7mm-270 WSM

[AWLEAPHART]

Has anyone done this before?
Anthony

 

[KaiserNorton]

You are aware there is a 7mm WSM already, aren't you?

 

[RDavies]

The current world F class champion used one and it seems to be relativley popular in England where they seem to have windier weather than most places.

 

[TonyR]

Search for posts under member "GLC" and you will find some discussion of the various ways to get to a 7mm on the WSM case. It seems that there are differences in the necks and bodies of the various WSM parent cases that make one better than the others.

 

[AWLEAPHART]

KaiserNorton,
Theres a differnce in in 270 WSM case compared to the 7mm WSM case.

 

[1000yardstare]

2010 Ontario F Class Champion used a 270WSM necked up to 7mm. He was originally going down to 6.5mm but changed his mind and went up to 7mm. He loaded with Win brass, Fed 210M primers, H1000 and 180 gr Bergers.

 

[AWLEAPHART]

1000yardstare,
Do you now how much H1000 was used? Thanks
Anthony

 

[1000yardstare]

Anthony,
He describes his competition load as "hot" so doesn`t want to give that exact load out.

His main concern is that the chamber reamers for the 7mm/270 WSM are all custom, each one reflecting the individual shooters ideas on design. He doesn`t know how other case capacities and throating lengths would compare to his.

He suggests looking at page 467 of the Sierra Manual for the 7mm WSM itself. Loads for H1000 and the 175 SMK are listed there and could be a starting point for the 180 Berger.

Bill

 

[GLC]

the 270/7 WSM is actually identical to the 300/7WSM you either neck "up" or down, I have used both cases with no real discernable difference, I even tried a group alternating with the headstamped 270 and the head stamped 300, group was very similar to the previous which was shot with matching brass, I do not mix them though!
The factory "7WSM" cartridge was tried and many of us had poor results, the case capacity is more than the wildcat versions and the neck is considerbly shorter, which is considered a dis-advantage.
I am sure there are people out that that have had great results with the Factory 7 WSM however it did not stand up to competition strings of fire for F Class in our trials.
I had good results with a wide range of powder and primers, so if the barrel and chambering job is reasonable I am sure you will achieve the desired results.
also Bill is totally correct with regard to a customer reamer, I suggest talk to an experienced gunsmith that has done this type of work and can advise accordingly.

Good Luck

Gary

 

[belldar]

I have a 7-270 WSM and so far so good. Likes norma brass alot better then winchester. Likes berger 168 VLDs so far. Haven't found a good load for the 162 amax. I think this girl is going to be a winner. Getting 1/4 inch groups whial fireforming brass. Let me know if you have any other questions. Just getting used to her.

Brent

 

[canuck]

I have never shot in a single firearm competition but plan to in a year or two. After lots of research I chose the 7mm saum as it has a longer neck and probably better barrel life than the 7mm/300 wsm. I have approx 750 out of mine and most of my groups are still in the .2s(sometimes better, sometimes worse) but it doesn't seem to have lost accuracy yet.