Need a hand diagnosing issue-Interarms Mauser 30-06

[NVScouter]

I have this 30-06 that is acting very wierd, and I'm thinking its mechanical now instead of my cast loads.

Backstory:

Picked up a diamond in the rough 30-06 around December, crappy higloss clearcoated stock, minor rust on barrel, extractor, baseplate, etc. I took it home and cleaned it like no tomorrow, starting my soakings the action/barrel in Marvel Mystery Oil for 24 hours.

Then I took the stock and stipped it completely, rechanneled 1" forward of the front reciever bolt to give a nice free float (no epoxy yet). Added a Limbsaver recoil pad lemmon oiled the stock twice daily for 3 days before linseed oil was used for sealer. It looks great, an amazing piece of wood hidden under that cheap hi gloss coat. I also noticed the rear reciever screw is fairly long and shave it a bit for smoother bolt operation.

The tigger was a chunky 10lbs, so I took it down to a semi smooth 7lbs for the first range session. Started with some Unique loads with 124g (113 LEE) and 224 (220g Lyman) rounds at 2400fps and 1600fps. 50 yards the 124s were around an inch and the 224s about 2". Both rounds shot pretty good but the 124s were about 3" low and the 224s around 7" low.

As soon as I moved to 100y the 124s were great still but the 224s dropped to about 13" low. So I posted here and got some 4350 recomendations. I loaded 40 rounds and some 168 Nosler matchs to double check. Much more recoil with these as they are a calculated (not verified) 2300fps. At 50 yards I shot about 1.5" with the 224s and around .75" with the 168s, so I think I'm in the ballpark. Back off to 100 yards and the 168s are a bit over an inch and the 224s are like 7" group......[smilie=b:, the only things that changed were range and going from 4X to 9X.

I suspect my scope/mounts/etc. So new weaver high tension rings and Pentax scope, I also hone my trigger a bit more so its a nice smooth 5.5lbs. Last night I headed back out and shot this at 50y with the same lot of 224s. I shot 6 rounds of site in first at 20y to get the scope close, cooled the rifle then shot. Heck yeah!
http://i44.photobucket.com/albums/f10/NVScouter/march213001.jpg

Backed off to 100y while the rifle cooled down to slightly warm (these loads didnt cause much heat FYI). Took a good rest over the truck bed and shot 3 rounds. Opened the rifle to cool and walked to the target [smilie=b:, Ok its gotta me be me right? I check for leading...nope. Loose mounts...nope. Shoot 3 more [smilie=b:[smilie=b: Out of ammo but I dont think any more would do much good.
http://i44.photobucket.com/albums/f10/NVScouter/march213002.jpg

I get it home and stip it thinking maybe rust in the firing pin or hang up (I think I felt some the last few shots). I pull it all apart, looks great no rust in the bolt or any leading. The only thing I keep coming back to is the rear reciever bolt sits pretty deep, I'm going to try and get a shoulder bushing to put in there today.

I need interpreitation of my groups as its really ticking me off, and I'm sure its something simple.

[pietro]

.

IMO, the bbl/twist is not stabilizing the lighter boolits enough to give the accuracy it does with the heavier ones, out where it counts.

It is what it is.


.

[NVScouter]

Sorry I do t mention the 124s I shot my first session out at 50 and 100. They shot great as did the 224s at 1600fps.

My problems are after the first shoot with faster loads. The 234g at MV 2400fps shoot great the first few rounds then go to a shotgun pattern at 100y.

[Harter66]

Nv,
I've 1 just like that . Its very case volume senitive and charge sensitive. 1load I've worked up goes from 5 under nickle to 3" in a half grain charge and will throw a round 12" out for a 1.5gr case wt change.

Food for thought

[W.R.Buchanan]

Your barrel is probably 1:10 twist. I doubt you are going to get good accuracy from 234 gr boolits as they are probably too long to stabilize with that twist rate. Trying to run them faster just creates a different problem. I assume you are using gas checks as you won't get any accuracy without them.

200 ish gr boolits like 311299 yes. You are looking for around 1700-1850fps for best accuracy.

Also, you may have created another problem when you free floated the barrel on that gun. Some guns just need the barrel supported.

Randy

[Tokarev]

200 gr out of 1:10 twist 30 cal show very good accuracy in my cheap Stevens 200, but 34 grains more would be stretching luck even in 7.92. +1 for bullet too long.

[Chicken Thief]

I shoot the Lee 300 AAC in a 1:12 Winchester with good results (1,364" long and 221gr)

http://i295.photobucket.com/albums/mm153/Chickenthief/Skydning/Til%20andre/R0011305_zps706414cc.jpg

http://www.midwayusa.com/product/938614/lee-2-cavity-bullet-mold-tl309-230-5r-30-caliber-309-diameter-230-grain-300-aac-blackout-tumble-lube-5-ogive-radius

This is 15 shots (at the right) fired from 55yds

http://i295.photobucket.com/albums/mm153/Chickenthief/Skydning/Til%20andre/R0011313_zpsffee5ffa.jpg

You might want to fiddle around with Don Millers spreadsheet.

http://en.wikipedia.org/wiki/Miller_twist_rule

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&ved=0CEIQFjAC&url=http%3A%2F%2Fwww.jbmballistics.com%2Fballistic s%2Fbibliography%2Farticles%2Fmiller_stability_2.p df&ei=zzdbUYP3N8vRsga2hYCADQ&usg=AFQjCNGg9OkKv06I57_NH8U2C64hnJcjLA&sig2=E-EQzr3-_z0b5KDzlECErg&bvm=bv.44697112,d.Yms

So NO your boolits are not to long!

[freebullet]

Your trigger is still to heavy, anything over 3 lbs on a high power is not good for me. 2-2.5 lbs. Is what I would use, you wouldn't believe the difference it can make.On heavy rifles if your going to free float you should probably pillar bed to keep things solid.