Pre-fit Lemmon? What’s your thoughts

[Teekerguy]

Buddy got a shouldered prefit in 223ai with a 1-6. It's got about 30 rounds down it. It fouled up super quick and bad using BLC-2 powder. But inside the bbl looks kinda funky to me what do you guys think. I unfortunately couldn't figure out how to upload the video but these are the best screen shots I could get. And these photos were after a couple hours of him scrubbing it with some M PRO7

 

[Deputy819]

I don't use BL-C(2) for anything, but from what I've read it isn't the "cleanest" burning powder out there. "I" would let the barrel show you it's accuracy potential on paper after @ 100 rounds or so before deciding on the "lemon" issue solely based on bore-cam photos.

 

[Teekerguy]

I don't use BL-C(2) for anything, but from what I've read it isn't the "cleanest" burning powder out there. "I" would let the barrel show you it's accuracy potential on paper after @ 100 rounds or so before deciding on the "lemon" issue solely based on bore-cam photos.

No his best group was 1.5" at 100 so that was his reasoning for digging deeper

 

[MagnumManiac]

Need more info…
Cut rifled?
Button rifled?
Lapped?
Stainless/CM?

How is it cleaned?
Single strokes pushing brush/patch/jag out the end, then back at breach?
Scrubbed without using a bore guide, brushing back and forth?

All of this makes a difference answering your query, your description of 'funky' means all of zero…

Cheers.

 

[Teekerguy]

Need more info…
Cut rifled?
Button rifled?
Lapped?
Stainless/CM?

How is it cleaned?
Single strokes pushing brush/patch/jag out the end, then back at breach?
Scrubbed without using a bore guide, brushing back and forth?

All of this makes a difference answering your query, your description of 'funky' means all of zero…

Cheers.

Not sure on the cut but lapped, stainless he soaked it with m pro7 and jag out the end and using bore guide brushing back and forth with a bronze brush

 

[Deputy819]

No his best group was 1.5" at 100 so that was his reasoning for digging deeper

Factory ammo?
Hand loads?
If hand loads did he have the correct seating depth?
Optimal charge weight?
Can he shoot?
Afraid we need a little more data than just 30 rounds, borescope pics and a 1.5" group.
I've had some pre-fit barrels that had some decent "tooling marks" that shot extremely well despite that.

 

[6.5saum/300rum]

No his best group was 1.5" at 100 so that was his reasoning for digging deeper

Was this fire forming brass or how many rounds have the brass been fired in this barrel?

 

[Teekerguy]

Factory ammo?
Hand loads?
If hand loads did he have the correct seating depth?
Optimal charge weight?
Can he shoot?
Afraid we need a little more data than just 30 rounds, borescope pics and a 1.5" group.

Hand loads, claims he was 10tho off the lands and I think he just found a load below max in the 223 load data and to add he split a few cases vertical and horizontal and the one that split horizontal was up high on the body not lower like case head separation. To me it seems like he needs to cool the load off a hair for FF the brass and I apologize for not being able to get a video uploaded but it literally looked like there were gouges and deep imperfections in the rifling

 

[Teekerguy]

Was this fire forming brass or how many rounds have the brass been fired in this barrel?

Yes fire form and he has 600 rounds to fire for m so I believe they were all virgin

 

[Teekerguy]

Hand loads, claims he was 10tho off the lands and I think he just found a load below max in the 223 load data and to add he split a few cases vertical and horizontal and the one that split horizontal was up high on the body not lower like case head separation. To me it seems like he needs to cool the load off a hair for FF the brass and I apologize for not being able to get a video uploaded but it literally looked like there were gouges and deep imperfections in the rifling

 

[MagnumManiac]

Now we see the real problem…
Anytime an AI does that during fireforming, there is an issue with either the chamber being large, or no negative headspace and the case ruptures longitudinally as it stretches to meet the bolt face, as evidenced by the circumferential case crack.

There is much more to this story.
I would be sending that barrel back…

Cheers.

 

[Deputy819]

to add he split a few cases vertical and horizontal and the one that split horizontal was up high on the body not lower like case head separation

Yep….this issue trumps the "funky" tooling marks and certainly warrants the barrel being sent back. I had this happen on a brand new .30-30 once….split the first 3 out of 5 cases (factory ammo) that I put through the rifle. It got sent back the next day.

 

[Rflshootr]

And 2ndly, the bullet should either be jammed into lands for fireforming, or, the cases should be necked up and then resized to create a crush fit false shoulder.

 

[huntinfool18]

I got a 6.5 prc that the bore looks like that and it's constantly a sub half moa rifle