Proposed: .270 T/C Rifle Cartridge
In July of 2007 Nick Ritenour wrote to me and suggested an article proposing a new .270 caliber cartridge based on a necked-down .30 T/C case, a ".270 T/C." Nick wrote, in part: "This cartridge would fill a hole in current factory load offerings for a short action, non-magnum .277 caliber." There has been a demand for such a cartridge for decades, so I agreed to do the article, which you are now reading.
The new .270 T/C's closest competitors would be the .260 Rem. and 7mm-08 Rem. Nick and I feel that the new cartridge could give both a serious run for the consumer's money. Nick also pointed out the proposed .270 T/C would face, "far less daunting competition than the .308 Win., .30-06, .300 WSM trio that the .30 T/C is facing." Add to that hunters using the new .308 Marlin and .300 Rem. SAUM, as well as the older .30-40 and .300 Savage and it becomes clear that the new .30 T/C cartridge is facing competition from a far greater number of established cartridges than would a .270 version. Another point worth noting is that Americans like .270 cartridges (for good reason!).
The .30 T/C bases its performance claims on a very progressive burning non-canister powder and a rather high maximum average pressure (MAP). We are assuming that in the creation of a .270 T/C Hornady could apply the same sort of powder technology and load to the same MAP as the .30 T/C.
If that is the case, then based on the ballistics of the .30 T/C, a new .270 T/C should be able to drive a 130 grain .277" bullet (BC .242) at a muzzle velocity (MV) of about 3000 fps and muzzle energy (ME) of 2597 fps. A 140 grain .270 bullet (SD .261) should be able to crack 2900 fps at the muzzle and 2614 ft. lbs. of ME.
There are so many 130 and 140 grain .270 bullets available with so many different ballistic coefficients (BC) that it is hard to accurately predict the downrange trajectory of a new .270 T/C cartridge should Hornady and T/C decide to introduce it. Since they chose Hornady SST InterLock bullets for the .30 T/C, we will use the existing Hornady 130 grain and 140 grain SST Interlock .277" bullets for our trajectory figures. The BC of the .277", 130 grain SST is .460 and the BC of the 140 grain SST is .495.
Here are the trajectory figures (in inches) based on those bullets fired from a rifle with a scope mounted 1.5" over bore.
The maximum point blank range (+/- 3") of the 130 grain bullet is 296 yards and the MPBR of the 140 grain bullet is 287 yards.
We think that these velocity, energy and trajectory estimates are reasonably conservative. Those numbers would definitely give the .260 and 7mm-08 some serious competition, essentially recreating the .270 Win. vs. .280 Rem. debate in short action cases. (A confrontation, you will remember, that the .270 won easily back in the day when it came to customers shelling out their hard earned cash for new rifles.)
The new .270 T/C would kick less than the .30 T/C with bullets of similar SD while shooting just as flat and penetrating just as well. Decades of experience in the field with .270 Win. and .30-06 rifles have shown that a 130 grain .270 bullet kills just as well as (or maybe a little better than) a 150 grain .30 caliber bullet. As Randy Wakeman likes to say, nothing can live on the difference. Which bodes well for the potential future success of a .270 T/C.
Nick and I hope that the powers that be at Hornady and T/C give the proposed .270 T/C serious consideration. We think that it is far more likely to achieve long term popular acceptance than the .30 T/C.
Copyright 2007, 2014 by chuckhawks.com. All rights reserved.