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

Nice! What are you launching them with?

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

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]

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.

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.

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

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

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

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

Short .308, Ive got a ton of 308 brass, It's just a 375 whisper(hush) PTG,

I don't know why I didn't say that before.

I'll play with different primer sizes, the small may be better for this application.

Lapua is comming out with some small primer 308 brass. But I may be able to

fire form some 6br straight up.

I have the reamers now, it's just a matter of time and money and stamps now.

Im gonna invest in a small cnc late to turn projectiles. I feel a 400ish gr

critter may be the ticket in this application. But the 350s are a good start.

Mike

I was thinking on trying one on the 308 case with trailboss in a bolt gun. You think that is going to be too much room? Any idea of the powder you are going to try?

Are you talking about Subsonic 308? Or like 30br? Trailboss and 180s are pretty awesome in a 308.

Powders well, N310, Tightgroup, lil-gun, and 3n38 to start.

Mike, pm sent.

"I don't guess I phrased that right - open up a 308 for 375, or neck down a 30-06 to 308 length sized .375 with trailboss". I have a long action Savage just begging to be changed into something suppressed...

Have decided to go with Pac-Nor 375-06 Ack. 1 in 8 for 335 and 350 gr bullets. Trailboss should work. Will have 15" of fast twist barrel left if anybody is interested. Have 32" Bartlein 11 to 10 twist on order for Allen Mag.. 8 to 10 mos out..

Im interested in the pac fast twist!! Hit me up.

Miike

Mike, I spoke with Sierra this morning, according to Dwayne, the 350 gr 375 SMK was a one time thing. They arent planning on making this a production item.:mad:
What are we gonna do now?:confused: Lehigh?..

Im sitting on about 1500 at the moment. Im working on getting some dies made to use fired 5.56 brass as jackets with a similar ogive to the 350 and Ill lathe turn the boat tail.

I think this bullet is great and I would like to make something similar if the investment would pan out with interest from the 375 allen mag shooters and 375 norma mag and 375/338 lapua

Ive got some pretty cool designs in the pipeline with Lathe turned brass and tungsten/bizmuth poly/nylon cores.

Hopefully in the next few months, ill have some available for testing 1st then sale.

350smk http://www.grafs.com/product/271993 they have em in stock for a good price.

Im hoping to have a 400ish grain bad boy to throw out at subsonic speeds

All will be good in the world of 375 land, I have a feeling

Mike

Good news on all fronts :smile: Thanks.

MIKEONE - PM me when ready to go. Would like to have a few...You wonder why Sierra won't make any more. Seems like there is a good market. Jamison International also sells the s. 350, but they like them!