August 28, 2006, 11:13 AM | #1 |
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.32 S&W Long Wadcutter
Reloading for my Benelli MP3S in .32 S&W L WC
This is a "New" ( to me) gun. Using 100 grain Hard Cast Double Ended Wadcutter bullets 3.2 grains of Unique Powder Seating to just barely under case rim Lee .32 S&W Long 3 Die set "Roll" Crimping ( and final resizing) with a Lee Factory Crimp Die ( .32 S&W ) ( just enough { I thought} to "round" the sharp edge off of the outside of the case mouth) They Shoot fine and VERY accurately. Feed and run the Gun very well Using data from "Steve's Pages": 3.2 should be just about mid range for this cartridge: Quoting "Steve" 32 S&W Long 98 grain Unique 3.0 > 3.8 100 Grain Unique 2.5 > 4.0 However……………………. I am getting Pressure Signs "Flattened and Ringed Primers" Some of each, some of BOTH and Some OK Have checked my Load weight several times ( using both a RCBS 10/10 AND RCBS Electronic) Once in a while ( not uncommon with Unique and RCBS Powder Measure ) I may get as much as 3.6 Most are at 3.2 > 3.3 This should be WELL within recommended limits Could it be the CRIMP ?? I looked at some "Factory" .32 S&W Long Wadcutters The outside edges of their cases looked "sharp" Are Wadcutters NOT supposed to be Roll Crimped I know that the .32 S&W Long headspaces on the rim While I have your ear Does anyone have any documentation of the MP3S? Parts breakdown/specs?? Know of a source for parts ( especially the screw/bolt that tightens the "Split bottomed" "Sight Block" to the barrel Or Magazines for same ( I have tried "Larry") TIA [email protected]
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August 28, 2006, 03:45 PM | #2 |
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Caution!
Wadcutters are normally crimped. However, they do NOT use the same loads as other bullet shapes of the same weight. This is because they take up so much more of the powder space when you seat them flush with the mouth of the case. That greater confinement raises the powder pressure significantly in a straight wall case. In the case of 3.2 grains of Unique, seating a bullet just 0.1" inches deeper will increase peak pressure almost 5000 PSI. This explains why a chronometer is not sufficient for load development validation; geometry of the load affects pressure.
For a wadcutter, a more reasonable load would be about 2.5 grains of Unique. Unique is a little slow to be the best choice, though, and about 2 grains of Bullseye or HP38/W231 are more normally used for these wadcutter loads. The faster powder is more efficient and burns more completely, which is why you need less of it. Velocity from a 6" barrel should run around 850 fps. Nick
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August 28, 2006, 03:51 PM | #3 |
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Danger, Danger Will Robinson.
I don't have any specific data for 100gr wadcutters but from what I do have it looks like your way over on powder. It looks like his data is for a rnl bullet instead of a wadcutter and even then it's a little high.
First thing you might want to do is research the gun. Make sure it is not designed for hollow based wc's only. The RBCS cast bullet manual no. 1 lists a 98gr solid based wc. The suggested load with Unique is 2.3 to 2.5 grains and this bullet has a crimp grove so it wouldn't sit as deep as your 100gr wcs seated flush. |
August 28, 2006, 04:29 PM | #4 |
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Thank YOu Rimrod AND UNcle Nick
Never thought about the Wadcutter vs "Normal" RN and the combustion volume thing.
You are exactly right I am sure Wow I WAS vastly over charging them. Sure am glad I noticed the primers I never would have guessed that they were overcharged from the way the gun fired ( which seemed fine to me) but as I said it is a "New to me" gun. I will cut back to 2.5 I thank you all ( and my Benelli thanks you as well) [email protected]
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