Forums
New posts
Search forums
What's new
Articles
Latest reviews
Author list
Classifieds
Log in
Register
What's new
Search
Search
Search titles and first posts only
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Rifles, Reloading, Optics, Equipment
AR15/10 Rifles
Mystery spiral on 223 bullet?
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="Pdvdh" data-source="post: 1291354" data-attributes="member: 4191"><p>Perhaps you meant to type something otherwise? For the record, both of my issues were related to the feeding of rounds into the chamber. The scars were identified before the bolt was thrust backward under recoil.</p><p></p><p>The scarring on my cartridge cases remaining in the top of the magazine was present and visible when I dropped the mag after manually letting the bolt ram home. The bolt had never yet moved rearward during the ejection cycle. I initially saw the scarring on some cases ejected under fire, which is what led me to investigate in the first place. To eliminate the scratch on the body of the cases, I removed some sharp edges from the forward-most, underside of the bolt, the location which would rub along the length of the underlying cartridge case while stripping and feeding the top round out of the in the mag and ramming it home into the chamber. This cured the case scarring.</p><p></p><p>The spiral scar on my bullets was observed after slow, manual extraction of the live rounds from the chamber. These rounds never experienced an extraction cycle and of course they can't, as they depart the front of the barrel at 3000fps prior to the extraction cycle. I cleaned off the feed ramp bolt lug recesses and observed the jacket-colored residue on both of the two feed ramp bolt lug recesses in the lower breech of the barrel, after letting a few loaded rounds ram home into the chamber. I rounded and polished the 90* angles and the bullet scarring problem was cured.</p><p></p><p>Your source of information on the cause of the tight spiral scarring is the manufacturer of the barrel, correct? </p><p></p><p>I just find it difficult to accept that you're the first AR15 owner to observe tight rotational spirals on your bullets if this occurs with any frequency. If it was common, and the cause was also commonly known, we'd find it on a Forum, somewhere or another. Multiple cartridge rotations while the cartridge is slammed forward 4"... If no one else is posting about this, it must be quite rare. Obsessive-compulsive disorder is more common among AR15 owners than owners of other firearms, in my experience... <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite1" alt=":)" title="Smile :)" loading="lazy" data-shortname=":)" /> I have a touch of it myself.</p><p></p><p>My cartridges rotate during feeding at a slow rate, based on the my bullet scar patterns. My scar pattern is identical to that reported by many other AR15 owners. Candy cane rate of rotation over length of the scar on my jackets.</p><p></p><p>If you seat your bullets 0.025" deeper, the spiral pattern might diminish or disappear. An easy test to the barrel manufacturer's theory. If the spiral is caused by 720* or greater cartridge rotation, it'll likely still be there. On the other hand, if there are any raised ridges in the throat that could imprint on the bullets, seating them deeper in the cases should reduce that imprint. A no-cost test. A good quality bore scope would also resolve the presence or absence of ridges imprinting on the the bullet surface near the ogive. But they're expensive, unless your buddy has one.</p><p></p><p>Of course, if your rifle shoots well and doesn't copper foul excessively, there's really no harm worth correcting.</p><p></p><p>The scars on my bullets were substantial. Same with my cases.</p></blockquote><p></p>
[QUOTE="Pdvdh, post: 1291354, member: 4191"] Perhaps you meant to type something otherwise? For the record, both of my issues were related to the feeding of rounds into the chamber. The scars were identified before the bolt was thrust backward under recoil. The scarring on my cartridge cases remaining in the top of the magazine was present and visible when I dropped the mag after manually letting the bolt ram home. The bolt had never yet moved rearward during the ejection cycle. I initially saw the scarring on some cases ejected under fire, which is what led me to investigate in the first place. To eliminate the scratch on the body of the cases, I removed some sharp edges from the forward-most, underside of the bolt, the location which would rub along the length of the underlying cartridge case while stripping and feeding the top round out of the in the mag and ramming it home into the chamber. This cured the case scarring. The spiral scar on my bullets was observed after slow, manual extraction of the live rounds from the chamber. These rounds never experienced an extraction cycle and of course they can't, as they depart the front of the barrel at 3000fps prior to the extraction cycle. I cleaned off the feed ramp bolt lug recesses and observed the jacket-colored residue on both of the two feed ramp bolt lug recesses in the lower breech of the barrel, after letting a few loaded rounds ram home into the chamber. I rounded and polished the 90* angles and the bullet scarring problem was cured. Your source of information on the cause of the tight spiral scarring is the manufacturer of the barrel, correct? I just find it difficult to accept that you're the first AR15 owner to observe tight rotational spirals on your bullets if this occurs with any frequency. If it was common, and the cause was also commonly known, we'd find it on a Forum, somewhere or another. Multiple cartridge rotations while the cartridge is slammed forward 4"... If no one else is posting about this, it must be quite rare. Obsessive-compulsive disorder is more common among AR15 owners than owners of other firearms, in my experience... :) I have a touch of it myself. My cartridges rotate during feeding at a slow rate, based on the my bullet scar patterns. My scar pattern is identical to that reported by many other AR15 owners. Candy cane rate of rotation over length of the scar on my jackets. If you seat your bullets 0.025" deeper, the spiral pattern might diminish or disappear. An easy test to the barrel manufacturer's theory. If the spiral is caused by 720* or greater cartridge rotation, it'll likely still be there. On the other hand, if there are any raised ridges in the throat that could imprint on the bullets, seating them deeper in the cases should reduce that imprint. A no-cost test. A good quality bore scope would also resolve the presence or absence of ridges imprinting on the the bullet surface near the ogive. But they're expensive, unless your buddy has one. Of course, if your rifle shoots well and doesn't copper foul excessively, there's really no harm worth correcting. The scars on my bullets were substantial. Same with my cases. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
AR15/10 Rifles
Mystery spiral on 223 bullet?
Top