Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
Member Login

Site Notices
Posted: 3/28/2009 5:53:41 AM EST
Can anyone recommend a good OAL for the 300gr SMK in a .338 LM Sako TRG-42? My Sierra manual lists 3.680, Vhit's manual lists 3.602 - that's a pretty big difference. I don't even have a factory round to compare it to.
Link Posted: 3/28/2009 6:08:22 AM EST
Standard answer –– use a Stoney Point Gage to find distance to lands, then decide if you want to go single-feed vice magazine-length.
Link Posted: 3/28/2009 6:22:38 AM EST
Got a link to the tool?
Link Posted: 3/28/2009 6:27:30 AM EST
Originally Posted By BlackOp:
Can anyone recommend a good OAL for the 300gr SMK in a .338 LM Sako TRG-42? My Sierra manual lists 3.680, Vhit's manual lists 3.602 - that's a pretty big difference. I don't even have a factory round to compare it to.


The real question is is whether you want the rounds to be mag length? ~3.680" is just about the limit for TRG-42 338LM magazines. I can load the 250 SMKs out to ~3.790", so I'd imagine you can get the 300 SMKs out past that if you want to single load them.

3.677" is as long as I've gone, staying mag safe.

Chris

Link Posted: 3/28/2009 6:37:49 AM EST
Here's the tool:

http://www.cabelas.com/link-12/product/0044519216354a.shtml


Send me a piece of your unsized fired brass and I'll make you a modified case for the tool that is fit to your chamber for $6 including return shipping.

Link Posted: 3/28/2009 6:55:51 AM EST
Thanks, I'll check it out.

In the absence of this tool, though, what's the best way to get a good estimate? I've taken some test rounds and painted them with black magic marker. It seems as though I'm getting feint land prints on them even at 3.680". 3.65" seems cleaner. Maybe it's just me and my eyes playing tricks... but shouldn't I be able to go out to at least 3.68" without touching the lands?
Link Posted: 3/28/2009 7:11:56 AM EST
Originally Posted By BlackOp:
Thanks, I'll check it out.

In the absence of this tool, though, what's the best way to get a good estimate? I've taken some test rounds and painted them with black magic marker. It seems as though I'm getting feint land prints on them even at 3.680". 3.65" seems cleaner. Maybe it's just me and my eyes playing tricks... but shouldn't I be able to go out to at least 3.68" without touching the lands?


I'm sure you're misinterpreting the manufacturing marks for rifling marks. You need to reseat the bullet back into the case, to the point on the bearing surface, where the ink rubs/scrapes off. That's a lot farther out than 3.680" like I said.

Do it again and do it more than a few times with different bullets and then average them all together for your COAL. Or buy the tool.

Chris

Top Top