New 150 matrix test

[elkaholic]

How do you get your 8-32x56mm scope within 1.6" of centerline of bore? My 6-24x50mm is 1.9" above centerline!

With the 1.6 inch scope mount height, I calculate a G7 BC value of 0.338

You were fighting a headwind!

Ooooops! That explains it! My conquest is 1.6" high on my 6.5 Sherman. The SS IS 1.9". I came up with .337 g7 which matches your estimate at 1.6" Usually, when you think something doesn't add up, there is a reason. Thanks for finding that error. That puts the b.c. MUCH closer to what I guessed in the first place......Rich

 

[barnesuser28]

With a scope height of 1.9", i get a G1 BC of .658 and G7 of .325 using shooter. That is crazy impressive for a 6.5 150 gr!

 

[elkaholic]

With a scope height of 1.9", i get a G1 BC of .658 and G7 of .325 using shooter. That is crazy impressive for a 6.5 150 gr!

I just got .324 and .654 on Jbm, so I think we probably have something pretty close.
Using .325, I get 1000 ft/lbs. @ 1160 yards with 1735' velocity which gives you expansion. Not bad for a little bitty case under two inches long!

 

[Pdvdh]

Approx. 45-50

With a scope height of 1.9" and including coriolis drift, your G7 BC value calculates to 0.320

With a scope height of 1.9" and with no coriolis drift, the G7 BC calculation would be 0.326

Coriolis drift provided 1.2" of bullet lift on target at 885 yds, because of your easterly azimuth. The BC reduction from 0.326 to 0.320 accounts for that 1.2" of height that was from coriolis drift, rather than from bullet BC efficiency. We're starting to swat at the knat's ***, but these sort of calculations help keep me acquainted with ballistics stuff.

I didn't think you could get your scope mounted that low without customizing the objective lens.

 

[elkaholic]

With a scope height of 1.9" and including coriolis drift, your G7 BC value calculates to 0.320

With a scope height of 1.9" and with no coriolis drift, the G7 BC calculation would be 0.326

Coriolis drift provided 1.2" of bullet lift on target at 885 yds, because of your easterly azimuth. The BC reduction from 0.326 to 0.320 accounts for that 1.2" of height that was from coriolis drift, rather than from bullet BC efficiency. We're starting to swat at the knat's ***, but these sort of calculations help keep me acquainted with ballistics stuff.

I didn't think you could get your scope mounted that low without customizing the objective lens.

Boy, this hurts! I was doing some charts with my 6.5 Sherman last and it has a Zeiss which IS mounted at 1.6". When switching back to my 6.5 SS, I just spaced it. Maybe I have too many wildcats

 

[bigngreen]

It's those little things that move the BC's a few point here or there but I would say we're already narrowing the window!! We'll take and do some shooting this weekend using the BC's phorwath just ran and see if we can get some numbers that start jiving with multiple guns and elevations, we ran the optic on my test board so tracking is nailed down on the new 6.5 Sherman and should give us a good dial beyond a 1000 yards.

 

[barnesuser28]

I am going to talk to Marshal and see if i can get in on the next batch of 150s and try them in the 6.5x284, i feel like they would be better suited for that cartridge than the 160s.

 

[Pdvdh]

Re: 6.5 efficiency

I'll admit the ballistic efficiency of the 6.5 is looking good. I've never spent any time considering it before. I've seen too many large brown bear around here for me to consider it as my Alaska hunting cartridge. I'm sure it would kill them from a safe distance with the proper bullet and shot placement. It's the ones at the unsafe distances that dictate my cartridge selection. But I now better understand the enthusiasm for the 6.5s.

 

[elkaholic]

I am going to talk to Marshal and see if i can get in on the next batch of 150s and try them in the 6.5x284, i feel like they would be better suited for that cartridge than the 160s.

I think there is no doubt they are better suited for that cartridge......Rich

 

[elkaholic]

Re: 6.5 efficiency

I'll admit the ballistic efficiency of the 6.5 is looking good. I've never spent any time considering it before. I've seen too many large brown bear around here for me to consider it as my Alaska hunting cartridge. I'm sure it would kill them from a safe distance with the proper bullet and shot placement. It's the ones at the unsafe distances that dictate my cartridge selection. But I now better understand the enthusiasm for the 6.5s.

Ya, I think you might be a little better equiped with your 30/375 S.I. for that game! A short action SS would sure make a nice sheep rifle though
Maybe if you talked nice, someone on the forum would build you one?....Rich

 

[Cold Trigger Finger]

Phorwath. You just need a big revolver! That's what I do with my Creed. I don't think the 30 is a lick better on big bear than the 6.5 . Now a 375 or 416, that makes a big difference on bbb.

IMO, long range and dangerous game don't go together. 50' is much better!!

 

[Pdvdh]

Phorwath. You just need a big revolver! That's what I do with my Creed. I don't think the 30 is a lick better on big bear than the 6.5 . Now a 375 or 416, that makes a big difference on bbb.

CTF,
I've got the .338 & .375 too.
Also Brenneke slugs in 12 and 20 gauge short barreled pump actions, for the closest encounters!

I would, however, always grab a .300 Mag over a 6.5 Mag, or even a 7 Mag. Force me into the alders to finish off a point blank range brown bear, I'll take Brenneke slugs in a short barreled pump action shotgun. However when my primary pursuit is long range hunting, I'm faced with compromise. Bear protection becomes the secondary priority, so the .308 and .338 Magnums fill the primary role of providing effective long range rifles, with the ability to readjust the attitude of an ornery bear should one shows up by happenstance.

 

[Cold Trigger Finger]

Its interesting the developments lately in 375 bullets. . Got my head churning about getting a CZ550 action for the Rigby and having a 378 Weatherby built on it. I have had smart bear problems where I wanted to deliver 4 k, ft lbs but couldn't get within less than 400 yards of the problem.

Sorry for the derail.!

 

[rcerro]

Anybody else try these? I emailed Marshal and he said they have some in stock so I ordered a box and a box of the 160's for my 6.5 saum built on a long action.