New BUllet testing Pt 2

[toolsofthetrade]

here is the fired brass from the 108's

Next up was 114gr Hornady INterbonds loaded with same brass and primer but 29.5gr of 8208.
Accuracy was not as good as the 108's measuring 3 shots were 1.88 and the 4th made it 2.39, but again, could've been some me factor in there, but I feel confident my rifle likes the 108 better.
Velocity spread was 2862,2860, 2864,2844
recovered bullet weighed 108gr and was .644 in diameter.
penetration was almost the same as the 108.


Incidentally I was also shooting my .308 and a new Ruger American in .30-06, I had two of the big (5 gallon) jugs left over with water in them so I shot them with the .308, load was 43.5gr of R15 pushing a Nosler CC 175gr. At 100yds this is what it did to the 1st jug

bullet completely fragmented, you can see a piece of the jacket came through from the inside, bullet did NOT pass through but split the jug

[Rust]

Those loads look pretty hot. Primer craters and from the photos it looks like your getting some swelling of the cases too. Have you measured the webs to see if/how much they're expanding?

[sneaky one]

Tools, those 108's are a bit warm. Still, a nice job trying something different. The 107-8 is my choice, (I hit 2700 +) your rifle seems to spin those better than the heavies. I add .5 gr. powder per 5grn. bullet wt. loss, using - A 112 Ibond, and 29.0 8208 was the starter setup,( mseric was there as a witness) -perfect primer on that one. Let me know what you're thoughts are. Dan.

[toolsofthetrade]

no I have not measured the web....I will check that out.

[toolsofthetrade]

ok, measured the case, the measurement at the base of the case prior to the recess to the rim (is this the web?) is .443, just up from that past the now shiny part measures .440, and the thick part in the recess between the case head and the base of the brass measures .369.
So...how is that?
according to the specs Ive seen its still below spec.

http://www.accurateshooter.com/technical-articles/cartridgediagrams/#65Grendel

[JASmith]

Have you done an unfired case and then the same case after one firing?

Best to measure about .14" to .15" up from the rim (very close to the extractor groove). That way you will be measuring the solid part of the web. Use a magic marker to scribe a line across the base so you can measure the same direction after the shot.

The after shot measurement wants to be in the same direction across the base and the same distance up from the base too.

The dynamics of the AR gas system make measuring above the web to detect serious pressure problematic when the bolt unlocks even just a little bit early.

[bwaites]

the dynamics of the ar gas system make measuring above the web to detect serious pressure problematic when the bolt unlocks even just a little bit early.

this!!!!

[sneaky one]

Bill, this what?