Long case length and flyers

[DLT]

Beside the obvious high pressure danger, can longer case lengths cause flyers ? Sunday while shooting my 6br the rifle was acting a little erratic and had 1 fired case that was a little snug during bolt opening. No pressure signs on any of the brass or primers. I don’t have a trimmer for 6br yet but my brass is bumped back .002 and running a load of 30.2gr of varget with a 95smk jammed .005. I’m using lapua brass with 8 firings on them. My loaded rounds have no problem chambering but some of the the fired ones are at 1.575 with the case mouths slightly rolled inward enough to where a bullet will not drop in. Can they expand/grow enough at firing to cause this as well as possible flyers ? My guess is for certain

 

[L.Sherm]

I'm betting your case length is to long and causing flyers.

 

[6BRA]

1.550

 

[coldboreshot]

Depends on what you mean by "snug". Two different effects come to mind... you've run out of chamber length after 8 firings and no case trimming or, you have a expanded cases at the base causing tough bolt lift on extraction, "clicker" which too after 8 firings. That would be reamer dimensions vs certain brass. If clicker, small base die. You do mention rollung of the case mouth. Get yourself a 6mm case length gauge plug from Brownells and gauge the chamber length. According to the reamer prints I have max case length is posted as 1.570". Sounds like you got some trimmin' to do. Your crunching that brass into the lead.

 

[DLT]

Depends on what you mean by "snug". Two different effects come to mind... you've run out of chamber length after 8 firings and no case trimming or, you have a expanded cases at the base causing tough bolt lift on extraction, "clicker" which too after 8 firings. That would be reamer dimensions vs certain brass. If clicker, small base die. You do mention rollung of the case mouth. Get yourself a 6mm case length gauge plug from Brownells and gauge the chamber length. According to the reamer prints I have max case length is posted as 1.570". Sounds like you got some trimmin' to do. Your crunching that brass into the lead.

Yea. If it was clickers which I have experienced I would like to say there would have been more than one. This one didn’t feel like one really to me. I’m banking on I better do some trimming.

 

[SeabeeKen]

I agree with @coldboreshot that you may be at the end of the chamber. Another possibility is you are jamming the longer cases into a carbon ring. I've seen this before. Are the cases that are showing pressure longer than the others? Can you bore scope your chamber to check for a carbon ring?
I keep my match brass trimmed .010 under chamber length. This minimizes carbon ring buildup.
The chamber length gauge mentioned in a previous post is a great tool to measuring this. Keep us posted please.

Ken

 

[DLT]

I agree with @coldboreshot that you may be at the end of the chamber. Another possibility is you are jamming the longer cases into a carbon ring. I've seen this before. Are the cases that are showing pressure longer than the others? Can you bore scope your chamber to check for a carbon ring?
I keep my match brass trimmed .010 under chamber length. This minimizes carbon ring buildup.
The chamber length gauge mentioned in a previous post is a great tool to measuring this. Keep us posted please.

Ken

I looked last night with a scope there is no carbon ring built up

 

[Mulligan]

Beside the obvious high pressure danger, can longer case lengths cause flyers ? Sunday while shooting my 6br the rifle was acting a little erratic and had 1 fired case that was a little snug during bolt opening. No pressure signs on any of the brass or primers. I don’t have a trimmer for 6br yet but my brass is bumped back .002 and running a load of 30.2gr of varget with a 95smk jammed .005. I’m using lapua brass with 8 firings on them. My loaded rounds have no problem chambering but some of the the fired ones are at 1.575 with the case mouths slightly rolled inward enough to where a bullet will not drop in. Can they expand/grow enough at firing to cause this as well as possible flyers ? My guess is for certain

Yes
CW

 

[LCazador]

Absolutely you will have clickers and flyers with cases that are too long. Extreme spread and bullet tension all over as well!

 

[DLT]

Absolutely you will have clickers and flyers with cases that are too long. Extreme spread and bullet tension all over as well!

What I kinda wanted to hear this morning gentlemen. I have 2, 6 creedmoor lee trimmers I’m going to cut one down and make it 6br length and solve this issue !!! That way I don’t have to wait on something to eventually get lost in shipping this time of year

 

[Kracken McGraw]

https://forum.accurateshooter.com/t...-with-a-custom-chamber.3856606/#post-36470785
Post #6 shows how to make a gauge with your own case and bullet.

 

[K22]

Take the guess work out of the case length issue. Get a Sinclair Chamber Length Gauge to measure the actual chamber length, apply their safety factor to establish the maximum case length for your rifle.

These gauges are inexpensive and easy to use. By using them, I've reduced my trimming to over 50% but have assurance that I am well within the maximum case length.

In your post you stated that the case mouths are slightly rolled inward. That seems to be a clear indicator that your cases are too long.

 

[LCazador]

Using a blueprint or a case length gauge and knowing your chamber length is important in starting load work process. Along with head diameter and neck diameter it's an important factor in determining what load will best perform in your rifle.

 

[358WCF]

I looked last night with a scope there is no carbon ring built up

Why not use the borescope to look at caselength/chamber interference? A picture=1000 words.

 

[DLT]

Why not use the borescope to look at caselength/chamber interference? A picture=1000 words.

That’s going down today

 

[DaveTooley]

Does a bullet freely slip back into a fired case? If not then there're too long. If they do then something else is going on.

 

[DLT]

Does a bullet freely slip back into a fired case? If not then there're too long. If they do then something else is going on.

After I annealed and tumbled before i started sizing I did grab a bullet just to see if I had doughnuts starting to form. That’s when I noticed several of the cases the bullet wouldn’t drop in that’s what ringed the bell for me

 

[DaveTooley]

Tumbling will close the mouth. Do the test after shooting a string. I spot check when shooting.

 

[DLT]

Tumbling will close the mouth. Do the test after shooting a string. I spot check when shooting.

If that’s so I have never noticed it. I will keep an eye out for that. I think I read once that steel pins would close the mouth up on some cases but never heard of corn cob media doing that. I’ll watch closely