7mm BSM?

[dave7mm]

Bryan Blake,

Thank you.
dave

 

[Fire Dog]

The 7 BSM uses a 300 WSM for a parent case, Lapua is best in our opinion. Take the WSM, run it in the 7 BSM FL die, and all forming is done in ONE pass. Originally we started with a bump back die, then the FL die, we now have changed some things internally to where ONLY the FL die is needed to form. All done in one push, nothing fancy. The brass comes out fully headspaced, full shoulder formed, match grade brass at new brass level. We have had most success with RL16, 4350H, 4831, 4831SC, N565. I will be doing a full write up soon and on our site. Full component kits on our site this month, so ahead of the June schedule, only for a limited supply.

Here is a single shot ladder at each charge for N565 for one example...View attachment 1658906

Here are some 1000 yard targets:

View attachment 1658907

View attachment 1658908

View attachment 1658909

View attachment 1658911

antunRC.
Thank you
Bump back the neck/shoulder on a 300 WSM case.
Looks like the trim length is .040 or so shorter than the WSM.?
Long neck.
35 degree shoulder?
Looks like two steps to get to the finished BSM case
No fire forming.
A tad more capacity than a standard 7mm SAUM?.
What are you using for dies?
What does BSM stand for?


dave

BSM........ Big Stomping Mother...

 

[dave7mm]

BSM........ Big Stomping Mother...

Blake Short Mag...

 

[longbow]

So couldnt the same bump die push back the 7PRC and do the same thing?

 

[SKWERLZ]

So couldnt the same bump die push back the 7PRC and do the same thing?

7prc has a skinnier body so less case volume at that shorter length than 7SAUM or this wildcat.

 

[Fire Dog]

Any guesses about barrel life?
I have a friend with a SAUM and 1,100 - 1,300 rds and it’s new barrel time….
Shoots great but “High Maintenance”…

 

[Bryan Blake]

Any guesses about barrel life?
I have a friend with a SAUM and 1,100 - 1,300 rds and it’s new barrel time….
Shoots great but “High Maintenance”…

One customer using RL16 for its life, got 1803 rounds on our barrel. 4 groove barrels may have a different life span, ours are 6.

 

[Bryan Blake]

So couldnt the same bump die push back the 7PRC and do the same thing?

7 PRC shares nothing with the WSM other than bolt face diameter.

 

[Fire Dog]

One customer using RL16 for its life, got 1803 rounds on our barrel. 4 groove barrels may have a different life span, ours are 6.

That’s good to know as I have a spare barrel from the 280AI build and will set it back a turn or two and re-chamber it once that the original .280AI one sees the end of life as I have a magnum bolt for that Pierce action.
Perhaps with the BSM as I like the longer neck, I’ll keep an eye on your site and see how things develop.

 

[dannyjbiggs]

Nice. Circa 2012, I developed a fairly identical wildcat formed from Norma .300 WSM brass after running into problems with the name-sake Remington-made brass for my 7mm RSAUM. I initially shot the wildcat in two forms: Unimproved (dubbed Gooseneck RSAUM) and Improved (dubbed Gooseneck Improved or GNI RSAUM). After a time, I discontinued with the GNI because in my wildcatting process I had to fire-form it and I didn't feel the extra case capacity was worth the effort.

Anyway, I had a good run with the wildcat over the years...it shot me onto a few US F-Open Teams. I've become quite rusty on center-fire F-Class post COVID...plan to hang it up altogether after a couple of Oak Ridge LR matches this year. If I choose it over the .284 Shehane, I'll be shooting a "straight" 7mm RSAUM, after removing its worn-out Gooseneck! After that I plan to have a straight 7mm RSAUM with an unfired barrel for sale, with lots of brass.

Best of luck to you,

Dan

 

[SKWERLZ]

One customer using RL16 for its life, got 1803 rounds on our barrel. 4 groove barrels may have a different life span, ours are 6.

I generally get 1500 trouble free rounds with my 7 saum 4 grooves running R26.
I can see R16 getting decent life, it was less spicy than I was anticipating similar to N165.

 

[Tx_Flyboy]

The 7 BSM uses a 300 WSM for a parent case, Lapua is best in our opinion. Take the WSM, run it in the 7 BSM FL die, and all forming is done in ONE pass. Originally we started with a bump back die, then the FL die, we now have changed some things internally to where ONLY the FL die is needed to form. All done in one push, nothing fancy. The brass comes out fully headspaced, full shoulder formed, match grade brass at new brass level. We have had most success with RL16, 4350H, 4831, 4831SC, N565. I will be doing a full write up soon and on our site. Full component kits on our site this month, so ahead of the June schedule, only for a limited supply.

Here is a single shot ladder at each charge for N565 for one example...View attachment 1658906

Here are some 1000 yard targets:

View attachment 1658907

View attachment 1658908

Hey Blake,

You mention conversion can be done in one step, however is neck turning still required?

New to wildcatting, so pardon the dumb question.

 

[Bryan Blake]

Required? No, but highly recommended.