Shilen 7mm mag help

I recently just got to take out a new build. Its a 116 flat back timed and trued by Stockade Stocks with one of their stocks and their recoil lugs installed the barrel is a Shilen SS 26 inch heavy sporter in 7 mm mag. I loaded up 20 shells touching the lands with 61 grains of 4831 and another 20 using 61 grains of 4350 I sighted in close at 50 yards to get on paper and all shots were touching so I was pretty excited but when I moved out to 100 yards everything went to sh&*%. I couldn't get a group under 2" with no real pattern just all over. My next plan is to back off the lands in .050 incriments until it tightens up the go back to powder changes. Any thoughts?

Both of mine were factory barrels, but they both liked IMR 7828 better than 4831. I never tried 4350.

Mike

Good plan to back off the lands on subsequent rounds. Is the action glass bedded into the stock, barrel floated in the channel, tang floated? Have you double checked mount and ring screws for loosness?

A chronograph will tell you volumes. What bullet weight(s) are you shooting, flat base or boat tail? Low Standard Deviation (SD) and Extreme Spread (ES) figures will tell you if the rounds will most likely be more accurate at ranges farther than 100 yards. It may be your bullets have not settled down at 100 yards and still have a bit of yaw opening groups. Try the same loads at 200 and 300 yards. Are you shooting three or five shot groups? With a sporter barrel, especially a magnum, three shot groups won't heat up the barrel like five shot groups would. Also recheck you barrel clearance when the barrel does heat up, you may find it's touching at some point in the channel. Let us know how it goes.

Headed back out this friday with a chrony barrel is floated bolts are tight

I have recently been developing loads with my new FCNS model 111 in 7mm rem mag with a match barrel. I have gotten a six shot group at 100 yds to a group size of .6". You have to remember, not every rifle/bullet combo likes to be touching the lands. Jump isn't always bad. Here's what I did (the same thing that Berger recommends to find the "sweet spot" with their VLD bullets) I loaded 10 rounds touching the lands, 10 rounds .04" off the lands, 10 rounds .08 off the lands and 10 rounds .12 off the lands. When I shot these rounds, I shot five from each group. My best group were the ones that were .08" off the lands (or jump). The rest all grouped about 1.5". Once you find out where your rifle likes the jump, then you can seat your bullets a little longer or deeper to see if you can improve your group size. And I mean move it very little. After you are satisfied that you have the best jump for your particular rifle, then you can try tweaking your powder charge to see if you can squeeze more accuracy out of it. If I would have only loaded to the lands like you did, then I would have been very disappointed. Give that a try. I bet you find that one of those groups will outshoot the others by a considerable margin. Oh, and next time I go to the range, I will shoot the same loads once more (using the remainder of the ammo that I loaded) remember, I loaded 10 rounds of each seating depth mentioned above. The idea is that next time I will shoot the remaining five rounds from each group to see if they follow the same pattern. Once they show me the same information twice, then I can be sure that the results are truly from the load and not from other factors such as shooter error. Hope this helps. Don't get frustrated, just systematically change things a little bit at a time until you get things where you want them.
Steve

+1 on what Steve said. As well, I recommend reading Dan Newberry's method (http://optimalchargeweight.embarqspace.com/) for finding your best powder charge. It sure worked for me in my Savage 110 in 7 MM Rem Mag.
You can read the Berger recommended method for finding seating depth at (http://bergerbullets.com/Information...20Designs.html) under the heading VLD Bullet Design near the bottom of the page.

Good luck.

Dennis

My sweet spot was 0.037inch off the lands with Berger 180 VLD and Reloader-22. I followed Bergers recommendations at 0.00 0.040, 0.080, and 0.120inch off the lands. The groups were DRASTICALLY different at 0.040 for me, then I fine tuned in.003inch changes. This was followed by powder adjustments (stockade gun...). I get 6-9inch groups a 1000yards with this gun.

Thanks guys I have some 168 berger's coming anyone have some powder recomendations for starting.

ofdscooby, if your interested, try going to "thebestofthewest.net",,in the forum on favorite loads, it give a LOT of info on loading the Berger 168's and 180's. The guys that used to be on the show shot elk out to 1000yds, and killed them, with a 7mag. Alot of info...but work up to the loads, etc, etc.......rsbhunter