300 Win Mag / H1000 / 200 Accubonds test ( Part 2 )

[TackDriver284]

From the last test, I used Lapua brass and speed was faster than normal with mid charges, Lapua brass H20 is 92.11 and Norma is 94.96, Lapua brass neck is .0015 thicker than Norma brass, loaded neck with Lapua brass gives about .0015" clearance while Norma has about .004" clearance. Groupings with Lapua brass was not great at all so I swapped cases and used virgin Norma brass. Still have 40 pieces,,,

Norma brass / H1000 / 200 Accubonds
76.5 gr. 2933 fps ave ( 3 shots )
77.0 gr. 2969 fps ave
77.5 gr. 2977 fps ave.
78.0 gr. 2992 fps ave

Recent test with Lapua brass ( August 4 , 2024 )
Fouler : 76.6 grains / 3,005 fps
77.0 grains / 3041, 3075, 3068 fps
77.4 grains / 3052, 3018, 3061 fps
77.8 grains / 3096, 3025, stopped shooting
78.2 grains N/A

3 shot groups today with Norma brass was a lot better than the recent test with Lapua brass which gave about 1.25 - 1.5 inch groups.
.020" off the lands and the last group opened up, so I will go back to 77 gr. of H1000 and seat deeper, looks like I'm in the ballpark. 2970 fps with 200 Accubonds is almost 4,000 lbs muzzle energy. It's good nilgai medicine.
Just called K&M to order the 30 caliber cutter, pilot and mandrel to turn those Lapua necks which is too thick and causing high speed and pressure issues.

 

[JD338]

Looks good Mark. Seems to be on track. Should make some fine Nilgai medicine.
When is your hunt?

JD338

 

[Aussie Wanderer]

That looks much better with the velocity gain increments and nice accuracy too. Chasing Nilgai should be an amazing adventure, best of luck with the hunts.

 

[IdahoCTD]

Looks like most of the problems are solved, good job.

 

[TackDriver284]

Looks good Mark. Seems to be on track. Should make some fine Nilgai medicine.
When is your hunt?

JD338

Thanks JD. Soon, unfortunately my buddy's in law shot that bull nilgai that was killing those buffalo. He needed it gone asap and my rifle wasn't ready. Oh well, going to wait a while and see what comes, and by then I'll be ready for sure.

 

[TackDriver284]

Thanks to some of the guys on here who helped narrow down the search to find the issue with the 200 Accubonds, Thank you @jimbires and @IdahoCTD.

 

[Cneelk]

Nilgai is excellent table fare as well, enjoy

 

[jimbires]

that looks much better . glad you're on the right track .

 

[FOTIS]

Nice horsepower!

 

[IdahoCTD]

Thanks to some of the guys on here who helped narrow down the search to find the issue with the 200 Accubonds, Thank you @jimbires and @IdahoCTD.

Your welcome. Sometime things so simple are amazingly frustrating. IMO that is a Lapua issue. Their clearances are too tight even for SAMMI spec chambers.