Brass Won't Chamber - Perplexed

[coldboreshot]

I'm having issues chambering resized brass out of my pre-64 M70 .220 Swift and cannot narrow down the cause.

I had reloaded once fired Hornady brass and noticed while at the range, some of them would not chamber in my M70. I figured I didn't have my FL sizing die turned down far enough. I did fire the rounds out of another .220 Swift later. I then cleaned the brass, ran a few through the FL sizing die, measured headspace with a comparator, and proceeded to test. They would not chamber. I then incrementally started to turn the die down to the point where I can no longer turn it down and still get cam over. Still will not chamber.

Fortunately, I was able to find a piece brass that was 1x fired and would chamber easily in the rifle. I proceeded to take measurements of that case and the other cases I had used to test that would not chamber.

Good Case

• Headspace = 1.728
• Case length = 2.196
• Case width at base= 0.442
• Case width at mid point = 0.425
• Case width just below neck = 0.405

Bad case

• Headspace = Started at 1.728, took it all the way down to 1.722
• Case length = 2.196
• Case width at base= 0.440
• Case width at mid point = 0.425
• Case width just below neck = 0.404

In every way I measured, it seems the bad case is smaller so I cannot figure out why it won't chamber but the other case will.

I'm guessing it might have something to do with the brass having been fired out of two different rifles but considering all the brass went through the FL die anyway, I'd think it would get it consistent. Both the good and bad cases all chamber in the other rifle, which is a Ruger No1.

What am I missing!?!?

Get yourself a chamber length plug from Sinclair Intnl and measure the chamber length. Even though the case lengths are the same and it works in one rifle's chamber, the other chamber may be slightly shorter and the case is jammed against the front edge. This could have been the cut of the reamer for that chamber. A sizing die is not going to touch the case length. Or, if you have a case trimmer, start with .001" increments and find at what length the case chambers. I'm betting, the chamber is a little short, not so much tight.

 

[Coyotefurharvester]

Going by Willytp's drawing, the op's brass is 0.038 long.

 

[Crosshair1]

Compare the case body diameter between the base and midpoint.
In the image it looks the case hasn't expanded to fit the chamber until about 0.300" from the base.

 

[Richard Jones]

^^ I have it a .077 long. Am I reading that correctly? His length of 2.196 - 2.1883? That's way under SAAMI.............. I could use some reamer print education.

So how is the other case chambering?

 

[copperking81]

I think I figured out the problem. Check out the picture, that photo was taken from the table top of my 1950s Delta Unisaw... the table top is super flat. And the rim is hanging just off the edge of the table top so it's not lifting the case in any way. There does appear to be a slight bulge just up the case a bit from the rim.

I don't know what's causing it. I can only surmise the die is jacked up or possibly the chamber in one of the rifles??? I use imperial case wax and up until I had the problem, the FL sizing die was only turned down just enough to kiss the base in the up position.

 

[copperking81]

That would also explain why all the measurements between the good brass and the bad brass were generally consistent with each other, or even larger in the good brass.... I was measuring all around the problem.

 

[Stan Taylor]

Personally I think you're pissing up a rope put new brass in your gun and don't worry about that other brass and your problems going to probably go away.

 

[Richard Jones]

So what does that measure right there compared to the "good" brass?

 

[dolek]

I think I figured out the problem. Check out the picture, that photo was taken from the table top of my 1950s Delta Unisaw... the table top is super flat. And the rim is hanging just off the edge of the table top so it's not lifting the case in any way. There does appear to be a slight bulge just up the case a bit from the rim.

I don't know what's causing it. I can only surmise the die is jacked up or possibly the chamber in one of the rifles??? I use imperial case wax and up until I had the problem, the FL sizing die was only turned down just enough to kiss the base in the up position.

Quote/Can you see on the brass just how far the sizing die has made contact ?/Quote


Post # 2...That's why I asked .

 

[qwk]

That bulge is very common on high mileage brass. I get that on cases that gave 20+ loads on them. Won’t chamber in other rifles if you don’t run it through a small base die first.

 

[Bill K]

Would someone explain this Camming over ? If your Shellholder is touching the bottom of the die, how can you cause any further reach by camming your ram/linkage any further, all you are doing is putting strain on the ram/linkage, are you not ?

 

[copperking81]

So what does that measure right there compared to the "good" brass?

Good = 0.442 vs Bad = 0.443

Now... the bulge is super fine so I don't know how much confidence I'd put in those measurements. I will say the good brass looks to have a ring in that same spot but not nearly as pronounced as the bad brass. If it were fired and then resized, I'd bet it be much closer though.

 

[copperking81]

So here is what I'm going to do... I'll pick up a bag of new brass, fire it out of each rifle and check for the ring. If no ring, I'll check for the ring after sizing. I'm guessing it will eventually show up after one of those steps.

 

[copperking81]

Would someone explain this Camming over ? If your Shellholder is touching the bottom of the die, how can you cause any further reach by camming your ram/linkage any further, all you are doing is putting strain on the ram/linkage, are you not ?

Yes, I think it does likely cause strain especially to the Forster set up. That said, it can be done.... I could get a solid turn and then some out of my die, from the point the die kissed the base. I don't like to do that but I did for the purposes of troubleshooting.

 

[copperking81]

Quote/Can you see on the brass just how far the sizing die has made contact ?/Quote


Post # 2...That's why I asked .

So what do you think the issue is then?

 

[Bill K]

Yes, I think it does likely cause strain especially to the Forster set up. That said, it can be done.... I could get a solid turn and then some out of my die, from the point the die kissed the base. I don't like to do that but I did for the purposes of troubleshooting.

Okay, then what is compressing, to allow more of the cartridge to enter the die, the base of the die or the shellholder. How can either compress any further once they are touching each other ?
Makes no sense.

 

[Stan Taylor]

I'm laughing my ass off didn't listen to a word I said.

 

[1911nut]

I found Winchester Swift brass has the thickest necks followed by Norma (0.0155”) then Hornady (0.0145”). I got the best results in my Swift using Winchester brass with a clean-up neck turn to 0.0165”

 

[Bill K]

I'm laughing my ass off didn't listen to a word I said.

That is okay, but you still are not saying how much the shellholder or die is compressing, after they touch. One or both have to compress to get anymore movement out of or into the die with the cartridge.

 

[Richard Jones]

Maybe the spring-loaded shellholder on the Co-Ax won't let the case up into the die far enough. Another reason why I have removed mine.

I still need schooling on reading a reamer print.............