This has me stumped.

[FOTIS]

OK help me out with this one.

WBY 338-378 WBY Mag Accumark. This is the best she will do! This is 104 gr IMR 7828. 225 AccuBond at 3250 fps. Every load shot like this (all 225 AB's)

Now I have not tested flat based bullets yet but do you think boat tails can make this much of a huge difference?

It is bedded from the factory and it has a very sturdy optic set up. Talleys and SWFA SS 3x15.

What say you?

 

[Dr. Vette]

That's like me and the 300 Wby. If it does better than what you show, it's not repeatable. I have the same thought about flat vs boattail bullets in that one.

 

[truck driver]

Just out of chance have you considered running Dewey's powder ladder test to see if you can find a flat spot node and then adjust the seating depth to bring it in.
Before I tried it the Nosler AB would set me in a fit to get good groups and must have went threw 200 of the .358 200gr AB before I got the seating depth right. Now it's usually 10 for the ladder and 15-20 for seating and it's done and repeatable.
I have found that I'm just an amateur reloader compared to most people here and shouldn't make suggestions on how to do it but this has worked for me with different calibers and different style bullets. So what have you to lose by giving it a try?

 

[SJB358]

Fotis have you tried backing that AccuBond up? Seems like the shorter they are the better they come around.

3250 with the 225 AccuBond is SICK buddy.

 

[FOTIS]

Yup no dice. Will be trying some flat based bullets.

 

[SJB358]

Yup no dice. Will be trying some flat based bullets.

Gotcha. Sometimes a rifle just hates a bullet. No amount of sweat, powder or demon unleashing will make them change :lol:

 

[joelkdouglas]

If it were me I would suspect the flinch was causing it! [emoji51]


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[FOTIS]

If it were me I would suspect the flinch was causing it! [emoji51]


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No chance

 

[OU812]

Fotis does that size of group only happen with 225 AB's? Just by chance have you checked the action screws? My old 338-378 would loosen the action screws after 7-8 rounds and it too was bedded, blue loc-tite didn't even help.

 

[FOTIS]

I have some 210 partitions and some 225 Sierra pro hunters. I will try them. I did try 3 different powders with the. 225 AccuBonds but they all were a no go. The rifle is bedded from the factory and screws are tightened at 65 inch pounds per wby recommendations

 

[joelkdouglas]

If it were me I would suspect the flinch was causing it! [emoji51]


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No chance

No doubting you! When I saw "104 grains of powder" I cry just thinking about it


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[69gto]

Fotis, I would try another scope unless that one has been proven with another load or on another rifle.

 

[JD338]

Fotis,

IMHO, the fast 338's beg for the 250 GR bullets. I'd give the
250 GR AB and 250 GR PT a try.

JD338

 

[Polaris]

I'm in the might not like that bullet camp. Too soon to tell, but this is definitely one possibility.

I had a .308 that shot anything...almost...lights out. Pretty much every bullet I ever tried shot into 1.5 MOA or better, often much better. The one exception was the 150 Sierra pro-hunter. Messed with this one for awhile. Different seating depths, powders, charges, primers. Checked all the screws and such. No dice. Shot 3-4" patterns with all. Maddening as either the Hornady SPFB or SPBT were in the sub-MOA category. Gave up on that bullet after supply was used up.

 

[OU812]

Is this a new to you rifle or has it shot well in the past? My 338-378 never shot well no matter what I tried, that's why it became a 388 lapua.

 

[FOTIS]

New to me rifle

 

[BretN]

I'd move on to the Sierra and PT bullets and see how it does with those. If a gun won't shoot either Sierra or Nosler bullets well, that's when I know there might be some other problem with the gun. Good luck with it, hope it does better. BN

 

[FOTIS]

This is what I am thinking. The scope is a proven 3x15 Super Sniper SWFA in Talley rings. I might try the 225 AB's again at maybe 40-inch lbs of torque just to see if there is a difference, and various 210 PT and 225 Sierras just to see.

Hey, worst case scenario she goes back to WBY. They are guaranteed to shoot well right?

 

[DON]

First thought I have is try the Partitions!

Don

 

[FOTIS]

That would really be something though.....if bullet selection can make such a HUGE difference.