Tale of Two Bullets

[ligonierbill]

Working up a new load for my Remington 700 using Re25 and Speer 160's plus Hornady 162 SST, I got an interesting result. Working towards the listed max load (bullet maker's manual), I could not drive the Hornady beyond 2,810. In fact, 68.2 grains gave the same velocity as the max 69.3, but with much better Std (26.4 vs. 52.5). The Speer acted more like you'd expect, adding a bit of velocity for each half grain to 2,920 at the max 70 grains. The max load also yielded the best Std of 17.6. No pressure signs with any load. Hornady tested in a 700 and got 3,000 at max. Speer used a universal receiver and got 3,012. All 24" barrels. I checked my chrono with some .22 target ammo, and it's pretty much on. Not too interested in getting 90 fps less than the Speer testers, but I think the result for the Hornadys is odd. So, I'll load Speers. What is your experience?

Also, any experience with the WSM family? Web searches indicate many folks are disappointed in the velocities they are getting. In theory (and advertising) these should be great rounds.

Oh yeah: 7mm Mag

 

[GeauxTide]

Looks like your barrel likes the Speer better. If I read the message right, you said 17.6 Std Deviation? A deviation below 10 would give an extreme spread of under 30fps and much better accuracy. I'd keep testing. I've not been impressed with the SM series. Expensive brass, light rifles, short barrels, short throats, fast recoil. I've had a 2.5" 7mm Mag since the 70's, so I'm biased. I've not heard of a 7WSM chrony 3050 with 160s or 2900 with 175s.

 

[Unclenick]

Bill,

You said you'd had no pressure signs, but failure of velocity to increase with powder charge is a pressure sign. Some guns have it occur at two levels because the first level is getting uneven bolt lugs to touch down, but either way, something is expanding the space available to the powder.

On the other load you seem to be doing better. I don't know what range you're shooting at? You're standard deviation might be improved on if your are going to shoot long range. The difference is a pretty big deal at 1000 yards, but will be utterly invisible at 100 yards for any but a benchrest rilfe shooting in the 0.1's.

 

[ligonierbill]

Still odd, since the only difference is the bullet. And I weighed each charge on a digital scale. But, them's the facts. I'll stay with the Speer bullets and give the Hornady to someone whose rifle might like them. I thought about COL, but I seated the bullets to the manual length, and Hornady used the same model rifle. This is a hunting setup, primary target elk. I won't shoot beyond 400 yards, and that's a stretch. I don't have the patience for 1000 yard match shooting. By the way, the new Re25 load replaces my good ole H870. The gun really liked that, but I used the last of my stock.