7mm/375 Ruger Project 7LRM

Terry Scott

Well-Known Member
Joined
Aug 31, 2010
Messages
317
Location
Reno Nevada
Living Reno Nevada has some great aspects, one of which is Safari Club, Rocky Mtn Sheep, and Elk foundation all come here for their annual show.
I had the opportunit to spend a great deal of time with G7 at some of these, and low and behold I am now the proud owner of one of their LR barrelled actions in 7LRM AKA 7 MM 375 Ruger.
I'm still a few weeks away from shooting, but I am looking for anyone with loading experience, or suggestions.
I want to shoot Bergers, 168VLDs most likely. The 7 LRM is very similiar to the 7 mag, and I do have some basic places to start, thanks to Mike and Aaron, but anything I can do to put myself ahead of the curve would be appreciated.

I'm hoping for 3200 fps with the 168 vld
 
Do you have a reloading manual?? That is the best place to start out at. Get some numbers from the book on where to start. You'll be able to choose a powder or two from some of these numbers the book is giving you. You'll need a chrono if you are set with that number because the book will give you an idea but it's never right on the money. Seating depth will also help you get a faster fps but will also help with accuracy.

It's going to take time to get the load you want but if you're willing to spend the time and effort you will be successful.

Good luck!
 
You can email berger and they will give you a load for a picticular bullet. They are in the process of building a manual, don't know when it will be ready.
 
Unless they pushed the shoulder back a lot it should be closer to the 7mm STW than the 7mm Rem Mag. Do you know the full/overflow water capacity of the case?

James
 
This cartrige is virtually identical in case capacity to a 7mm dakota. So you could start there. Didn't gunwerks give you ammo for this? If so just pull a bullet and weigh the charge. They should tell you what powder there using. What loads did they tell you to start with?
 
Yes, the 7-375 Ruger will be very close to the 7 Dakota. Dakota advertises 3200 fps for a 160 gr bullet out of a 25" barrel. I think the 375 Ruger case might be a good candidate for good performance with RL17, but RL17 might be a little fast for that volume vs cal? I think I would be looking at powders like H1000 and Retumbo if RL17 doesn't work well. You might try calling Dakota Arms and getting some load data from them. The cases are similar in shape and volume.

-Mark
 
Thanks All, I think I have a great starting point.
I did also get help from the boys at Gunwerks they were very helpful.
The barrelled action is already for being glass bedded. (only got here yesterday) If it shoots as good as it looks it will be a screamer.
Oh and Len if you read this,it looks like it will push the 168 bergers easily past 3200FPS.....
Thanks again everyone:)
 
I own a Gunwerks LR 1000 in the 7MM LRM with the new G7 scope. Mine shoots 180 VLD at 3035 it is a mild load but scary accurate. THe Gunwerks load is 72 gr of H1000 Fed gm215 m primer. Hope this helps. If yours is half as accurate as mine youll be VERY VERY VERY happy. Gunwerks has got a real good thing going and I will be a customer for a long time. Not to mention Aaron and Mike are very helpful and the customer service is second to NONE. Thanks Gunwerks.
 
3035 with a 180 seems low. Especially with that much powder. The 7mags I build for guys run 3000 - 3050 with 180's using 70gr of Retumbo in 26 - 27" tubes. I figured this case would run them faster, something similar to a 7-300 Win Mag.
 
The 375 Ruger has approx 99 grains of capacity. You will loose 4-5 grains when you neck your brass down but that still leaves you with 93- 95 grains depending on the brass of course. That is right inline with the capacity of a 7mmSTW. I would think starting loads for the STW would be a safe starting point. There is a lot of data out there for the STW. Depending on your max OAL the useable capacity could be even better due to the shorter case length of the Ruger reducing encroachment into the powder capacity.
 
This is a very helpful thread to me as well. I am trying to have a 7 lrm built by my local gun smith and was looking for some strting info. What have you guys found out now lately? Hop you had time to shoot it.
 
I believe that the GunWerks load is 72grs. of H1000 lit with a 215 primer. My load is 72.8grs of H1000 lit with a 215m coal 3.455" for 3135fps at 12' from the muzzle. I will advise you to start lower and work your way up.
 
In my 7-300win AI which is close in capacity ,I have gotten the most velocity and least pressure withRetumbo
Extremely accurate as well.
I Have worked up to 83gr retumbo with 162 amax with no high pressure signs.
I got 3220fps with80gr then my chrono batt died before I could test the higher loads.
 
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