.30 carbine crimp question

[macgunner01]

hey guys,

got a quick question on .30 carbine crimping, so i thought i'd send it over to you guys!

using a dillon 550b with 3-stage RCBS carbide dies, i'm currently guessing at how much crimp i should apply. also, after the cases go through the first 3 stages (including full-length sizing), when the crimp is applied, the case kind of "bulges" around the bullet slightly. Is this "bulging" normal for .30 carbine?

OAL is at 1.680", and case OAL is between 1.280" and 1.285". both cases in pictures 001 and 002 are bulging, but the right casing in both pictures bulges more than the left (the right casing having more crimp applied then the left casing).

Also: depending on how much crimp I apply depends on if there's a gap between the bullet and the mouth of the case. not sure which one is correct amount of crimp.

in pictures 003 and 004, the "gap" case is on the left, and the "no-gap" is on the right. in my first 100rnds ever loaded, i believed they looked like the left-side "gap" case (with no signs of overpressure on the fired cases). the gap is approximately 0.001", and the bullet is firmly seated.

components are Sierra 110gr FMJ bullets, sitting on 1 S&B and 1 Aguila casing.

any suggestions on how to proceed?

http://i240.photobucket.com/albums/f...30carb_001.jpg
http://i240.photobucket.com/albums/f...30carb_002.jpg
http://i240.photobucket.com/albums/f...30carb_003.jpg
http://i240.photobucket.com/albums/f...30carb_004.jpg

Thanks!

Information

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[HighPowerShooter]

The buldge is normal... as for your 'gap' you want to remove the belling completely... so your 2nd pic shows the correct crimp.

[Litt'le Lee]

Just because you have carbide dies,,you still need lube !!,,only straight wall brass requires no lube..not using lube will result in head seperation,,speaking from experience

[macgunner01]

thanks for the responses, guys

highpowershooter: i'll definitely go with the crimp used on the right casing, then. thanks for the advice!

Litt'le Lee: i most certainly still use lube when sizing the cases. i use the dillon spray lube, lube up a bunch of cases, and every second or third casing put into the dies is a lubed case.

[Larry Gibson]

thanks for the responses, guys

highpowershooter: i'll definitely go with the crimp used on the right casing, then. thanks for the advice!

Litt'le Lee: i most certainly still use lube when sizing the cases. i use the dillon spray lube, lube up a bunch of cases, and every second or third casing put into the dies is a lubed case.

You really need to quit crimping the case mouths. The >30 Carbine headspaces on the case mouth and absolutely no crimp is required. If you do anything simple taper crimp to straighten and remove the case mouth flare. You are asking for some serious misfires in eithe and M1 Carbine or a Ruger BH.

Also the bulge below the base of the bullet is caused because the case is sized too much. It is called the "coke bottle effect". If you don't want it then simple back out the FL carbide die a little at a time until it goes away.

Larry Gibson

[macgunner01]

Thank you for your reply, Larry!

You really need to quit crimping the case mouths. The >30 Carbine headspaces on the case mouth and absolutely no crimp is required. If you do anything simple taper crimp to straighten and remove the case mouth flare. You are asking for some serious misfires in eithe and M1 Carbine or a Ruger BH.

I definitely know about not crimping the bullet into place. My only question was how much of a taper is sufficient (because of explicitly not wanting to apply too much taper). The RCBS dies have a taper crimp die, and the most I'd ever apply is just to straighten the case belling.

Also the bulge below the base of the bullet is caused because the case is sized too much. It is called the "coke bottle effect". If you don't want it then simple back out the FL carbide die a little at a time until it goes away.

Larry Gibson

That is a great piece of info to know! I will definitely keep that in mind! A case suffering from the "coke bottle effect" is still safe to shoot though, correct?

[USSR]

A case suffering from the "coke bottle effect" is still safe to shoot though, correct?

Correct.

Don

[dukeofdata]

Buy a box of Winchester or Remington or Federal or MagTech, or etc. .30 Carbine ammo. Measure the case mouth diameter of their loaded ammo. Produce yours to the same dimension.

[macgunner01]

thanks Duke and USSR for the info! it is greatly appreciated!

[macgunner01]

i thank you guys for all the helpful hints! i loaded up a test batch of 50, using Sierra 110gr FMJ Bullets sitting on top of Win-296 and Remington 7 1/2's.

All brass was trimmed to COL between 1.280 and 1.285. OAL was between 1.6785 and 1.6810. Are those sizes ok?