Load dev for a mates .284win Tikka

Here is the initial load testing for a mates .284win tikka 21.75" (was 22") that he bought 2nd hand. The barrel is rather pitted, the crown and 6mm of the muzzle was rotted out rough until i trimmmed,recrowned and rethreaded it.
Its pretty lightweight at 3550gram ready to shoot (incl suppressor).

I used GRT to simulate some loads and pressure. The chamber must have been cut with a match reamer throated for 175-180gr class bullets. The 162gr eld-m seated perfect above the neck/shoulder junct is still jumping 0.100", i like about 0.050" for eldm and eldx pills in other cartridges.

I was trying 3 powders with the 162gr eldm seated to a COAL of 3.150". All are ladders going up in .2gr increments. I shot the ladders round robin starting from the lowest charges (ie 2209,2213, sf, sf, 2213,2209,2209...). Numbered shots on target are actual load/shot order for each powder ladder. Recorded on my camera.

Attachment 285835
Attachment 285836

Attachment 285830
Attachment 285831
Attachment 285832
Attachment 285833

The 2209 appears to be the most consistent powder for POI across the charge spead. The SF wasnt bad either so I will have a run with some more of those, probably continuing the ladder charges a few more steps too.

Looks good the eldm at any of those speeds will be deadly

It's a wonder it shoots that well given the apparent barrel condition. Must have suffered some significant neglect to get like that.

Quote:

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Originally Posted by 6x47

It's a wonder it shoots that well given the apparent barrel condition. Must have suffered some significant neglect to get like that.

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I have a video of this bore. Its shit house, i had trouble trying to find where to cut the crown to avoid having it interrupted by some pitting.

Ive accurised a bunch of firearms in the last couple of years. Bore pitting is less important. The last 10mm of muzzle and the crown are the most important for precision. The muzzle has to be the tightest bit of bore and the crown has to be sharp and uninterrupted to have an even muzzle gas/blast pattern to not uoset the bullet. My opinion is that it effects boattail bullets the most as the tail acts like a rudder on the bullet and the uneven muzzle gas steers it.

@6x47

I have seen that tikka ceracoated barrels appear to pit/rust worse that normal tikka s/s barrels. Are they a lesser stainless because of the ceracoating (cost ofset?)

Quote:

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Originally Posted by Roarless20

I have a video of this bore. Its shit house, i had trouble trying to find where to cut the crown to avoid having it interrupted by some pitting.

Ive accurised a bunch of firearms in the last couple of years. Bore pitting is less important. The last 10mm of muzzle and the crown are the most important for precision. The muzzle has to be the tightest bit of bore and the crown has to be sharp and uninterrupted to have an even muzzle gas/blast pattern to not uoset the bullet. My opinion is that it effects boattail bullets the most as the tail acts like a rudder on the bullet and the uneven muzzle gas steers it.

@6x47

I have seen that tikka ceracoated barrels appear to pit/rust worse that normal tikka s/s barrels. Are they a lesser stainless because of the ceracoating (cost ofset?)

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Maybe ceracoat gives a false sense of security and less care is taken?

Quote:

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Originally Posted by Roarless20

..
I have seen that tikka ceracoated barrels appear to pit/rust worse that normal tikka s/s barrels. Are they a lesser stainless because of the ceracoating (cost ofset?)

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It makes no sense that they're any different to the std barrels. I can see merit in the comment above. Much the same owner mentality of CM v "stainless".

Most production rifles cerokote seems weak compared to getting a rifle done after the fact makes me wonder about cerokote on a production line are the barreled actions sitting around for a period before getting coated and locking in salts and moisture the cerokote on my rifle has being a game changer to the exterior maintenance on extended harsh trips ie Stewart island or wet weeks of bush stalking

more likely the "dont clean your rifle until it stops shooting straight" mentality...

and then they try to sell a second hand rifle (with "fired less than 100 rounds").