It has been a lot of time that we were waiting this to happen and this year at IWA 2015 they have showed it. However what they did it was not just a new barrel with a .338lm chamber but much more. In this article it is not my intention to talk about performance of the new Blaser Long Range in .338lm. What I want to clarify is how they made some things possible and how can an existing Blaser R8 owner install a .338lm barrel on its rifle.
Lets see first why this caliber was not so simple to introduce in a blaser R8 platform. The Cartridge Over all Length(COAL) by C.I.P. Is 93,5mm. Here is the first problem, because you can insert in a Blaser R8 magazine cartridges with a max COAL of 91,7mm (ATZL) and appx. 92,5 standard trigger. So lets see what have they done to make it possible to insert a cartridge with a COAL of 93,5mm.
First they made a new trigger assembly that is good only for .338LM. Don’t overlook that with an ATZL trigger it is not possible to insert CIP cartridges in the magazine. In this case you will have to single feed your ammo or handled it to a max COAL of 92.2mm!
Second thing on the lover part of the barrel they made a special groove that makes possible to chamber CIP .338LM cartridges from the trigger assembly.
They also made the .338LM barrel longer(68,5cm) than their magnum barrels (65cm), but the barrel is still of the same dimensions as a match (22mm) or semi weight (19mm). You can not get a standard one (17mm). So if you want to add this barrel to your existing R8 platform you have to have a match channel for a match barrel or a semi weight channel for a semi weight barrel. It doesn’t matter what kind of stock do you have, it is only important that the stocks channel is the same or bigger than the barrel type.
I didn’t mention the bolt head since the new LM bolthead is nothing else than the JE bolthead with LM marks.
I hope that this article clarifies some questions. In case that you have additional questions you can find the discussion of this article on Eu-LRH forum. Don’t hesitate to ask in case that you have additional questions.