Reloading 280 AI

[wsq]

Had a friend have this problem with hornady dies 7 stw Jarrett rifle probably a tight chamber after trying everything we could think of we called hornady they had us back the die up been fine sense

 

[BountyHunter]

I'm not being defensive and certainly have nothing to prove, but the "cam over" advice was given to me by technical support at Redding. I was using the Redding T7 press, Redding dies and shell holder for my then new 270WSM. Before asking for help from Redding, I couldn't close the bolt even after adjusting the die to touch the shell holder. Their advice solved that problem; I then removed the firing pin/spring assembly from my bolt (Rem. 700) and continued to adjust the sizing die until the weight of the bolt handle alone would just close the action.

Of course that is what redding says about cam over, or more accurately their lawyers!!! They flat out do not care about brass life or accuracy. Just will it chamber. Yes, it will chamber IF you set the shoulder back .010- .020 every time UNTIL you get case head separation. It amazes me that people still do not get the fact that not every die does not accurately fit every chamber. Does not mean it is a bad die, just will not fit your chamber maybe and you should try another mftr. Cam over is NOT the miracle cure.

 

[xsn10s]

Ask and yee shall receive!!
Many thanks to all, xsn10s nailed it.
The once fired, FL sized and blackened case had the blackening rubbed off at the radius and shoulder. This is my first experience with a cartridge with a radius. So I'm glad I asked.
Let me see if I have this right,
1. I should move the shoulder back
2. Check neck length
3. Shorten the case a bit.
To accomplish this, mill the shell holder.
Did I get it right?

Just to make sure it sounds like the sharpy got scraped off the shoulder and maybe the shoulder/ body junction. A picture would help with figuring out the issue. I always like to try the KISS method and do simple things first before getting more evasive. Such as using a factory matching shellholder. If that doesn't do it try a different lube, I like Imperial Sizing wax. You could also make sure your expander ball is well polished and make sure the inside of the case mouth is well lubed while sizing, although I clean the interior by tumbling afterwards. Camming over is also another method, but I always do this first. Set up dies by just touching the die to shellholder with the ram up. And then FL size and when the ram is in it's top position while sizing brass look for a gap between the die and shellholder. If you get a "gap" between the dies and shellholder then slightly cam over the press. Finally you could mill or turn a shellholder. But I'd call the manufacturer first to see what they have to say.

 

[xsn10s]

But I'd still like to see a picture of the sharpied case and another that was sized, but not sharpied.

 

[whirlwindjml]

I recently set up Redding FL sizing die for my 6.5 PRC. I had to make contact with the shell holder to get .002 shoulder bump.

well that one will be easy to set up every time.

 

[Tree Farmer]

Apparently, touching the shell holder is wrong. If that gives you the proper shoulder bump, what should I do different? Somehow make it harder to get to the same result?

 

[25WSM]

Tree farmer
Touching the shell holder is not wrong when setting up die. If you raise the ram and screw die to touch it's ok. If that's where you need to be to get the proper setback. A die set up like this will not cam over. There is enough flex in the press and there will be a gap between the die and she'll holder. Cam over is what you don't want. That happens when you need to screw the die in farther than the shell holder touch position. This forces the shell holder to get crushed against the die so harder the press handle will get hard to move past the bottom of the stroke and then cam over. If this is occurring before you have the proper setback then the die is too deep on the inside. Cutting .010 off the bottom of your die will fix it. Or taking a little off your shell holder top. Most guys that come to me for help just learned to screw the die down till it touches and call it good. Problem is not all dies are the same depth and not all chambers are either. So without a way to measure your setback when sizing your brass you are just watering the grass into the wind so to speak. It would be nice if all the reloading manuals would teach people this. Hope this helps.
Shep

 

[xsn10s]

Presses have some flex an play in the linkage. You can see this when you set up the dies just touching the shellholder and then stop at dead top center stroke while sizing brass. If you cam over to take up that gap, or cut the die you'll still be doing the samething. Which is turning the die in to size more and increase pressure on the press. I've cut dies before for different reasons. In either case good luck.

 

[Tree Farmer]

Yes it does. Thanks! Actually, that's where I ended up. I went through the process of sizing/measuring in increments until I reached .002 shoulder bump, and it was repeatable. At that point I was happy and my load development went very well. The value of this site is not only the good technical information it provides, but also why something works.

 

[xsn10s]

Ask and yee shall receive!!
Many thanks to all, xsn10s nailed it.
The once fired, FL sized and blackened case had the blackening rubbed off at the radius and shoulder. This is my first experience with a cartridge with a radius. So I'm glad I asked.
Let me see if I have this right,
1. I should move the shoulder back
2. Check neck length
3. Shorten the case a bit.
To accomplish this, mill the shell holder.
Did I get it right?

Hmm I may have misunderstood the OP's post here. I'm wondering if the shoulder is developing a slight buckle causing it to scrape. In either case Ackley Improved cartridges don't often need FL resize. Most people neck size only until the cases stretch enough to need FL resize, which is one of the benefits of the AI cartridge. The shoulder angle decreases trimming. Your case stretching to max length is kinda a tell. I suggest you set up your dies to neck size only before trying anything else. And polish up the expander ball in case it's too rough and stretching the case when getting pulled out.

 

[nicholasjohn]

Yes it does. Thanks! Actually, that's where I ended up. I went through the process of sizing/measuring in increments until I reached .002 shoulder bump, and it was repeatable. At that point I was happy and my load development went very well. The value of this site is not only the good technical information it provides, but also why something works.

Knowing why & how something works is VERY helpful. There are things that I have been doing for years correctly, and they worked every time - but I never knew why. ( I was doing them that way because somebody had taught me to do it that way - the old "do it that way because I said so.") These guys on this forum can tell us WHY, and it's always better to UNDERSTAND a process than to just know that it works.

 

[claybreaker]

If you don't have a comparator set that works on cases. And you want to compare the shoulder set back of 2 different pieces of brass. In the short term I have used an empty pistol case (9mm, 40S&w, etc) that will go over the rifle case mouth and touch the close to the datum line on the rifle case. Then measure between the head of one case to the head of the other. This will not give an absolute measurement that you can use, but it is ok for a relative measurement (shot/new/good case versus one than doesn't chamber).