I have been shooting in CMP matches for about 10yrs on and off but I'm ready to get a little more serious on my non budget.
I have read alot about both RL15 and OTM bullets so I am trying to work up an accurate load.
I wanted heaver bullets but the Hornady 68gr HPBT Match Is all that is available to me at this time.
I am shooting a Colt a2 H bar Match 1 in 7 twist, it is bone stock.  The only accessory I have tried is a Game Reaper
carry handle scope mount to test the accuracy of my reloads.  Well I gues I should ask a question.

How accurate is a carry handle mount?

What powder charge has been good to anyone using the Hornady 68gr and RL15?

What kind of accuracy?

What kind of velocity?

Any help would be greatly appreciated.  I am shooting a 200yd reduced course.  My score is usually between 400 and 420.

you have to start somewhere
the 68s will work fine
i have been using 24.9 with very good sucess
i tend to use the 75s more though just like them better
i have tried the carry handle mount just remember to keep checking the tightness - mine tends to slip and go loose
match ammo will help you a lot so good start

I would recoomend redding dies, full length standard, and the competition seater, only because once set up it is dead on repeatable for  every bullet you use. just write the numbers down in a log, and you always have it. the FL dies, just bump the shoulder back .002-.004   I use 4 because I had a failure to feed at .003 and a few at .002 and not one at .004.   For your load I used 25.3 of RE15 and it was dead on with the same load in Varget. less than .5 moa. Great load at about 2950 fps.  24.5 is another good one I had success with, a little more towards the .5 moa but good. Cannot remember the velocity. 25.3 was in the "accuracy node" where there was no real change between 25.2 and 25.4, so even if I err a tenth either way I get good results.  However, probably the best money spent for you right now is a float tube for that rifle. Leave the rest as is, and it will suprise you and you can start building a better foundation in position. How well you can shoot is by far a bigger factor in your success and enjoyment in the sport than how well your rifle can. Next sights. Then a trigger, or a little work on your stock one. . . .  that should theorhetically take you to master level, expert easily.  a 1 MOA rifle will, in theory, be capable of a 800-80X on a perfect day. a 1/4 Moa rifle thats the latest and greatest wizzardry, will still score the same.... on a perfect day.  COincidentally, I can hover around low master with my rifle with the 1MOA loads or the < .25 MOA lazer beam loads..... It is currently as far as my ability will take me. Rifle is not a limiter. My simple small add up by the end of 80 rds mistakes are. If I cut those in half and keep up with fundamentals and build my positions, I will end up a solid master. Keep at it and maybe HM one day. but thats up to me, not my rifle.  

Float tube is what I recommend. Seriously. I know I took it astray a bit, but it will be the best investment. It will allow you to build yourself into a shooter more than a perfect load will. Other than that, treat RE15 like Varget , but cleaner, and you will be fine.  Its a dandy powder for the little AR.  With a 55 Grain bullet or less you could fill it to the mouth and probably never have a pressure issue.  *0 grainers, be more careful with those... 24,5 works out to about 2820 FPS. with those.

Sir;
My recommendations below are given through what works best not based on what is the most expensive.

The 68 gr. Hornady in my experience is a fair practice bullet. When bullets become "available again, get yourself some 60 gr. Sierra HP's for your 200 yard matches. One thing, you don't need a boat tail bullet for 200 yards and the 60 is just plain and simply put, a very accurate bullet! Least expensive too!
Your okay with RE-15 and later on, you may want to use Hodgdon or IMR-4895 with bullet weights under 77 grain. RE 15 is better suited to the heavier bullets like the Nosler or Sierra 69's,77's and 80's.
I have found that the carry handle scope mounts are not well suited to load or accuracy development due to the scopes height in relation to your position behind the rifle.
Since you are getting more serious about the sport, I would recommend the following up grades ASAP. RRA NM rear sight. Rear aperture .040" diameter in 1/4 x 1/4 minute. Front sight post width to suit your eyes. I am old now but even twenty three years ago I shot best with the standard battle sight width which is what you have on your rifle now. The .072". Smoker up good!  Second, you need a RRA NM float tube!
If your averaging near sharpshooter scores now, your ready for better bullets and need the two up grades I listed above.
Continue with your good shooting and always remember this. You will only get out of High Power what you yourself put into it!  And I don't mean money

Edited to include getting a trigger upgrade in addition of the sights and float tube. Get RRA NM trigger! Right out of the package a great trigger!

Dave McGrath

Wrangler quote
"If your averaging near sharpshooter scores now, your ready for better bullets and need the two up grades I listed above"

I do not know how I am classified.  How do I rate my scores in CMP Garand matches.

Thank you all for the input but more is welcome and wanted.

I'm all hopped up on mountain due because I'm shooting in my first M1 Carbine match tomorrow.
They are letting me and a friend borrow 2 rifles to compete.

Edit- I am sad my colt has to stay home.