270 140GR TSX Vertical Stringing

Yoter · 05-14-2007, 09:36 AM

I tried my first batch of TSX bullets out of my 270 this weekend. I loaded 3 batches of 10, all with H414 powder. Loaded them with 52, 53, and 54GR powder respectively. Each of the groups printed close to the same pattern. A vertical line about 2.5" long. First shot was at the top and they went down from there. The gun is a Ruger M77 and was cleaned thouroughly with Wipe-Out foam cleaner prior to shooting. I also put 3 fouling rounds through it before starting my actual tests.

One note, is that 53 grains is max reccommended for this load with the original x bullets. The Barnes website suggests that the max on the TSX may be a bit higher. I however will not load over 53 grains anymore because my primers were slightly flattened with 54 grains. I am wondering if I need to back the powder charge off even below where I started with these.

Agshooter · 05-14-2007, 02:02 PM

Decreasing your load may be a good idea w/ the look of your primer. It depends on many variables. In addition to your powder charge, how close you are loading your bullet to the lands can make a big difference as well. If the bullet is right up against the lands, then pressures can rise significantly. I don't know if you have a chrono, but they are very helpful in determining the performance of your load. If you are getting higher velocity than the load manual's, then you are probably overpressure.

Also, vertical stringing happens many times when you don't allow the barrel to cool between shots. Were you waiting a few minutes (at least) in between shots?

Yoter · 05-14-2007, 02:11 PM

I do have a chrono but wasn't using it on Saturday. I was only allowing about 1 minute in between shots for cooling. I will try both suggestions when I go out next. I have never had this type of issue with firing 5 shot groups with any other rifle requiring that much cooling between shots. I always let it completely cool after a 5 shot group.

kelbro · 05-15-2007, 10:54 AM

The TSX grouped the best with near-max loads in both of my .270s. My experience is with the 130grs though and not the 140s.

Yoter · 05-15-2007, 01:58 PM

Kelbro,

Was the near max you ended up with according to the data for the original X bullets? That is all we have to go on at this point isn't it?

kelbro · 05-17-2007, 10:34 AM

Yes, for the XBT. My data also shows 53 as a max for the 140s. If you e-mail Barnes, they will send you the latest data. My request was back in Oct 2006 so they may have more current data by now.

bronko22000 · 05-21-2007, 06:17 PM

I've called Barnes a few times for load data for the TSX bullet and in every instance (30-06, 300 Win Mag, 7mm-08) the max. charge they gave me was LESS than for their XBT bullets. They also told me that near or above max you will get erratic bullet performance - with groups opening up.
In you case you say you are getting vertical stringing. Just wondering if your barrel is floating or not. Also, are you resting the stock or the barrel on the rest? And is the stock resting on the bag at the same point? Are you holding the rifle the same with each shot? (cheek pressure, grip, shoulder pressure, etc. ) There are so many varibles to look at but I would suggest you drop down a grain or two and be more conscious on shot to shot consistancy next time out. Lets us know how you make out.

Yoter · 05-21-2007, 10:28 PM

I e-mailed Barnes for the load data and they did send it to me. H414 powder is not even on the list for the 140gr TSX. I bought some H4350 and have loaded a few up to do some testing with.

To answer bronko's questions, I have not floated the barrel, the stock is resting on the bag, not the barrel. I believe that my form is ok, since other rifles group quite well. I am going to be more consious about letting the barrel cool in between shots next trip out. For this rifle I will be satisfied with 1-1.5 MOA.