Bullet weights

[T-Mac]

I am no expert by any means, so maybe I have a dumb question...but anyway;

I have been working up 130 grain loads in .270 WSM and have tried a lot of different powder brands and charges previously - all with Hornady 130 SP...and now recently, with a different bullets. (Hunting loads).

Last time out I wanted to see if some different bullets would perform better, or worse.
I shot some 130 Nosler Partitions and some 130Speer BT Spitzers, along with some of the (known)130 Hornady SPs..
I achieved really poor accuracy with the Speer BT spitzers. Meanwhile the Nosler Partitions shot about the same as the Hornady SPs with same charges of same powder. (Re-19). The wildness of the Speers surprised me because I was very careful on seating depth on all so they were all the same amount off the lands (as close as possible anyway).

Last night I grabbed 10 bullets from each box and weighed them on my (PACT) scale. The Hornadys were very uniform being mostly 130.0 a couple 129.9 and one @ 130.1. Same for the Noslers.

The Speer bullets varied from .4 under to .6 over. Gee, I only tried 10 random bullets out of a box. That seems like a lot of difference to me...(you can see where I am going with this).

Like I said.. I am no expert...but would this weight differential be a factor enough to account for the inaccuracy I experienced with those Speer 130s?

 

[Scorch]

I tried Speer bullets years ago and never went back. Accuracy was terrible, expansion was inconsistent (either nothing or explosive with 145 gr 7mms), so I just won't use them anymore.

And yes, the variation you saw is normal. Hornady, Nosler and Sierra are a lot more careful about quality control with their bullet weights. They built their reputation on accuracy. Speer built theirs on bullet toughness.

 

[Dreadnought]

Bullet shapes and lengths can also affect accuracy. Bullets' sectional densities and your rifle's twist can affect how accurate rounds of identical mass but of differing brands are through the same gun with the same powder load. I picked up a copy of "a practical handloading handbook" from the library (I don't remember if that was the exact title but it was copyrighted '76 or '77), there was a long section on identifying exactly what length bullet works best with the twist rate of your rifle.

 

[arizona hunter]

The only Speers I've used are the 180 gr. Grand Slam for my 30.06; made up four different loads with the top one at 2700 fps, using H4350 and all shoot around 1.25" to 1.50". Not to bad for accuracy. This is the only powder I ever tried. Most likely they could do even better with another powder.

 

[temmi]

I do believe variations in bullet weights affect the final accuracy. I weigh each bullet and sort them into lots of the same brand ,style & weights.
I do not believe that the weigh variation has a HUGE affect but it is one of the things you can do to reduce the group size…
If you find one bullet shoots best in your rifle… and it suits your purpose, keep it. Not all bullets shoot equally well in all rifles.

 

[amamnn]

I've had the same experience with Speer bullets. Not only were weights wildly varied, but the ogives, as well.