finicky .338 mag

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fairview mick

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I have a Weatherby Vanguard in .338 Win Mag. I have tried quite a few differnt loads and I'm having trouble finding a load that will give me consistant 1 moa or better all the time. I'm shooting from a bench, using a lead sled rest. The barrel has been free floated, and I have an excellant scope. Most of the time I load Hornady 225 and 250 grain bullets at different muzzle velocities. Ther have been times that the first two shots of a group of three will be 1/4 inch and then the third will be an inch and a half. What the hell is going on??????????????????????????
MIckey
 
How long are you waiting between shots? My Savage .338 will act like that unless I am really, really patient. It heats up real quick, and seems more affected than my 7 Mag. I have a lead sled but no longer use it. Don't think that's your issue, though. Let her cool off (always good advice!)
 
I'm no expert but after reading many threads on TFL about this or something like it . It can be many things from the stress never being relieved from the barrel . This can cause the barrel to expand and contract differently in areas and the barrel shift POI . The bore may not be perfectly centered in the barrel and that can cause one side of the barrel to heat up faster then the other side and that will change POI when barrel heats up . the barrel and receiver may not be square and true to each other . As the barrel heats up the area of the barrel that is pressing more against the receiver will push the barrel in one direction causing POI shifts . Those are some of the hardware issue they may be present . Then there's the software issue ? Are you using Match grade bullets . I'm really just getting into the whole accuracy thing and the mind boggles at how many things cause inconsistencies . Are you jumping the bullet or are they pretty much up against the lands or just off ? I hear jumping can sometimes cause inconsistencies . OH so many possibility

What I'd like to see come from this thread is what do you start to look at first and what would be the proper way/order to start to eliminate issues one step at a time . I see guys all the time have a problem with something and they change 2 or 3 things and that fixes the problem . The problem with that is they don't know which one of the 3 thing they fixed was the actual problem
 
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As Metal God stated, there are a bunch of reasons this could be happening. Check the to make sure the barrel is not making contact with the stock after you shoot the rifle, while the barrel is still hot. Also shoot a few 10 shot groups, tracking each shot, so you can see if there is a pattern to what's happening.
 
using a lead sled rest.
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That'd be my first suspicion. IME, the higher the recoil, the less the gun likes being in a Lead Sled.

Try shooting off sandbags.

Also, are these handloads? If so, I'll move this to the handloading forum for more exposure and it would be helpful if you included the pertinent load information.
 
I disagree Brian . Just because they are hand loads in no way makes that the likely problem . I have started threads thinking one thing and was quickly turned another direction . Maybe move to general rifle .
 
I didn't say handloads would be "the problem".

Folks who are into handloading for rifles (probably) know about rifles. Folks who shoot rifles but don't handload will (probably) not know much about handloading. Therefore, if the OP is using handloads, it seems likely that the overall greatest knowledge base for his problem would be handloading.

If the OP wants it to stay here, even though he's using handloads, all he has to do is say so.
 
What I'd like to see come from this thread is what do you start to look at first
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I would start with least expensive and work towards more expensive. Just guessing that this is a hunting rifle.

1 let it cool for 5 minutes between each shot. That will rule out the uneven barrel/action surfaces and stresses in the barrel. If it works and, if it is a hunting rifle that might be all you want to do. First shot counts most. If it is a target only gun not so much. Then you take it to a smith to true the action/barrel faces.

If letting it cool doesn't change anything go to 2

2 switch to sandbags and ditch the lead sled. If that doesn't help, make sure the stock is not flexing enough to touch the barrel. If it is, remove more stock material to restore the free float.

3 try match grade bullets of several varieties. Also try different powders.

4 bed the action to the stock. This could also be number 3 on the list, unless the next powder/bullet combo works. If you do it yourself it is less than $50.

Sounds to me like the barrel is heating up and shifting poi.
 
The most frequent cause of poor accuracy with heavy recoiling rifles shot from a bench is the shooter's inability to manage the recoil exactly the same way for each shot. It doesn't take much of a position or grip change to cause a 1 MOA error. Therefore, I don't think this issue is caused by the ammo or rifle alone. Most folks shooting heavy kickers will get better accuracy shooting from prone slung up properly and resting the stock's fore end on a bag. This assumes the shooter doesn't flinch or yank the trigger back hard disturbing the rifles aiming direction before the bullet leaves the barrel.

Shooting procedure. . . If you don't see the muzzle flash of the round firing, your aiming eye was closed when the round fired and you have no idea whatsoever where the rifle was pointing when the round fired. Discard any bullet hole that happens when you're shooting blind.

The above aside, it's also important that all the screws in the hardware are snugged up and nothing's loose. Stock and scope mount/rings screws need to be checked.

Handloads. . .The difference between match and standard bullets at 100 yards is only 1 or 2 tenths of an inch; at most. Don't blame the bullets. But it is possible to kludge up the components either by selection or assembly.
 
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Answers to all the help for my .338

Thanks you all for the input. Alot of informed people on this forum. That's I've been with it as long as I have. Thanks again. I'll give oput a few know facts. The stock is not touching after heating up. I have run two dollar bills from front of the stock to the action with out any touch. I hand load the Hornady bullets exclusively(225 grain sst) using either RL19 or H4350. The gun hates IMR 4831. Lat week I tried some Speer 250 gr matchking and that was not real good. They were between 2600fps to 2700 fps, using rl 19 and H4350.
I know when I have a good squeeze on the trigger, because, it will somewhat surprise me. Also, I have a great Timney trigger that is set for about 2&1/2 pounds with zero creep!!!!!!!!! Bt the way, I scale measure EVERY load, no matter what I'm loading, whether it's a light .38 for my wife's target gun, or my .338.
Thanks so much.
Mickey
 
Bart B, I agree with you from an accuracy standpoint that prone is steadiest. The catch 22 is that prone is the worst position for absorbing recoil.
 
Bart is right on about holding rifle exactly same shot to shot. This is extremely important on heavy recoiling rifles!!!! The rifle begins to recoil while the bullet is still in the barrel so even the slightest difference in cheek weld, grip on stock, etc. will affect POI.

Strapped up in a sling in prone position is an extremely accurate shooting position, but if not comfortable w/recoil can distract some shooters.

Since you are getting two shots together and one flier, I would concentrate on position from shot to shot before looking at ammo/equipment.

Regards,
hps
 
Mickey, read one of your post about accuracy from your Ruger 388mag and 1" groups so you know how to shoot and can handle the recoil.

You might want to try different bullets beside Speer.
 
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