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Posted: 4/2/2009 4:19:12 AM EDT
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Hey Everyone,
I've been reloading for a while now. I've got a pretty decent setup with a Rock Chucker at it's core. I'd like to purchase an 550 or 650, but have questions as to how accurate I can get the meters. I realize this comes down to what powder I use, but other than that, are there any issues I should be aware of? I reload .223 and .308. Also, I had a question about case trimming and using a progressive. What's the proceedure? Do I trim cases before I though them into the loop? Thanks, Wicked |
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Well I have done some nice stuff with prepped brass on my 550 with 69 SMK's and BLC2.
some key points- -To do it right you just don't go round like your pistol ammo. Size on one press session then off the press you can prep; TRIM, and then tumble off the case lube and inspect your brass . Then you run them back through knowing your brass is in good shape and correct length. I stroke with station one empty, then insert the prepped case and prime, then I rotate. -pick a powder that will drop consistently.....ball powders are the easy route, polishing and modifying or even replacing the powder system are other ways to get consistency with stick powders. - do your load work up so that your powder charge is in the middle of a zone, say hypothetically 23.6 of smoke brand 123 powder is a bit loose but things tighten up with 23.8, 24.0 and 24.2 all print the same on paper and 24.4 is the most accurate but starts to shift impact a bit and 24.6 are flattening primers, then stick with 24.0 as it's in the middle of a good node. You may think that 24.2 would be the place to be for the maximum safe velocity or maybe even 24.4 for a bit more. But errors between 24.2 and 24.4 will be shifting your shots. Staying in the middle of the node with 24.0 covers you for small errors in powder drop. A slight error either way will print the same on paper. This may also cover you for small differences in case volume, bullet weight, temp swings etc. This will also keep you from bumping past the max safe load with some comfortable breathing room. Other than shooting off the bench or bagged and bipod shooting, this ammo will shoot better than me (prone, offhand, sitting). Aw heck it probably even shoots better than me off the bench too. 
good luck and have fun shooting. |
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thanks,
I've been reloading for 20 something years but have really tuned up my reloading methods and understanding by surfing the web. Arfcom, M14forum, and sniper's hide have some very accomplished reloaders and shooters. They've driven me to invest more time in research and I've purchased books like Zedikers for differing viewpoints on loading. You don't use all the tricks all the time but it never hurts to have a greater understanding to help make sound decisions on where you invest your time and money to accomplish a goal. Sometimes you trade off maximum accuracy for enhanced safety or speed/ease of reloading because you know for the application that the difference on the target isn't worth the time. Hey It's like growing up!
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Steelonsteel covered a lot of ground, just want to add: Don't settle on what is necessarily your best grouping load if you can find one close to it with a much wider sweet spot in the powder charge.
My best 243 load opens up with .2 grains either way. Not a great candidate for a progressive. On the other hand the 223 load I use has a .4 grain margin either way and my groups don't change. I may be able to find a load that will group .1 better but loose that wide sweet spot in the load. |
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I just posted this in another thread on a related topic. I think it addresses your concerns about throwing charges.
Hodgdon makes a line of "short cut" powders. These are extruded powders that have relatively short granules, 1/2 or 1/3 the length of normal extruded powders. These are easier to throw with consistency. My Dillon 550 throws Hodgdon Varget charges of 36 gr with a standard deviation in weight of 0.12 gr. This means +/- 0.3 gr variation in charge weight, with about 90% within +/- 0.24 gr. With this degree of consistency, I have been unable to detect any difference in muzzle velocity or 200 yard group size between thrown and hand weighed charges. When I did the experiment to measure thrown charge weight variations using IMR-4064, I measured a standard deviation in charge weight of 0.14 gr out of a 42.0 gr charge. IMR-4064 is a conventional extruded powder (large granules). That same Dillon throws Ramshot's TAC powder, a ball powder, with astounding consistency. 24 gr charges are thrown with a standard deviation of 0.014 gr. This means +/- 0.04 gr variation in charge weight with 90% within +/- 0.03 gr. Muzzle velocity variations and 200 yard group sizes are no better than those of Varget (may actually be a little larger group). It takes a little practice and a consistent technique to get these results but nothing out of the ordinary. Oneof the best ways to teach yourself to thropw consistently, is to it. Throw charges and weight them, each of them. Weigh and record 100 thrown charges. Try it. Regarding the other elements of precision reloading, you lose absolutely NOTHING using a Dillon progressive. They can size, prime and seat as well as any press out there and better than many. Regarding trimming, you should always size before you trim. I think the two competing trimming systems are the Giraud and the Dillon. The hot ticket for the Dillon trimmer places the sizing dies and trimmer in a separate tool head dedicated to this operation. When it is needed, about every three reloads, you run them through the trimmer before finishing the reloading. You also run them through the regular sizing die after trimming to allow the die and ball to remove (crush) the burr. Then, reload as usual. |
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Yep, Steelonsteel has it down. As did the poster with telling you to aim for the mean of the best-grouping charge weights.
I load from .380ACP to 308 on a LoadMaster progressive. I size and decap separately for rifle cases, but otherwise the setup is the same. For 308 I use the perfect powder measure. For Varget, it's as good as the post above stated his Dillon was, and it delivers 168gr Wideners OTM's almost on top of each other at 100 yards. I use a double auto-disk for 223 and smaller cases, and that's pretty consistent with H335 and (*gasp*) Varget too. For super-duper long range stuff, using a trickler, scale, and single-stage is probably better, but I suspect that the difference is miniscule for most of us, and that primers vary enough at 500m+ that they start being a bigger factor in group size than .1 grain charge variations. There was a link on the precision rifle part of the forum about this or something. |
| I use my 550 for quite precise ammo. However, I use it more as a single stage. I prep and prime all cases, then fill with powder from electronic scale, then seat bullet. Not quite progressive, though I'm pretty quick at it. Not having to trim fireformed rounds is great. |
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