6gt axis build

[wywindsor]

So I have more time than money and a mill and lathe. I bought a 6.5 creed at walmart for 2 Benjerman's. I built an aluminum chassis and screwed on a criterion 28'' 1.7.5 twist barrel. My first outing at 34.6 gr. of varget for 50 rounds was ES of 5 at 2905 average 108 bergers. This was 2 sessions of the same load. There was light extractor marks on some. Primers were not bad at first and worse later each time. Primers were cci 400.

Are axis actions notorious for showing signs of premature pressure? Thoughts

[Robinhood]

I don't believe it is the action. It has been said that prior to the first 150 rds you might drop a grain. Then work up to your current load, you might even see 2950 speeds at that point.

Good luck with the Gay Tiger. It is a bad-arse round.

[sharpshooter]

Cut the barrel back to 27" and you will pick up about 100 fps. and the pressure will drop. You will find those bullets ( 105 to 108 gr) will shoot the best between 3020 and 3080 fps.

[GrenGuy]

Robin & ss have offered good advice. What brand of brass are You using? Is this the first firing on the brass? Until the brass is fire formed to the chamber, I don’t pay much attention to signs. Also, I prefer CCI 450’s for their performance and thicker cups.

You’ve chosen a good round...Good Luck

[wywindsor]

I have alpha brass. How far should the firing pin extrude from the bolt face?

Thanks

[Dave Hoback]

.035” is optimum.

[Whynot]

Cut the barrel back to 27" and you will pick up about 100 fps. and the pressure will drop. You will find those bullets ( 105 to 108 gr) will shoot the best between 3020 and 3080 fps.

This is interesting.... Would you mind expanding on this. Specifically the pressure drop? I would think that far down the barrel that pressure would already be dropping rapidly- so cutting 1" off couldn't impact it....?

[GrenGuy]

Cut the barrel back to 27" and you will pick up about 100 fps. and the pressure will drop. You will find those bullets ( 105 to 108 gr) will shoot the best between 3020 and 3080 fps.

Sounds like knowledge gained from a wealth of experience. I have a 30” 284 Win Barrel that I haven’t been able to get to shoot, that I might give that 27” idea a try.

[wywindsor]

I.'m going to give the barrel 200 rounds and see what happens. I hope nothing as this is a lapped barrel. I have h4350 and 6.5 staball both I will try. I chase speed and accuracy both. the wind blows like no other in Wyoming.

[sharpshooter]

There is an optimum barrel length for every cartridge/bullet combination, and powder range to give maximum efficiency. When you find the efficiency, you'll find the accuracy.
Take into consideration how much barrel does it take to completely burn X amount of Y powder? The best case scenario, the powder is completely burned when the bullet exits the muzzle, not before.
If the powder is consumed 2" before the muzzle, meaning there is no push left, the next 2" is drag. It is also still pressurized. You could judge from a primer or a case and think that it was over pressure.
In fact the pressure isn't higher, it's duration was longer.
The 6 GT fits right in the middle between the 6 BR and the 6x47 Lapua, so the powder range is between Varget and 4350. I have had several 6 x 47 Lapua barrels, and they have all shot the best @ 27".
Have shot several 6BR's and Dashers....they shot the best at 26".

The first Brux barrel I shot in 6x47 was 28", the fastest it would go with a 105 was 2940 fps. It would shoot 1/4 groups at 200, but at 600 maybe 3" at best. After about 800 rounds I added a muzzle brake and freshen up the chamber and while I had it in the lathe, I whacked an inch off before I threaded it for the brake.
The original load was 37.7 of H 4350, and the pressure was right at the top. After the rework, I went with 38.0 of H4350, which gave me 3050 fps. and a noticable drop in pressure. This is where this gun come alive! Now the norm was < 2" @ 600.