HELP PLEASE!!! .308 accuracy issues

[ackertjosh]

Hey all well i got a .308 at auction not to long back and have been trying some reloads for dad so he can take it up Moose hunting this year.
The rifle is a BRNO 601 YKK
The 1st load i tried were some old 180gr Pro Hunters ontop 43.5 gr of Varget, Remington Cases and Federal Match Primer Results were a 2" group. Not happy with that so i went back to the drawing board and loaded up some more in different powder weights from 40-44 taking .5 increments up.. Every load shot the exact same 2" groups .. Decided to try maybe a lil lighter bullet so i went and bought some 165gr Speer Hot Cor and Some 168gr Remington Cor Lokt

These loads tested with Varget and Benchmark trying all different powder weights and still a consistent 2" group...

Is it possible that im missing the sweet spot and should start going up in .2 measurements or is this all the gun has to give? its in very clean condition and the rifling is like new so have a hard time believing its the rifle... as for my reloads it could be.. i do reload for 22-250,6.5x55 and .222 and have never run into something like this but there is a first for everything.. Any ideas out there on what could possibly be the issue?? all loads are at the same COAL of 2.800.. The only thing i can think of is the primers maybe??

Thanks Josh

 

[Sharps '63]

Iron sights or scope? Sounds lie a bedding issue. That or action/scope screws that need to be tightened.

A.308 that won't group is almost unheard of.

 

[9.3mauser]

Changing primers isn't going to make a huge difference in accuracy. If the magazine allows for it, try seating the bullets farther out so they're closer to the lands. If you happen to have any Nosler Ballistic tips, give them a try as they seem to be consistantly good performers in any rifle I've tried them in.

Other things to consider are the scope and mounts. If the groups are strung out in a particular direction it's probably a bedding problem.

It may be that this is simply a 2" gun, which is not the end of the world as far as hunting rifles go.

 

[ackertjosh]

The scope came with the rifle.. its a Simmons 1.5-5 highpowder rifle scope.. Nice looking scope I have thought about taking it off and trying a better scope.. I would like to get a Burris or Vortex or Leupold Maybe thats the next thing in order for the rifle... The BRNO rifles come from the CZ factory and are very high quality rifles(own 2) and are known to shoot very well so i thought that the BRNO would be just as good.... I will try to lenghen my COAL and see what happends but im tryin to refrain from doing so since there are other guys in the hunting party who also shoot .308 and i can just see them running outta ammo and grabbin one of these and have them not chamber or even worse over pressure and then that would not be good having a bolt stuck closed with a moose running back into the bush lol....

How will the Nosler Btips work on moose?? might they not be a bit to explosive? would an accubond be the same BC and SD? if so ill pick some of those up...

The groups are more in a triangle then anything.. not a straight line or anything just a 2 inch triangle..(3 shot) (5 shot) groups are more of a circle.

Josh

 

[9.3mauser]

How will the Nosler Btips work on moose?? might they not be a bit to explosive? would an accubond be the same BC and SD? if so ill pick some of those up...

I personally wouldn't use ballistic tips for moose, but if you're trying to troubleshoot accuracy problems, it's one more variable to check. I would use premium bullets and live the the ho-hum accuracy myself. 2 inches really isn't that bad for moose or even deer at normal hunting ranges.

 

[maynard]

Check the bedding and check to see if the barrel is free floated. If it is free floated you may need to put a pressure point on at the end of the fore stock. If there is a pressure point, you may have to remove it. In a hunting weight barrel it is a hit or miss type of thing with free floating the barrel. Some rifles will shoot better with a slight pressure point, some will shoot better free floated.
Another fact just might be that the rifle is a 2" rifle, not the end of the world for a hunting rifle. Put a bullet into a 10 inch kill zone on a moose and it will die very quickly, maybe not DRT but if won't run too far off.

 

[nitro-express]

Used rifles can suffer from several issues, and most have been mentioned. I would like to add that from my experience I've noticed many suffer from a bad crown.

Also try shooting a 165 Sierra HPBT over 44 grains of Varget. That is my 308 rifle checking load, if that don't shoot, you have a problem. It's possible, with this bullet, to seat closer to the lands than any other, especially with a 2.8" magazine. IMO this bullet will be OK on moose.

A hunting rifle that will group any ammo into 2 inches is still a decent hunting rifle.

 

[sunray]

"...a consistent 2" group..." Far and away good enough for any hungting rifle. Friggin' amazing for a lot of 'em. You're trying to get one hole groups for a rifle that doesn't need 'em. There's no moose that will care what groups the rifle that killed him shot. Can your Da shoot that well?

 

[cosmic]

The Zkk has an additional screw in the forend. Its effect can be to deaden vibration and barrel whip - much the same as a pressure point. This can make it difficult to "tune" a load to the barrel harmonics. Loosen or remove the screw, and see what happens. Make sure the other action screws are tight and the barrel channel is clear.
From another perspective, the screw is doing what its supposed to do - make the gun insensitive to ammo. This was not a bad feature 40 years ago, when very few people reloaded, and factory ammo was limited in selection.

 

[Tex Critter]

This is 10 shots at 100m from Rem 700 .308 using 43.5gr Win 748, Horn 165gr SPBT, WLR Primer & Fed Brass. The tenth shot (flyer 6 ring) was a bent tip. Don't know if it was the bullet or me.
Loaded with a Lee Turret press with Lee dies. .308 is the BOSS.

 

[purple]

If you are getting consistent 2 inch groups with no flyers that tells you that the barrel is performing in a consistent manner, the crown is OK, and that the sighting system is OK too. Most sporting rifles don't get shot enough to cause any serious degree of barrel wear, but some rifles shoot better with a fouled bore while others shoot better with a clean bore. Assuming that your barrel is fouled to one extent or another, I'd try a copper removal routine using agents like hopes No9 Benchrest, Sweets 7.62 or Butches Boreshine. JB paste is also useful to remove metal fouling from a bore. The amount of bore fouling really can't be judged by eye.

Try again after the bore is thoroughly clean. If there isn't a noticeable change I'd look at the barrel contact at the forend tip. Lighter barrels tend to shoot better with some stock pressure at the forend tip. Generally 5-7 lbs pressure to lift the barrel out of contact with the wood is the aim. if you already have contact at the forend tip and it still doesn't shoot well, you could experiment with a floating forend. To try this put some metal (beer can) shims in the stock just ahead of the cutout for the recoil lug of the action until there is no contact between the barrel and the forend tip. Make sure the guard screws are good and tight before any shooting and check this while shooting.

The .308 shoots well with a wide variety of powders in the IMR 3031 to Varget burning range. Primers have the least effect on group size. Varying the seating depth of the bullet can make a big difference in how a rifle shoots the same bullet. The loaded ctg must work thru the magazine and action, but if the magazine and functionality permit, try various bullet seating depths. To figure this out, use a fired case with no primer and powder, lightly distort the case mouth so that it will hold a bullet securely, insert a bullet that has been coated with magic marker ink and then insert the dummy round in the chamber and close the bolt, noting the OAL length of the dummy before doing this. If you see rifling marks on the bullet try again with the bullet seated a bit deeper and re-inked. Repeat the test until you no longer see rifling marks on the freshly inked bullet. A good starting point for shooting is with the bullet .020 away from engaging the rifling, assuming that it still works thru the magazine and action OK. Distance off the rifling can be adjusted by seating the bullets deeper and continuing to test fire.

If things don't improve and the rifle still shoots consistent 2 inch groups, that's not a bad thing. Many animals have been shot with rifles that shoot bigger groups than this.