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Discussion Starter #1
In the past when I handloaded I generally just copied the COL of a factory load for my handloads. Mostly because I did not own calipers, now I do so in the quest for accuracy I want to do some experimentation with COL, but I am not quite sure how to do it.

Now I did know to determine what the max COL for my gun. I used a low tech approach that I read on another site.

1. insert wooden dowel into the muzzle til it contacts breechface (3/16 fits good)

2. Mark dowel, I used a razor across the muzzle it made a thin line that would be easy to to repeat for the next step.

3. Put a head into the chamber and gently press it against the rifling.

4. Insert dowel until it contacts the head, mark location.

5. The reading between the marks is max COL for that type of head in that gun (Note the 32 and 40 grain Hornady heads as far as I can tell give the same max COL)

The reading I got is 2.280, I have some factory 32's and they measure 2.245 for a jump of .035". I am assuming that .035" it going to be the max amount of jump. So when I make up test loads how big should the steps be.

I have to admit that at least with the 40 grain loads I had been contacting the rifling and they shot pretty well. Here is what I was thinking for the lengths I would try (with the 40 grain head).

2.275 -.005
2.265 -.015
2.255 -.025
2.245 -.035

Is .010 too big of a jump?
 

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Discussion Starter #3
That is a cool tool it's on my list right after Paco Kellys Nasty Nose tool. But ahad of that is finish paying off a Stevens 200 in 270, a lyman case timmer and 20 cal pilot, glass and a bipod for said 270.

Too many toys not enough money.
 

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If you have a dial or digital caliper (and if you don't, they are under $15 at harborfreight.com) the easiest way to do it with a Handi is drop the bullet into the chamber and measure the distance from breech to back of bullet. Add to this measurement the length of the bullet, and you have the COL of a cartridge with the bullet just touching the lands.
 

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Discussion Starter #5
Thanks Mitch, I gave it a try and oops I come up with 2.300 for the 40 gr and 2.301 for the 32 gr, and that means the hornady factory loads are jumping about .050 and they are still giving really good accuracy. I guess that I have to adjust my col trials abit.
 

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Aulrich, here is a COL gauge that you can make for about 15 cents. Works the same way as the stoney point gauge at about $70 :eek:

http://www.mikeswillowlake.com/coal_gauge.htm

My page needs updating but I'll explain here how I do it now. It's the principal of operation that matters and you will probably find ways to improve.

I no longer glue the base case into the head of the measure case. I drill the hole a bit (a very little bit) under size and then slightly split the neck of the base case if needed to get it into the measure case. This way, once the bullet is placed in the measure case you can remove the base case to allow a more centered placement of the calipers (yeah, you are going to have to spring for those calipers :lol: ) Also, if the bullet is showing a tendency to move around in the neck of the measure case, split the neck with a fine hack saw blade and that will allow you to squeeze it tighter or open it to looser. (hope this makes sense and it shows the need to update my page!! :shock: )

Also, the next time you have finished loading up some ammo for a trip to the range, pick five rounds at random and measure them with your calipers. Surprise!! :shock: Most bullets have slight variations in the length of the tip. Especially soft nosed bullets and your five bullets will vary in length probably more than your planned set back from the lands!

There are devices made (collimnators? sp :eek: ) that measure from the ogive for a much more accurate measurement. The poor mans collimnator is the bullet seater removed from your seating die :)
 

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Discussion Starter #7
Thanks for reposting that longcruise I was about to search for that link. Every method I use seems to give me a different number. I was aware that the bullets varried abit in length So I tied to use the same bullet all of the time. I'll give it a try.
 

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Quick, This is 17 shooter from the PM site, Thanks for the accolades. Now how do I PM you
 

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Howdy 17 Shooter! Welcome aboard!! Click the PM button at the bottom of my posts or click my name on any list, that will take you to my profile, then click pm.

Tim
 

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Discussion Starter #10
Longcruise I guilt the gauge last night and with that bullet I got 1.310 the caliper down the chamber method was getting me 1.308 so I think I have a result. What I did next it to use the same bullet in a permanent guage case (no primer or powder) I set it to be .010" off of the lands, so the next time I make this load I could just run the seater down to where it makes contact with the guage bullet.

As luck would have it it seems I have picked the shortest bullet in the box, if it was not for the handi being a single shot this could have been a problem. In my guns with magazines I will go through the head to find the longest and use that one just in case I run into the magazine max lenght before hitting the rifling.

Long cruise at some point i'll have some questions re the load ladder procedure that you have post it looks interesting. Thanks for the help.
 

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Long cruise at some point i'll have some questions re the load ladder procedure that you have post it looks interesting. Thanks for the help.
Glad that worked out for you.

If you have any questions on the ladder test I'd be happy to help. sometine in the next few weeks I'll be running a test and will post the actual procedure and result of that test on my site.
 
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