Too Much Taper Crimp?

[SQLGeek]

Hey folks, long time lurker finally getting a little more active on the forum.

I haven't been reloading that long and have been slowly working up a load for .45 ACP with Berry's 200 gr FP bullets and HP 38 in a S&W M&P 45.

I had to pull the first batch I did as they were too weak to cycle the gun. This is what the bullets looked like.

Completed cartridge on left, new bullet middle and pulled bullet right.




Is this too much taper crimp? Not enough mouth expansion?

From my notes, I have the OAL set to 1.15" and an outer diameter at the case mouth of .470" after crimping. The bullet is .452".

I set the OAL based on what would plunk and spin freely in my pistol barrel with a crimp. The bullets had to go a fair amount lower to not engage the lands.

Thanks in advance!

 

[CMV]

That looks like a lot to me. Just enough to remove the mouth flare is all i do pretty much. See a slight ring on a pulled bullet, but not deformation like that. Pull a few factory loads & you'll see. Sometimes RMR has pulled bullets for sale & they have pictures you can zoom in on. That would be another way to see how little deformation a crimp should do to a bullet.

 

[garandsrus]

Yes, way too much crimp. The taper crimp should not distort the bullet.

 

[Virginia Jim]

Be careful with powder loads at or below the recommended starting load. You didn’t say what your load was but light loads and a heavy crimp could result in a squib.

 

[mdi]

I've been reloading semi-autos for quite a while and when explaining a crimp to a new comer, I suggest to forget the term "crimp" and use "deflare". In semi-autos the bullets are not held in place with a crimp, neck tension does. Use a taper crimp die to "deflare" your handloads just enough to get a good consistent plunk. A lot of reloaders measure the case mouths post crimp and quote a diameter, but I no longer measure that as there are many variations that will affect the measurement and, at least for me and the many, many 45 ACP handloads I've assembled, a precise diameter isn't needed, just a good, consistent "plunk" (my 3, 45 ACP guns feed and chamber my handloads quite well)...

Yes, the bullet on the right has way too much crimp...

 

[SQLGeek]

Be careful with powder loads at or below the recommended starting load. You didn’t say what your load was but light loads and a heavy crimp could result in a squib.

Thank you. I'm up to 5.0 gr of HP-38 but need to increment higher as I'm still getting sooty cases though the gun did cycle. My first load was 4.6 I believe and it wasn't cycling the gun but no squibs. I made up 20 of those and put them in the magazine, chambered and fired one at a time while checking for squibs because I knew I was light.

Man plan is to start over with the bullet seating and crimp and see if I can avoid deforming the bullet and then loading a batch of 20 and working my way up again.

 

[Texas10mm]

Part of your problem might be that extremely excessive crip.

I've shot 200 gr lead SWC bullets with 4.2 gr 231 and they cycled just fine in everything I've tried. Yeah the cases are a bit sooty but that's always going to happen at low charge weights...unless you're using Clean Shot.

 

[LiveLife]

Too much taper crimp?

outer diameter at the case mouth of .470" after crimping. The bullet is .452"

Definitely too much taper crimp.

Case wall thickness averages around .011"+ at case mouth and I usually add .022" to the diameter of the bullet for taper crimp to bring flare just back flat on the bullet. If the case wall is thicker than .011", then it will apply slightly more taper crimp - https://www.thehighroad.org/index.p...nd-bullet-setback.830072/page-3#post-10712225

So for .452" sized bullet, .452" + .022" = ~ .473" taper crimp

With this amount of taper crimp, pulled bullets show almost no indent.

Issues with using too much taper crimp is it can deform and reduce the bullet diameter which will decrease neck tension. Also with plated bullets, using too much taper crimp can cut through the copper plating and cause leading and reduced accuracy.

I'm up to 5.0 gr of HP-38 but need to increment higher as I'm still getting sooty cases

With 200 gr plated bullets and W231/HP-38 below 5.2 gr, I found powder burn was inefficient (sooty and unburnt granules) and starting at 5.2 gr, no unburnt granules and accuracy improved.

So try bumping up the powder charge to 5.2 gr.

BTW, here's Speer load data for TMJ which is thick plated bullets - https://reloading-data.speer-ammo.c...iber_451-454_dia/45_Automatic_200_TMJ_SWC.pdf

• 45ACP 200 gr TMJ SWC W231 OAL 1.275" Start 5.6 gr (826 fps) - Max 6.3 gr (931 fps)

And I have used lead load data with Berry's plated bullets with good results. Here's Hodgdon's load data - http://www.hodgdonreloading.com/data/pistol

• 45ACP 200 gr Lead SWC W231/HP-38 COL 1.225" Start 4.4 gr (771 fps) - Max 5.6 gr (914 fps)

 

[SQLGeek]

Excellent info, thank you! I went and started from scratch on setting up all of my dies tonight.

Using a post of yours I had found a long while back about doubling case wall thickness and adding the bullet diameter, you get what you should be taper crimping to. I settled on 0.473". Glad to see this confirmation.

Thank you also for the load data. That's good to know about Speed TMJ. I had been working on Hodgdon and Hornady data to figure out my start. My findings are similar about incomplete powder burn at 5.0 so I will bump to 5.2 and try again.

Here are the results from tonight. Previously loaded bullet on left, new bullet middle and newly loaded and pulled bullet right.



I think I've got the dies dialed in. I made up 5 dummies, they all plunked and chambered fine. OAL is 1.15". Just a touch of taper on the crimp.

Thank you all very much for the feedback!

 

[LiveLife]

OAL is 1.15"

OK, found the picture I was looking for.

This is comparison picture of factory PMC and CCI 230 gr FMJ along with Berry's 185 gr HBRN and HSM 230 gr HP reloads. If you look at the HP, you will notice it is essentially RN with tip cut off and thus requires much shorter OAL. (Most bullet manufacturers reference RN bullet and make the HP/SWC cuts around RN contact points that will bump the feed ramp/ride the chamber wall). Your 1.150" seems to correspond to my 1.147" for similar nose profile bullet.

Here are the results from tonight. Previously loaded bullet on left, new bullet middle and newly loaded and pulled bullet right.

Looking good and look forward to the range report.

 

[FROGO207]

FWIW I only make 5 rounds of each step when working up a load to begin with. The accurate one gets more rounds made on either side of it. 20 rounds at starting load is a waste of supplies. Sometimes I will only make 3 of the first two steps then go to 5 rounds.

 

[Walkalong]

Just adjust the die to remove all the belling/flare on the shortest cases, which will give a slight inward crimp on the longest cases.

Berrys 230 Gr RN

 

[lordpaxman]

Is this too much taper crimp? Not enough mouth expansion?

Yes. No. You’ve gotten a lot of good feedback on your first question, but certainly if you didn’t have enough belling you’d have a difficult time seating a bullet. It’d be difficult to hold the bullet in position, and, you may get quite a bit of shaving when the bullet seats. The other aspect of over-crimping is that is can reduce neck tension, as the brass springs back a bit. Along with all the other advice above, I’d recommend you always check bullet setback as part of the QC process. From your pictures it appears you do have sufficient neck tension as the bullet is bulging the case but it’s always a good idea to press it really hard on the bench and measure any decrease in COL. Then feed one in the gun with the mag and a slide release chamber, and measure again to see just how much setback there is. Good luck!

 

[mdi]

I quit measuring crimp diameter mainly because using mixed brass the case walls do vary in thickness, and yep, even some bullets vary .0015" bullet to bullet so a consistent "crimp" can be too heavy or too light. I'm not an engineer, just a lifelong machinist/mechanic and have found K.I.S.S. to be the best method for a procedure (even though I do like to know and understand the theory behind a procedure). For a consistent measurement of the case mouth crimp, I would have to measure all the various manufacturer's case walls, sort by wall thickness, and readjust my dies with each case wall thickness. But I get excellent consistent ammo using a "deflaring" tool and the plunk test...

 

[LiveLife]

I quit measuring crimp diameter mainly because using mixed brass the case walls do vary in thickness ...

For a consistent measurement of the case mouth crimp, I would have to measure all the various manufacturer's case walls, sort by wall thickness, and readjust my dies with each case wall thickness. But I get excellent consistent ammo using a "deflaring" tool and the plunk test...

I hear ya.

And not to mention some newer headstamp brass that vary case wall thickness on the same case so 12/3/6/9 O'Clock measurements can be different, sometimes wildly.

In the myth busting thread, I found case wall thickness at case mouth (Down to .100" below) to range from .010" to .014" with most average being .011"-.012" - https://www.thehighroad.org/index.p...nd-bullet-setback.830072/page-3#post-10712225

That's why I resorted to simply adding .022" to the bullet diameter for my taper crimp amount as I found, it not only returns flared case mouth flat back on the bullet but very slightly more if the case wall is thicker.

Yes, KISS.

 

[AJC1]

How I taper crimp...
Measure the seated bullet diameter near the base of the bullet. Then measure the entire cartridge length wise in the calipers. Screw down the die until they match. This effectively gives you zero crimp and just removes the flare. This is your zero point and you may not need to go any further. I add a tiny amount more for jacketed and use zero for lead.

 

[SQLGeek]

I have been trying not to obsess over measurements too much because I know there are variations in components and my own measuring technique. I do like being able to have some measurements though in addition to visual confirmation I'm on the right track.

I failed to mention last night that I trialed dummies in a variety of case lengths from .887 to around .891 and that mouth expansion, seating and crimp all seemed to be acceptable.

I imagine I'll have all of this figured out just in time to order more bullets and I'm sure I won't be able to find these again anytime soon.

 

[LiveLife]

I have several factory/aftermarket barrels with some of the tightest chamber and shortest leade I have seen in my life (Over 10 aftermarket barrels) and they do prefer taper crimp returned flat on bullet and slightly a bit more - https://www.thehighroad.org/index.p...g-oal-col-for-reference.848462/#post-11068321

If you have barrels with SAAMI max dimensions, you won't have to fuss with precise finished dimensions of your rounds.

But I can tell you one thing, my finished rounds WILL work in any other pistols/barrels, even SAAMI minimum barrels.

 

[SQLGeek]

I’d recommend you always check bullet setback as part of the QC process. From your pictures it appears you do have sufficient neck tension as the bullet is bulging the case but it’s always a good idea to press it really hard on the bench and measure any decrease in COL. Then feed one in the gun with the mag and a slide release chamber, and measure again to see just how much setback there is.

Thank you. I had cycled the dummies a few times and found they did not move.

I tried tonight with the one dummy I had left and pushed it hard against the bench and the concrete floor. Not a bit of setback so it seems I'm good.

With how deep I was seating these bullets, I was already pretty leery about setback so it's nice to know I'm good to know with that.

 

[lordpaxman]

That’s good to hear there’s little to no setback. In addition to the “push” test, I’ll take a round and “thump” it a few times on my wooden bench. Totally unscientific, but I feel those bullets should not move, so if they do something is wrong.
The other thing to consider as you back off the crimp to “just enough”, is a case gauge of some kind. You of course, can always use your barrel but having a gauge on the bench is easier for me. I employ a Shockbottle 100 hole gauge but that’s mainly for speed and efficiency. Good luck!

 

[Alex Clayton]

Many years ago I was rolling some .38. Gun had such a tight cylinder I was having a hard time getting ammo to work. Bought a Lee Factory Crimp die and all of a sudden no problems. I took to buying one for every caliber in hand gun I load. The extra step to me was well worth how well they work and how easy it is to swap dies now. No more setting up the proper crimp. No more having to make sure all the cases are the same.

 

[SQLGeek]

You of course, can always use your barrel but having a gauge on the bench is easier for me. I employ a Shockbottle 100 hole gauge but that’s mainly for speed and efficiency. Good luck!

I only have one .45 pistol for now so my barrel is ok for testing. I'd love to get a Shockbottle 100 one day but it's a ways down on my equipment list. I need a chrono first.

 

[Texas10mm]

I only have one .45 pistol for now so my barrel is ok for testing. I'd love to get a Shockbottle 100 one day but it's a ways down on my equipment list. I need a chrono first.

I use the EGW seven hole gauges. They're much less expensive.

 

[SQLGeek]

I've looked at those too. The Shockbottle looks cool because you can transfer them to a 100 round ammo box in one move.

 

[Bill M.]

What if you do put too much taper crimp on a thick plated bullet. Does it actually hurt anything? Mine distort the bullet just a little but the plating does not come off when I pull them. I seat and crimp in separate operations. I think the pressure inside the case expands the case when the round is fired so I do not think there is a lot of "pull" on the plating. Right now I fell better with a tight crimp because I have been reading for years and years how important a tight crimp is.