Anyone use a 7mm wsm?

[dave]

Just wondering if anyone uses a 7mm wsm for br? Im intrested in what loads are used etc as im thinking of trying my hand using what i have at the moment as a starting point and of all the cals i have i think the 7mm would be the best choice.

Cheers
Dave

[Kenny]

Dave,

I have had the idea just like you about a short mag, after some research and talking to a few who have tried it ...it seems they are more than a little frustrating to play with.

I am playing with a 7mm wildcat design at present that's pretty much what TZ has already done, from the results those blokes have got it seems to work well....so fingers crossed it will work for me

KY

[steven]

Dave,

I'm fairly sure David Kerr from Melbourne shoots a 7mm WSM. Go to actbenchrest.com and look at the results for 500m Fly. There are equipment lists in with the results.

Steve

[Rinso]

Dave,

Steven is correct Dave Kerr did run a 7mm WSM and he was using a 1:10 barrel with 73 grains of AR 2217 pushing a 162 Hornady. Federal primers probably 210's maybe 215's and Winchester brass.

cheers
Rinso

[Tony Z]

This cartridge i tried within moments of the brass turning up in the country. To say it was a disappointment is an understatement. The barrel throat washed away very quickly and the accuracy suffered very badly at the 400 round mark. Recently on BRC, Dave Tooley said he had built one of these and at the same 400 rounds area the accuracy went away for him aswell. He thought it to be the barrel, so he replaced it to have the exact same thing happen with the second barrel. Others have had similar results citing that the barrels were well and truly fucked in 800 rounds. 1200 competition rounds of acceptable accuracy in this cartridge would be highly unlikely. As a hunting round for smacking deer they're fine for a shooters lifetime.

It comes down to what your level of accuracy is. Some are happy with little and a barrel in this chambering could see 2 or 3 seasons of match shooting. Whereas with me, once they start to wonder over the target randomly and can't shoot sub 2 inchers at 500 M in good conditions, then it's time to replace things.

If you do decide to go with the cartridge there are three suggestions i can make. Firstly use the faster burning rate powders in the standard chamber. Secondly if you want to use slower powders, get a chamber with a longer neck, about 350 to 400 thou minimum, so as to to save the throat a bit. Thirdly, build yourself a 280 Ackley Improved, almost the same performance level with a host of parent cases to choose from aswell as 2000+ rounds barrel life span.
Best of luck which ever way you go.

Tony Z.

[Rinso]

Tony,

I seem to recall Dave G playing with one of these as well .. I don't think it came anywhere near expectations for him either.

dave,
Don't let all this bother you too much the 7WSM you have will do to start LRBR or at least have a go with .. you can always re chamber down the track.

cheers
Rinso

[Kenny]

Yeah Rinso DG is one of the blokes I have spoken to about it, I am sure he will comment when he drops in

KY

[dg]

kenny and rinso

spot on fellahs.

the 7mm/300wsm ( original 300wsm formed to 7mm to try and maximise neck length) was the most disappointing and frustrating rifle/calibre project i have ever undertaken.

i outsmarted myself big time !!!

perhaps if i had used an action with a much larger barrel tenon ( instead of an older savage), maybe i would have avoided or minimised the case expansion/bulging and consequent short case life problems.

ie. on the wsm case a significant portion of the case is supported by the barrel tenon, which does not leave a great deal of surrounding metal for containment of pressures and support.

funny how this predicament, which still exists in some factory wsm chambers, does not get reported in gun reviews??? maybe they don't reload the cases.

apart from the above problems, i was also disappointed with barrel wear and erosion, which was evident after borescoping at approx. 160 rounds.

the achievable working velocities were not that much in front of what the 280 ackley could give (as TZ also points out) and required significantly more powder to attain a small increase in velocity.

on a positive side, the extreme spreads achieved using 2217 and 2225 were consistently small and ran over a 2-3 grain spread, which i have never experienced with any other cartridge used so far.

not to be entirely negative, but perhaps if better and more consistent brass quality/sizes were available and if a different set up was used ( an action with a 1.125" barrel tenon), then maybe the results achieved would have been much different.

the end result was, that after 2 years of frustration, i abandoned the wsm and rechambered and re barreled to a modified 280 ackley.

dave - don't be put off by my experiences
good luck in your endeavours
send a pm if you require any other info or load data

cheers
dave g

[dave]

Dont be put off nah just kidding, was just throwing the idea out there as i have a 7mm wsm thats doing nothing and thought it could be used here but seems it may be more trouble than its worth. Think i might stick with something simple to start with like a .308 for starters and go from there, have a 6.5 tube that i wouldnt mind turning into a 6.5x47 but i will begin with the ye olde 30 cal and go from there, thanks for all the advice guys it was great!

Cheers
Dave

[Rinso]

dave,

Where are you located ? Maybe we can help you out a bit if you are coming to a shoot.

cheers
Rinso

[dave]

Rinso,

Im located in the beautiful western district of Victoria in a tiny town called Moyston (birthplace of Australian Rules Football ) fortunately my parents live in town in Ararat(10 mins away) and there new house by chance backs on too the fullbore range and the sound of .308 shots ringing out once a month is half the reason i got thinking about it so thought it will probably be the best starting point and then god knows how far not too mention how many $ i will spend

Cheers
Dave

P.S A bloke has offered me unofficially an Omark .308 thats had a bit of work done to it has a 29" kreiger barrel, tactical stock, new trigger, ken farrel base and rings etc etc get some pics of it soon so will have to get you all to have a squizz at em! Otherwise i have another omark action that i thought Shane could work on from scratch but will see how goes!