Well, I just finished the first 277 Allen Magnum to come out of APS. This new Allen Magnum was designed at the request of my good friend Richard Graves with the intent of him building a very large 185 gr ULD RBBT speicifically for this new chambering.
Basically, the 277 Allen Mag is nothing more then the 7mm Allen Mag necked down to 277 with no other changes. Performance with same weight bullets will be roughly 150 fps over what the 270 Allen Magnum will produce as the 277 AM is based on the slightly larger and much stronger 338 Lapua parent case.
The new round is not the only unique thing about this rifle. This rifle is the very first design of my Extreme Sporter V-Block rifle system.
The idea was to take the design of the Heavy V-Block but modify it and streamline it to work in a rifle in the 10-12 range instead of 25 to 30 lbs for my Heavy V-Blocks. And doing this while still offering the extreme stability that the V-Block barrel bedding system offers as well. The stock design of choice for this system was the McMillan A-5.
This pic shows the stock with the V-Block bolt ports milled in the stock and the V-Block attached to the barrel next to the stock, showing how it will be positioned in the stock when finished. As with the Heavy V-Block, the Xtreme Sporter V-Block has a totally free floated receiver. Nothing behind the recoil lug bares solidly on the stock in any way. The barrel is held solidly into the V-Block by two 1/4-28 bolts.
The main issue with the Xtreme Sporter V-Block is that the block needs to be dimensioned to fit into the slimmer forend of the A-5 which requires alot of machining and tapering of the Block. I wanted as much metal in the block as possible to retain rigidity and stiffness but was limited in what the final shape could be. The final result looks like it will be plenty stiff for extreme accuracy.
This is the finished rifle ready for load development and range testing. Componants are a Rem 700 LA converted to single shot, fully accurized, Holland Comp recoil lug, Special Lilja Xtreme Sporter V-Block contour barrel, 30" fluted 1-8 3 groove. Holland QD brake, McMillan A-5 stock, Rifles Basix 1.5 lb trigger and APS V-Block.
Finished rifle weight is roughly 13.5 lbs as she is seen in the pictures. Certainly not a lightweight sporter but if the system performs as it should, the rifle will produce consistancy far above what a conventional 13 lb rifle will produce.
Performance wise, we are looking to break 3500 fps with the 169.5 gr ULD RBBT and hopefully get the new 185 gr ULD RBBT up to the 3300 fps range. If we can get this, the 277 AM will rival the 7mm AM/200 gr ULD RBBT combo ballistically.
As with all the Allen Magnums, these are Full throttle big game rifles, not varmint rifles so the shortened throat life is much less of a concern then a high volume shooter.
This rifle was designed and built, along with the new round to reach out and hammer Canadian whitetails out to 1000 yards reliably in a portable rifle system. Hopefully it will do this easily.
All opinions welcome if you care to share your thoughts on this idea.