7MM WSM Reloading Help Please!!

[Flea21]

I’ve been in the process of purchasing a custom 7MM WSM. Decided to go with the 190gr Berger projectiles, an 8.5 RH Twist Barrel and I have H4350 powder, tons of it. My issue is there’s no load data for this round and I feel like I may have shot myself in the foot, pun intended. I’ll be $4k into this build and I feel like I may have wasted my money, ugh.

Someone please help me, Thanks in advance.

 

[Maxduty]

7 Rem Mag - 7 WSM - 7-08

Same Data LOADS FOR WSM & 7-08 will be designated pls 7-08 added.............please identify as such.........

www.snipershide.com

 

[Softtail103]

Berger 180 VLD over 68 grains of H1000. Winchester brass with Winchester magnum primers. Works great for me.

 

[Bacarrat]

IMO thats too fast of a powder for that round and that bullet weight. Will need a slower powder to get it up to speed with good case fill. When I was running a 7WSM, I was using 4831SC with great results.

 

[SonoranPrecision]

I thought I was SOL when I decided to start getting into 7saum, as I too only had H4350 at my disposal. Turns out there is a reasonable number of F Class shooters running 180 class bullets with H4350 out of 7saum. So I tried it, and it works just fine. Maybe it’s similar with 7wsm. As mentioned above, the focused 7wsm/rem mag/-08 thread will give more specific info.

 

[Flea21]

I thought I was SOL when I decided to start getting into 7saum, as I too only had H4350 at my disposal. Turns out there is a reasonable number of F Class shooters running 180 class bullets with H4350 out of 7saum. So I tried it, and it works just fine. Maybe it’s similar with 7wsm. As mentioned above, the focused 7wsm/rem mag/-08 thread will give more specific info.

Thanks for the ray of sunshine. I’m very concerned being that I chose 190gr Berger’s which are even more heavy. I had an opportunity to get a ton of 4350 and I went for it thinking it’s the right move but Berger has really discouraged me.

 

[SonoranPrecision]

Thanks for the ray of sunshine. I’m very concerned being that I chose 190gr Berger’s which are even more heavy. I had an opportunity to get a ton of 4350 and I went for it thinking it’s the right move but Berger has really discouraged me.

What are the specs on the rifle? Long or short action? Barrel length? Intended purpose?

 

[Flea21]

Its a 7MM WSM built on a short action with an 8.5" RH Twist 26" barrel. My intended purpose is to shoot paper out to 750-1000yds when I can. I live 3 hours away from any range more than 200yds. A buddy of mine loves this caliber and he made a believer out of me and I spared no expense but I feel like I fudged up with the powder situation considering whats going on nowadays.

 

[SonoranPrecision]

Its a 7MM WSM built on a short action with an 8.5" RH Twist 26" barrel. My intended purpose is to shoot paper out to 750-1000yds when I can. I live 3 hours away from any range more than 200yds. A buddy of mine loves this caliber and he made a believer out of me and I spared no expense but I feel like I fudged up with the powder situation considering whats going on nowadays.

Ok, so a few things.
1) On a short action, with the 190’s you’ll likely be single feeding due to overall length restrictions.
2) H4350 will work to some degree, but definitely will not be optimal. You’ll have low case fill, and hit pressure before the velocity get to where it should be for that barrel length.
3) If all you are doing is shooting 750-1000 yards, then for now, I’d recommend dropping down to a 160gr class of bullet. It will EASILY get you to those ranges, and work much better with that powder. Then once components come back you can work on the 190’s with a more optimal powder. I think there’s someone in the PX selling 162 amax’s right now.

 

[Flea21]

Ok, so a few things.
1) On a short action, with the 190’s you’ll likely be single feeding due to overall length restrictions.
2) H4350 will work to some degree, but definitely will not be optimal. You’ll have low case fill, and hit pressure before the velocity get to where it should be for that barrel length.
3) If all you are doing is shooting 750-1000 yards, then for now, I’d recommend dropping down to a 160gr class of bullet. It will EASILY get you to those ranges, and work much better with that powder. Then once components come back you can work on the 190’s with a more optimal powder. I think there’s someone in the PX selling 162 amax’s right now.

I had manners make me a prs-t with mini chasis and dbm so im not single feeding them considering what that cost me. Part of me wants to rebarrel it, but for $700 more dollars and search for different projectiles at gouge prices, i think it may just go on the PX or sit in the safe... ugh, what a waste!

 

[SonoranPrecision]

I had manners make me a prs-t with mini chasis and dbm so im not single feeding them considering what that cost me. Part of me wants to rebarrel it, but for $700 more dollars and search for different projectiles at gouge prices, i think it may just go on the PX or sit in the safe... ugh, what a waste!

What action is it?

 

[Flea21]

What action is it?

MacBros

 

[SonoranPrecision]

MacBros

So just a thought, you could could have your gunsmith rechamber the barrel to 7mm Sherman Short Tactical (SST). It is a shorter case, with less case capacity. This would do two things. First, the shorter case would make it possible to mag feed those 190’s. Second, the smaller case volume might give you better case fill with H4350 (still not ideal, but probably better than 7wsm).
You’d be in full wildcat territory, but Sherman sells the brass and dies, so those are at least available. And the cost to rechamber would probably be less than what you would lose by selling the rifle, and you’d actually have a rifle afterword.

 

[Flea21]

Okay, my apologies to everyone for overreacting.. I was really bummed there for a little bit.

Berger is developing a load for me with that powder and I noticed it’s used on their 180s in their manual so I’m sure it’ll work for now and maybe for the long haul but once H1000 is available I’m sure that will be a more ideal powder to go with.. thanks to everyone for talking me off the ledge! Lol . My apologies again!

 

[SonoranPrecision]

Okay, my apologies to everyone for overreacting.. I was really bummed there for a little bit.

Berger is developing a load for me with that powder and I noticed it’s used on their 180s in their manual so I’m sure it’ll work for now and maybe for the long haul but once H1000 is available I’m sure that will be a more ideal powder to go with.. thanks to everyone for talking me off the ledge! Lol . My apologies again!

Glad to hear you’re not giving up on it! Check back in when you do load development, I’m interested to see how it does. Especially with those 190’s at mag length!

 

[Steel head]

I’d imagine you should get an ok speed with H4350 but your definitely giving up speed to H1000 and R26.

In a 7 WSM your going to have a ton of bullet in the case at mag length and probably a bit of the ogive in the neck at a 2.94 mag length.

 

[SonoranPrecision]

In a 7 WSM your going to have a ton of bullet in the case at mag length and probably a bit of the ogive in the neck at a 2.94 mag length.

I was curious about that too. 7wsm has a case length of 2.100. The Berger 190’s have a nose of 0.823. So technically it will fit, but not much room to tune seating depth. Fortunately the hybrids handle jump pretty well.

 

[Steel head]

I was curious about that too. 7wsm has a case length of 2.100. The Berger 190’s have a nose of 0.823. So technically it will fit, but not much room to tune seating depth. Fortunately the hybrids handle jump pretty well.

It’s ogive just barely clears in my 7 saum case which is shorter.
The 190’s do quite well with jump.
I’m interested in how much speed the OP can get with H4350 without smoking cases and primers.

 

[SonoranPrecision]

It’s ogive just barely clears in my 7 saum case which is shorter.
The 190’s do quite well with jump.
I’m interested in how much speed the OP can get with H4350 without smoking cases and primers.

Definitely. Out of 7saum, h4350, 175 Berger’s, and a 22” barrel, I start seeing pressure around 2875. No experience with anything heavier though.

 

[Flea21]

Glad to hear you’re not giving up on it! Check back in when you do load development, I’m interested to see how it does. Especially with those 190’s at mag length!

Thanks Bud.. will do. I plan to get all the data I can and will share my findings once I do. If I can match the book data of the 180s, I’d be content. I’ll also definitely play with the length a little past mag length to see if I get a considerable difference after that.. and obviously, I’ll share what I find out from that.

 

[mcfred]

Paper won't know the difference in velocity at 750-1000. Hodgon has one H4350 data point for a 175gr projectile starting at 49gr/2545fps. 190s probably won't be too different, Berger will have guidance. If it's accurate, the Berger 190's BC will buck the wind better than most other projectiles at longer ranges even if you're a bIt low on velocity. I'd at least try it, before looking for a "solution." You've already spent the money, at least try it.

FWIW, you'll only need about 10lb of a more suitable powder to burn out a barrel. That shouldn't be too hard to manage.

 

[Outlaw45]

168 vld with H4831sc I believe 64.0grains. Easily 1/2moa.

 

[Flea21]

UPDATE.... I havent shot it yet, but BERGER got back to me with some load development data. I thought I'd share it with you here for anyone that's curious...

H4350
2.940 Cartridge Length
Via QuickLoad
Starting Load 51.2grs @ 2512 FPS
Max Load 55.3grs @ 2715 FPS
90% Approximate Fill Ratio

I'm looking forward to seeing how this performs in my rifle. Once H1000 or a more ideal powder is available, I'll get some data for that as well, so on and so forth.