Sized Cases Not Chambering

[norcalkh]

I am new to reloading and am having issues with a few cartridges chambering. I have loaded and shot 100-150 rounds for 7mm Rem Mag. In my last couple batches I have had 3 rounds that will slide into the chamber, but won't allow the bolt to cam-over. This brass was reloaded for the 2nd time. Overall case length is in spec, and shoulder/neck lengths appear also in spec. I don't have a mic to check the rim. I'll also note that I'm loading 1.2gr below the maximum charge listed from Barnes. I haven't noticed the bolt being hard to open or extractor marks on reloaded cases.
Components:
Hornady Brass
Federal Gold Medal Magnum Primers
IMR 7828ssc at 64.5gr
Barnes 145gr LRX
OAL- 3.318
Firearm- Tikka A7

 

[Mule3006Elk]

Full length resize and set shoulder back 0.001-0.002"?

 

[JakeSCH]

This is due to not being full length resized enough. Basically when you FL re-size many say to bump back the shoulder 2 thou, but really you just need to bump it back enough to allow the bolt to cam-over.

 

[Newtosavage]

Every time I have this happen, it's a case I missed in trimming, or the resizing die had unknowingly unscrewed just enough in the press that the case shoulder didn't get set back enough.

 

[Mule3006Elk]

This is due to not being full length resized enough. Basically when you FL re-size many say to bump back the shoulder 2 thou, but really you just need to bump it back enough to allow the bolt to cam-over.

Agree. Even 0.001 no hard bolt close. I usually go 0.001 +/- 0.0005 but it does take some experience with dies.

He is new to reloading.

Starting from basics, have you measured to the datum line on a few fired cases to know what your shoulder is in a fired case? Only then can you gently bump the shoulder 0.001". You need a gauge to measure to the shoulder. I use the Hornady Lock-N-Load Headspace Comparator.

 

[JRMiller]

Agree. Even 0.001 no hard bolt close. I usually go 0.001 +/- 0.0005 but it does take some experience with dies.

He is new to reloading.

Starting from basics, have you measured to the datum line on a few fired cases to know what your shoulder is in a fired case? Only then can you gently bump the shoulder 0.001". You need a gauge to measure to the shoulder. I use the Hornady Lock-N-Load Headspace Comparator.

^This

 

[norcalkh]

Agree. Even 0.001 no hard bolt close. I usually go 0.001 +/- 0.0005 but it does take some experience with dies.

He is new to reloading.

Starting from basics, have you measured to the datum line on a few fired cases to know what your shoulder is in a fired case? Only then can you gently bump the shoulder 0.001". You need a gauge to measure to the shoulder. I use the Hornady Lock-N-Load Headspace Comparator.

I will look into getting a guage for accurately measuring the shoulder.

I screwed in the sizing die a scosh of a turn and re-sized the cases. It was a bear to get the press to cam over, but they chambered. I will look into getting the die set better.

Thanks for all the input!

 

[Mule3006Elk]

I will look into getting a guage for accurately measuring the shoulder.

I screwed in the sizing die a scosh of a turn and re-sized the cases. It was a bear to get the press to cam over, but they chambered. I will look into getting the die set better.

Thanks for all the input!

No worries my friend.
I think that will solve your issue. When you're talking about 0.001" you really need the right tools.
Not sure if you clarified but are you using a FL resizing die or neck only?

 

[norcalkh]

No worries my friend.
I think that will solve your issue. When you're talking about 0.001" you really need the right tools.
Not sure if you clarified but are you using a FL resizing die or neck only?

I'm using a FL die.

 

[Mule3006Elk]

I'm using a FL die.

Copy that.
If your case length is correct it must be a shoulder issue.

 

[eoperator]

Funny that you post this i have the same problem this afternoon.

barrett fieldcraft 308
lapua brass 2nd loading
redding fl die
case length trimmed and tripple checked

Even with die bottomed out, bolt close was very difficult. This is the first time sizing with this die, hopefully it has something to do with the die.

 

[Mule3006Elk]

Funny that you post this i have the same problem this afternoon.

barrett fieldcraft 308
lapua brass 2nd loading
redding fl die
case length trimmed and tripple checked

Even with die bottomed out, bolt close was very difficult. This is the first time sizing with this die, hopefully it has something to do with the die.

Check your datum line. As noted above, I used the Hornady Lock-N-Load Headspace Comparator.
This is a very easy way to check your headspace control. If you don't, your bolt closure will feel tight and you are essentially headspacing your brass when you close the bolt.

 

[Mule3006Elk]

Example purposes:

Fired 30-06 brass: 2.045" to the datum line.
After FL resize which bumps the shoulder back: 2.044-2.0445" to the datum line.
Without the Hornady Lock-N-Lock Headspace Comparator I could not achieve this level of control.
It's an invaluable tool on my reloading bench.

 

[gelton]

This is an interesting topic because I have never had a bolt not close on bolt action reloads and have reloaded extensively for years. For bolt action, I mostly just neck size with a Forster die and have always been fine.

However, reloading for an autoloader I have had numerous problems. 6.8 spc with RCBS small base sizing die, pulled the bullets on a number of rounds that I am embarrassed to admit and reloaded them, only to find that about 2/3rds of them still don't chamber even when using a case length headspace gauge...to be sure everything was set up correctly...mindblowing.

 

[Mule3006Elk]

I've never reloaded for an auto. Hopefully, one with experience in the realm will chime in.
I have Redding dies. There c/s is phenomenal and really helped guide me when I was a newbie.
I didn't have a mentor so I would call them.

Maybe call RCBS?

 

[amassi]

I am new to reloading and am having issues with a few cartridges chambering. I have loaded and shot 100-150 rounds for 7mm Rem Mag. In my last couple batches I have had 3 rounds that will slide into the chamber, but won't allow the bolt to cam-over. This brass was reloaded for the 2nd time. Overall case length is in spec, and shoulder/neck lengths appear also in spec. I don't have a mic to check the rim. I'll also note that I'm loading 1.2gr below the maximum charge listed from Barnes. I haven't noticed the bolt being hard to open or extractor marks on reloaded cases.
Components:
Hornady Brass
Federal Gold Medal Magnum Primers
IMR 7828ssc at 64.5gr
Barnes 145gr LRX
OAL- 3.318
Firearm- Tikka A7

Welcome to the wonderful world of belted magnums
Check your brass right above the belt
If it's over .510 you have a bulge above the belt that your die cannot resize.

Sent from my SM-G892A using Tapatalk

 

[rayporter]

if your die is bottomed out on the shell holder you may need to grind a thou off of the shell holder to get enough sizing. or you can buy several shell holders in the chance you will find one that will push the case up in the die a little more. shell holders are not all the same size. i keep one of every brand around for that reason [ plus one that has been ground on]

 

[norcalkh]

Welcome to the wonderful world of belted magnums
Check your brass right above the belt
If it's over .510 you have a bulge above the belt that your die cannot resize.

Sent from my SM-G892A using Tapatalk

Thanks for the tip. I will get my hands on a mic and check them. Will standard loads do this to certain cases, or is it only a symptom of high pressure charges?

 

[amassi]

Thanks for the tip. I will get my hands on a mic and check them. Will standard loads do this to certain cases, or is it only a symptom of high pressure charges?

Your full length die deosnt size down to the belt. Every time you full length size brass will flow down to the belt and eventually bulge. Larry Willis makes a collet die to fix this. I've "saved" once fired milsurp 300 winmag brass with it. I have to run weatherby brass about every 3rd firing through the collet die

Sent from my SM-G892A using Tapatalk

 

[norcalkh]

Your full length die deosnt size down to the belt. Every time you full length size brass will flow down to the belt and eventually bulge. Larry Willis makes a collet die to fix this. I've "saved" once fired milsurp 300 winmag brass with it. I have to run weatherby brass about every 3rd firing through the collet die

Sent from my SM-G892A using Tapatalk

So does that collet die hold the shape of the brass or do you draw the shell through the collet to "re-size" the shell above the belt?