45 ACP crimp

[ptt811]

I load my 45 ACP on a LEE Loadmaster and Use a LEE Factory Crimp Die. How much Crimp if any should I put on it. ( how much do you turn the knob ) What is the Purpose of the Crimp ? Does it help when it feeds into the Chamber ?

 

[straight-shooter]

If your using FMJ bullets then the FCD is a good die to use. If your loading lead bullets then don't use the FCD because it will slightly swage the bullet diameter enough that you'll get leading. In this case use the crimp on the seating die.

On FMJ and Lead only crimp enough to straighten the case and maybe .001 beyond that and you should be good. Yes, crimping does aid in smooth chambering in a .45 ACP. I found this out the hard way once when I didn't crimp quite enough and the rounds were not chambering.

 

[Chance]

Don't over crimp

On 38/357 you roll the crimp into the bullet. Is ok since these space on the rim of the cartridge at the rear. On autos (380, 9mm, 40 and 45 ACP) the cartridge spaces on the front rim of the brass.

 

[rockhopper46038]

I use about 3/4 turn of the crimp knob after setting the die per the instructions (i.e. running the die down until it touches off on the case rim). Thats what it takes to get my crimp dimension to .4690-.4695, which is what my 1911s like. In reality, no crimp is necessary for .45ACP - you just need to straighten out the "bell" in the case mouth. As for why; well I do it primarily to resist bullet setback, but by theory a crimp done correctly will improve performance by providing for uniformity of neck tension, and by keeping the bullet stationary for that tiniest fraction of a second longer that will allow the powder ignition to develop more pressure and more fully ignite.

 

[Rob377]

Not enough crimp and the bullet gets shoved back into the case when being chambered, sometimes leading to bad things, like failures to fully chamber, or like kaboom things in the worst case.

Too much crimp and accuracy suffers, In extreme cases, it may cause ignition problems as the cartridge (in semi autos) headspaces on the edge of the case. If the crimp is so extreme that the lip is dug in to the bullet, the cartridge isn't held in place when the firing pin hits it.

Fine tuning crimp can aid in accuracy and in how clean or dirty the powder burns.

measure the very edge of the case, between .472 and .468 or so is a good range to start with.

 

[ptt811]

Yes I am shooting Lead bullets in USPSA....and that is kind of why Im asking.. Some of my rounds dont Chamber well, usualy you can get it to go just by Smacking the Slide to finsh chambering the round. Not been a big issue but in the Gaming world any issue is a problem.

 

[mospeada]

Yes I am shooting Lead bullets in USPSA....and that is kind of why Im asking.. Some of my rounds dont Chamber well, usualy you can get it to go just by Smacking the Slide to finsh chambering the round. Not been a big issue but in the Gaming world any issue is a problem.

If you are shooting LSWC bullets, you may want to try checking your bullet seating depth. If it is a bit long, the shoulder of the LSWC can engage the rifling on the barrel as the round is chambered and hold it out of battery a bit.

 

[Hiker1911]

As Rockhopper stated, about 3/4 of a turn after setting per the instructions. If you're ready to experiment with a few cartridges, make some with 1/2 turn, and compare them to the 3/4 turn cartridges during shooting practice. You might not notice any difference in accuracy, or otherwise.

If you need the instructions word for word, shoot me a PM.

 

[billybob44]

How much Crimp if any should I put on it

As been stated, you are removing the "Bell" shape from the mouth of the case more so than applying a "Crimp".
There will be a slight taper, and most brass will measure .468" to .470" OD at the edge of the case mouth.

Once you establish that the seating length is correct-that is that the ogive of your bullet is not bottoming out on the rifling of your barrel-you can apply the proper crimp.

Field strip your gun+use the barrel as a "Head Space Gauge". This is done by (With a VERY clean barrel) dropping a factory load into the chamber-listen for the "Clunk" noise it makes when dropping the chamber. Apply just enough crimp to your seated bullets until that same "Clunk" is heard when the load bottoms out on the chamber of your barrel.

Each to his own-BUT-it is known around here that I AM a "Dillon Fan Boy". You WILL find that the Dillon dies, with their "Hair Pin" style seating and crimp dies, are the "Spoilers" for cast bullet loaders. When you develop the lead/wax slag+shavings up in the seater, and crimp dies, the Dillons can be taken apart-cleaned-and back together without loosing your settings. This is a great time saver if you are loading cast bullets in any kind of a large volume. I also like Redding, and RCBS dies, but as far as I know, Dillon dies are the only die set with this feature.
Oh yea,and get with Andrew @ ProFire Arms & Supply, and he can set you up with a NICE Dillon RL550/650, and the Dillon dies+conversion kits..HA HA...Bill..

 

[Double T]

Also, slug the barrel. Make sure you are using the correct diameter boolits.