22x47 Lapua Build

[FreddyD]

Building a short barrel 22x47 Lapua to shoot 77TMK or 80-85 grain bergers for a night coyote thermal rig. Thinking 18" barrrel carbon or steel. Looking for action suggestions and barrel manufacturer and twist suggestions please. Any reamer suggestions for the smith as well.

Thinking using manners night stalker stock when available.

Thanks.

 

[jzerfoss]

I have a 20" 22 creed which is close... I would go with the minimum twist possible for the heaviest bullet you want to shoot. I don't know from personal experience, but @Frank Green believes 5 groove barrels may help reduce/prevent bullet jacket separation. If your gunsmith cuts the throat separate, then I would send him a few cases with bullets seated where you want them. If not, you will be limited to whatever he has on hand. Lots of great actions out there so it's kind of personal preference.

 

[FreddyD]

Thank you sir.

 

[jzerfoss]

Thank you sir.

This will help with your twist selection https://bergerbullets.com/twist-rate-calculator/
Also don't go with a reamer that's tight neck

 

[FreddyD]

Thanks

 

[Frank Green]

I have a 20" 22 creed which is close... I would go with the minimum twist possible for the heaviest bullet you want to shoot. I don't know from personal experience, but @Frank Green believes 5 groove barrels may help reduce/prevent bullet jacket separation. If your gunsmith cuts the throat separate, then I would send him a few cases with bullets seated where you want them. If not, you will be limited to whatever he has on hand. Lots of great actions out there so it's kind of personal preference.

The odd number of grooves distorts/upsets the bullet jacket less. Which in turn does help fight bullet failure.

Twist rate, bullet issues, damage to the bore or a really rough throat either from chambering or from shooting.... these things also can cause bullet failure.

Also now I have proof that 5R rifling helps the flight of the bullet... which leads to more consistency or if you will better accuracy. When you run really high pressure ammo or things similar to that.... burrs can be formed on the bullets jacket. I've seen them and they measured as big as a 1/32". This burr can effect the bc of the bullet by as much as 5%. You might not see the effect at short range but it will have a bigger impact at longer distances on how the bullet flies. This was found when doing ammo/bullet testing on 5R barrels vs 4 groove and 6 groove barrels. The 5R rifling never caused the issue.

 

[FreddyD]

Very insightful. Thank you for that information.