I need help I can`t figure it out Sig 357

I tooled up to load Sig 357, As I wanted to play with this round . the problem is the LOA 1.135 , it will go from 1.135 to 1.145 or 1.130. I use brass that is all one time fired the same head stamp (Speer) cleaned, Redding dies dillon 550 every thing is clean the load is #A9 and speer 124 gr, XTP (sig) I have taken the seating die apart and cleaned it 4/5 times , I tryed belling the case from almost no bell to way to much bell. I started out using Redding taper crimp die . I ajust the LOA to 1.135 then the next round will be 1.130 to 1.145 . I know it has something to do with the neck of the case , I thought the crimp die might be part of the problem so baught a Lee FCD and it still will do the same thing. So I ask anybody that loads the 357sig if they have the same problems , and what will it take to make good reloads with it ?? PS. I full length resized the brass.

I don't load this cartridge so is just a wild guess. Could it be varying primer seating/projection affecting your OAL measurements? Have you tried loading some dummies that eliminate all but case and bullet as variables?

make sure that your seating stem is clean. If you have been using cast then there is probably lub build up forming.
also, try seating and crimping in two different steps.
atr

fivegunner, have you measured a handful of seated only rounds for COAL variances to eliminate other options besides the neck/crimping?

I don't recall ever having that problem with .357 sig. Are you using a seating stem that is flat rather than cupped? Did you lube the cases for sizing or use a carbide .40 die? If you lubed the cases, I assume you cleaned them after?

Since the .357 sig headspace a off the shoulder I don't believe it is as sensitive to seating depth. If I did have this problem (it's been a while since I messed with .357 sig) I probably would have just seated on the shorter side and lived with that variance.

What kind of press are you using, and what condition is it in?

A progressive press with a rotating shell plate could have problems in or under the plate or in any of the dies in any of the stations that might cause larger than normal variations in OAL, since the plate could cant under differing pressure in each station.

Other problems I've had include cracked press frames, handles and powder measure (that is case activated by a powder funnel that doubles as a flare die).

Thanks for all of the replys, Yes I did and checked everything you guys brought up, I played with it for 2 hours yesterday . I did load 100 rounds they still had different LOA 1.230 to 1.240. went to the range and shot them all, they went though the 226 with No problems I only shot at 15 yds, off hand they didn`t all go into a small hole but were close, I was more concerend about Reliability than Accuracy. my next test is to replace the seating die. I will Figure this problem out . Thank you all

the dillion 550 has some play in the frame to tool head fit... if a few thousandths variation is too much you can use this kit to lock it down :

https://www.uniquetek.com/product/T1230

for most auto pistol loads small differences in OAL don't cause much problem unless you are running them right at max length to chamber or run in your mags...

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Originally Posted by slam45

the dillion 550 has some play in the frame to tool head fit... if a few thousandths variation is too much you can use this kit to lock it down :

https://www.uniquetek.com/product/T1230

for most auto pistol loads small differences in AOL don't cause much problem unless you are running them right at max length to chamber or run in your mags...

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Thank you Slam45,I think I will try this out Thank you for the info, It makes sence now!!

Quote:

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Originally Posted by slam45

the dillion 550 has some play in the frame to tool head fit... if a few thousandths variation is too much you can use this kit to lock it down :

https://www.uniquetek.com/product/T1230

for most auto pistol loads small differences in AOL don't cause much problem unless you are running them right at max length to chamber or run in your mags...

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I believe the small play is there by design because it allows cases on multiple stations to self align with the dies.

i think you are correct as to design tolerance, my 550 has been loading since 1980 and i can work around OAL variations most of the time... for some loads locking down the tool head makes life simpler and provides one less variable in the loading process...

Quote:

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Originally Posted by kayala

I believe the small play is there by design because it allows cases on multiple stations to self align with the dies.

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I inside chamfer all the case necks on my 357 Sig brass and it makes a big difference. You only have to do it once for each case. Give it a try and see if it improves your seating problem.

Hope this helps.

Fred

Slam45 was right on the money!! Life is good again my problem is Gone, Thank you Slam45.

Quote:

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Originally Posted by ReloaderFred

I inside chamfer all the case necks on my 357 Sig brass and it makes a big difference. You only have to do it once for each case. Give it a try and see if it improves your seating problem.

Hope this helps.

Fred

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This really helps seating bullets ...

Quote:

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Originally Posted by slam45

i think you are correct as to design tolerance, my 550 has been loading since 1980 and i can work around OAL variations most of the time... for some loads locking down the tool head makes life simpler and provides one less variable in the loading process...

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Thanks for letting us know. I’ve considered buying the Uniquetek kit several times.

For others still reading, another source of irregular OAL that I’ve found is not keeping the stage full. That probably no longer matters once the screw lockdown system is installed.