7mm WSM- Wondering what are the negatives?

[mikegaiz]

Well shut my mouth......

 

[TZaun]

I think the issue is that there are not any good 7mm bullets, I have tried several and never got anywhere. That is the only reason no one is shooing them. The BC on most 7mm are out of sight,,,,,

Interesting take on it Mike. Don't confuse my questions with someone arguing with you. What makes Berger, Sierra, and Lapua bullets less accurate in a 7mm vs. 6mm? Are you referring more to the fact that custom bullet makers aren't making great 7mm bullets? I have just started into a 7 SAUM project for F-Class and have not tried JLK or Cauterucio bullets in it yet. I focused too hard on 195 Bergers and have now switched to 183 Sierras. So far they seem much, much better. The 284 guys seem to be getting somewhere with 180s. Does it then turn to the added recoil of anything bigger than the 284 that contributes to less accuracy and not so much the quality of bullets? Is a higher BC bullet, by nature, less accurate than lower BC bullets?

 

[dkhunt14]

Interesting take on it Mike. Don't confuse my questions with someone arguing with you. What makes Berger, Sierra, and Lapua bullets less accurate in a 7mm vs. 6mm? Are you referring more to the fact that custom bullet makers aren't making great 7mm bullets? I have just started into a 7 SAUM project for F-Class and have not tried JLK or Cauterucio bullets in it yet. I focused too hard on 195 Bergers and have now switched to 183 Sierras. So far they seem much, much better. The 284 guys seem to be getting somewhere with 180s. Does it then turn to the added recoil of anything bigger than the 284 that contributes to less accuracy and not so much the quality of bullets? Is a higher BC bullet, by nature, less accurate than lower BC bullets?

I think what Mike is saying is they weren't accurate enough for BR. I know enough guys tried the 7 WSM and couldn't win. In F-class the higher BC would help with wind drift. They don't need to be as accurate as IN BR. We need raw accuracy for 10 shots. If one or two leak out an inch or so, it will most times cause you to lose. Many times 1/4 inch or less costs you the relay win.The 7 SAUMS I saw seemed to be a little more accurate. Matt

 

[Laurie]

Does it then turn to the added recoil of anything bigger than the 284 that contributes to less accuracy and not so much the quality of bullets? Is a higher BC bullet, by nature, less accurate than lower BC bullets?

Recoil is definitely a factor in 7mm v 6mm. Many years ago when the Remington 40X was The precision rifle, Remy shot a test group with every rifle before delivery and enclosed the test target with the rifle on delivery. After years of doing this, the average of scores of groups for each cartridge was published and there was a straight correlation between cartridge size / kick and average groups with 222 Rem providing the smallest value and 300 Win Mag the largest.

In F-Class, cheating the wind usually outweighs any slight loss of precision by using a larger cartridge with higher BC bullets. In theory, 6mm BR can still win national level long-range matches, but in practice the necessary settled conditions rarely apply throughout a match.

Another factor why the WSM may be popular in the UK is shooting two on the mound alternately with only two 'sighters' instead of string shooting with unlimited sighters. This makes wind reading harder as conditions can (and often do in our climate) change considerably between shots and under the 45 second rule, once the target reappears after your partner's shot, you can't wait and wait for a condition to return. It also slows shooting down, so the considerable heat that the WSM generates has a chance to radiate off between shots. (This also helps barrel life too and UK 'Effers' usually obtain round counts with the WSM that US shooters have trouble believing. The cartridge is rarely loaded up to the absolute maximum either which also helps.)

I don't believe that one can draw correlations between high BC and lower precision insofar as bullet design as a subject in itself goes. The very high BC 6mm and 6.5mm Berger Hybrids are doing pretty well in mid and long range BR as far as I can see.