RUAG Ammotec UK have responded to the NRA’s ban on using a certain batch of its .308″ Win match ammunition.
In a statement dated 8th April, Phil Unwin, RUAG’s UK managing director, said:
We are disappointed by this action but accept that during the 2013 Imperial Meeting at Bisley the NRA informed us about this problem. However, we dispute that it was an ‘unacceptably high rate [of blown and leaking primers]’.
During the 5 year period of the contract with the NRA for supply of .308 Match ammunition all of our production was manufactured to and within CIP specifications.
Use of this ammunition in non-CIP compliant rifles is not recommended and may well lead to problems; however this is not the fault of the ammunition.
We maintain that Batch No. 261919 was made to approved CIP specifications and RUAG Ammotec have no doubts as to its safety and performance in CIP approved rifles. However as a reputable manufacturer and to maintain market confidence we had already withdrawn the small remaining stock from sale.
The difference between permitted NRA Target Rifle bore/chamber dimensions and CIP dimensions could be one of the many factors contributing towards the popping primers.
The NRA’s Rule 150 permits Target Rifles (as defined) to have certain internal dimensions reduced below the CIP specification. This dates back to the days when Radway Green (RG) supplied ammunition for the Imperial Meeting. For reasons best known to RG’s engineers, their 7.62mm bullet was under-sized compared to usual commercial .308″ bullets. Thus, in the pursuit of accuracy and consistency, the NRA obtained dispensation from the Proof Houses for TR barrels to use reduced internal dimensions. NRA Rule 150 (as stated in the 2014 Bisley Bible) states that, for TRs chambered in .308″ Win or 7.62mm NATO:
…the following concessions are permitted:
the bore diameter must not be less than 0.298”.
the groove diameter must not be less than 0.3065”.
the throat diameter must not be less than either the bullet diameter or 0.3085”, whichever is the greater.
the minimum throat length may also be reduced but only to such an extent that the bullet of the cartridge in use is not in contact with the rifling.
Standard .308″ Win bore dimensions are .300″ bore diameter and .308″ groove diameter. The SAAMI .308″ chamber drawing gives a diameter of .310″ for the throat, which is identical to the CIP .308 chamber drawing‘s metric equivalent of 7.87mm. It can thus be seen that the NRA-spec chamber is tighter than the permitted CIP .308″ Win chamber, as we’ve neatly tabled up for your reading pleasure below.
The NRA does assure all Imperial Meeting competitors that issued ammunition will be suitable for use in Target Rifles, stating in the Bisley Bible – that is, the NRA book of rules: “If reduced bore or groove diameters as above are used, only ammunition developing an average max pressure less than 3650 Bar under CIP test conditions may be used. NRA ammunition “as issued” will satisfy this limit.”
Clearly something went wrong somewhere between the NRA and RUAG, as the CIP-compliant RWS ammunition made by RUAG was blowing primers in a significant number of non-CIP-compliant rifles used by NRA TR competitors. This is not a suggestion that the RUAG ammunition did not conform to the 3650 bar limit. Indeed, many shooters report that batch 261919 performed perfectly well for them in their Target Rifles.
UKSN does think it was exceedingly cheeky of RUAG to take a full batch returned to them by a trade customer on the grounds that it caused problems in use, only to repackage it and try selling it on to retail customers.
Nonetheless, the NRA ban on that batch remains in force. With RUAG withdrawing the batch from the market, that would seem to be an end to the matter.
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