Home Forums Hunting & Shooting Ask The Gunwriters TTSX seating depth

First post here. Yesterday I loaded 50 rounds of Barnes TTSX 110 grain for a 270 winchester with 56 grains of H4350. Should be pushing more than 3200fps. The last groove from the base to the tip of the bullet is completely exposed past the case mouth, but I loaded exactly to Barnes suggested COAL. Is this normal for the TTSX bullets or should I bury all the grooves so it's just the entire bullet tip sticking out?

Normal most times.

Only your rifle knows. Some rifles like them right out to the lands. Some rifles won't shoot until they are way off the lands an eighth inch or more. I have a 270 that shoots 110 grain TTSXs into 1/2 inch high by caliber wide groups with 55.5 grains of H4350 an the velocity is tight on 3170 FPS.

Ok so how deep do you seat yours?

I start at factory length, if I’m getting an inch or better, I’m happy.

I generally follow the Barnes suggestion, and started with them .05 off the lands. Generally, they shoot well there, or seated a little deeper.

The "problem: (if it can be called that) is that Barnes TSX's, of whatever kind, can also shoot more accurately when seated very close to the lands. In my experience this depends on whether the rifle is a typical factory job, where the chamber may or may not be perfectly centered, or whether it's a custom rifle, where the chamber IS perfectly centered. This means the rear of each land begins the same distance in front of the chamber, so the bullet isn't tilted slightly by the lands on one side being longer than the other.

While in general TSXs (whether tipped, or LRXs, or whatever) do shoot more accurately when seated a little deeper than most lead-cored bullets. But that does NOT mean they always do.

I'd have to go find my range book and look it up. Like Hanco I start with what Barnes advises and if it doesn't give me better than an inch I Move up to .010 off the lands and back up .010 at a time until I get accuracy. That's the most efficient way I found to solve them and some rifles can be really picky about all monos. I have seen .005 make an 8 inch difference in group size. I have solved more than 50 rifles for mono and have yet to learn how to shortcut the process of finding seating depth.

The TTSX is finicky, one OAL will work in one rifle but not in another.
Best advice is go opposite of anything hanco says and it will most likely work just fine !!

+1

I found them very easy, have loaded to the top of front groove in 338, 708 and 260 with MOA results and basically max book charges using Nosler data.

The old X bullets were very sensitive to seating depth (jump to lands). I have not found that to be the case with TSX or TTSX in several calibers and many rifles. Generally starting at COL suggested in the manual works and you can adjust longer or shorter to see if it makes a difference making sure you don't go too long where they won't fit in your magazine or function through your action. IME most cartridges function well with good accuracy seated with the case mouth even with the first groove. As always YMMV.

Minor point but if I can get good accuracy and have the mouth of the case at the top of one of the ridges I am happier. When the mouth ends up over the relief groove I am always getting lint and dirt inside the case mouth from carrying rounds in my pockets.

0.010" off the lands works well in every rifle I use them, which is at least five that come to mind at the moment.

Also, 3080 - 3100 fps seems to be a sweet spot, even when the round is capable of higher speeds, or it might just be coincidence.

Follow Barnes' directions. Generally that means the case mouth is at the base of the first groove. Accuracy has been great, never deviated from their instructions. Never worried about lint.