Copper Bullet Ring

[wallz]

Some facebook posts say its common when the base of the bullet used can't handle the pressure of the load. Try another brand of bullet.

https://www.facebook.com/groups/483423046019868/posts/1512174893144673/

Obviously my searches never found this info.

Thanks for this. This is exactly what is happening.

I don't really see shaving the bullet off while seating, as that is absurd, but the back of the bullet bulging from the pressure seems just about right.

Its weird, because the ones from the 450BM that I recovered do not show any deformation on the back end at all.

Mind you now that I'm thinking about all this more, the BM I'm running a 20" barrel, and pushing these at 2260fps. The Raptor is a 16" barrel and I started to see this issue at roughly 2200fps. Def running them hotter in the raptor with the shorter barrel.

This is making more sense now. Still weird, but making more sense!

 

[sean69]

I think this my be caused by issues compounding.... Barnes site says these bullets are 100% copper - so no softer alloy... and you say no issues in the 450BM - similar but not exact....

- using a bullet designed for use with a sabot in a lower velocity muzzle loader
- Lil’Gun shotshell/magnum pistol powder

Seems to me that a bullet designed for use with a sabot may not be made to the same tolerances as one that is not - I don't know, I am guessing but it makes manufacturing sense to not swage them if it's not necessary...

These are completely unsubstantiated but point to powder selection ... you wouldn't say but did note you load them a little hot...

No Reduced Loads: Like H110, Lil’Gun behaves unpredictably if you attempt to load it below the published minimum charge weights. Never attempt to make light "plinking" or subsonic loads with Lil’Gun, as it can cause erratic ignition or extreme pressure spikes.

Lil’Gun: Extreme Heat: Lil’Gun burns significantly hotter than comparable powders like Hodgdon H110, Winchester 296, or IMR 4227. In rapid-fire semi-automatic AR-10 platforms, it can heat up your barrel remarkably fast, potentially leading to faster throat erosion if you shoot long strings without letting the barrel cool.

Could the powder be heating the bullet enough to melt a bit or expand it a bit???? darned if I know.

 

[wallz]

The only time I see the term "shaving the bullet when seating" is pushing it into a muzzle loader. Which I am not doing, as it is going into a brass center fire case.

None the less, the BT bullets came in last night and I pulled the other flat base bullets and replaced them with the boat tail ones. Range trip slated for this evening, camera in tow. Just have to remember to not pull the bolt after firing and slip the camera in to have a look before opening the bolt to get picture. Well, hopefully with the BT I won't see anything there and will carry on with finding a load. My first of several planned trips is getting tooo close, and I would love to have this rifle set up for the task.

No way the powder is cooking the copper. But I can see an over pressure on it to flatten it out a bit, mushroom the back end enough to have to shave off when going past the chamber lip. The easy way would be to recover one of these previously shot bullets, but don't really have a means for that.

Hopefully after todays range trip, all this will just be a learning experience for myself and others that read this, tread this path after. I'll update after the range trip.

 

[wallz]

Well, an interesting range trip for sure.

I started with the new loaded MTZ boat tail design that I pushed into the loaded brass that I had set up for a quick ladder test at 200m.

Had a few extra rounds so sent them at 100m just to make sure the scope was set.

After the first firing, 2362 fps, I pulled out the camera, before I opened the bolt and looked into the barrel. There was a faint copper ring left behind. I popped the bolt and tried the go gauge. While tight, the bolt still closed. New brass, empty, same thing the bolt closed. Ran my next loaded round and the bolt closed. Okay, there was a ring happening, but not as pronounced, and I was able to get 3 rounds down before a no bolt close occurred. These were all over 2300 fps.

Pulled the barrel off, and pulled the rings. Yes, there was remnants of a few of them from the 3 rounds I fired. The BT design, while still expanding and shearing off on the chamber lip, was making a difference. Most of the ring remnants where removed with a brass brush, so they were not as embedded into the lip.

Put it all together again, and ran 2 more rounds before the "no close bolt" happened. These were running well over 2300 fps.

Came home and cleaned up the barrel, and loaded up some lighter loads, and figure if I keep them in the 2200 fps range I can get away with running these TMZ bullets. This is a 16" barrel, so at 2200 fps I'm okay with that, for the 400 range max that I'm comfortable with. I regularly shoot out to 1000m plus, so this is not a feat for me at 400m, its more of a "I think the bullet still has enough energy out there to kill game effectively" at that range.


One of the fellas out at the range last evening had a great learning experience watching me pull off a barrel, and tinker, and have it all back together again, and in no time shooting down range. He was blown away at the barrel camera, and my optics set up for recording my range time. Most just don't realize how "easy" this really is with pre fit items and barrel nuts. No vice, or special tools required. With a brake on it, it is pretty easy to line up to the previous headspace. Yes I know that is not the only thing that I use to check, but it is a quick available line up.

He even asked me to sit behind his rifle and send a few down range, as he was second guessing himself as user error in checking his scope. Three quick shots on the phone cam, and he got to see the benefits of what I was doing. He left happy and comfortable to be able to reach out to 200m with his set up. Win, Win in my books. He is carrying his fathers, what looked like original setup. Always a bonus when you can give some positive confirmation to any shooter.

I think we chatted longer than I was at the range for what I set out to accomplish.

 

[wallz]

Okay, Finally got to have a range visit, and got lucky with no one else out there. Friday night on a long weekend, I guess not eh.

I dug around in the berms a bit and was able to recover a few of my previous bullets. Pics attached. One was from today, which was going considerably slower than the previous days batches were.

Tomorrow I should be able to hit the range in the am for a quick seating test, and then hopefully be ready for next weekends hunt.

Anyways a few pics of the recovered bullets. They def seem to be shearing off, and the weirder part is worse on one side than the other. A good outcome was the copper retention was phenomenal. Most weighed at 284 ish grains, and only one was lower. This is from a 290 gr bullet.


The one side that you can see a shear.



The other side, not as pronounce of a shear, if even any.



This was another, of the good side.



Same bullet of the other side. I think this was one that I shot tonight, at a reduced speed.




Another shear.



Can see it again on this one.



Top bullet is from last year, shot out of my 450BM, recovered from my moose.



Another recovered bullet, again with a pronounced shear on one side. This was the good side.


This was the worst side.





Why they seem to be shearing more to one side is a complete mystery, but the pressure pushing the bullet to one side, or warping out of shape onto one side might seem plausible. Seems like if I keep them below 2250 fps I'm not causing enough of an issue to leave the ring on the chamber lip.

 

[WKAYE]

Okay, Finally got to have a range visit, and got lucky with no one else out there. Friday night on a long weekend, I guess not eh.

I dug around in the berms a bit and was able to recover a few of my previous bullets. Pics attached. One was from today, which was going considerably slower than the previous days batches were.

Tomorrow I should be able to hit the range in the am for a quick seating test, and then hopefully be ready for next weekends hunt.

Anyways a few pics of the recovered bullets. They def seem to be shearing off, and the weirder part is worse on one side than the other. A good outcome was the copper retention was phenomenal. Most weighed at 284 ish grains, and only one was lower. This is from a 290 gr bullet.


The one side that you can see a shear.
View attachment 1202069


The other side, not as pronounce of a shear, if even any.
View attachment 1202070


This was another, of the good side.
View attachment 1202072


Same bullet of the other side. I think this was one that I shot tonight, at a reduced speed.
View attachment 1202074



Another shear.
View attachment 1202075


Can see it again on this one.
View attachment 1202076


Top bullet is from last year, shot out of my 450BM, recovered from my moose.
View attachment 1202077


Another recovered bullet, again with a pronounced shear on one side. This was the good side.
View attachment 1202078

This was the worst side.
View attachment 1202079




Why they seem to be shearing more to one side is a complete mystery, but the pressure pushing the bullet to one side, or warping out of shape onto one side might seem plausible. Seems like if I keep them below 2250 fps I'm not causing enough of an issue to leave the ring on the chamber lip.

Crooked chamber ?

 

[KyleSchenk]

Okay, Finally got to have a range visit, and got lucky with no one else out there. Friday night on a long weekend, I guess not eh.

I dug around in the berms a bit and was able to recover a few of my previous bullets. Pics attached. One was from today, which was going considerably slower than the previous days batches were.

Tomorrow I should be able to hit the range in the am for a quick seating test, and then hopefully be ready for next weekends hunt.

Anyways a few pics of the recovered bullets. They def seem to be shearing off, and the weirder part is worse on one side than the other. A good outcome was the copper retention was phenomenal. Most weighed at 284 ish grains, and only one was lower. This is from a 290 gr bullet.


The one side that you can see a shear.
View attachment 1202069


The other side, not as pronounce of a shear, if even any.
View attachment 1202070


This was another, of the good side.
View attachment 1202072


Same bullet of the other side. I think this was one that I shot tonight, at a reduced speed.
View attachment 1202074



Another shear.
View attachment 1202075


Can see it again on this one.
View attachment 1202076


Top bullet is from last year, shot out of my 450BM, recovered from my moose.
View attachment 1202077


Another recovered bullet, again with a pronounced shear on one side. This was the good side.
View attachment 1202078

This was the worst side.
View attachment 1202079




Why they seem to be shearing more to one side is a complete mystery, but the pressure pushing the bullet to one side, or warping out of shape onto one side might seem plausible. Seems like if I keep them below 2250 fps I'm not causing enough of an issue to leave the ring on the chamber lip.

Crooked chamber ?

My thoughts as well. Looks like you've got a concentricity isses. Do you have anyone locally that can indicate that barrel for you?