View Full Version : Resizing from 30-06 to .270?

08-07-2010, 12:25 PM
I was messing with some brass today, and I ran a piece of 30-06 brass through a .270 sizing die. The result seemed to be a decent looking .270 case, but the neck was considerably shorter than the suggested trim to legth. My question is, would it be okay to resize brass like this, and to shoot it from a .270? Is there a way to lengthen the cases? Will these be accurate if I shoot them? I'm sure someone has done this before.

08-07-2010, 01:36 PM
I've made and used them before. Worked good for me with jacketed bullets, but I never tried them with cast boolits.

08-07-2010, 03:52 PM
Back in the early 1960s, my first commercial centerfire rifle was a Win. M70 "Featherweight" in .270. (Sure wish still owned that one!!) I'd just started reloading and formed most of my brass from miltary 30-06...of which I had an almost unlimited supply at the time. This was my first serious attempt at load development and, as I recall, I managed to, at least, equal factory load accuracy. (Also, at the same time, I was using bullets pulled from milsurp 7x57 ammo and swaged down to .277 using an arbor press and a homemade die.)


08-07-2010, 04:22 PM
Ans to all is: Yes. This is one of the easiest/most basic cartridge conversions & a perfectly normal situation. The .270 case will run a nominal 1 mm longer than '06.

To "lengthen" the case: simply FL size, load & fire them a couple times, measuring their resized lengths. Should take 3-4 firing/resizing cycles to stretch-out to a native .270 length. After that & only then, do ya get to start trimming them ...... Funn !!

08-07-2010, 04:46 PM
+1 on the above. The only item to be careful of is that as you are sizing down the neck area becomes thicker. The change from .308 to .270 is not that great But if your rifle has a tight .270 chamber-neck diameter the thicker neck wall may cause a tight fit.
I learned all this sizing some .308 down to .243. Most worked fine but a couple had just thick enough neck walls that they chambered a bit tight and one upon firing caused the primer to leak a bit. You may not have any problems. Just be aware.

08-08-2010, 01:33 PM
Thanks guys! All great information. I often find myself running short on .270 brass, so this might be good for future reference.

08-09-2010, 06:22 AM
Yes it works and I size 06 down to 25-06.

08-09-2010, 04:16 PM
I make all my 25-06 brass from 270 brass. Real sweet, real easy. Just size, trim and fireform.
I save my30-06 brass for my ------30-06, and also make my 8mm-06 AI brass out of my 30-06 brass. Very nice.

08-09-2010, 09:47 PM
I have gone both ways with 30-06 and 270 brass and it works both ways. In fact I found some once fired 270s recently and just resized them to 30-06 as I do not own a 270 at present. Both cases also are good for making any of the military Mauser brass except for the 6.5X55 Swedish stuff. I personally made or make 7 mm, 8mm, 6.5X57mm from them.

08-12-2010, 10:12 PM
I've been told that Jack O'Connor was actually, technically, shooting .270-'06 all them years, because he was doing exactly that - necking (USGI) .30-06 brass down to .270! This was during the era when milsurp .30-'06 AMMO went for a penny a round.

I like to form .35 Whelen brass from unfired .270 brass, since Whelen brass is frequently difficult to find. Expanding .30-06 brass yields a case that's .030-.040" short in the neck; using .270 brass yields a case that frequently needs a very minor trim before loading. I have to run it through a .280 Remington neck sizer as an initial step, because Redding's tapered .280-to-.35 expander crushes about 10% of the brass, otherwise.

09-20-2010, 09:39 PM
All good info here, gents.
But please remember: this conversion is prone to fatigue splitzz, & sometimes it occurs @ the 1st fireform. :groner:

Thus, anneal them necks !!

09-23-2010, 05:50 AM
Does one have to turn the necks after making .270 from .30-06??


09-24-2010, 06:30 PM
Turn Necks ?
Only if that rifles chamber is on the tight side and the case wall that hair to thick with a seated boollit.
Just place a cast boolit of proper size for that throat in a resized case (no powder or primer) and gently push the case with boolit into the chmaber. If it seats properly no problem.. Close the bolt and again " Feel" for reisistence. If there is no "Sticking" you are fine.

09-29-2010, 09:35 PM
i been reforming 30-06 and 270win into 6.5x55 ,with ag-42 the fly over 10 yard to the right. there always planty of 30-06 or 270win brass on the grund.

and with die and can reforme 30-06 into 7.62x39. but with heavy work[smilie=s:

09-30-2010, 12:54 AM
My experience sizing 30-06 to 270 follows what Sanchez said. Some brass products seem to respond better than others. Split necks are the common result if some products aren't annealed.

I've re-sized 30-06 to 270, 30-06 to 280, and 30-06 to 25-06 having good results with RP, WW and Federal brass. I've had frequent neck failures with Frontier brass which is no longer produced.

I believe it's important to anneal all brass whenever the neck size has been modified, and as other have said, beware of tight neck problems that can elevate pressures. Also be aware the head stamp isn't changed and that can cause some dangerous confusion when two different caliber rifles using 30-06 brass are taken to the range (ie, a 280 and a 30-06).

Resizing/fire forming works well with some belted magnum cases too. 264WM to 338WM is a long stretch but it has worked for me. So does 264 to 7mm mag. The fabulous wildcat, the 30-338, originated from a 338WM case necked down to 30 caliber. All my cast 338 boolits are loaded in fire formed 264 cases.

10-03-2010, 10:18 AM
[QUOTE=TDC;1013238] .... beware of tight neck problems that can elevate pressures ..... QUOTE]

More good points missionary5155 & TDC! I also seem to recall that some brands/headstamps of brass are more prone to said situation (RP jumps-out, along w/ most GI brass).

Bottom line: measure wall thickness after resizing, turn (or ream) neck, trim OAL, then measure neck OD on loaded round.