I finally got some primers - working up a load?

warrenb

warrenb

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Heres another dumb question.
When working up a load how many bullets do you make for a given charge in order to find a good group and maximum velocity.

For instance I started at the minimum powder charge making 5 rounds then increasing the charge in half grain increments and making another 5 rounds.

eg.
243 Nosler BT 55 grain, H4895 40grs, 5 rounds
243 Nosler BT 55 grain, H4895 40.5 grs, 5 rounds
243 Nosler BT 55 grain, H4895 41grs, 5 rounds

The reason I'm asking is becasue I'm trying to find out if my 9 1/8th twist barrel will like small grain bullets. I have a bunch of bullet samples but only 15 of each.
Is this a stupid way to work up a load or should I just make one or two rounds in each charge till I find my maximum pressure and then make 5 rounds a grain or so below max?

Thanks for your patience.

PS. At this point I'm just looking for a grouping that indicates that a given bullet has a chance of working well in my gun. I'l then go out and buy lots to experiment with.
 
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I start at the minimum, .030 off the lands and go up a grain at a time 3 to start and as I get close to the max 6 each and go up to max 1/2 grain at a time.

The barnes manual uses a simpler system, load one each at starting increments and then one each at 1 or 1/2 gr increments until the load you really want to use. The theory is you want to use the load with the max velocity that is safe in your gun and all the starting loads are for is to make sure they are safe.
 
Both you guys are making a lot of sense. I'm over complicating things as usual.

I do not know why they don't teach this in school. I would never have dropped physics. :)
 
Do this. You will find a 1 in 9.125 will prefer heavy bullets though.
Beginning with the starting load given in your manual, load 5 rounds only. Go up by half a grain of powder, loading 5 of each keeping them separate until you get to the max load in your manual.
Then go shooting. Shoot at 100 yards, for group only, slowly and deliberately off a bench.
Change targets between strings of 5 and allow time for the barrel to cool.
When you find the best group, sight in.
 
I do the 3-shot groups thing on unknown (I typically load 4 to get by a known pull) loads. If they're looking good, I'll try them in 5's and vary weight up and down by .2 grs.
I doubt you'll get a 55 gr bullet within 30 thou of the lands in a .243. The bullet would be falling out. The 55's I seat to whatever the book COL says and tune with powder charge weights and it's pretty easy to find a good recipe. Friend of mine seats them out so far I can yank them with my fingers and his Ruger can't shoot like my Vanguard. You won't pull my 55's with your fingers.
 
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