FMJ 158g roll or taper crimp when no groove

[winfreeokra]

I’m a relative newb that has thus far only loaded various flavors of WC and SWC’s in 38 and 357 at target velocities. I ordered some FMJ 158g from NER thinking they’d be good for full 357 Mags and noticed after ordering they have no cannelure or crimp groove.

My readings have lead me to believe that the taper crimp is appropriate in this situation but will it provide enough retention for full house 357? Thought I read for taper crimp in 357 once to keep it below 1000fps. So maybe still roll or FCD on these for a little more bite?

How would you utilize these:

A. Taper crimp but keep velocities down?
B. Roll crimp and load as you please?
C. Taper crimp will be fine at above 1000fps?

 

[Reloadron]

I use a roll crimp on all of my 38 Special and 357 Magnum loads. Not saying a taper crimp is a bad way to go but I have always gone with a simple roll crimp using several die brands. That includes light loads and wad cutters.

Ron

 

[winfreeokra]

I use a roll crimp on all of my 38 Special and 357 Magnum loads. Not saying a taper crimp is a bad way to go but I have always gone with a simple roll crimp using several die brands. That includes light loads and wad cutters.

Ron

This is what I’ve done thus far as well, including with the fake-ish cannelure on the xtreme bullets. I have ended up with a taper crimp die as well though so was just wondering if that was the right road to take or if the hotter loads should stick with the roll crimp. I’m assuming either will be fine otherwise how would semi-autos shoot heavy recoil loads?

 

[243winxb]

full 357 Mags

Load some up witb the crimp of your choice.
TEST- Fill the revolver cylinder, shoot all but the last round in the cylinder. Remove unfired round & measure OAL. How much has it moved?

 

[Reloadron]

This is what I’ve done thus far as well, including with the fake-ish cannelure on the xtreme bullets. I have ended up with a taper crimp die as well though so was just wondering if that was the right road to take or if the hotter loads should stick with the roll crimp. I’m assuming either will be fine otherwise how would semi-autos shoot heavy recoil loads?

I would absolutely try the suggested above by 243winxb. That is a heck of a good little easy test.

Ron

 

[winfreeokra]

TEST-

this makes perfect sense of course. Just having read to use taper crimp when no groove in various places across the interweb got me wondering.

 

[243winxb]

A taper crimp would be my first choice. No damage to the bullet. Is bullet plated or a real FMJ.

 

[Walkalong]

Depends on how tough the plated bullet is. You may have to keep velocities down, but they may take a fierce taper crimp and still shoot fine over 1000 FPS.

I have run the X-treme 158 Gr SC at 1250ish with 2400 using a medium taper crimp, shoots great.

I have run a Powerbond 125 Gr at 1250ish with a very heavy taper crimp with excellent accuracy.

The X-Treme 158


The Powerbond

 

[winfreeokra]

A taper crimp would be my first choice. No damage to the bullet. Is bullet plated or a real FMJ.

These are real FMJ vs plated purchased specifically to push faster than the plated I have.

walk along…good to know there is some room yet with those also.

 

[Ru4real]

this makes perfect sense of course. Just having read to use taper crimp when no groove in various places across the interweb got me wondering.

Yea, that “rule” is one of those web myths that just gets repeated as a “must do”. Definitely not a “must do”. Test for your self and see.

Personally, I roll crimp all 45 Colt, 357 and 38 Special on bullets without crimp groves because in my testing they proved more consistent velocities.

 

[Herman B]

I ordered some FMJ 158g...thinking they’d be good for full 357 Mags and noticed after ordering they have no cannelure or crimp groove.

My readings have lead me to believe that the taper crimp is appropriate in this situation but will it provide enough retention for full house 357? Thought I read for taper crimp in 357 once to keep it below 1000fps.

How would you utilize these:

A. Taper crimp but keep velocities down?
B. Roll crimp and load as you please?
C. Taper crimp will be fine at above 1000fps?

No cannelure or crimp groove in your bullet. And apply a roll crimp - how? Roll-crimped brass needs a void - has nowhere to go without it. But a void can be created by swaging the bullet - a nice way of saying 'deforming.' Doesn't jibe w/ accuracy, may cause separation. A few generalizations about crimps...

Taper crimp - for bullets without groove/c'lure, nothing more than removing the flare/straightening the brass, does zero for neck tension/retention. Over-do a tc and decrease neck tension - brass springback is .001, lead is .000. Terribly overdone tc swages the bullet and approximates a profile crimp. Proper tc appearance takes one shape with litmus being, 'returned to straight or not'. Anything beyond 'straightening' is no longer a tc. TC will not provide added retention for proper combustion nor prevent 'jump' in proper magnum loads. TC's (in theory) are to be more precise due to headspacing needs of mouth (vs roll crimped cartridges 'spacing on rim). Overcook a tc and the round may seat deeper in the chamber, bullet into leade, increasing pressure, etc.

Profile crimp - (Redding only?) hybrid between taper and roll. Must have a void. See Post #8 Powerbond - what I would consider a light profile crimp. Appearance varies depending on die adjustment. May increase tension re: combustion and jump. For rimmed rounds - not used for headspacing mouths. Firm to heavy profile looks/performs much like a roll.

Roll - short version: very distinct turning-in ('roll') of brass into groove/cannelure. Various appearances/dies. Increases retention re: combustion and jump. For rimmed rounds - not used for headspacing mouths.

 

[Walkalong]

An old post about crimping.

https://www.thehighroad.org/index.p...-and-crimp-in-two-stages.623417/#post-7699828

 

[GeoDudeFlorida]

I’m a relative newb that has thus far only loaded various flavors of WC and SWC’s in 38 and 357 at target velocities. I ordered some FMJ 158g from NER thinking they’d be good for full 357 Mags and noticed after ordering they have no cannelure or crimp groove.

My readings have lead me to believe that the taper crimp is appropriate in this situation but will it provide enough retention for full house 357? Thought I read for taper crimp in 357 once to keep it below 1000fps. So maybe still roll or FCD on these for a little more bite?

How would you utilize these:

A. Taper crimp but keep velocities down?
B. Roll crimp and load as you please?
C. Taper crimp will be fine at above 1000fps?

View attachment 1007547

Use a micrometer or accurate caliper and measure the diameters of a few bullets. If they are .3570"-.3575" or larger, you can use them easily in .38Spl or .357 Magnum. Then you'll need to take into consideration the weight and recoil energy effects on YOUR revolver.

When I see "38 caliber" and no cannelure I immediately think ".38 Super" and if they measure .3550"-.3555" or thereabouts, but under .3570", then I'm thinking that's what you have and you will need to load them a little lighter in a small-framed, light-weight .357Magnuim revolver to avoid having the bullets unseat and lock up your cylinder.

 

[GeoDudeFlorida]

I’m a relative newb that has thus far only loaded various flavors of WC and SWC’s in 38 and 357 at target velocities. I ordered some FMJ 158g from NER thinking they’d be good for full 357 Mags and noticed after ordering they have no cannelure or crimp groove.

My readings have lead me to believe that the taper crimp is appropriate in this situation but will it provide enough retention for full house 357? Thought I read for taper crimp in 357 once to keep it below 1000fps. So maybe still roll or FCD on these for a little more bite?

How would you utilize these:

A. Taper crimp but keep velocities down?
B. Roll crimp and load as you please?
C. Taper crimp will be fine at above 1000fps?

View attachment 1007547

This thread may help...
https://www.thehighroad.org/index.php?threads/357-fmj-rnfp-question.890287/

 

[bluejay75]

If you can find one of these…this is what I suggest.

Won’t work on 38 Special but there is none better for 357.

https://www.titanreloading.com/lee-357-magnum-collet-style-crimp-die