9mm Overpressure Due to Crimping Too Tight?

[35remington]

Take an unsized case. Put Dacron fluff in it to support the bullet in the case at the right overall length.

Taper crimp it to your desired dimension. Tap the bullet firmly against the bench. Watch the bullet move.

Jacket material is hard enough that the taper crimp does not form a sharp edged abutment for the case mouth, and the bullet still moves.

Don’t look at the ring in the jacket and posit it does something by looking at it. Actually test the effect of the taper crimp itself by doing what I have suggested and then try to tell me about how effective it is. Fee free to try varying amounts of crimp.

[6bg6ga]

Take an unsized case. Put Dacron fluff in it to support the bullet in the case at the right overall length.

Taper crimp it to your desired dimension. Tap the bullet firmly against the bench. Watch the bullet move.

Jacket material is hard enough that the taper crimp does not form a sharp edged abutment for the case mouth, and the bullet still moves.

DonÂ’t look at the ring in the jacket and posit it does something by looking at it. Actually test the effect of the taper crimp itself by doing what I have suggested and then try to tell me about how effective it is. Fee free to try varying amounts of crimp.

Why would I want to use a unsized case? That makes absolutely no sense. When you reload you do not reload unsized cases. Friend, I have been reloading 50 years now. Every single time I reload I test for any bullet movement after seating the bullet and I ALWAYS get some movement. I then taper crimp just enough to remove the flair and check for bullet movement and I always have to adjust and apply more taper crimp and this DOES stop any further bullet movement. Now, i realize what your next thought is going to be and that is your going to say that my FL sizing die is worn out. Well also tried this with band spanking new Dillon and RCBS dies...same thing. New brass with new dies...same thing.

Now, I'm not going to make a believer out of you because you cannot seem to understand. I suggest that you try the following ..load some 40 cal loads fill the mag after checking OAL on all of the rounds. Now shoot one and unload the magazine and check the OAL on all the rest. Guess what? They just changed and if you had continued to fire them off the possible result would have been some rounds where the bullet had backed into the case and resulted in excessive pressure. Friend I've seen this in person and I have witnessed a 40 blow up as a result of this. I like I said realize that you cannot accept this so I wish you the best of luck and hope as a result of your unwillingness to understand this that you do not blow up a prized firearm.

By the way take a look at the 9mm bullet that has been over crimped and tell me that you cannot change the diameter of the case. It would appear that I have done so. Note the contact point on the bullet.

[35remington]

To determine the effect of crimping alone. Remind yourself the case mouth is the same diameter as the sized case if enough crimp is applied. We are talking about the ability of the crimp alone to hold, are we not? Why not test it alone?

This separates the effect of the crimp from the holding effect of sizing. If the “ring” works as you claim this test should be performed to see if it indeed does. Pull many factory bullets and note they do not have an embedded crimp ring. They rely on tension as the primary factor as do I.

My bullets do not move when no taper crimp is applied. This is a simple function of correct sizing die diameter and expander diameter. When using Lee dies in my 45 ACP, the bullets move. A switch to correct RCBS dies fixed that. Proper loading procedure is to find dies that apply enough frictional force. Since my experience is like that of most others I discuss this with I cannot explain why you have difficulty. What you experience does not seem to be the common situation.

All I can ask you to do is try it. I have been reloading awhile myself. Ironically so doing makes the bullet hard to remove from the case but not at all hard to push in.

[35remington]

Keep in mind I am speaking only of conventionally jacketed bullets, not lead ones or thin plated ones. Your typical true FMJ, for instance.

I could and did apply a vicious taper crimp in my not tight enough dies. Bullets still moved. No amount of taper crimp on a jacketed bullet of the above description is the proper solution for dies that do not apply enough sizing or have an improper expander.....in my very considerable experience, I will add.

I have not blown up anything as a result of my practices. Probably because I am aware of what is working. If your bullets are in danger of receding into the case simply from gently bouncing around in the magazine your frictional fit is loose. The inertial forces applied to the bullets from being fired in what is really a low recoiling pistol while residing in the magazine are really modest.

Yep, have an M and P 40. Shield 40 too, which is a lot snappier.

Incidentally, have tried your “test” a number of times in both guns by shooting part of a magazine, then topping it off, shoot part of a magazine, and repeat. This was not done on purpose but mostly to have a fully loaded pistol when taking shots of opportunity when walking about or plinking. The bottom rounds in the magazine were exposed to repeated firing and moving about. None telescoped as you predict. I’m okay.

[44MAG#1]

One thing all of you can say in a positive way is Mr. Mountain has proven by his post that every Harry, Dick and Tom will believe what they want and load their ammo the way they want to.
The human mind is an awesome thing. Right, wrong and indifferent all wrapped up into one.

[Dusty Bannister]

Posters to this thread might consider taking a little break before continuing beating on this guy. First he gets a beating because his grandson is not being smart and safe in his efforts to get "free lead" by breaking down auto batteries. Lots of swats to G'Pa for not stopping that. And now he is getting beat up again because he is not answering your demands fast enough to suit you. Maybe he has a family emergency? Maybe he got sick? Maybe he just decided to not participate as the whipping boy any longer?

If you can't be civil, maybe you can try being silent for a bit and let things settle down.
Dusty

[IllinoisCoyoteHunter]

Explain how you can get tension when you have an ever so slight springback in the brass? We can all agree brass has springback, right?

Winelover, maybe after multiple firings your brass was work hardening and causing even more brass springback coming out of the sizing die causing inadequate bullet tension.

[Plate plinker]

It’s not rocket science. Follow the manual get a chronograph start low and work up.

[DonMountain]

One thing all of you can say in a positive way is Mr. Mountain has proven by his post that every Harry, Dick and Tom will believe what they want and load their ammo the way they want to.
The human mind is an awesome thing. Right, wrong and indifferent all wrapped up into one.

Hello again everybody. I apologize for not responding sooner on this question. And I am not offended in any way by all of the answers to my question. In fact some of the discussion made me laugh. I am slowly proceeding on the 9mm Luger reloading job. And things are improving. I am using Winchester brass. Remington 1-1/2 small pistol primers. 3.8 grains of Bullseye with every load measured on a RCBS 10-10 scale that has been zeroed before each loading session. And an ACME+ Coated 9mm 115 RN-NLG lead projectile. I got the most improvement by measuring the mouth of the case and setting the mouth at the book measurement of 0.380". A factory Winchester round was 0.376". And my previous loadings were at 0.377". So, I carefully set my taper crimp die to just squeeze it to the maximum that will fit in my gun at 0.380". And the primers look much better with this load and an Over All Length of 1.100". But still not quite like the factory Winchester loads do. So on my next set of reloads I have increased the OAL to 1.125" and I haven't shot those yet. Another thing I have noticed, was I accidentally set one of the bullets about 0.025" deeper than intended when I was adjusting my bullet seating die. And with my Quinetics bullet puller I had a heck of a time pulling one of these loads with the case mouth still belled and not crimped into the surface of the bullet. So, I am getting an awful lot of bullet friction or tension without even crimping. My reloading is being done with a 30 year old set of Hornady dies that I have used in the past without any problems.

[Walkingwolf]

9mm is a high pressure round, unless you load negative pressure you are going to get more flattened primers than with a low pressure round like 38 spl.

If this bothers you switch to magnum primers, and reduce your load to account for the hotter primer.

[Soundguy]

My experience is like yours. I have 50 years reloading and I started out with 38/357 as my first caliber to reload. I then graduated to 45acp. my first 38/357 dies employed the roll crimp that simply rolls the edge of the case into the ring on the bullet. When I started reloading jacketed bullets I found a need to have a better crimp as the roll is worthless on jacketed. i then purchased the carbide dies and an optional tapper crimp die.

I will attempt to over crimp a 9mm bullet and post a picture for those that are either unwilling to accept the fact that taper crimping DOES apply pressure to either a lead or JACKETED OR PLATED bullet. If you still cannot understand it or grasp the concept there is no hope for you in my opinion.

Roll crimp worthless on jacketed? Very much disagree.

I shoot many many magnum and belted mag loads with big jacketed projectiles and I assure you a hefty roll crimp works just fine.

[DonMountain]

Ok, I fired the 15 rounds with the 0.380" case mouth dimension, OAL of 1.125" and the 3.8 grains of Bullseye with one stovepipe. All of the primers look good now like a factory round. So I am getting close to the solution. Since I got that one stovepipe I am going to reduce the case mouth dimension to 0.379" and increase the OAL to 1.135" to see what effect that has. I am getting close to the maximum length the clip will fit. And I may up the load to 3.9 grains of Bullseye to improve the ejection, which for several of them was within a foot of the gun on the table I was shooting off of.

[c1skout]

I thought Rem 1 1/2 primers were not to be used in high pressure cartridges. I bought a brick of them a few years ago and used them in 38 target loads.

[DonMountain]

I thought Rem 1 1/2 primers were not to be used in high pressure cartridges. I bought a brick of them a few years ago and used them in 38 target loads.

I have never read that in any reloading manuals and I usually use them in my Webley in 38 S&W. But that didn't work out since the Webley's firing pin indent is too extreme. So I switched to small rifle primers for them. And was trying to use them in low loads in the 9mm Luger. Maybe they will work out better in the 380.

[Plate plinker]

Don you are headed in the right direction keep going. The 1.100" seems like that was a bit on the short end. All guns are different, but my experience was that longer functioned better in my pickier guns than short and the extra volume is easier to work with than the dangers of shortened ammunitions. Your missing variable is the chronograph it really helped me develop my shooting. Hope you have one or can borrow one.

[redhawk0]

I shoot 9mm from an old German Luger P-08. I know...we're not apples to apples here. But...I shoot cast lead from a 124gr Lee Truncated Cone mold. My OAL for my loads are 1.150" and I use Hodgdon HS-6 (6.0gr) with Win-SP primers. I know apples to oranges isn't the best way to help here...but giving my OAL might be helpful.

[EDIT] one last thing...I checked my specs for 9mm and the stated MAX OAL should be kept below to 1.169"

redhawk

[35remington]

Stove piping is mostly likely an ejection problem from loads being on the too light side. The weak ejection throwing the case barely clear that you have noted is a clue. A looser grip on occasion may turn a barely ejecting load into a stovepipe. Taper crimping aids in feeding by removing the mouth flare and helps avoid chambering hangups, which Is a distinctly different problem than stovepiping.

Things did not add up, which is why I commented. Loads at the starting level and stovepiping which you mentioned in your first post indicate pressures will likely be low. You have further confirmed that because you further said ejection is weak. When “primer signs” contradict what is known, best to not automatically assume that primer appearance is a definitive indication of high pressure when three out of four visible and verifiable indicators say it is not.

That is why most said more info is needed. We can probably definitively say your primer problems are not pressure related. Taper crimping is not a pressure influencing variable when applied in any reasonable manner. Taper crimping should not be applied to such a severe degree that the case mouth is reduced below the SAAMI spec diameter of the front of the barrel’s chamber headspacing stop shoulder, but you would have to be taper crimping with great force to accomplish that. That dimension is smaller than anything you have mentioned using so far.

To know for sure what helped, change one thing at a time and you will find it. It is often helpful to measure the case mouth diameter of factory ammo using the same case brand to see what is a reasonable range of finished case mouth diameter. Federal 124 HST and cheapo Tula FMJ measures .377.” Hornady 135 Critical Duty, which in having a cannelure might make you think is would be taper crimped slightly smaller in diameter, is actually larger at .378”

FWIW.

I must confirm that the Remington 1 1/2 primer is not intended for full power 9mm pressure levels. It has a thin cup which will pierce. This is not a pressure sign. It just means the material the primer is made from is too soft to withstand higher pressure levels. Do not load these hot. I have pierced these myself going a little too far. These are better in the 38 Special/380 pressure range. They may work fine in 9mm if you do not increase the throttle too much.

Increasing bullet seating depth while keeping everything else the same will raise pressure. Decrease will lower it. How much depends upon how much shorter or longer.

Besides fitting the magazine, remove the barrel from the gun and make sure the loaded rounds fall into and out of the chamber freely and the base of the case does not protrude beyond the hood or chamber extension. Make sure all primers are seated a little below flush.

[Soundguy]

Agreed, the stovepipe might indicate undercharge for that gun.

[35remington]

An inexpensive chronograph gives considerable peace of mind and helps assure whether loads are within reasonable limits. When just making loads that work the gun it is not a necessity, but when questions arise it will help you determine if “high pressure” is present or not, and in terms of being a reliable indicator is much better than looking at primer appearance.