crimping your 9mm?

[c_brutsche]

thanks again guys...i am learning more on here than even in the books i have been reading

[craighmarshall]

I am using a Lee 4 die set on a Classic Turret and was wondering, can i over crimp?

I use Bullseye and I set my charges @ 4.4 (disc 46) and 4.8gr (disc 49)
set my RN's to 1.139 - 1.140 and the FN's and HP's at 1.093-1.095
Could I over crimp creating a high pressure situation?
Load for both an XDM and a Marlin Camp 9 rifle.

[Arrdy]

A crimp/tight grip on the bullet also creates a high(er) pressure situation. Some powders like this and burn cleaner. It's a balance between good, not enough, too much.

When I work up a load, I always use a chrono as a check. You'd be surprised how much a good crimp can effect a load's repeatability .... and accuracy. I crimp just enough to get the accuracy I want.

[LisaA]

Great information in this thread!

[West Chester]

I use a rcbs 3 die set for 9mm. I went with an aftermarket barrel to be able to shoot lead bullets rather than the more $$$ jacketed.

[Arrdy]

I use a rcbs 3 die set for 9mm. I went with an aftermarket barrel to be able to shoot lead bullets rather than the more $$$ jacketed.

?????

Been shooting hard lead cast bullets from my 9mm's, 45 acp, 357 and 44 for years with no lead fouling .... I keep the loads to about 1000 fps or less, about 800 fps on the 45 acp.

A crimp die is a good investment.

[Guns N'at]

I am using a Lee 4 die set on a Classic Turret and was wondering, can i over crimp?

I use Bullseye and I set my charges @ 4.4 (disc 46) and 4.8gr (disc 49)
set my RN's to 1.139 - 1.140 and the FN's and HP's at 1.093-1.095
Could I over crimp creating a high pressure situation?
Load for both an XDM and a Marlin Camp 9 rifle.

Not by the "crimp" action; implying that the bullet will be gripped more tightly, but exactly the opposite effect caused by its over use, then potentially yes. Removal of case flare with taper "crimp" dies is the goal and its sole function. Proper case-to-bullet tension is the mechanism of safe and sure bullet retention, by the interaction of proper bullet diameter to internal case wall dimensions in cartridges like 9mm that headspace off the mouth.

Over doing taper "crimping" can cause a very poor bullet-to-case tension situation, because greater application of "crimp" is sizing the bullet and case to a degree that the case springs back, but the bullet remains at the smallest sized dimension. Your goal of "crimping" extra hard actually backfired, and now a very real danger of high pressure setback exists, because there is little to no tension/friction/pull between the bullet and case. Best of all worlds is good tension and a case cannelure applied just below the base of the bullet shank.

IMO and experience, properly made and applied three die sets, with the seater/crimper properly used is all that is needed, but I do however like to use a separate conventional taper "crimp" die in the forth position for convenience, not necessary, and folks like Dillon and others include this 4th conventional TC die. While on the topic of "crimping", I have never once felt the need for a post sizing die, Ala Lee FCD... I don't want the setback preventing 'bulge' removed, potentially undersizing the bullet, and for every pistol and die set I own, be it RCBS, Dillon, and Lee pre FCD supplied, ammo made with them works just peachy, just like like it has for many decades before I started reloading.

[West Chester]

?????

Been shooting hard lead cast bullets from my 9mm's, 45 acp, 357 and 44 for years with no lead fouling .... I keep the loads to about 1000 fps or less, about 800 fps on the 45 acp.

A crimp die is a good investment.

I am sorry, I shoot a 9mm Glock with the polygonal rifling which does not do well with lead bullets.

9mm uses a taper crimp because it headspaces on the case mouth. A simple 3 die set will be all you need.

[Arrdy]

I am sorry, I shoot a 9mm Glock with the polygonal rifling which does not do well with lead bullets.

9mm uses a taper crimp because it headspaces on the case mouth. A simple 3 die set will be all you need.

My 92F and P95 will spit out almost anything you can shove in it's 'mouth'. And because these are just plinking guns, along with my 1911 clone, lead is fine most of the time. I find my ballistics are more consistant if I run a Lee Factory Cimp die as my final step. With my G23, I have 16 fps as my exteme spread in 50 rounds. I was around 80 fps without the crimp. Ameican Eagle factory loads were 60 fps. Your results may vary.

I was responding more to your remark that you bought an aftermarket barrel so he could shoot lead bullets. As I said, I don't have problems using lead loads in my pistols or 1892 Winchester .... but that sweetie was meant for lead and black powder.

[West Chester]

Your Beretta and Ruger use conventional rifling, Glock uses polygonal.

From the less than reliable Wikipedia, but you can do your own research

The manufacturer Glock advises against using lead bullets (meaning bullets not covered by a copper jacket) in their polygonally rifled barrels, which has led to a widespread belief that polygonal rifling is not compatible with lead bullets. Firearms expert and barrel maker, the late Gale McMillan, has also commented that lead bullets and polygonal rifling are not a good mix. Some have made a point of the fact that neither H&K nor Kahr explicitly recommend against lead bullets in their polygonal rifled barrels, and feel that it is probable that there is an additional factor involved in Glock's warning.

However, Kahr's FAQ does include a warning that lead bullets can cause additional fouling[7] and recommends special attention to cleaning after using them. In addition, while H&K doesn't warn against the use of lead, at least one well-documented catastrophic incident in an H&K pistol[8] may be related to this issue. Furthermore, Dave Spaulding, well-known gun writer, reported in the February/March 2008 issue of Handguns Magazine that when he queried H&K about their polygonally rifled barrels that they commented: "It has been their experience that polygonal rifling will foul with lead at a greater rate than will conventional rifling."

One suggestion of what the "additional factor involved in Glock's warning" might be is that Glock barrels have a fairly sharp transition between the chamber and the rifling, and this area is prone to lead buildup if lead bullets are used. This buildup may result in failures to fully return to battery, allowing the gun to fire with the case not fully supported by the chamber, leading to a potentially dangerous case failure. However, since this sharp transition is found on most autopistols this speculation is of limited value. The sharp transition or "lip" at the front of the chamber is required to "headspace" the cartridge in most autopistols.

Another possible explanation is that there are different "species" of polygonal rifle and perhaps Glock's peculiar style of polygonal rifling may be more prone to leading than the particular styles employed in the H&K and Kahr barrels.
Leading is the buildup of lead in the bore that happens in nearly all firearms firing high velocity lead bullets. This lead buildup must be cleaned out regularly, or the barrel will gradually become constricted resulting in higher than normal discharge pressures. In the extreme case, increased discharge pressures can result in a catastrophic incident.