7MM Br. Special Application

[lelongcarabine]

Heres one for ya! I need some safe subsonic data for the 7BR Remington cartridge. Anyone out there with experience with this case in a rifle?
I have a premium 7MM tube with a 1-8" twist, jgs reamer and a Remington action. While I know there is a plethora of data for HV loads. How about some data for 950fps-1030fps with the 160-180 grain bullets?
I know there can be a negative stigma about this application. However, I live in an area with a growing population and need to shoot quietly. I use subsonic ammo in my .22 just to keep on tolerable(shooting) terms with the neighbors.
I often have the opportunity to take deer behind my studio/shop(legally, of course) but dont want to scare the neighbors. Your input is appreciated. Greg

 

[lelongcarabine]

PS, Cast bullet loads are good fodder also. I have lots of lead! Greg

 

[mattri]

Don't have any information for you but its a great question. Good job addressing "stigma" as well. I would love to shoot with a suppressor for the same reasons but don't even want to start down that road. Anyway great topic.

 

[2644ever]

LeLong, since you have an 8" twist, it makes things a lot easier! Use the 175 Sierra #1940, it has a high bc, is long enough to use up a lot of inner volume and its terrific sd is required due to the low speed you intend to drive it.
Start with 9 grains of Vihta N120 or 7 grains of N 350. No filler. Or try the US (roughly) equivalents of these powders and you shouldn't be disappointed.

 

[Wild_Bill]

try Hodgdon Trail Boss with a 175 MatchKing or if you want better expansion the 162gr A Max start with 8 gr and work up or down until the desired speed is achieved it is a lot bulkier than other powdes and ususaly 10gr is used in a 308 for a sub load.

Cheers Bill

 

[lelongcarabine]

Thanks for the replys, Gentlemen! Is this data that you have actually used?
I am concerned about the possibility of "Secondary Explosive Effect" of certain reduced loads. Thats one of the reasons I posted this query. I know that, in the past, Lyman was famous for reduced cast bullet data for large cartridges. That data was tested.
The jacketed bullets I would use will be molycoated. Thanks again for your replys. Greg

 

[TonyR]

I believe that there is a discussion of reduced loads with TrailBoss on the Hodgdon website.

 

[lelongcarabine]

Thanks Tony and Wild_Bill! Heres the link if anyone else is interested, including some proven reduced load data. Greg

http://www.hodgdon.com/PDF/Trail-Boss-data.pdf

 

[lelongcarabine]

2644ever, I am interested in your VV Data also!

When I get this put together, it should sound about like a "Cat Sneeze" when fired ;D!

 

[lelongcarabine]

Heres some more general information that I have found in researching this project. I was set to sell the barrel and reamer until I read these articles. Lots of history(links) and many bunny trails, but, you may find it interesting. Enjoy! Greg

http://members.shaw.ca/cronhelm/DevelopSubsonic.html

PS. In retrospect, I think the .30BR would be a better candidate for subsonic loads.