I have a new aftermarket barrel for a Blaser R8 that is giving me some big trouble. Chambered in 6.5-300wby, the cases are cracking upon first firing with factory 130gr ammo. The sixth one split halfway up. What is wrong with this barrel?
Case separation on first firing
- Thread starter propliner
- Start date
6.5 shooter
CGN Regular
- Location
- Medicine Hat
WOW best guesses: would be nice to see the case necks but here we go. 1) Is there some oil or lube in the chamber causing the brass to slip as the round fires? 2) Is the rifle chambered/ rifled in the right caliber or case? 3) Are you reloading or using factory ammo? I am seeing a ton of pressure signs so, if factory try another box of ammo. If reloads drop your charge at least 10%. Finally I would take the rifle to a smith and have it checked out. There is something going on and it is hard too diagnose from a couple pictures.
Best of luck
Best of luck
It looks like a headspace issue as no new factory ammunition is likely to do this. The scratches on the brass are concerning as well since it's an indication of a poor chambering job. Get the rifle checked with a headspace gauge before firing it again.
I would say chamber is bad judging from the scuffed up brass not to mention the split cases. I would return the barrel along with pics of brass and split case. Any reputable maker would give you a refund. Dont think I would accept a replacement if the makers quality control is that lousy. Never should have been sold imo.
Once again, belted cases headspace on the front of the belt, not on the shoulder like 30-06 type rimless cases. The length of the chamber is immaterial to headspace on a belted case. However if the chamber is too long the case will blow out to fill this void on first firing, this appears to be the problem here. This, coupled with the obviously rough finish in the chamber points to a faulty chambering job. Return the barrel along with these cases and a good written description of the problem, get your money back and find a new supplier.
Why take on the work/liability to attempt to fix a 'new aftermarket barrel' instead of the manufacturer and/or smith who did the work? If this was your own work, then the options are limited.
From POV, this is a safety issue, if brass is ruled out.
Bad brass and a terribly finished chamber... give it back to who ever did the chambering as the chamber has been done poorly with a rough finish. A few years ago Weatherby was having nothing but troubles with this cartridge and their rifles... this looks like faulty brass...
The primers don't indicate that issue
For my 300WM I resize the brass to headspace on the shoulder which seems to prolong case life as the brass is worked less on sizing and firing. If you shoot factory ammo this is moot as the brass is used only once and so should not be a problem.
- Location
- Western Manitoba
I suspect comments above have indicated your issue(s) and possible solution - if you do have a bore scope, might be interesting to see what is there, for the cases that have NOT separated. I am with those above who question the quality of that chamber wall's finish - should be shiny like a mirror in there when you look with flash light - maybe install a white patch just past the leades to get a better look - some will say a proper chamber wall will have minor cross hatch marks - I do not think any of the rifles here - even the WWI rifles - produce cases with marks like you show in your pictures.
May be an aberration but any outfit with that bad of QC maybe a replacement is a risky proposition. Persoanlly I'd want a refund.
- Location
- Western Manitoba
"Head space" for a belted case, or a rimmed case, has nothing to do with the location of the neck or the shoulder. That is the distance from the closed bolt face to the forward edge of the belt or rim. But you are correct - in OP's first picture, sure looks like the case shoulders have been pushed forward, in that chamber, when fired.
Is typical in a Weatherby case and chamber for the outside shoulder and the neck junction to be "rounded" - not "sharp edged" - was Roy Weatherby's "double venturi", I think he called it.
If the case shoulders HAVE been pushed forward as much as shown in first pictures, would think that would be visible to the eye - simply by standing a fired and unfired case side by side on a flat surface - perhaps with some lined or graph paper behind to see any difference in length.
For cases that DO headspace on their shoulder - like 30-06 or 308 Win - is usually defined by SAAMI as a theoretic diameter - like 0.400" along the shoulder, then the shoulder angle defined versus the centre line. Is not the "whole" shoulder face in those rimless cartridges that sent head space - not the point of the neck to shoulder junction, and not the "point" of the case shoulder. But this belted case does not do that - a "headspace" gauge will only gauge from bolt face to forward face of the belt recess in that chamber. The assumption is that the reamer was ground to spec - when it is advanced far enough to create correct "head space", the grind has created a case shoulder and, usually, the neck diameter and a throat diameter that is appropriate for that cartridge. Maybe there are reamers that cut the case body area and then a separate reamer is used for the belt - if so, I have never used them.
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