Tight chamber

Slimfinn

Handloader
Nov 28, 2018
961
837
Working on my next project 25-06. When closing on the go gauge you can feel a slight resistance. Try with some factory ammo, bolt closes on both Remington 100 and 120 but not on Nosler 115bt. Bolt also closes on sized cases. With everything new and unfired, do you ream the chamber 0.0005-.001" deeper or shoot what chambers and allow everything to settle in?
 
I’m guessing your project has a shouldered barrel. How much is the sized brass bumped? If 2 of the 3 factory ammo and your sized ammo close I would say you’re good.
See if you’re oversizing your brass , throw a piece of scotch tape on the back of your sized brass and see if it closes.
 
You have two different brands of bullets so the O-give could be different and causing you to be jamming the Nosler brand into the lands check for rifling marks on the O-give of the Nosler rounds. Also if they the Nosler ammo is shorter than your magazine you may want to lengthen the chamber to accommodate longer length ammo. A little free bore shouldn't hurt anything and give you more flexibility.
 
Patrick,

I had an issue with factory loads being "tight" in a new barrel. I thought the chamber was reamed too short but when I bought a go gauge, the bolt closed easily. Upon further analysis I discovered that the neck to shoulder junction of the chamber was very sharp with no radius. However, the factory ammo had a radius at the junction of the neck and shoulder. I could actually see impressions made by the chamber on the factory brass. My sizing die had a sharp edge at the neck to shoulder junction and resized brass (bumped back only 0.001") would chamber just fine. Check your factory ammo to see if the neck to shoulder junction has a radius instead of a sharp corner. Dan
 
Working on my next project 25-06. When closing on the go gauge you can feel a slight resistance. Try with some factory ammo, bolt closes on both Remington 100 and 120 but not on Nosler 115bt. Bolt also closes on sized cases. With everything new and unfired, do you ream the chamber 0.0005-.001" deeper or shoot what chambers and allow everything to settle in?
Are you stripping the bolt to check the headspace? Speaking for myself only, it’s hard to get a good feel for it otherwise. Unlikely but the Nosler ammo could be long. I’d shoot it before I went at it with a reamer.
 
Having a no-go could help as opposed to putting tape on the back of the go gauge (it compresses). A stripped bolt is always the best to go, but isn't always necessary. Most likely the lands are short. I have a 243win that was this way and only 1 of 4 factory ammo would close. Checked coal and it was .035" short.
 
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Are you stripping the bolt to check the headspace? Speaking for myself only, it’s hard to get a good feel for it otherwise. Unlikely but the Nosler ammo could be long. I’d shoot it before I went at it with a reamer.
Yes the bolt is stripped, I think I will try a few rounds and see what happens and recheck.
thanks for all the input fellas
 
I'd say that the observation is due to variance in the ammo and the rifle is fine. The head to shoulder length on factory ammo varies by manufacturer. This it to accommodate different chamber dimensions present in rifles the ammo could be used in. An RCBS Precision Case micrometer would easily determine if this what is occurring.
 
You could try seating a factory loaded shell slightly deeper to see if it will chamber. It may help you cut to the chase.

JD338
Would blackening the bullet and case neck down through the shoulder with a sharpie work to see where the contact is? Based on his issue, it might be worth a try? Thoughts?
 
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