Fireforming .280AI from .270

[frostop]

Since this is a rimless cartridge, if I wanted to fireform from 270 brass I should do one of the following;
1:Run through the AI dies, load with light load and seat into the lands Or;
2:Run through 30.06 die than through AI die to create false shoulder than cream of wheat fireform???

I have fireformed rimmed cases before but not rimless and I have read that you could get some stretching when fireforming with light loads and bullets seated into the lands???

I would rather do the Cream of Wheat forming if possible since I can do that at home but if not advisable than I will go the other route. Your expert advise please??


Gary

 

[ZSteinle]

I have done the necking up to 30 cal and cream of wheat and worked well. Used some green dot powder and went to town fire forming.

 

[MudRunner2005]

I usually do a mix of 1 and 2. Then I trim them after resizing them BEFORE fire-forming them, with an extra 0.020" to make up for length when the shoulder and walls blow out.

 

[Demon061]

Quick question: What's the major advantage of the .280 versus the .270?

 

[MudRunner2005]

Quick question: What's the major advantage of the .280 versus the .270?

Brass or caliber? If caliber, the simple fact that you have the ability to shoot 180-190gr bullets. Plus, 7mm bullets have a high BC.

 

[FEENIX]

Quick question: What's the major advantage of the .280 versus the .270?

I don't want to hijack this thread so I'll do a one time response to your query.

1. Check out page 6 of 12 SAAMI velocity and piezoelectric transducer pressure test >>> http://www.saami.org/specifications_and_information/specifications/Velocity_Pressure_CfR.pdf . .270 Win's pressure limits is comparable to that of .280 AI.

2. In my area on the shelf availability of brass goes to the .270 Win, heck they seem to be the only brass that are constantly available around here.

3. It also depends on your set up. With today's advancement in barrels, powders, bullets, etc ... end-users are pushing the envelope. For instance, my .270 AI with 30" 1:8 twist 3-groove propels the 175 Matrix VLDs (165/175 BCs are in the .640/.650 range) in excess of 3000 FPS (2919 FPS while fire-forming).

Just my 2-pence for your thoughts. Cheers!

 

[frostop]

I found a deal on an Encore 280AI barrel, Up until that I was debating between the 270 and 280. The 280 does have a lot more bullets available especially in the heavier weight. And no need to buy or search out special bullets at high prices.

Thank you for all the replies.

Gary

 

[Demon061]

Very cool.