The NRA is urging users of rifles with adjustable cheek pieces to carefully check clearances between the furniture and the working parts after a shooter accidentally fired a round when he caught his rifle’s open bolt against the stock.
The full notice, as published on the NRA website, reads as follows:
URGENT SAFETY NOTICE
BARNARD RIFLES AND OTHER MODERN RIFLES WITH ADJUSTABLE CHEEKPIECES
An accident on 4 July 2015 at Bisley, fortunately resulting in only minor injury, has highlighted a safety issue.
In the accident, the firer had partially withdrawn a live round, so that it was engaged in the boltface by the extractor. While attempting to feed the round into the chamber, a slight rotation and lateral movement of the bolt when fully open allowed the cocking piece to be repositioned outside rather than inside the groove in the adjustable cheekpiece. When the lateral movement was reversed, the cocking piece fouled on the cheekpiece and was released, allowing the firing pin to fall on the cartridge, which fired outside the breech.
All owners of modern target, match and F class rifles are to check that it is not possible for any part of the stock to foul any part of the firing mechanism. Owners of Barnard rifles are additionally advised to check the knurled cap that retains the firing pin for full engagement on a regular basis.
Barnard actions are particularly susceptible to the problem identified, but it is at least theoretically possible that it could arise on a Swing, Paramount, RPA or other modern action where the cocking cam rotates complete around the firing pin to allow the firing pin to hang on the trigger sear. Actions derived from the Mauser, such as the Musgrave, Parker-Hale 1200 and Cadet Target Rifle, are not susceptible to the problem.
I W ROBERTSON
Technical Investigations Co-ordinator
National Rifle Association
1600 hrs 5 July 2015
UK Shooting News imagines the consequences of a round firing with the bolt fully to the rear were not pleasant, either for the firer or those next to him on the firing point.
It appears from the detail given that the shooter opened his bolt, with a round under the extractor and on the bolt face, and presumably wiggled it. What UKSN knows as the full face bent of the cocking piece (the piece of metal that sticks out from the underside of the bolt which is held to the rear by the main sear – which in turn is the little metal item in the bolt raceway which moves downwards when you pull the trigger) was dislodged from its normal position by the cheekpiece. The wiggling action knocked it free from the cocking cam, leaving the striker free to fly forward and fire the round.
Confused? Here’s some not-entirely-helpful diagrams by me followed by a better explanation from somebody else.
So. Diagram 1, knocked up by the crack UKSN Graphics Department:
Here’s another picture, with apologies to HPS-TR whose website we pinched it from for instructional purposes. The striker is pictured in the cocked position and highlighted with the red arrow.
In the words of Adam Leech over on the UK Fullbore Target Rifle group on Facebook, who explained this far better than I managed:
I think the issue is where the adjustable cheek piece has an area at the front of it milled out, so that as the bolt is drawn back, the rear of the bolt goes into this recess. By the sounds of it, once in this position, the bolt has rotated slightly (as they naturally do) and the lug of the cocking piece on the underside of the bolt has slipped over the edge of the recess in the cheekpiece.
When the bolt has then been moved whilst open (and again has rotated slightly – in the opposite direction this time), the cocking piece lug has been pushed off its flat, cocked position on the rear of the camming surface that pushes it back when you unlock the bolt. As Sam Huish said, just like using a de-cocking tool. The firing pin has fallen forwards & struck the round attached to the bolt face by the extractor.
Please spread this warning as far and wide as you can, particularly to owners of rifle types mentioned above.