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jerrold
06-21-2020, 09:53 AM
How much should a 550 gr. boolits weight vary when cast. 1 gr. + or - a impossible goal.

Dapaki
06-21-2020, 10:53 AM
I am SO glad this was not about MY weight!

I no longer weigh my boolits unless I am gathering a group for a particular reason, my 500gr .45 boolits can vary by 5gr (+_ 2gr) even with good casting techniques.

Burnt Fingers
06-21-2020, 10:59 AM
If casting from a single cavity, with proper technique you should be able to get very close to +/- 1 grain.

country gent
06-21-2020, 11:21 AM
+I ladle cast and over pour the molds I cast a lot of the old west silhouette 550 grn from a brass 2 cavity mould. I run the pot with 20-1 and around 725*. Flux every 100 bullets or so. My pot is big 125 lbs or so. so it maintains heat well.

I normally cast with 2 moulds alternating each pour, I fill the farthest cavity then the closest pouring the rest of the lade in and letting it run back into pot This keeps base and sprue hot and molten longer allowing for better of gassing and better fill on the shrinkage.

Normally my runs will be +-.5 grn from the pot after a visual inspection. 1 grn is doable and attainable [ractice and tune your technique as you go and it will improve as you go.

Kraschenbirn
06-21-2020, 11:46 AM
Don't cast anything as heavy as your 550 grainer but easily obtain +/- 1 gr. from my 420 to 515 gr. .45 cal. molds using a bottom-pour Lyman pot. Actually, I've got one mold from Accurate with less that .2 gr. variance between cavities that yields awfully close to +/- .5 gr. (by random sampling) from 25-1.

Bill

JSnover
06-21-2020, 02:19 PM
How much should a 550 gr. boolits weight vary when cast. 1 gr. + or - a impossible goal.

+/- 1 grain is easy once you get everything dialed in. I cast 500 grain boolits for my 45-70 out of 20-1 alloy, +/- .5 grains.

Beerd
06-21-2020, 02:43 PM
plus or minus 1/2 grain, you guys are good!
..

Wayne Smith
06-21-2020, 05:26 PM
plus or minus 1/2 grain, you guys are good!
..

You notice they are not telling you how many they toss back!

RyanJames170
06-21-2020, 09:18 PM
what would could do, once you cast up a bunch is sort them all out by weight.

and then work up a decent load.. and then once your happy with that.. do test loads with the best bullet to bullet consistency and then purposely load a batch with the biggest variance you can find in your bullets. and see how the groups differ if the groups dont differ enough to matter to you, then you will only need to sort for defects and ones that are way to light indicating a air pocket in the bullet.

country gent
06-21-2020, 09:40 PM
I normally pre heat the moulds to temp, then toss back the first 10-15 drops depending on mould, from then its keepers and visual sort for defects usually very few

Pre heating, basic culling at start and a good solid cadence goes long ways in consistency

charlie b
06-22-2020, 06:03 PM
I've never had cast bullets that close in tolerance. Most of the time mine are a 2 or 3 grain spread. Just as an example, the last batch of 210gn .308 bullets I cast were between 209.5 and 211.8. I sort into groups of .5gn, eg 211.0 to 211.4.

megasupermagnum
06-22-2020, 07:21 PM
The heaviest bullet I cast is a 770 grain 12 gauge slug. I'm sure there are outliers, but the bulk of them are plus or minus 2 grains. Cast as good as you can, and sort each bullet by weight. You will end up with plenty plus or minus 1 grain. When I sort, it's for hunting, and I get really picky. Plus or minus .2 grains is about all I allow. If I were to sort these 770 grain bullets for hunting, I would likely allow plus or minus .5 grains.

Harter66
06-22-2020, 10:55 PM
1% is a good goal . I've been well impressed with a 457193 , NOE version 458132 , and MP 462-420 . The 3c NOE poured 100 keepers on 35 pours inside 5 gr on a 535 gr . The MP pours 1 ea PB HB at 417 and 380 gr over under a half gr less obvious defects aside . The Lyman is a single and pours within a gr also less obvious defects .

I ladle 50/50 .

Bad Ass Wallace
06-22-2020, 11:31 PM
plus or minus 1/2 grain, you guys are good!
..

It will depend on the quality of the mold, my Paul Jones molds (3) throw very consistant +/- 0.5gn, the PGT mold from Victory is also similar quality.

When I ryn casting classes, I get participants to pick 5 boolits out from a packet of Hornady 0.458 jacketed boolits and five at random from a box of cast. The Hornady vary from +3gn to -4gn. The cast boolits just +/-0.5gn.

charlie b
06-23-2020, 07:28 AM
Yep, bulk bullets will do that. I compare my .308 bullets to the Sierra Match Kings and Hornady A-max. The SMK's are usually +/- 0.1gn, the A-max's are +/- 0.3gn.

robg
06-23-2020, 08:29 AM
i work to 1% variation in weight for all my boolits 223 too 45-70 /50gn-405gn.