7MM WSM velocities
 

After reading a post about WSM loads, I got curious about what velocities Mine is cranking out. I borrowed my pals CHRONY that we have used to develop loads in the past and was quite amazed. I tested 2 bullets, the nosler 160accubond and the speer 145 grand slam. The nosler had 72 grains of MAGPRO behind it and it registered 3289 to 3350 fps

The grand slam had 73 grains of MAGPRO behind it and it clocked 3300 to 3350.

The H4350 was behind a hornady 139 grain BTSP and it wasnt consistent. 3189 to 32?? if I remember correctly. The tests were inconclusive with the h4350, it wasnt real accurate and the wind was blowing the CHRONY off the table at that point.
I am truly amazed with the 160 grain loads. That is an unexpected velocity. I was thinking of more like 3150 or so. It was real accurate at those upper registers along with the grand slam being accurate as well. A slight bit of warning though, the primers and brass did start showing excessive pressure signs with the 160 grain loading of 72 grains of magpro.

I thought the CHRONY was just wigging out so I checked it against a known 243 loading and it came right out. The 243 loading is a 100 grain hornady BTSP in front of 40 grains of H4350 at 2950 fps.
So, the WSM project is coming off nicely! EJ

RE: 7MM WSM velocities
 

Yeah that sounds like a dangerous load to me - by like 200fps!!!

RE: 7MM WSM velocities
 

Those numbers are unreal......either the chrony is bad or you are on thin ice.....howdid the spent cases look?? Did you clean the cases and seat a new primer".... I suspect the primer sockets are blown. There is no way to beat physics......you have a dangerous load IMHO. Be careful. Regards, Rick.

RE: 7MM WSM velocities
 

The primers on the 160 accubonds are badly cratered. I checked these on a CED chrono and they are verified. The 160 load is dangerous. Amazingly accurate but I aint doin that again. The cases do take the new primers just fine.
On the other hand, the grnad slams show no signs of excessive pressure and are real accurate as well. This thing blows the crap out of the old 7mm rem mag I was using. I liked the old 7mm, but it just didnt offer much advantage over the old 270 I was using before that. This is more like it! I am not interested in super velocities for the sake of super velocity, I was wanting to achieve 3200 to 3250 for a 140-145 grain bullet with accuracy in a lighter shorter rifle (short action). Looks like I found it! I couldnt be more sold on the 7mm WSM, the only thing I dont like is the lack of availability of brass. I just order a bunch at a time.

I have had a few people ask me about seating problems and I havent had any. The magazine on my rifle handles the rounds well, feeds every time even with 160's. I got some more 160 grain accubonds I am gonna try with 70 grains of magpro. If anyone is interested, I'll post the velocities of this round as well. EJ

RE: 7MM WSM velocities
 

What 7mm Short Mag do you have? I've been tossing around the idea of buying myself one. Thinking about a Browning A-Bolt Stainless Stalker.

RE: 7MM WSM velocities
 

RR:

Yeah, thats kinda what I was thinkin.

RE: 7MM WSM velocities
 

We have been playing around with a 300 WSM and RL 22(26 inch barrel). We have been approaching velocities of 3300 fps with a 150 grain Sierra MatchKing Bullet. This is a hot load, but no indication of excessive pressure. The load is not very accurate. I have found some accurate loads with 4831-but thevelocities are around 3100 fps.

I have seen different rifles in the past thatyou could get 200 to 300fps variationswith the exact same load.

I have never used MAGPRO-is it comparable to RL22 or RL19, as well as 4350, or 4831??? Iam new to RL 22, but I have been using 4831 for a long time.

I also think that the 3300 fps with a 160 is high, but I can believe that anything is possible. After all we are approaching that velocity with a 150 grain 30 caliber??? Shouldn't the 7 WSM approach or be equal to the 300 WSM if the bullet weights are comparable??? After all, alot of guys on this siteare alwayssaying that the 7mm is superior to the 30 caliber??? Tom.

RE: 7MM WSM velocities
 

I went to the Reloader site and saw the same thing you did. I have only loaded for a couple of 7mm's over the years, and I always loaded the heavier 175's.

I can not debate the difference between comparable bullet weights and different caliber's. I have never studied it that well-so I will take your word for it. I just find it a bit amusing when some member's say the 7mm is superior to the 30 caliber-yet you are saying the larger caliber will yield a slightly higher velocity??? I got to remember this one.

I have also found it hard to compare velocities between caliber's(with the same weight bullet), when I have seen 200 fps swings with the same load, but different rifles(with comparable barrel lengths). Tom.

RE: 7MM WSM velocities
 

That 140 would sure make a great long range ground hog load!!! How many shots do you think your barrel will take with that load??? But then I guess you could always set the barrel back a bit. Tom.