Quarterbore's Forums

Quarterbore's Forums (http://www.quarterbore.net/forums/index.php)
-   Other Subsonic Topics (http://www.quarterbore.net/forums/forumdisplay.php?f=60)
-   -   Welcome to the .375 350gr SMK (http://www.quarterbore.net/forums/showthread.php?t=3089)

MIKEONE 11-17-2009 03:09 PM

Welcome to the .375 350gr SMK
 
Well I finally got some bullets for my .375 build. I could not get any info or pictures and that pissed me off so here are some pics, 1.75 in long so a 10 twist should be fine.



These should be interesting with a .40 cal pistol can.:grin:

:welcome:

[IMG]http://i201.photobucket.com/albums/a...o/bbbsmk-1.jpg[/IMG]

[IMG]http://i201.photobucket.com/albums/a...oto/cutk-1.jpg[/IMG]

[IMG]http://i201.photobucket.com/albums/a...hoto/cut-1.jpg[/IMG]

Mike

Spook 11-19-2009 10:08 AM

Nice! What are you launching them with?

strycnine 11-19-2009 10:25 AM

Quote:

Originally Posted by MIKEONE (Post 16390)
Well I finally got some bullets for my .375 build. I could not get any info or pictures and that pissed me off so here are some pics, 1.75 in long so a 10 twist should be fine.



These should be interesting with a .40 cal pistol can.:grin:

:welcome:

[IMG]http://i201.photobucket.com/albums/a...o/bbbsmk-1.jpg[/IMG]

[IMG]http://i201.photobucket.com/albums/a...oto/cutk-1.jpg[/IMG]

[IMG]http://i201.photobucket.com/albums/a...hoto/cut-1.jpg[/IMG]

Mike


That's a serious chuck of copper and lead:eek:! What you going to shoot them out of?

MIKEONE 11-19-2009 11:31 AM

Lets just say for now, something that requires a few stamps and some custom reamers to arrive so I can make dies and chamber the barrel. :smile:

[IMG]http://i201.photobucket.com/albums/a...ocketstart.jpg[/IMG]

Artful 11-22-2009 02:22 PM

Quote:

Originally Posted by MIKEONE (Post 16424)
Lets just say for now, something that requires a few stamps and some custom reamers to arrive so I can make dies and chamber the barrel. :smile:

Tease - I saw a 375 WCF contender barrel with a 1:12 twist and thought about making one up. I have a NEI mold that you put 3/8 copper tubing in and cast a jacketed bullet - it would be a sweet cheap toy.

LouBoyd 11-22-2009 04:00 PM

That must be a new bullet from Sierra. It's not in my Quckload database. Could you post it's important dimensions for handloading? Those would be:
Overal length
shank length
boattail length
boatail diameter.
Has Sierra stated it's G1 BC? I'd expect it to be close to the 300 grain 338 SMK. It would deliver 16% more energy at the same velocity just because of the added mass.

I haven't seen this bullet before but I've looked at what could shoot the 375 330 grain Lehghs subsonic and concluded that they would work nicely in a bolt action using a cartridge like a 7mm BR but with a .375 neck. It would probably be easiest to make by necking down 308 brass, The shoulder would only be .06" larger than the neck, but that's plenty. I'd expect that to be good for the 350 SMK too.

Dies would only requre reaming the neck area of a 7mmBR die to .400 +/- and using a 375 expander ball.

A custom chamber reamer might be requried but I thnk it could be chambered using a 7mm BR reamer with an overside pilot (or a solid pilot in a well aligned lathe) to cut the shouilder followed by a 375 Win Reamer to cut the throat and neck.

The 375 WIn cartridge has 48 grains capacity compared to about 41 for a 378-7mmBR and about the same pressure rating. The smaller capacity should give a little better velocity consistancy. The other advantage of the 7mm BR is it's shorter and uses a 308 size boltface. To me it sounds like a good use for a 30-06 or 270 mid length Win 70 or similar requiring no modifications other than a barrel change. I'm not sure with the Sierra 350 SMK but I don't think 375-7mmBR with the 330 grain Lehighs will fit in a 2.8" or even a 3.0" short action.

pud-knocker 11-22-2009 06:49 PM

Quote:

Originally Posted by LouBoyd (Post 16459)

.....That must be a new bullet from Sierra. It's not in my Quckload database......


I heard that Cheytac had a special run of them made for their 375 chey, jamison is making the brass, 160gr H20 capacity, lots of BOOM.....something close to a buck a piece for the .375 / 350gr......

here are a few thread links.....

https://www.24hourcampfire.com/ubbth...2442390/page/1


http://www.snipershide.com/forum/ubb...Number=1400575

http://www.jamisoninternational.com/...ytac/288874203

MIKEONE 12-12-2009 12:50 AM

I did a workup in Quickdesign, and got a projectile that is close in most regards, without going to a coordinate plotting machine. Ill post it when I find what computer it's on.:rolleyes:

im gonna do a ar-10 and a bolt so when the parts and stamps arrive it's on.

Should be fun.

Mike

MIKEONE 12-12-2009 09:29 PM

This is the first attempt, The ogive radius may be a tad off lol and the bearing surface!! I cant seem to find the 2nd one I did but here's something

http://i201.photobucket.com/albums/a...75smkclose.jpg

Mike

Spook 12-16-2009 09:18 PM

Mike is this gonna be a a 375 off a 6BR case?


All times are GMT -4. The time now is 04:27 AM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2016, Jelsoft Enterprises Ltd.