.260 AI Primer question

[Think4Self]

Quick question for the experts here. I finally got some Alpha small primer brass for a .260AI Lee Gardner chambered for me (FYI: you can’t go wrong with Lee, this thing shoots lights out while forming brass!) and I went to form some brass today when I noticed this. Not sure what is going on and would be interested in any ideas you guys and gals might have.

I shot 50 rounds and this may be representative of a dozen or so. Now that I look at the large primer brass I may see a little cratering, but nothing like today.

41 gr of IMR4350, 142 gr SMK, 2.830” OAL

This is the Alpha with Remington small primers


This is Peterson with large primers (Federal)

 

[butchlambert]

Looks ok to me. Do you have an .062 firing pin, if not have Lee bush your bolt and turn your firing pin down.

 

[paperpuncher]

If you aren’t using a Mag primer consider trying that it might help

 

[SKWERLZ]

Which Remington primer?
I’d definitely run the 7 1/2 in a high pressure cartridge especially if your running a big pin.

 

[Think4Self]

Looks ok to me. Do you have an .062 firing pin, if not have Lee bush your bolt and turn your firing pin down.

Well you definitely pointed me in the right direction. Turns out the firing pin is chipped on the end.

 

[Think4Self]

If you aren’t using a Mag primer consider trying that it might help

Only have standard in small, but I’ll keep my eyes peeled

 

[Think4Self]

Which Remington primer?
I’d definitely run the 7 1/2 in a high pressure cartridge especially if your running a big pin.

If I still have issues after I get the firing pin replaced I’ll see what happens. I have a couple thousand of these, but if they still act up I have a couple boxes of CCIs I can try.

 

[SKWERLZ]

That’ll do it

 

[6MMsteve]

take the pin out put a good radius on it, advance it to original protrusion

 

[Fast14riot]

Yeah, its your firing pin. I run 205m in my 260AI, but have also shot WSR and 7-1/2 without issue. I did have my firing pin bushed and turned.

 

[Bill Norris]

Been running CCI BR-2, 200, 250, & 34 and Fed 210M with no issues in both my 700 and 40X 260AI.

 

[DaveTooley]

take the pin out put a good radius on it, advance it to original protrusion

You don't want a full radius. That has excess space on the sides for cratering. Flat with the edge eased works bestl

 

[6MMsteve]

You don't want a full radius. That has excess space on the sides for cratering. Flat with the edge eased works bestl

I could get someone hurt, I need to get back under the shadetree and whittle