Taper Crimp

[38SPL HV]

I'm always trying to find the most accurate load. I'm considering using taper crimps on my 38 Spl +P lead loadings (below 1,000 fps). I've always used a medium heavy roll crimp on my 158 gr swaged lead +P loadings, accuracy was pretty good but a taper crimp may get me equal or better accuracy with less stress to case mouths.

I used taper crimps long ago on 38 Spl 148 gr HBWC loads with good success. Wondering how taper crimp would perform on 158 gr swaged lead 38 Spl +P loadings?

Any advice or experiences are appreciated.

 

[HKSmith]

I'd be concerned about bullets jumping crimp and tying up your revolver, especially in lighter guns. You can certainly give it a try, just bring a dowel with you to push the bullet back in if needed.

 

[bigedp51]

I use a taper crimp on my S&W 29-5 light .44 magnum loads using 231 without any problems.

 

[rockquarry]

For all .38 Special loads, standard pressure and +P, I've found a taper crimp to provide better overall accuracy in comparison to a roll crimp. I haven't roll-crimped a .38 Special load in a long time, but, the difference between the two crimps is often slight.

I use a Redding taper crimp die and cast bullets only. These days, I seldom load anything but factory equivalent standard pressure loads. Regardless of the intensity of the loading, I've never found a taper crimp to be inadequate. Granted, there may be some isolated exceptions that I'm unaware of.

Some claim a heavy roll crimp is necessary for heavier loads of slow-burning powder. "Heavy crimp" is a relative "eyeball" term for which no standard exists; some such crimps can distort a bullet to the point of causing inaccuracy.

 

[rwsmith]

Swaged bullets are inherently soft....

Barrel fit is as much or more of a factor than velocity, but soft lead bullets tend to lead more when they get close to 1000 fps.

I think taper crimping revolver rounds is fine if that gets you the best results. But if you have a lighter gun and heavier loads, the bullets may tend to back out by the time the last round is fired. A very slight roll crimp can usually prevent this.

I have a very light alloy J frame 38 special that would probably be worse on backing bullets out than most guns. Shooting the same load in my 686 probably wouldn't budge them one iota.

My old Speer #9 did a test with increasing loads with various levels of crimp. Only the non-crimped bullets at heavy loads showed signs of bullet backing out.

 

[SMSgt]

If you don't get bullet jump, it's not a concern.

 

[38SPL HV]

Thank you guys

 

[ArchAngelCD]

I do not think it's a good idea to use a taper crimp on lead bullets. I see no reason to think it will improve accuracy.

 

[patrickd]

I'd be concerned about bullets jumping crimp and tying up your revolver, especially in lighter guns. You can certainly give it a try, just bring a dowel with you to push the bullet back in if needed.

As long as you don't over expand the case mouth you'll have plenty of case tension even without a tight taper crimp. At least I've never had any bullets creep out on my loads and those are with plated bullets that have no crimping groove. I just flare the mouth just enough to get the base started in and let the bullet stretch the case as it is seated. Never had any issue and I never even used a taper crimp.

 

[rockquarry]

I do not think it's a good idea to use a taper crimp on lead bullets. I see no reason to think it will improve accuracy.

Has your experience with taper crimping proven it not to work well with cast bullets?

 

[Nevada Ed]

In all my years loading all weights of lead bullets in 38 spl. and 357 Mag....................

I have used light, medium and a heavy crimp on my lead bullets.
A light crimp on target loads ...
a medium crimp on factory loads........
and a HEAVY crimp on "Hang on" loads............

A taper crimp is great for 9mm etc. pistol loads but I see no reason
why one would want to put it on a revolver load that does not
chamber on the front of the case but on the rim of the case....
which can lead to set back or forward movement of the bullet.

Both, bad.

Why use pistol loading steps, on a revolver load ?
Do you put diesel in your gasoline automobile?

 

[ArchAngelCD]

Has your experience with taper crimping proven it not to work well with cast bullets?

It's not that the taper crimp doesn't work well, it's just that I saw no accuracy improvement so why take a chance on bullet pull for no benefit?

The only time I now use a .38 Special taper crimp die is on thin plated bullets and more so on the Speer shot capsules when building snake shot loads.

 

[fredj338]

Just go to a light roll crimp. A taper cripm over done can swage a bullet down. Even 0.0005" can affect accuracy in lead bullets.

 

[rockquarry]

Both types can distort bullet / reduce diameter if applied too heavy.

 

[gwpercle]

If you are into accuracy , like me , you may want to try this.
A 120 - 124 grain , cast lead , truncated cone bullet , like the Lee 356-120-TC or the NOE 358-124-TC-GC (my choice).
I had cast a bunch for 9mm , they dropped from the NOE mould .3575 and I decided to try some 38 special +P loads with 6.1 grains Accurate Arms #5 and taper crimped with the 9mm crimp die.
Fired from an old Ruger Blackhawk , 15 shots at 25 yards grouped into a 1 3/8 inch circle....sort of surprised me ...I'm 67 , blind in one eye and half blind in the other. I have talked to others who have had such results with Truncated Cone Cast bullets and taper crimping. I didn't have any bullets jump crimp. This shook my long held belief that SWC's and roll crimps were best.
A lighter load of 5.5 grains of Accurate Arms #5 grouped into 1 1/4 inches. Might be something for you to try out.
I ran the bullets through a .358 sizing die just to lubricate them but have discovered even when sized .357 they are just as accurate in my S&W model 64 target gun .
Gary

 

[rockquarry]

I've found a number of S&W revolvers that are slightly more accurate with .357" cast bullets than they are with .358". Same with Colts. However, the difference isn't generally great enough that I would use two different sizes, though I did try that. Too much trouble...

 

[mikld]

FWIW; Don't be too concerned about roll crimping lessening case life. 38 Special brass is everywhere, easy to find and cheap, even if you buy new. If that's the only reason to try a taper crimp, I wouldn't bother. I know many reloaders use a taper crimp on their 38 HBWC loads, but not many that use one on full loads with heavier bullets.

Just a couple thoughts; I wouldn't try to load swaged bullets to +P levels and I'd stick with roll crimping. I would test the amount of crimp starting light (load a cylinder full, shoot all except one, measure the OAL of the last round to see it the bullet crept out. If so, add a bit more crimp and retest)...