338 Snipetac data needed

[lazylabs]

Does anyone have data they are willing to share? How about any experience with the rocky mountain bullets in this caliber. I got a stack of 300 SMK's but I need to pick up a keg of powder to start with. What powders have you seen the least amount of temp change with?

Thanks

 

[Joel Russo]

Best to get a hold of Dave Viers, he'll give you all the info you need.

In the mean time...

My suggestion is to start with the 300 SMK as you most likely have a 10 tw barrel. Use H50BMG, and target 3200 fps. That's where you'll get the best accuracy, and case life. Depending on how fast or slow your barrel is, you will most likely fall in around the 132-135 gr area. Start around 127 grain and work your way up.

Need more help, shoot me a pm.

 

[blackwidow]

I use retumbo in my 375 cheytac. Seems to be the powder to go with with the cheytac sized cases. I have a 32 in barrel and am getting 3165 fps with rocky mountain 370 gr bullets. I'm using around 130 gr of powder.

 

[lazylabs]

Do you have any chrono data for the same load at temperature extremes? How do you like the rocky mountain bullets? It's hard to spend $215 to try a bullet that may not work well in that specific barrel. It might be interesting to see if the new Hornady bullet will handle 408 velocities. I just don't want to waste 1/4 of the barrel life finding a bullet/load.

 

[blackwidow]

I tested those in august and it was around 80 f I used retumbo in my weatherby I had and maybe had about 20 fps difference between summer months and cold winter months. I got the bullets from lawton barrels in montana they were on sale for 135 for 100 and they seem to stabilize fine in my 1-11.5 twist. I just did a ladder test with them with out the crony till I saw a sweet spot then went back did a refined ladder test and got right under a inch at 400 yds so I cronied them at 3160 used maybe 15 rounds to find the load. If I had the 338 snipetac I woud go for the 325 gr bullet rm bullets has. Bc is over 1.0

 

[lazylabs]

I ordered a 10 twist barrel before I saw the 325's and I am not sure they will stabilize in it. It is a 34" barrel so that should help keep the velocity high.

 

[Joel Russo]

The 10 twist will not stabilize those 325's.
Unless you really want to have the longer barrel, there's no need for it as you can pull the same velocity with a 30" barrel.
When I say same velocity, I mean the velocity that I have found that gives the best accuracy and the most case life...

 

[lazylabs]

The barrel is off getting chambered by Dave this week or next so it's staying 34. I am building it bull pup style with a barrel block so it should be fairly rigid and transportable. Joel, when I get really ****ed off building the stock I will be calling you to get me a A-5L....haha

 

[Joel Russo]

That should be a neat package. Dave Wilson built an Edge in the same configuration. I made him a thumbhole stock after he whittled away on the pattern. There's a thread on here about the rifle.

Took me a while, but I found the thread.

http://www.longrangehunting.com/forums/f23/338-300-rum-bullpup-posted-dave-wilson-19728/

 

[lazylabs]

Joel

That was where my idea started. I talked to Dave about getting some info from him about his design and even getting a copy of his stock. I got a little distracted and ended up just getting around to the project now. I am still going with the barrel block with integrated sight rail and trigger mount point. I am going to weld the block into a square AL tube as the base. I am thinking about making the rest of the stock fully adjustable sort of anschutz inspired.

I may bug you for some chunks of laminate to make a pistol grip and cheek piece out of. I got a piece from you before to extend the stock on my 50 cal and it worked out great.

 

[Joel Russo]

That sounds like a neat project. Wilson is really happy with his rifle, and it really shoots well.
I remember sending off some wood to you quite some time ago. Glad it worked out.

If you need some ideas with the stock, just give me a jingle, I may be able to save you some frustration...