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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
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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.


Sent from my iPhone using Tapatalk
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Matches - Non-PRS / 2018 Snipers Unknown Challenge
« Last post by WheatonArms on September 03, 2018, 03:58:04 PM »
The 2018 Snipers Unknown Challenge will be held at the Clinton House Plantation in Clinton, SC on Oct 5-7 2018. It is a team match. For more information visit:
https://www.fenixstrategies.com/snipers-unknown-challenge.
There are still a few slots available. This match has a amazing prize table. A brief overview of the prize table showcasing some of the non-serialized items and sponsors is available at: https://www.instagram.com/wheatonarms/

Date Oct. 5-7 2018

City & State Clinton, SC

Street address 15171 SC-56,
Clinton, SC 29325

Start time 7am

Round count Approx. 150rds

Cost $500.00 per team

How to register https://www.fenixstrategies.com/snipers-unknown-challenge

Contact info for the match director Robbie@wheatonarms.com

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Bolt Guns / Is it legal
« Last post by AIRBORNE6869 on September 02, 2018, 10:55:48 AM »
Is a Remington Long Range in 30/06 legal to use in PRS matches??
I have such a rifle I use for long range Mule Deer hunts with 165 Sierra BT's, and it wears quality glass.   My purpose in starting in PRS is just because it looks so darn much fun and it would be excellent practice for hunting.  Serious competition is not my game any more, but shooting long range is fun.  After my service years with the 101st ABN I shot NRA Standard Service matches for many years and reloading is a hobby.
So is the Remington Long Range in mostly stock condition legal to use in PRS matches?

Thanks 
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Border Wars Rifle Series / Re: WTS 1 spot Lodi, WI Shoot Sept. 1st, 2018
« Last post by Mhager63 on August 31, 2018, 02:49:04 PM »
Dutch84 do you still have a registered spot for Lodi 9/1 for sale?
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Introduce Yourself / Re: Hello from Mississippi
« Last post by marler5811 on August 31, 2018, 01:48:33 PM »
What part of MS are you from?  I grew up in Laurel.
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Border Wars Rifle Series / WTS 1 spot Lodi, WI Shoot Sept. 1st, 2018
« Last post by dutch84 on August 27, 2018, 08:06:53 AM »
Please PM me if interested.  Full price (no more, no less).  Thanks
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