Forming 7x57 from 30-06 - question

[HuntingBronco]

Need some advice. I have my Hornady 7x57 die cranked all the way down. When I put the brass in the chamber, bolt closes with more resistance than normal. I checked and everything is good except the die doesn't seem to be pushing the junction of the neck to the shoulder down far enough. Two on left are formed from 30-06, brass on right is factory 7x57 round fired in my rifle. You can see on both formed pieces a witness mark from closing the round in the chamber. I am thinking next step is to load them up and see what they look like once fired. (Am I on the right track?) First time doing this - desperate times...desperate measures. (I have had 275 Rigby brass on backorder from Midsouth for 3 months and I refuse to pay $2/ea for nosler and am not interested in PPU brass - especially when I have lots of extra 30-06 brass.)

 

[Lefty7mmstw]

Sometimes when shortening brass the spring-back is enough that you actually need to go further than normal die limits by a bit to get usable brass. I had to run my 6.5 creed dies all the way down just to get 243's and 308's to make some semblance of a creed brass, and those were tough to chamber. I don't do this any longer as creed brass is available, but if I were still forming creed brass this way I'd have either shortened the base of the die a bit so the brass can go deeper, or get a Redding shellholder with the higher base (the competition shellholders?) to shove the brass in just a bit deeper.

 

[can1010]

it is definitely a springback issue. if it will close in your chamber with resistance you can fireform with a lighter load and it will straighten it self out.
if it wont chamber or has extreme resistance then annealing and resizing before loading will solve your problem.
if you don't have annealing equipment then the Redding comp. shell holders will work or a little trick that works is a thin feeler gauge between the brass and shell holder will do the same thing as the Reddings or a piece of a business card cut to fit will do the same as a feeler gauge and will cost you nothing but is only good for a handful of cases then you have to cut another one.
good luck on your cases I make 308 out of 30-06 because of the lack of 308 cases

 

[HuntingBronco]

what about cream of wheat forming loads - given shortage of all good things...???

 

[Dean2]

I have made 7x57 out of 270 brass, they work fine. I also use a lot of Sellier and Bellot brass as well as Privi (PPU). Both are excellent brass and I actually prefer both to Norma. We get loaded ammo for $2 each so usually buy loaded 173 grain Sellier, and then re-use the brass. The laoded ammo has been very accurate, under MOA in 7x57, 7x57R. 7x65R and 9.3x62. To be honest, some of the rifles I have to work hard to beat the groups with hand loads. Now to your specific problem, lube your cases well, FL size, withdraw the case, turn it 90 in the shell holder and run it through again, withdraw and turn 90 one more time. They should fit better and as long as you ca nchamber the loaded round shoot them with a mid range load. That will fix your issues with the tight chambering. Let us know how you make out with the rotating sizing.

 

[Seabeeken]

I had a similar issue forming 8 mm Mauser to 7x57. Fire form it but be sure to check brass thickness in the necks To be sure there is enough clearance in the chamber for bullet release

 

[can1010]

what about cream of wheat forming loads - given shortage of all good things...???

the COW method will work just fine if you have some pistol/shotgun powder. you can also just use cheap bullets and light loads as fun practice loads

 

[HuntingBronco]

Well I got and shot a mix of rounds with bullets and ground up oatmeal sealed with soap sitting on top of some shotgun powder. The way it was, I had essentially a false shoulder, so the brass was tight in the chamber when fired formed. (I was burning up old shotgun powder and old SACMAG primers) - Unfired on left, range of Oatmeal fireformed with range from 10-18gr and then two fired with bullets on right.)

 

[can1010]

looks good. 17 and 18 look to be the best formed for your COW method. having a false shoulder and a little resistance when chambering is a good thing. check neck clearance and reanneal and then enjoy your new brass.

 

[Dean2]

They came out nice. Did you try the rotating the brass method of resizing them down to 7x57?. How do they chamber after fire forming and before resizing as that will tall you if you got a good FF on them.

 

[HuntingBronco]

Can - how do I check neck clearance? Short of casting the chamber.

 

[Dean2]

Can - how do I check neck clearance? Short of casting the chamber.

Measure the expanded neck size of the one you fired with a bullet in it then measure the neck size of the same case resized with a bullet seated in it. If you have more than .002 from fired to loaded you are good to go.

 

[can1010]

Dean2 has it right. just measure a fired round and a sized and loaded round .002 minimum I prefer a little more .004 for a clean bullet release.
a quick check is to see if a bullet fits in a fired case your ok if you cant or is tight then you need to turn necks.. take a bullet to the range and check as you eject fired case then you will know if you have a problem that needs attention and weather you should continue shooting.

 

[HuntingBronco]

You guys are super helpful. Here's what I have:
Outside diameter after sizing: 0.306-0.308 (slight variance)
Outside diameter after firing: 0.323-0.325
Outside diameter with bullet seated: 0.308-0.309

By my math, clearance is atleast 0.015"-0.017"

GTG?