gnappi
.375 Atomic
Posts: 1,537
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Post by gnappi on May 22, 2023 6:26:05 GMT -5
I messaged Starline last week to ask about .480 Ruger brass, and I haven't heard anything in reply. Not really expecting to, either. Guess I'd better get busy buying some .475 Linebaugh to trim down. The one "gotcha" with the Harbor Freight mini chop saw is that the LOA of the trimmed case "may" be a bit uneven. Finish trimming on a case trimmer like a Lyman or Lee cheapie will true up and remove the ~.001" to .003" but I've left them as is.
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gcf
.30 Stingray
South Texas
Posts: 306
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Post by gcf on May 22, 2023 13:58:15 GMT -5
GCF, I was surprised at their detailed reply also but it did steel me into the mindset to "expect the best, plan for the worst" mindset. So, I did not need to ream the cases using my bullets and I suspect there will not be a need with others. I haven't cast any of the Lee 400 grainers yet but all of my loaded ammo drops right into my case gauge and SBH cylinder... we'll see after I cast some 400's next winter. I had these different brand cases to measure, Hornady, Starline and Federal: * NOTE: On loaded cartridges I used a Lee 325 GC (no gas check crimped on it) powder coated and it measures .4785". For all measurements I used an 8" Mitutoyo dial vernier and a 4" Digital vernier. Mouth of NEW sized Hornady .475 Linebaugh uncut wall thickness .016" (tested three) Mouth of NEW sized Hornady .475 Linebaugh cut to .480 length wall thickness .015" (tested three) * loaded cartridge .498" OD case below bullet to .501" below the crimp Mouth of new sized Federal .480 brass wall thickness .014" to .0145" Mouth of once fired Starline .480 brass wall thickness .015" --- * loaded cartridge .498" OD case below bullet to .501" below the crimp PS, none of the brass I measured were any where near the .012" - 0125" you measured. Interesting - thanks for the info. I just checked a once fired Starline .480 from the same batch - with a cheapo tube mic, & got .013 - .0135. I'm sure the Mitutoyo are more accurate, but guessing different batches (even from the same manufacturer) vary a bit in thickness. Reason I asked originally, Is that I've noticed that marginally lighter loads (with Longshot), don't seal as well. One of my goals, is an accurate, but somewhat lighter than full house, heavy bullet load, and was wondering if heavier (or lighter) brass, would have an effect. Probably a non-issue...
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gnappi
.375 Atomic
Posts: 1,537
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Post by gnappi on May 22, 2023 18:31:18 GMT -5
GCF, I was surprised at their detailed reply also but it did steel me into the mindset to "expect the best, plan for the worst" mindset. So, I did not need to ream the cases using my bullets and I suspect there will not be a need with others. I haven't cast any of the Lee 400 grainers yet but all of my loaded ammo drops right into my case gauge and SBH cylinder... we'll see after I cast some 400's next winter. I had these different brand cases to measure, Hornady, Starline and Federal: * NOTE: On loaded cartridges I used a Lee 325 GC (no gas check crimped on it) powder coated and it measures .4785". For all measurements I used an 8" Mitutoyo dial vernier and a 4" Digital vernier. Mouth of NEW sized Hornady .475 Linebaugh uncut wall thickness .016" (tested three) Mouth of NEW sized Hornady .475 Linebaugh cut to .480 length wall thickness .015" (tested three) * loaded cartridge .498" OD case below bullet to .501" below the crimp Mouth of new sized Federal .480 brass wall thickness .014" to .0145" Mouth of once fired Starline .480 brass wall thickness .015" --- * loaded cartridge .498" OD case below bullet to .501" below the crimp PS, none of the brass I measured were any where near the .012" - 0125" you measured. Interesting - thanks for the info. I just checked a once fired Starline .480 from the same batch - with a cheapo tube mic, & got .013 - .0135. I'm sure the Mitutoyo are more accurate, but guessing different batches (even from the same manufacturer) vary a bit in thickness. Reason I asked originally, Is that I've noticed that marginally lighter loads (with Longshot), don't seal as well. One of my goals, is an accurate, but somewhat lighter than full house, heavy bullet load, and was wondering if heavier (or lighter) brass, would have an effect. Probably a non-issue... I can't help with the heavier / lighter brass issue but I have some light(er) 325 grain loads and red dot that worked real well for me. PM me if you're interested.
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Post by lar4570 on May 24, 2023 8:58:25 GMT -5
If your Longshot loads aren't sealing, then you'll need to go to a faster powder to create enough initial pressure to expand the brass and create a seal.
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Post by bigbore5 on May 24, 2023 18:02:48 GMT -5
What are y'all measuring brass thickness with? I use a Mitotoyo tube micrometer when I used to make 300BO brass. Never checked anything else since I don't shoot rifles much anymore.
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gnappi
.375 Atomic
Posts: 1,537
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Post by gnappi on May 25, 2023 6:19:51 GMT -5
If your Longshot loads aren't sealing, then you'll need to go to a faster powder to create enough initial pressure to expand the brass and create a seal. Funny you should mention that. My undocumented Red Dot loads are what I'd call "warm" but some cases still experience gas blow by. I've never experienced gas blow by on .41 mag, .44 mag, .45 Colt to the degree I get with the .480. My 4227 loads from the Lyman manual are likely anemic and are horrid for gas blow by. It's so bad I had to swab out the cylinders after only a couple of rounds to use them up. Next I'll try upping my 4227 loads closer to those shown on the shooter's reference site for 325 gr GDHP's for my 325 PC'd bullets. 4227 Starting Powder: 24.0 gr Starting Velocity: 1,295 Starting Pressure: 32,600 Max Powder: 27.2 gr
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gcf
.30 Stingray
South Texas
Posts: 306
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Post by gcf on May 26, 2023 11:45:06 GMT -5
If your Longshot loads aren't sealing, then you'll need to go to a faster powder to create enough initial pressure to expand the brass and create a seal. Funny you should mention that. My undocumented Red Dot loads are what I'd call "warm" but some cases still experience gas blow by. I've never experienced gas blow by on .41 mag, .44 mag, .45 Colt to the degree I get with the .480. My 4227 loads from the Lyman manual are likely anemic and are horrid for gas blow by. It's so bad I had to swab out the cylinders after only a couple of rounds to use them up. Next I'll try upping my 4227 loads closer to those shown on the shooter's reference site for 325 gr GDHP's for my 325 PC'd bullets. 4227 Starting Powder: 24.0 gr Starting Velocity: 1,295 Starting Pressure: 32,600 Max Powder: 27.2 gr For 4227, you might try magnum primers. Cleaner burn when used in moderate 44 magnum (Keith bullet) loads, & no difference in accuracy. Haven't tried 4227 in my 480..., yet.
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gcf
.30 Stingray
South Texas
Posts: 306
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Post by gcf on May 26, 2023 11:54:15 GMT -5
What are y'all measuring brass thickness with? I use a Mitotoyo tube micrometer when I used to make 300BO brass. Never checked anything else since I don't shoot rifles much anymore. I think that's probably the best tool for the job.
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gcf
.30 Stingray
South Texas
Posts: 306
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Post by gcf on May 26, 2023 12:39:49 GMT -5
If your Longshot loads aren't sealing, then you'll need to go to a faster powder to create enough initial pressure to expand the brass and create a seal. Well that certainly makes sense. Interestingly though, I get zero blow by w/ HS-6 (plus nicer groups), & only w/ the slightly faster Longshot. Might also bump the Longshot loads a bit. To be honest, the smoked case with the LS isn't even that bad - just noticeable... Tried Unique briefly w/ the PC 385 grn 640HP bullet in use, no smoked case - but wasn't getting the accuracy. May need more work there. Then there's 231. Got some. I know some use it in the 480, but it seems like it would be a better fit with lighter CB's. I'm currently working with 385 grn 640's & un-coated LBT 400WFN - that I haven't even tried yet... I think the moderate loads / blow by problem in the 480, is that the brass is designed for 40K+ pressure loads, & not 30K "moderate" pressures. In addition to brass thickness, their may be (??) a difference in the actual brass alloy used for higher pressure cartridges. Someone more familiar with metallurgy could possibly speak to that.
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gcf
.30 Stingray
South Texas
Posts: 306
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Post by gcf on May 26, 2023 12:50:57 GMT -5
Interesting - thanks for the info. I just checked a once fired Starline .480 from the same batch - with a cheapo tube mic, & got .013 - .0135. I'm sure the Mitutoyo are more accurate, but guessing different batches (even from the same manufacturer) vary a bit in thickness. Reason I asked originally, Is that I've noticed that marginally lighter loads (with Longshot), don't seal as well. One of my goals, is an accurate, but somewhat lighter than full house, heavy bullet load, and was wondering if heavier (or lighter) brass, would have an effect. Probably a non-issue... I can't help with the heavier / lighter brass issue but I have some light(er) 325 grain loads and red dot that worked real well for me. PM me if you're interested. Got no lighter bullets (yet), or Red Dot available. What 325 grainer are you using - & where are you finding it?
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gnappi
.375 Atomic
Posts: 1,537
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Post by gnappi on May 26, 2023 17:12:21 GMT -5
I've been a bullet caster since the late 70's / early 80's so whenever I get a new launching platform for a new bullet I cast and powder coat my own. For the 480 I currently have the Lee 325 GC mold but with powder coating I do not gas check the bullets.
I also recently acquired the Lee 400 grain molds which I have not cast yet but there's a chance some or possibly all the gas blow back will be self healing with the heavier bullet? Dunno. I'll see after we get a cool spell in south Florida.
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Post by bigbore5 on May 26, 2023 17:48:29 GMT -5
For a great bullet from a really affordable mold that's quality rivals any, I really like the 476-415 swc from Arsenal.
I have a few Arsenal molds and think they are very under-rated.
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gnappi
.375 Atomic
Posts: 1,537
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Post by gnappi on May 26, 2023 22:15:48 GMT -5
For a great bullet from a really affordable mold that's quality rivals any, I really like the 476-415 swc from Arsenal. I have a few Arsenal molds and think they are very under-rated. Thanks, I've used steel molds (Lyman etc.) and aluminum from Lee but that mold in brass in a 5 cavity looks excellent. I'll keep them in mind should my Lee molds give up the ghost!
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Post by bigbore5 on May 27, 2023 8:30:54 GMT -5
That would be a big heavy mold in five cavity size plus being brass. I use the four cavity aluminum. Love it. I'll post a pic later today.
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gnappi
.375 Atomic
Posts: 1,537
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Post by gnappi on May 29, 2023 10:11:19 GMT -5
That would be a big heavy mold in five cavity size plus being brass. I use the four cavity aluminum. Love it. I'll post a pic later today. I have several 4 cavity steel molds and the weight doesn't bother me if the support bracket on my furnaces is set up right, likely due to the fact my right arm compared to the left resembles a fiddler crab :-)
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