Home Forums Reloading Big Game Rifles 7-08/7x57 and TTSX

Folks:

I know that it's possible with C&C bullets to use 7-08 data in the 7x57 case in order to bring the old cartridge up to modern velocities, keeping an eye on the chronograph, of course. Does the same hold true when loading for monos like the TTSX?

Thanks

RM

I think you'd be fine Mike. The 7x57 has enough extra throat and case space I've never ran into issues while using the 140 ETips.

The principle involved is the larger capacity of the 7x57 providing a reduction of pressure relative to the same charge in the 7-08 using the same projectile. I don't see why this would change with the type of projectile.

I'm thinking I might have to up the charge in order to gain the 7-08 velocity, assuming accuracy holds.

Oh yes, I was just thinking out loud about the relative case capacity principle. If I were to do it I'd have no qualms about using more powder to achieve the same or even a little more velocity out of a larger capacity round.

Thanks to the both of you. With all the warnings about monos not acting exactly like C&C, I was just wondering if the principle would still hold. As an aside, my BIL finally caved and sold me his Cabela M70 Fwt Super Grade that has a whopping 37 rounds through it. I'm thinking a 120-gr TTSX just might be a bit of fun on a few summer pigs.

Thanks again.

Man, what a great score Mike! Congrats on that rifle!

The real difference in velocity/pressure was with the X bullets. The grooves on the TTSX make them act much more like C&C. I've used other mfgr's data with TTSX (with discretion and a chronograph) and still have my eyes and fingers.

Thanks. He shot it a bit on the range and then killed one animal with it. His two favorite hunting rifles are a Browning X-Bolt (.308) for bad weather, and a M70 Classic Super Grade .270 when the sun is shining. The Featherweight was just sitting in the safe feeling lonely so, as I said, he finally caved and it now has plenty of company. I adjusted the trigger with an Ernie spring and shot it Saturday afternoon with a couple of factory loads. Of the four different loads off the bench, it put three 140-grain factory Core-Lokts into .660". I'm thinking that this one has potential.

Good to know. Thanks!

Man I wished I’d have grabbed one when they were out there. Awesome rifles. Some had some nice wood as well.

Sounds like it’ll be an easy shooter as well.

I sure hope so. My other one (regular Fwt) is giving me fits. Now that the lease is idle, I'm going to swap out the scope, load up another batch of Match Kings, and try it again. So far it's been pretty inconsistent, so if this doesn't work I'm thinking it might go to someone for an examination and remedy. I really want it to a shooter as well. In the meantime, though, this SG will be a lot of fun.

My sons 7x57 featherweight was a pain until I full length bedded it. Now the darn thing does great with about everything.

Good luck with it. I know you won’t stop till it’s right.

Thx.

Interesting - I’ll have to keep this in mind. Hunting around for a 7x57 to round out my .257 Rob & 6mm Rem.

I,too. have a LW Super Grade.

It groups 5 shots well under an inch with145 LRX and StaBALL 6.5 with 210 primers. Seating depth is critical with 3.10" being ideal. 2900 fps was easily achievable with 50.5 grains.

Still experimenting with the 150 grain Sierra. 2850 should be achievable with StaBALL. 3.00" OL seems best so far.

With other powders I would not exceed 2800 with the 145 LEX or 2750 with the 150 grain as the Hodgdon manual shows a 100 fps advantage for StaBALL.

Cheers,
Walt

Seems to Mike. FWIW the Ingwe Special REALLY liked 160 gr TSXs pushed pretty hard.

Is your other one properly glass bedded and does it also have a proven scope and mounts on it? What's the bore condition? The classic 7mm08 I had was a great shooter after I removed the factory hot blue bedding and replaced it with something better, trigger fine tuned and adjusted to a very clean 2.5 pounds and worked up a load for it. It shot moa for 5 shots. Definitely good enough for hunting with.

Oddly enough, it shoots itty bitty groups with factory 158-gr Prvi Grom loads. I've never bothered to shoot anything else in it, but it's good to know it likes the 160-grain TSXs. I'm surprised you went that light in it, though!

That's one of the reasons I'm swapping out the scope for a FFII, at least for this test. The mounts are fine. The bedding could be an issue - BACO hot-glue - we'll see. I'm more of a hunter than a tinkerer, so if all this fails I'll need to consider some other alternatives. Thx.