I made up a bunch of 10mm target loads (180 jhp\10 grains Blue Dot). Seems the brass might be pooched. I can physically push the bullets in, up to .05". If I cycle them through the gun they shrink around 0.001-0.008. Are they safe or should I pull the bullets and start over? Thanks.

Are you properly crimping the brass?

And secondly, and more importantly, is it the correct brass for the 10mm?

As an example, .45 ACP and .45 Long Colt are very different. Yet they will both say .45 on the brass.

In Christ: Raymond

Definitely the right brass. 4f Win\Fed. I put a light taper crimp on it. Should I try more? I am fairly new to reloading.

If you are crimping the brass correctly, then it is just a matter of readjusting your equipment so that the bullet is the correct O.A.L. when finished.

As an example, I use the Dillon XL650. And I will adjust the seating die to seat the bullet to the EXACT depth. But as it progresses to the last stage (the crimping stage), it will reduce the finished O.A.L. by the same numbers you posted.

So it is just a matter of playing with the dies until you achieve the desired C.O.L.

Let me also throw another wrench into your gears.

If you are using ONLY ONE BRAND OF BRASS, all will be copacetic. But if you are using MIXED BRASS...well, now there another factor thrown into the equasion. Different brands of brass are just that - different. Some are thicker walled, some have harder/softer brass, some are shaped differently internally, etc...

So what does this mean?

Well, as an example: If you have your seating die set-up to the correct C.O.L. for Federal brass, but then use Speer or Starline brass - the bullet may now seat deeper or shallower than for the original Fedral brass.

Another thing to consider is that the C.O.L. specified in manuals are usually the maximum seating depth. So you have a smidgen of room to play with if you are reloading mixed brass. (You can always make them a tad larger, which will still work with your weapons chamber). But here is the catch to the latter situation - the accuracy will be effected, but not by much. If you are a good shot, and are shooting competition targets/plates at 7 to 20 yard distances...no problemo. But if you are NOT too good of a shot, and you are in competition shooting targets at up to 25 -yard distances, then this may play a factor in your hitting the target/plate or not.

Reloading is such a great science. You gotta invest in the correct tools to mold the bullets and weapon to function EXACTLY like you want them to. (Reloading press, and a reliable scale & chronograph as a bare minimum). Don't rely on other peoples data. (Take my word on this, THERE ARE ABSOLUTE IDIOTS OUT HERE ON THE INTERNET). Take the time to do the research yourself.

Oh yea...and in closing...depending on the bullets you are reloading, do not over crimp them.

Some of the CAST LEAD or PLATED bullets need a slightly tighter crimp. But some of the thick-walled JACKETED bullets - like Hornady XTP's - do not need such a tight crimp.

Just use common sense and a good eye. Don't deform the bullet from overcrimping. Don't load to maximum pressures. (It's just plain STUPID to make nuclear loads). And remember that a hotly-loaded bullet in cold weather will just be hot...but in hot weather that same bullet will be "nuclear" and unsafe!

Best wishes.

In Christ: Raymond

This post has been edited by RaymondMillbrae: April 5th 2009 10:51 PM

I am just going to pull them and start over. Thanks for the advice.

I just thougt about something else. Are you RESIZING the brass before reloading it?

Anyhoo...starting again from the beginning is a good idea. Patience is a virtue.

Purchase a DILLON KENETIC PULLER to disassemble your bullets. (Click on the latter link).

It is a great investment, and you can probably find them cheaper at Gunbroker.com or eBay.

In Christ: Raymond

I have an RCBS kinetic puller. It has been used many, many times. Looking at a collet puller though to speed things up. I am resizing the brass, running it through a carbide die. The brass has seen 2 hot loads and a min load before this loading.

Cool.

Check for cracked or bulged brass.

Also, in answering your post question, "HOW MUCH DOES THE PRESSURE RISE WITH AN UNDERLENGTH CARTRIDGE"?

I'm not sure with the 10mm, as I have not done a check with this yet. But I have done it with a .45 ACP round, and below are my results.

Weapon: Nighthawk Predator (w/5" in bull barrel)
Bullet: Rainier Ballistic .45 ACP, 200 grain SWC
Temps: aproximately 70 degrees


The first one was loaded at a C.O.L. of 1.225" with 4.5 grains of Tightgroup, for an expected 800 FPS.

Results: 694.9 FPS average of 8 shots

The second one was loaded at a C.O.L. of 1.230" with 4.7 grains of Tightgroup, for an expected 825 FPS.

Results: 563 FPS average of 8 shots.


Conclusion: Even though I used more powder/grains, the shorter C.O.L. made a bigger difference in the bullets performance. Even though it had LESS POWDER, it still shot 132 FPS faster than the bullet with more powder because of the shorter C.O.L.

In Christ: Raymond

Assuming the brass was properly sized, you need a stronger crimp. The bullets should not move at all under hand pressure once crimped.

I have never had an issue like this. I find it a little confusing. With sized brass, I can move the bullet before crimping just from the tension of the brass on the case.

This leads me to believe one of three things has happened when I hear of this scenario. First, the brass was not sized. Second, the brass was improperly sized. I suppose this could be due to a defective sizing die, but I have never heard of such an occurrence. Third, excessive bell/flare prior to bullet seating. Cases should be belled/flared just enough to barely start the bullet.

If you don't have a set of calipers, you might consider them. They really help in ensuring the appropriate amount of deformation at each step.

When I first started reloading 10mm I was faced with the same problem. Bullet Setback. It is a bad deal, I would set them aside and pull them, reuse the components. Not the end of the world by a long shot, after all ya get to reload!

The thing that was giving me setback was two different types of brass. Most of my once fired brass is Starline. I had a small amount of once fired R-P headstamp mixed in. These were the ones that were setting back. Turns out the R-P brass was just a bit thinner walled. That and my resizing die was not set all the way down. So the Starline was just barely resizing enough to work, not so with the R-P. This was determined by measuring the inside diameter of the case after resizing. Lowering the die fixed my setback issues.

Being new to reloading, this led me to take another look at the whole process again.

It is case neck tention that hold the bullet to the proper over all length, not crimp. If you case is not resized small enough, it cannot hold the bullet. It is a friction press fit. Too much belling will also affect case neck tention.

Taper Crimp should only remove the belling. Outside diameter at case mouth after taper crimp = case wall thickness + bullet diameter + case wall thickness.

Hope this helps, Stay Safe Eh?

I forgot about this one. I ended up just using a heavy taper crimp to hold the bastiages in place. I'd say 50% of the set back somewhat. I am using RCBS Carbide dies. Doing everything as my manual instructs but reloads move up to .055" when cycled through the gun.

I think the problem is the fact most of the cases were subjected to a very heavy load. Would over max loads possibly stretch the brass out? 11.2 grains\180jhp of blue dot was getting me about 1350 fps out of my souped up G20. Primer tension is fine I have only chucked one brass out with the oldest batch of brass. I have since adopted a policy of sticking to the manuals... Currently on the 5th reload with the old stuff.

I am still left with this same problem though!

Run a case through your sizing die. Measure the inside diameter. It must be smaller than your bullet outside diameter.

Put the smallest amout of belling on the case to allow the bullet to start. Measure the inside diameter and verify it is still smaller than bullet.

When seating the bullet, this is a press fit. You should not be able to move bullet by hand once its seated. Bullet is now held in place by case neck tention.

The crimp on auto brass just straightens out the belling.



If you can push the bullet in the case, the case is to big, I believe it is a resizing issue.

Hope this helps, Stay Safe Eh?

Just to clarify, my bullets do not move freely. If I press down with my thumb with very significant pressure I can make it move up to a few thou. Cycling the rounds through my gun cause them to shrink a bit as well. If proper COL is 1.25 running them through once will shorten it to 1.246 then 1.242. The numbers vary and many don't budge. They don't seem to shrink after that though it must raise pressure needlessly. Can too much taper crimp be bad? I hear it doesn't help accuracy but anything else to worry about?

My take is the bullets shouldn't move at all.

What brand(Lee/Dillon/RCBS) and type(steel/carbide) is the sizing dies are you using? The sizing dies need to squeeze the brass back to close the casing up to be able to hold the bullets tight.

How about your expander, is it too large? Could the expander be too large and opening the case mouths too much.

I have had great luck with the RCBS carbide die set for 10mm and also 40S&W even though the dies were made before the shorter 40 came out. I don't quite get the full crimp on the 40S&W cases but I do seem to get enough.

You may need to experiment with a few settings to get the set up right.

Good luck!

I am using RCBS carbide dies. I am going to just shoot this stuff. If this were even a warm load I would worry but it is the minimum in Speer's manual. I put a heavy taper crimp on them though, are there any issues with that?