Hunting Washington Forum

Equipment & Gear => Guns and Ammo => Topic started by: iusmc2002 on November 26, 2012, 10:06:05 PM

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Title: C.O.L. question
Post by: iusmc2002 on November 26, 2012, 10:06:05 PM

I made something like the Hornady OL gauge by drilling the primer pocket out of a case and tapping it for a long bolt I had on hand.  I just wanted to see how it would work out. 
For S&G, I tried one of the 168gr AMax I've been using, and got a COL of 3.555" to the lands, consistently; and the published COL is only 3.340".  I know for a fact that that COL won't fit in the mag, but if I backed off the lands 0.020" or so, would that be safe to shoot?   :dunno:
 I know every chamber is different and all that.  Right now the 168gr are seated to 3.400" and are getting decent accuracy, plus they fit in the magazine. 

What do you think?  Is it advisable to attempt a COL of 3.530?  Just wondering if it could increase the accuracy while still being safe.

Thanks  :tup:

Title: Re: C.O.L. question
Post by: Huntbear on November 26, 2012, 10:23:28 PM

It would be safe.. the only real limiting factors are your magazine and feeding.. 

Title: Re: C.O.L. question
Post by: jaymark6655 on November 27, 2012, 05:21:09 AM

Completely safe.  In fact I think some Berger bullets tell you to seat them so they touch the lands when chambered.  I think when you start making them too short is when problems can happen.

Only way to find if it will increase the accuracy is to experiment.

Title: Re: C.O.L. question
Post by: dontgetcrabs on November 27, 2012, 05:43:28 AM

Yes safe if you back off on the powder charge and work back up. Without the extra jump there could be a pressure spike that might cause problems. All of my bolt guns shoot best over max col.  :twocents:

Title: Re: C.O.L. question
Post by: Curly on November 27, 2012, 06:48:32 AM

Published COL doesn't really matter that much.  It is just a standard that factory ammo is loaded to.

If your mag will allow it, load it to be just short of touching the lands if you want.  I have a 300 Win Mag that I load out to around 3.63" and the magazine is long enough to accept those long bullets. :twocents:

Title: Re: C.O.L. question
Post by: BULLBLASTER on November 27, 2012, 08:36:52 AM

I usually work up powder charge at magazine length until I see pressure signs and then back off. This is then my Max load. Then I will shoot groups at different oal to determine best seating depth. I usually make changes of 0.03 inches and shoot 2 groups. Berger has an artical out about this method of load development. In short the published Max coal may not be the Max you can load. In my 300 rum the published coal is 3.600 inches and I am lading them to 3.810 inches. I had a longer magazine box installed to accept and feed the rounds.

Title: Re: C.O.L. question
Post by: iusmc2002 on November 27, 2012, 05:48:43 PM

Well, that was a wasted exercise.  Sort of. 
The two 5 round groups I shot were over 1.5", nearly doubling the size of the normal groups I get.  Oh well, now I know.

Thanks for the advice guys  :tup: