The following observations, based on a single unclear photograph, can only be considered casual without the benefit of physical inspection, actual measurement and closer failure analysis.
A the fore-end loop probably lies between 5.5 & 6.5" from the breech. IF conventionally bored it is unlikely that a 20 ga shell would enter that far.If bored with a different internal profile measurement is required.
B The failure may have eminated from directly in front of the loop.Method of attachment and possible Heat Affected Zone issues need to be considered
C Actual wall thickness before & after the failure need to be measured,recorded and analyzed. Merely measuring WT at edge of break will only show degree of elongation and thus thinning prior to ultimate failure.This will typically be 6-10% depending on the alloy.
Other areas to consider are fatigue , blockage and material defect.
I strongly suggest your friend do the following.
A. DO NOT CLEAN THE GUN! Store in a silicone impregnated sleeve
B. Save all remaining cartridges from box/ batch . Note where and when purchased.
C. Ask any and all witnesses to record their observations, what guns and gauge of guns they were shooting.
D. Clearly record whether or not he had any 20 guns/shells at on his person , when and for what he last used that hunting coat ,pants etc.
E. If he feels he has a valid claim against another party consult a personal injury lawyer.
FYI. If he goes to an attorney this afternoon it will typically be a year before it goes before a judge to decide jurisdiction and start the process of admissions, discovery and depositions.
Good Luck and I hope your friend makes a speedy recovery.
If I can be of further assistance, feel free to contact me by phone 920 876 3745.
Hugh Lomas
