Idiot Needs Help

matthaias

Member
Joined
Sep 14, 2020
Messages
17
Location
Nevada
I measured CBTO of my 7RM with Berger 168 VLDs using the Hornady OAL Gauge and Bullet Comparitor. I stopped pushing when I barely felt resistance, not jamming, and the bullet came out with the modified case 3 out of 5 measurements. I averaged this measurement and took 40 thousandths off, went to chamber a round, the bolt won’t close!

I had to seat the bullet to 99 thousandths off the lands as measured by the tool to get the bolt to close without resistance. What am I doing wrong? I could understand if the brass wasn’t sized correctly or if the modified case wasn’t seated completely when taking measurements, but that is not the issue.

I’m renting a uni throater to get my chamber to where the bullet isn’t seated past the shoulder. But I am still baffled by my experience.
 

338 dude

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Mar 1, 2016
Messages
1,860
Location
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I measured CBTO of my 7RM with Berger 168 VLDs using the Hornady OAL Gauge and Bullet Comparitor. I stopped pushing when I barely felt resistance, not jamming, and the bullet came out with the modified case 3 out of 5 measurements. I averaged this measurement and took 40 thousandths off, went to chamber a round, the bolt won’t close!

I had to seat the bullet to 99 thousandths off the lands as measured by the tool to get the bolt to close without resistance. What am I doing wrong? I could understand if the brass wasn’t sized correctly or if the modified case wasn’t seated completely when taking measurements, but that is not the issue.

I’m renting a uni throater to get my chamber to where the bullet isn’t seated past the shoulder. But I am still baffled by my experience.
I would not mess with your chamber just yet I have had problems that sound a lot like yours where they modified case does not very closely resemble my chamber therefore when you use your own cases your bolt does not close you know if it’s your bullet or the case take a black sharpie color your bullet put it in action and try to close the bolt remove the bullet and look for marks on the bullet if you have a 5 groove barrel you’ll see five distinct marks where it removed the black from the bullet if it is not touching the bullet it is definitely the brass I do not use the Hornady modified case anymore I would have one made from a fired piece of brass from my chamber or just use the colored bullet Mark method load the bullet Long chamber confirm Marks then seat the bullet .001 deeper color it again chamber it look for Marks keep doing this until you do not have marks that +.001 is your touch measurement
 
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338 dude

Well-Known Member
LRH Team Member
Joined
Mar 1, 2016
Messages
1,860
Location
Tn
I measured CBTO of my 7RM with Berger 168 VLDs using the Hornady OAL Gauge and Bullet Comparitor. I stopped pushing when I barely felt resistance, not jamming, and the bullet came out with the modified case 3 out of 5 measurements. I averaged this measurement and took 40 thousandths off, went to chamber a round, the bolt won’t close!

I had to seat the bullet to 99 thousandths off the lands as measured by the tool to get the bolt to close without resistance. What am I doing wrong? I could understand if the brass wasn’t sized correctly or if the modified case wasn’t seated completely when taking measurements, but that is not the issue.

I’m renting a uni throater to get my chamber to where the bullet isn’t seated past the shoulder. But I am still baffled by my experience.
Also you’re an only an idiot if you do not ask for help!!
 

matthaias

Member
Joined
Sep 14, 2020
Messages
17
Location
Nevada
Thanks guys!

Its definitely the 7-28 comparator. The brass is new Nosler, I even ran it all through the sizing die because of some dented necks, it appears to be dimensionally consistent with the modified case, I will confirm when I get my headspace comparator. I will try the other methods presented here to get some more insight into what is going on. This if my first time loading, I have done a ton of reading, but I might be doing something wrong.

Regardless of what I find using the wheeler method I will probably use the uni throater to seat the bullets longer, leaving .080” or so to chase throat erosion.
 

Troutslayer2

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Joined
May 28, 2010
Messages
365
I had to polish the plastic part of the Hornady tool because I was getting a lot of resistance, so much that it would stall out entirely and I would think I was at the lands when I was not.
 

matthaias

Member
Joined
Sep 14, 2020
Messages
17
Location
Nevada
338 dude, thank you for the vote of confidence that I am not an idiot. However you might change your tune after I confess what was going wrong. I was improperly setting my bullet seating die and crushing the shoulder on the case. I realized when I switched to my 300WM in Norma brass, and the shoulder deformation was very pronounced. I switched back to my 7RM dies and loaded a round (with the seater die correctly set up) at 0.010" off the lands as measured with the OAL gauge, and sure enough it chambers and ejects no resistance.

Thank you for the help everybody, that was fairly embarrassing! Should I delete this thread, or might it be helpful for other first-time reloaders?
 

vancewalker007

Well-Known Member
Joined
Mar 30, 2013
Messages
410
I was getting a lot of resistance, so m
338 dude, thank you for the vote of confidence that I am not an idiot. However you might change your tune after I confess what was going wrong. I was improperly setting my bullet seating die and crushing the shoulder on the case. I realized when I switched to my 300WM in Norma brass, and the shoulder deformation was very pronounced. I switched back to my 7RM dies and loaded a round (with the seater die correctly set up) at 0.010" off the lands as measured with the OAL gauge, and sure enough it chambers and ejects no resistance.

Thank you for the help everybody, that was fairly embarrassing! Should I delete this thread, or might it be helpful for other first-time reloaders?
Don't feel bad about this. I have years of experience reloading and weird stuff still occurs in my reloading room. I was recently measuring throat changes in my 2 7mm LRMs and my new 6.5 PRC. I proceeded to load up some 7mm LRM rounds and forgot to swap the 6.5 ogive insert back to the 7mm insert. I noticed it after going to the range and shooting the mistakes. So, what I was thinking was 50 off was really 170 off. The silver lining was the 170 off shot great so I'm sticking with it but measuring with the right insert now ;-).
 

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