. In passing, I knew a guy who had a tight-necked 6.5/06, and used that reamer for a field chamber with the .25/06... worked fine.

Crockett
08-31-2013, 08:03 PM
Well, Ken Howell in his book Designing and Forming Custom Cartridges, under making .25/06 cases, says "...Or resize .270 Winchester brass full-length in the 25-06 sizer die, trim to length, and deburr...

So yes, with the possible exception of neck diameter, you should be fine. As Dick points out though, most factory chambers assume a largish neck. In passing, I knew a guy who had a tight-necked 6.5/06, and used that reamer for a field chamber with the .25/06... worked fine.

Thanks fellas -- I'll proceed with caution and keep an eye on pressures.

Crockett

ebb
09-01-2013, 10:01 AM
I resized a bunch of 270 win brass in my 25-06 die and loaded them. The first 5 worked perfect the 6th was another story. The primer was in the magazine well, and the brass hit the bolt face so hard it was impossible to tell which brand the brass was as the headstamp was gone. I have reformed many different pieces of brass in this same way and never had a problem, I make 243 and 7-08 into 260 brass with great success but the 270 to 25-06 was disastrous. If I were you and planed on doing this I would find a good way to measure neck thickness (not dial calipers) and make sure that ever thing is safe.

kansasvet
09-01-2013, 01:54 PM
I just completed sizing 50 Win. 30-06 down to 25-06. I was surprised that the difference in neck thickness from
factory Win. 25-06 only averaged .0005 to .001.
The factory 25-06 went .014 to .015 and the sized down 30-06 went .0145 to .0155. This is using a tubing mike
so the .0005 measurements are approx.

Wilbur
09-01-2013, 05:53 PM
Verify everything - including headspace.

Ebb said use something better than dial calipers to measure but if you can't see it with a dial caliper it's not enough....assuming a half decent caliper...

alinwa
09-01-2013, 09:33 PM
I resized a bunch of 270 win brass in my 25-06 die and loaded them. The first 5 worked perfect the 6th was another story. The primer was in the magazine well, and the brass hit the bolt face so hard it was impossible to tell which brand the brass was as the headstamp was gone. I have reformed many different pieces of brass in this same way and never had a problem, I make 243 and 7-08 into 260 brass with great success but the 270 to 25-06 was disastrous. If I were you and planed on doing this I would find a good way to measure neck thickness (not dial calipers) and make sure that ever thing is safe.

Did you verify your length? There is a reason for your problem and my guess is length first, then diameter a distant second as the culprit..... a DISTANT second let me add as I've fired many rounds so tight I could feel the casenecks scrubbing into the chamber necks, to good effect......."scuff-fit" as coined by an un-named HOF BR shooter who has also done well with this tight fit. Scuff-fit because if you remove the loaded round from the chamber there are distinct scuff marks from the chamber neck.


al

Larry Elliott
09-01-2013, 09:50 PM
I haven't done this specific job, but have used .308 Win cases to make .300 Savage cases for a Remington factory chamber, and all I needed to do was trim and deburr the mouths. This conversion requires that part of the .308 case shoulder is in the neck of the .300 case which should be thicker than the neck.

Al is correct there was something terribly wrong with the .270 case formed to .25-06 if that much excessive pressure was developed on firing. If it were neck thickness there should have been some difficulty in closing the bolt or some other sign that something wasn't right.

When I was a young lad I read Jack O'Connor's shooting columns in my dad's Outdoor Life magazines, and back in the late 40's brass was still hard to find and such esoterica as neck turners were unheard of. If someone came on a supply of .30-06 military brass they sized it to fit what they needed. In serious reductions, say down to .257 Rob'ts or .250-3000 they may have had to ream necks, but for .270's and .25-06's they just ran the .30 cal cases into the FL die for the appropriate caliber and hoped they didn't lose too many cases in the process.

ebb
09-02-2013, 01:25 PM
I have always believed it was neck dia. that was the culprit, I may be wrong. The bullets were seated into the lands and so it was a light enough load that it was safe with all the other cases. It was a Ruger 77 R and I have always assumed the chamber was on the big side and OAL of the brass was OK. I usually trim to length with any new brass to the gun but could have missed one.