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  #1  
Old 03-04-2017, 01:34 AM
4th_AD_son 4th_AD_son is offline
 
Join Date: Oct 2009
Location: Eastern Pennsylvania
Posts: 1,358
Default Shim Question

Anyone shoot an Alaskan scope on a 1903A4 (faux) and required a shim to get up to 600 yards, or is there enough adjustment? I don't have access to a 600-yard range and don't want to go down to Camp Blanding and find I can't get sighted in.
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  #2  
Old 03-04-2017, 07:25 PM
ceresco ceresco is offline
 
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No way to tell unless you know where your adjustment is starting out. It will depend on how much elevation you have used to get to 300yds. You must do some testing and shim if needed. With typical 30-06 loads, hitting 7 inches above POA at 100 yards is close for 300yds. If you can get impacts 36 to 41 inches above your point of aim at 200 yards you will be close enough for your 600 yd zero. Google the 1000 yard sighting target--shot at 50 yards it actually works. Typical loads for 30-06 are 46-47grs IMR4064 with 155gr HPBT, for 175gr bullets: 55 to 59grs H4831. Things get more difficult if you hold bottom (or even top) of black because the bull diameter goes from 18" at 300 yards to 36" at 600 yards..... Good Shooting. ...
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  #3  
Old 03-04-2017, 08:11 PM
Slapshot Slapshot is offline
 
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Location: Kalamazoo County, Michigan
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Here's the 1,000 yd. target Ceresco mentioned:
http://forums.thecmp.org/showpost.ph...52&postcount=9
As noted in the post, you can make your own by using the measurements shown in the photo. If used correctly, the target will get you on paper at the distances shown.
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  #4  
Old 03-04-2017, 11:05 PM
4th_AD_son 4th_AD_son is offline
 
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Location: Eastern Pennsylvania
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Quote:
Originally Posted by ceresco View Post
No way to tell unless you know where your adjustment is starting out. It will depend on how much elevation you have used to get to 300yds. You must do some testing and shim if needed. With typical 30-06 loads, hitting 7 inches above POA at 100 yards is close for 300yds. If you can get impacts 36 to 41 inches above your point of aim at 200 yards you will be close enough for your 600 yd zero. Google the 1000 yard sighting target--shot at 50 yards it actually works. Typical loads for 30-06 are 46-47grs IMR4064 with 155gr HPBT, for 175gr bullets: 55 to 59grs H4831. Things get more difficult if you hold bottom (or even top) of black because the bull diameter goes from 18" at 300 yards to 36" at 600 yards..... Good Shooting. ...
ceresco: Are you saying, I should run the elevation all the way down and count the clicks to the top, then determine how many clicks up to 200 yds (my club's longest range) and find the remaining number of clicks I have available?
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  #5  
Old 03-04-2017, 11:40 PM
4th_AD_son 4th_AD_son is offline
 
Join Date: Oct 2009
Location: Eastern Pennsylvania
Posts: 1,358
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Thanks for the feedback. I ordered a box of ST-1 sighting targets. The weather looks good for Wed and Thurs here in the Philadelphia burbs. I already have 200 yd targets, so I'll get sighted in at 200 yds on 50 yd range using the ST-1 target, and then test it out on the 200 yd range. Anxious to see how this works out.
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  #6  
Old 03-05-2017, 12:35 AM
ceresco ceresco is offline
 
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Use the ST-1 target at 50yds. If you have enough elevation to make it to the 300 and 600yd levels, you will be OK at a 300-600yds match. Also, shoot at 200yds and adjust elevation until you hit approx 42 inches (this will aproximate your 600yd setting) above point of aim as a secondary check. If your scope will pass both tests, you don't need to change the shims. The optimum is to have the scope's elevation and windage working near the center of their travel, but not worth screwing around a lot. The windage is easy because you have the base adjustment screws--shimming is tedious by comparison. I like strips cut from beverage cans for shims... Good Shooting. ..
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  #7  
Old 03-10-2017, 01:33 AM
4th_AD_son 4th_AD_son is offline
 
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Location: Eastern Pennsylvania
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Hey Guys,
A big Thank You for pointing me in the right direction. My order of sighting targets arrived today so I went right off to the range. 64 degrees, sunny, and very, very windy - snow tomorrow!

I had some thin brass material so I made a shim and stuck it under the scope.

On the 50-yard range, using the ST-1 target, I got sighted in at 600 yards, 300 yards, and 200 yards. I switched over to our 200-yard range and was about 2 clicks low using HXP ammo. Came back to 50 yard range and validated the step changes between 300 and 600 yards. I feel pretty confident that I'll be very close to be sighted on at 300 yards, and know that 11 clicks up will get me to 600 yards.

I have a shipment of Hornady match ammo coming so I'll have to go back and get re-calibrated before heading off to Florida.

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  #8  
Old 03-13-2017, 11:25 AM
Pinecone Pinecone is offline
 
Join Date: Jan 2014
Posts: 487
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JBM Ballistics - http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi

Run the numbers on your ammo. Sight in at 100 yards. Dial the scope up as high as it will go, counting the clicks. Compare to the data for 600 yards.

For a 168 gr Sierra Match King at 2900 FPS muzzle velocity, it looks like you will need 13.3 MOA of up adjustment for 600.
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  #9  
Old 03-13-2017, 11:40 PM
4th_AD_son 4th_AD_son is offline
 
Join Date: Oct 2009
Location: Eastern Pennsylvania
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Pinecone: Thanks for the great link! I just received my order of Hornady H81170 from the e-Store. I ran the calculations and it looks like I'll need 11 clicks up from 300 to 600 yards. If I did this correctly, it is exactly what I determined by using the ST-1 sighting target.

I really appreciate all the input from all of you that responded. I feel confident that I'll be able to get zero'd in real quick once I get on the line at Camp Blanding. Thanks much!

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  #10  
Old 03-14-2017, 11:15 AM
Pinecone Pinecone is offline
 
Join Date: Jan 2014
Posts: 487
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I use JBM at home, and Ballistic AE on my iPhone at the range.

GREAT tool.

When I am at my club in the fall, I end up helping people do 3 round sight in, and set zero for Maximum Point Blank range.
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