Explaining Headspace - Page 3 - The Firearms Forum

LDBennett · 09-03-2012, 08:03 AM

oneidapj:

For a bolt gun crimping is not necessary if the neck tension is tight enough to securely hold the bullet in the case with normal handling. For good brass and good bullets that is always the case. For any gun that has really heavy recoil, is lever or pump operated or semi-auto you should crimp. Crimping hunting ammo might be a good thing to do as extra ammo is often carried loosely in the pockets.

For rifle cartridges there are two ways to crimp but the cases must be all trimmed to the same length (AFTER SIZING!!!) for the first method.

1). The seating die comes with a crimping ring up inside the die and is engaged by adjusting the die down in the press. The end of the case hits that ring and folds against the bullet. You must be careful to not over crimp as you will collapse the wall of the body of the case or expand that area of the crimp such that it will not fit into the chamber. There are dimensions in the reloading manual and the neck must never exceed those limits in the area of the crimp.A collapsed wall of the body of the case may also not fit into the gun's chamber. A little crimp is better than none.

2). LEE makes a rifle only Factory Crimp Die (FCD) that works on a completely different principal and is a much better way to go. The die is a separate die for crimping only. It has a collet that closes on the end of the neck to push the end of the neck horizontal into the bullet in about four discrete places around the neck of the case. While the cases must be trimmed there is a greater variation allowed as long as none exceed the max case length listed in the manuals. You can over do this too and distort the bullet but a little crimp is better than none.

For ammo that I must crimp (heavy recoil ammo, lever or pump gun ammo or semi-auto ammo), I use the LEE FCD exclusively if I can get it for the caliber of choice.

In your case the bottom line is crimp your hunting ammo and forget about crimping target ammo.

LDBennett

oneidapj · 09-03-2012, 12:52 PM

Okay, think I got it. Just have to get a case lube pad and a case trimmer and then I can get started. Thank you very much.

bluesea112 · 10-03-2012, 04:28 PM

Crimping = better accuracy and consistency. (tighter groups)

lcn · 04-11-2013, 10:14 PM

New here. Just been looking around. Been casting bullets and reloading for over 50 years. Rifles, pistols and shotguns. I am impressed. You guys rock. The explanation of headspacing was better than very good by all. For the newbees here you can't go wrong, listen up. These guys know what they are talking about.

woolleyworm · 04-11-2013, 10:23 PM

Quote:

Originally Posted by lcn

New here. Just been looking around. Been casting bullets and reloading for over 50 years. Rifles, pistols and shotguns. I am impressed. You guys rock. The explanation of headspacing was better than very good by all. For the newbees here you can't go wrong, listen up. These guys know what they are talking about.

Welcome to TFF lcn ! I grew up in Darrington and have family all around you. I sure don't miss the cold though, alot more nice shooting days down here in TX.

I do miss the size of the muleys though.

Glad you enjoyed the headspace thread and appreciate your comments.

Semper Fi,

Woolley

BlackEagle · 04-12-2013, 02:28 PM

Welcome to TFF, Icn. There is a host of experience and shooting wisdom on these forum pages, and people here are glad to share their wisdom and experience with newcomers. Glad to have you aboard and hope to hear from you.

09-03-2012, 08:03 AM	#51
LDBennett Advanced Senior Member Join Date: Dec 2003 Location: Hesperia, CA Posts: 5,715	Re: Explaining Headspace oneidapj: For a bolt gun crimping is not necessary if the neck tension is tight enough to securely hold the bullet in the case with normal handling. For good brass and good bullets that is always the case. For any gun that has really heavy recoil, is lever or pump operated or semi-auto you should crimp. Crimping hunting ammo might be a good thing to do as extra ammo is often carried loosely in the pockets. For rifle cartridges there are two ways to crimp but the cases must be all trimmed to the same length (AFTER SIZING!!!) for the first method. 1). The seating die comes with a crimping ring up inside the die and is engaged by adjusting the die down in the press. The end of the case hits that ring and folds against the bullet. You must be careful to not over crimp as you will collapse the wall of the body of the case or expand that area of the crimp such that it will not fit into the chamber. There are dimensions in the reloading manual and the neck must never exceed those limits in the area of the crimp.A collapsed wall of the body of the case may also not fit into the gun's chamber. A little crimp is better than none. 2). LEE makes a rifle only Factory Crimp Die (FCD) that works on a completely different principal and is a much better way to go. The die is a separate die for crimping only. It has a collet that closes on the end of the neck to push the end of the neck horizontal into the bullet in about four discrete places around the neck of the case. While the cases must be trimmed there is a greater variation allowed as long as none exceed the max case length listed in the manuals. You can over do this too and distort the bullet but a little crimp is better than none. For ammo that I must crimp (heavy recoil ammo, lever or pump gun ammo or semi-auto ammo), I use the LEE FCD exclusively if I can get it for the caliber of choice. In your case the bottom line is crimp your hunting ammo and forget about crimping target ammo. LDBennett Last edited by LDBennett; 09-04-2012 at 06:25 AM..

09-03-2012, 12:52 PM	#52
oneidapj Member Join Date: Sep 2012 Posts: 11	Re: Explaining Headspace Okay, think I got it. Just have to get a case lube pad and a case trimmer and then I can get started. Thank you very much.

10-03-2012, 04:28 PM	#53
bluesea112 Advanced Senior Member Join Date: Nov 2005 Location: West, TX Contributor Posts: 1,257	Re: Explaining Headspace Crimping = better accuracy and consistency. (tighter groups)

04-11-2013, 10:14 PM	#54
lcn Member Join Date: Apr 2013 Location: Mount Vernon, Washington Posts: 28	Re: Explaining Headspace New here. Just been looking around. Been casting bullets and reloading for over 50 years. Rifles, pistols and shotguns. I am impressed. You guys rock. The explanation of headspacing was better than very good by all. For the newbees here you can't go wrong, listen up. These guys know what they are talking about.

04-12-2013, 02:28 PM	#56
BlackEagle Advanced Senior Member Join Date: Nov 2011 Location: UK Posts: 3,171	Re: Explaining Headspace Welcome to TFF, Icn. There is a host of experience and shooting wisdom on these forum pages, and people here are glad to share their wisdom and experience with newcomers. Glad to have you aboard and hope to hear from you.