.38 Super OAL??

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.38 Super OAL??

Post by dronning on 8/21/2017, 11:46 pm

What are some starting points for loaded round OAL? I've read anywhere from 1.21-1.27
I'll be testing both
Magnus 147 
Dardus 126 

Do you crimp or just eliminate the bell?  
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dronning

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Re: .38 Super OAL??

Post by noylj on 8/22/2017, 7:52 am

You crimp to eliminate the bell.
Starting point? I make up two dummy inert rounds and find the COL that fits the magazine and then reduce the COL until both feed and chamber easily.
With a 1911, I find the COL that puts the case head flush to just below flush to the barrel hood is usually best.
FMJ is usually 1.250-1.265, depending on the ogive.
L-SWC is usually 1.265-1.275", depending on the length of the "nose" (shoulder to meplate).
JHP can be as short as 1.215 or as long as 1.261.
Re: COL
Your COL (Cartridge Overall Length) is determined by;
your barrel (chamber and throat dimensions)
and
your gun (feed ramp)
and
your magazine (COL that fits magazine and when the magazine lips release the round for feeding)
and
the PARTICULAR bullet you are using.
What worked in a pressure barrel or the lab's gun or in my gun has very little to do with what will work best in your gun.
Take the barrel out of the gun. Create two inert dummy rounds (no powder or primer) at max COL and remove enough case mouth flare for rounds to chamber (you can achieve this by using a sized case—expand-and-flare it, and remove the flare just until the case "plunks" in the barrel and lock the die body down temporarily).
Drop the inert rounds in and decrease the COL until they chamber completely. This will be your "max" effective COL. I prefer to have the case head flush with the barrel hood (or a few mils higher than where the head of an empty case aligns with the barrel, as all cases are too short and I prefer to minimize head space). After this, place the inert rounds in the magazine and be sure they fit the magazine and feed and chamber.
You can also do this for any chambering problems you have. Remove the barrel and drop rounds in until you find one that won't chamber. Take that round and "paint" the bullet and case black with Magic Marker or other marker. Drop this round in the barrel and rotate it back-and-forth.
Remove and inspect the round:
1) Scratches on bullet--COL is too long
2) Scratches on edge of the case mouth--insufficient crimp
3) Scratches just below the case mouth--too much crimp, you're crushing the case
4) Scratches on case at base of bullet--bullet seated crooked due to insufficient case expansion (not case mouth flare) or improper seating stem fit
5) Scratches on case just above extractor groove--case bulge not removed during sizing. May need a bulge buster.


Last edited by noylj on 8/22/2017, 7:55 am; edited 1 time in total

noylj

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