hey guys i have been having abit of trouble working up loads for my new custom 7mm stw. it has a shillen match stainless barrel finished at 28 inches, i have tried r22 and imr 7828 with both 140 grain partitions and 139 grain sst's. still looking for the guns sweet spot so to speak. any advice or exp.you could lend would be greatly appreciated. thanks. mark
My own stw's both prefer 7828 behind 140gr ballistic tips.Accuracy averages 1/2" in both with muzzle velocity of 3500fps.Both have 26" barrels-one schneider and the other kreiger.Overall length of 3.660" in both cases.
My 7mmSTW likes H1000 in all the loads I have tried with nos.par. 140 gn. and 160gn. Sierra 140 and 160 it shoots little bitty groups with both types of bullets... Good Luck 3006ultra
I have had very good accuracy and velocity by using full charges of RE25 and 140gr B-Tip's or SST's. I do, however, load the bullets into the rifling and have noticed a significant improvement in group size by doing so. VH
I use the same bullets as Varmint Hunter in 140 grain and seat them out as long as possible. I use 7828, but don't dare publish the powder charge. With 160s and above, I switch to Nosler Partitions and H1000 powder.
Posts: 3490 | Location: Colorado Springs, CO | Registered: 04 April 2003
IMR 7828 and H1000 are both a bit on the fast side for the 7 STW with bullets of 140 and up, at least in the two rifles I've owned in that caliber. I haven't tried H Retumbo or RL 25, so I can't say how they work, but thier advertised burning rates make them STW candidates.
My best results have come with WC 872, a surplus powder available from several dealers. This is with bullets from 140 to 175 grains. WC 872 is very economical, but I won't mention any charges I use since surplus powders do tend to vary in burning rate from batch to batch and a shooter should work up carefully in the individual gun when using them.
Posts: 13259 | Location: Henly, TX, USA | Registered: 04 April 2001
quote:Originally posted by 3006ultra: My 7mmSTW likes H1000 in all the loads I have tried with nos.par. 140 gn. and 160gn. Sierra 140 and 160 it shoots little bitty groups with both types of bullets... Good Luck 3006ultra
3006ultra, what was your charge (of H1000)and what kind of velocity with the 160gr Nolser Partitions?
Posts: 61 | Location: Stockholm, N.J., USA | Registered: 10 May 2003
My 7 STW like the Nosler 140 gr Partitions and the BTs much closer to the lands. Like an earlier post, my best loads using 7828 are beyond current book maximums. Case life isn't great, but accuracy is exceptional.
Posts: 3490 | Location: Colorado Springs, CO | Registered: 04 April 2003
Twist was not mentioned. In the ten years I spent developing loads for the STW, I found twist to be a critical factor. One Shilen barrel had a 1:9 twist with eight lands and was unusable because of the pressure curves generated in launching the bullet.
The best ever for velocity and low pressure was a four groove at 1:11 twist. It would stabilize bullets up to 168gr. This 26in Krieger barrel liked V550 for 140gr Ballistic tips, and 7828 for 120gr X bullets. Velocities were in the 3500 range for the 140gr and just over 3700 for the 120X bullets.
By comparison, that fast twist barrel could barely get 175 partitions up to 7mmRem speed without blowing the primers. RL25 did not exist when I got out of 7STW, but I would suspect this might be a great powder for the heavier bullets. It is insensitive to temperature, relatively dense, and seems to have a very uniform burning rate. Unlike H1000, it is not sluggish to ignite.
Posts: 108 | Location: Star Meadow, Montana | Registered: 30 April 2003
Bud H, I use 80.3 gns. of H1000 with a 160 gn. nosler. And 83 gns. for the 140 gn. I use 8mm mag. Rem. brass neck down and trimed to length.A 215 federal mag.match primer. Remember to reduce thease loads by 5 to 10% and work up. AS these are top loads. I have not run these loads across the crono. Hope this helps
3006ultra, Thanks, yes this helps. I just loaded a few rounds but before I could try them I had a minor accident (not firearms related) and I look like the icon attached. Have to wait a couple weeks before I go popping any rounds. Eye injuries (however minor) and recoil do not go together.
Posts: 61 | Location: Stockholm, N.J., USA | Registered: 10 May 2003
My stw likes H4831 regular cut behind a nosler ballistic tip. It is a high pressure load so I am a bit afraid to post it other than to say it is above max in any loading manual. 3/8" groups regularly, but I don't shoot it much in order to save the barrel.
Posts: 18352 | Location: Salt Lake City, Utah USA | Registered: 20 April 2002