I will be doing some load development with the 140 gr SST in 264 Win Mag soon after snow leaves. Is this a 2 diameter bullet that I can seat farther out than the Sierra 140 gr? As far as construction, do the SST and Sierra GK compare?. I hope the load of 62 gr H4831 will work and I also have 7828 and RL 25 to use. Any useful data and opinions are welcome. Planned use is open country mule deer and it may see service on a moose this fall.

BR

Can't help you with the profile or construction of the SST as I haven't used any of them. If you have one of the older .264 Magnum chambers with the virtually non-existent throat, I would suggest having the throat lengthened to allow seating normal bullets out as far as the magazine will allow.

Any of the current 4831's are too fast for best velocities with 140 grain bullets in a .264. 7828 is better, but still not optimum. I haven't tried RL-25, so can't say. H-870, which I understand is no longer available, or Accurate 8700 is a good match for 140's. Hodgdon Retumbo is another possiblity. My favorite is surplus WC 872, but it may be hard to come by in Canada.

Good luck!

Stonecreek- my rifle is a new M70 Supergrade with a short throat. Is AA8700 as "dirty as 870". I assume they are comareable powders but can I use the same load data for 8700 and H870?

Thanks
BR

I can't say as to how "dirty" 8700 is as I've never used any. However, I never found H 870 to be particularly dirty, either.

8700 may or may not be the same spec powder as H-870, but your gun is not the same as my gun, either. Loads with 8700 can certainly be worked up from starting load recommendations with H-870, just as H-870 loads should be approached.

There are a couple of Vhitavouri (sp?) powders made for the .50 cal MG, the numbers of which escape me at the moment. I haven't used them, either, but if they are availble in Canada, you might want to give them a try. With the 140 grain bullet, the slower the powder the better. You may have to trickle powder through a long drop tube in order to get the right amount of some of the slowest powders into the case.

I don't shoot a 264 Win Mag, but if I did, I'd try RL25 or H1000 with the 140 gr. bullets.

I've tried the 129 gr. SST s , and I think the nose profile is the same as the 140 s .

The ogive is very long and sleek . You can seat them out a long ways . But in my particular rifle with a 24 inch barrel , both accuracy and speed were disapointing. I topped out at about 3200 fps with several powders , including RL 25 and H870 .

I have both on hand. The SST measures 1.400" long and the ogive on my gauge is at .916". The Sierra 140 boat tail game king is 1.250" long and the ogive is at .907". Even if the gauge is incorrect, the difference in ogive locations is the same. The Hornady will need to be seated .009" deeper.

I am still working the bugs out of a 6.5 WSM. I feel the Sierra's are or will be a better bullet for our applications. This is based soley off of one animal with the Sierra. I took an Axis doe (similar to whitetail in size) at 74 yards. Avioded a shoulder shot, but took a slight quarter shot just behind. Broke a few ribs and exitted. The exit wound looked nice. Seemed to be double caliber and no more. Looked like a Partition exit. This was at a starting velocity of over 3150 fps. I have shot some game with the Hornady 140 Interlock. Unless there was some serious improvements on this new SST, these bullets at 264 Win velocities are not fit for coyotes.

66 gr of RL 25 with a 140 Sierra BT worked wonders for me. Also 62 gr of H4831 works great...again 140 Sierra GK. This last combo did 1" at 300 yds regularly....if you let the barrel cool! Both were right at 3200 fps or so.

[ 09-02-2003, 23:04: Message edited by: POP ]

Battleriver:

I can't get the SST'S to group worth a darn in my 6.5-06, or either of the 270's I own.

To say the least they have been very disapointing. As a matter of fact I was so disgusted with them, I threw um out. Ballistic tips, and Sierra Spitzers have given me the best accuracy in the 264 cal.

Jerry

I have recently started developing a load with the 129gr SST's in my 6,5x57R and results have been very disapointing, in a gun which, so far, has showed excellent accuracy with all combination tried.

With so many other accurate loads found so far, I am not goin to keep on working with these ad infinitum.

A couple of tries with a different primer, or seating depth, or whatever, and very likely dust them afterwords.

montero

Are these SST's equal to an interlock .... toughness wise? Or are they a Ballistic tip with a different look?

I have never shot the 129 SST through a 264 Win. Mag but I did try it in my Krieger barreled 260. It was with out a doubt the sorriest bullet accuracy wise I have ever shot, and the same can be said of the 165 SST in my 308. It was a repeat performance of extremely poor accuracy. For a mid weight 6.5 mm bullet I went to the 120 Sierra Pro Hunter and it shoot sub .5 MOA repeatedly. I went to the 140 GameKing for a heavier bullet in my 260 and that bullet shoots very nearly as well as my F class load with the 142 MatchKing. All I did was put throat wear on two very good barrels with the SST. Seafire tried to tell me before I tried them, but I didn't listen.

Shoot Safe, Shoot Straight....RiverRat

Put me down as another dissapointed SST user . I thought that 129 gr would be THE bullet for my .264 , but groups ran 2 inch+ , while ballistic tips will easily go 3/4 MOA in my rifle.

Never shot anything with the SST s , but from digging them out of a dirt backstop , my impression is that they are pretty soft ......

129 gr. SST has not been a good shooting bullet in my m700 260 rem. 1.5-2" groups on average. It will put 120 gr. Nosler Ballistic Tips into 1" or less all day.

My 24" barreled Win 70 .264 does best with H4831, H450 and IMR 7828. H870 and AA8700 were not accurate. A fellow .264 user described the Sierra 140 GK as a "varmint bullet" and I agree. I killed 3 small deer with it. It did fine at 300 yds where velocities fell off but I had two blowup and that soured me on them. I know many do not like Barnes X-bullets but I have had excellent results with the 120 X on deer. Your rifle and mileage may vary.

I have used the sst in several different cals(30/06--150&165,7/08-- 139,260-129,270wsm-139) and have taken deer with all of them(except with the 270 wsm just got it this year) from 40 to 200 yds and have never recovered a bullet yet,all pass throughs with a small hole on one side and a big hole on the out side.On a good day all of them shoot around an inch or better,waiting to try the 270wsm out on one at 3250 fps and 139sst it will shoot less than 1/2 in groups on paper.
Shot a group yesterday with the 260(129 sst) at 300 yds to see what it would do 2 were touching and one was 2in low.At 100 was getting constant .6 and .7 groups (Rem bdl 24" barrel)Got one group of .585 and shot one group with the interlock 129 and got a group of .765.

Switched to the 125 Partition and RL 25. I get 3300 fps and .7" at 100 yds. That takes care of all bullet issues