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1
Bolt Guns / PRECISION RIFLE
« Last post by mustangmike67 on October 07, 2018, 09:29:47 AM »
HAVE A RUGER 6.5 CREEDMOOR. WHERE CAN I BUY 10 ROUNDS MAGAZINES FOR IT, NEED HELP!
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General Discussion / PRECISION RIFLE
« Last post by mustangmike67 on October 06, 2018, 08:12:33 PM »
Have a RUGER 6.5 CREEDMOOR , where can I buy 10 round magazines for it, need help!
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Parts & Gear / PRECISION RIFLE
« Last post by mustangmike67 on October 06, 2018, 08:06:39 PM »
where can I buy 6.5 Creedmoor 10 round magazines ? need help
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Reloading / Re: ES/SD, Primers, Neck Tension, Give me your input!
« Last post by Rooster on October 05, 2018, 06:16:23 PM »
Okay, this thread has some age on it, but I'm trying a new place to participate in topics that I see here without the drama & dick swinging that I see elsewhere...

To the topic, I've never quite been able to calculate why there is so much emphasis placed on SD. For me, ES seems to be adequate. If I know the range of velocities over a reasonable representation, I can effectively predict a POI at given range - within an equally reasonable impact 'range'. Now, not being an acedemic or statistical analyst, maybe I'm missing something regarding the significance of SD over ES...

I use a chronograph for two things: 1) to assist in determining a stable, repeatable load, and 2) to provide a starting point for a ballistic solver.

Stable loads, at least in my experience, tend to level out (in terms of velocity) over a small range of powder charges, indicating a 'node'. Even when I have trouble interpreting what a ladder test or a group test of same charge has printed on paper, the velocity readings can assist in interpretation. I've always found that anytime I've been under 20 fps ES, I have a well behaved load. And this is WAY out of what many PR guys claim to be "acceptable".

As for the use of velocity for ballistic solvers, I've never seen an accurate solution derived from a measured average from a chronograph alone. It ALWAYS requires field verification. Always.

Knowing your speed & ballistic coefficient is all neat 'n stuff, but unless you go out and verify & record results at various ranges in various conditions, it's all just theoretical reference material. The target doesn't lie. But the target will tell different stories on different days. Hard data is the only data you can rely on.

Rooster
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Reloading / Re: OAL vs CBTO Illustration
« Last post by Jeff M on September 30, 2018, 07:04:05 PM »
Well done. This is something all new rifle reloaders should read.
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Reloading / OAL vs CBTO Illustration
« Last post by Rooster on September 21, 2018, 11:22:37 PM »
For what it may be worth to some members here, while sorting out a new-to-me .223 AI, I've come up with a small sampling of throat location examples in a given rifle according to different bullets. I thought this may serve as a decent example of the differences between overall length (OAL) of a loaded cartridge and cartridge base to ogive (CBTO) determinations that we hear so much about, yet may still be a bit foreign to some.

We always see reference to OAL in loading manuals, and these are usually determined by magazine limitations and/or recommended seated lengths by the manufacturer for a given bullet. This doesn't often reflect what dimension an individual rifle's throat location is, according to rifling engagement on the ogive of the bullet, relative to the base of the cartridge (or more properly, the face of the bolt when firmly engaged with the lug abutments of the action).

Following are a few photos that some may find useful. I'm sure those 'in the know' will forgive the fact that some cases are formed .223 AI cases & some are still straight .223 cases. I assure you, all are properly sized according to the headspace in my machine.

The bullets: 40 Berger FB, 50 Nosler Ballistic Tip, 55 Speer TNT, 55 Hornady V-Max, 69 Sierra Matchking, 75 Hornady ELD-M. I just realized I didn't include the 68 Hornady BTHP Match in this photo. Oh well...


Photo simply showing each bullet's description.


Photo showing OverAll Lengths of each bullet according to the engagement of their respective ogives on the rifling.


Photo of each loaded cartridge with accompanying (to the left) bullet to illustrate the difference between OAL and equal distance to rifling (or lands, as some call it) engagement of different bullets.


Here you can see the differences that OAL lengths & CBTO lengths play. Magazine limitations, bullet shank engagements with the case neck, & powder space encroachment all have the potential to be considerations with you and your rifle, no matter the cartridge or bullet of your choosing.

I've done this for many years and have never really considered outlining any of it until now. I hope it has some use for someone out there.

Rooster
7
Optics / Re: Kahles 624i issues
« Last post by Pvt.Donut on September 12, 2018, 04:01:01 PM »
Did you install the 20 MOA on correctly? Maybe you installed it backwards and it's sloping the wrong way?

I think Kahles notes the Elevation adjustment range at 25.5 MIL. I believe they mean from center so 51 MIL total. You said you needed one full rotation, I'm assuming UP, from center to zero. So that gives you 15.5 MIL from zero to max elevation. Plus the 20 MOA base (6 MIL) give you back that 6 MIL. Now you're sitting at 21.5 MIL which is pretty standard and should get you out to 1,000-1,400 yards while still having a 100 yard zero.
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Bolt Guns / Re: Is it legal
« Last post by Pvt.Donut on September 12, 2018, 03:47:15 PM »
As long as you stay under the velocity restriction of 3,200 fps you should be able to compete. Pretty sure I've shot a local match and a guy was running a 30-06.
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Introduce Yourself / 308 VS 30-06
« Last post by Hammershell on September 11, 2018, 12:07:13 PM »
I am fairly new to the long range shooting sport.  I am enjoying it very much.  My question is - there seems to be quite a few long range 308 rifles used but I have not seen any 30-06 ?   What are the reasons for this ?   Thanks in advance for your answers.
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Semi-Autos / Re: Lets see those semi-autos
« Last post by GoatRock on September 04, 2018, 05:16:22 PM »

My pair of 6.5 Creeds.


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