I just Bought a Rock River .223. I have been reloading for alot a years but never for an AR type rifle. Im shooting 69 sierra's and not crimping them at the moment. SO far my rifle shoots well with anything I put in it. I thought you were supposed to crimp all AR loads? The factory Federal match with 69 Sierra's wernt crimped. Thats the load I duplicated for my rig. Open to all suggesstions thanks Scott.
-
Having trouble using the site?
Contact support
Crimp or no crimp?
- Thread starter Scott H
- Start date
Re: Crimp or no crimp?
Im useing the RCBS small base 2 die set. So i need to seat all my bullets and then go back and put a light crimp on them?
Im useing the RCBS small base 2 die set. So i need to seat all my bullets and then go back and put a light crimp on them?
Re: Crimp or no crimp?
I am just sayin what i use, i know some people dont crimp and thats there choice, but it is kinda violent with the gas gun slammin rounds in, i use a redding dies with a redding taper crimp, with a real light crimp, and to be honest my dpms shoots 3/4 inch all day at 100 yards, so i am happy with it.
I am just sayin what i use, i know some people dont crimp and thats there choice, but it is kinda violent with the gas gun slammin rounds in, i use a redding dies with a redding taper crimp, with a real light crimp, and to be honest my dpms shoots 3/4 inch all day at 100 yards, so i am happy with it.
Re: Crimp or no crimp?
Friends shooting High Power don't crimp any of the loads with 69 thru 80 gr SMKs. That said if you are not trying to shoot 600 yards and/or shooting for score, lot to be said for crimping.
Friends shooting High Power don't crimp any of the loads with 69 thru 80 gr SMKs. That said if you are not trying to shoot 600 yards and/or shooting for score, lot to be said for crimping.
Re: Crimp or no crimp?
I plan on useing my rifle calling coyotes and varmint hunting. I also like to shoot steel with to about 600 or so. I want it to function properly and safely. My loads all shoot great but i havent crimped any of them. How is the easiest way to set up my seater to crimp? Thanks Scott
I plan on useing my rifle calling coyotes and varmint hunting. I also like to shoot steel with to about 600 or so. I want it to function properly and safely. My loads all shoot great but i havent crimped any of them. How is the easiest way to set up my seater to crimp? Thanks Scott
Re: Crimp or no crimp?
There is a reason military grade cartridges used in auto loading rifles are ROLL crimped into a bullet with a cannelure.
Match bullets (no cannelure) and taper crimps are for game guns.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wyosniper</div><div class="ubbcode-body">I would lite crimp, cause it could shove that bullet back deeper and cause more pressure. When it slams the next round in. </div></div>
This is a patently false statement. Seating a bullet deeper, whether by choice or during the counter recoil phase (loading), increases free bore which DECREASES pressure.
There is a reason military grade cartridges used in auto loading rifles are ROLL crimped into a bullet with a cannelure.
Match bullets (no cannelure) and taper crimps are for game guns.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wyosniper</div><div class="ubbcode-body">I would lite crimp, cause it could shove that bullet back deeper and cause more pressure. When it slams the next round in. </div></div>
This is a patently false statement. Seating a bullet deeper, whether by choice or during the counter recoil phase (loading), increases free bore which DECREASES pressure.
Re: Crimp or no crimp?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Randy G.</div><div class="ubbcode-body">Crimping = Neck Tension
The Sierra Reloading Manual has a section called "Gas Gun Reloading". Neck Tension is addressed here. It's a very informative section.
</div></div>
Page 178...
IMO, the Sierra Manual is best available.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Randy G.</div><div class="ubbcode-body">Crimping = Neck Tension
The Sierra Reloading Manual has a section called "Gas Gun Reloading". Neck Tension is addressed here. It's a very informative section.
</div></div>
Page 178...
IMO, the Sierra Manual is best available.
Re: Crimp or no crimp?
Thanks for the advice I just read the Sierra manual. i think I will turn down my expander ball and go on. I appreciate the advice. Thanks Scott
Thanks for the advice I just read the Sierra manual. i think I will turn down my expander ball and go on. I appreciate the advice. Thanks Scott
Re: Crimp or no crimp?
Rather than crimping to increase neck tension, I turn the expander ball down one or two thousandths to increase neck tension. If all your cases aren't exactly the same length, the crimp can vary wildly in how much it is applied. Shorter cases may even have no crimp applied.
As with all reloading, consistency is the key. If you trim everything to exactly the same length, it probably won't matter whether you use a crimp, or smaller expander ball to get the proper neck tension.
Some people feel that crimping increases accuracy. My experience is the opposite of that. Every time I try a crimp on precisely trimmed cases, my accuracy decreases, even when powder capacity is changed to make up for the increased pressure of the crimp. When I went to the turned down expander ball method, my accuracy improved.
The military has to use a crimp because the ammo is often used in full auto firearms. My ammo is for matches.
However, I will admit that at the last match, I did have one failure to chamber when a bullet got pushed back into the case. There is always a first. Out of the last 10,000 rounds I have fired, this is the first one where the bullet was pushed back into the case. Clearing the malfunction cost me 5-10 seconds more on the stage.
Rather than crimping to increase neck tension, I turn the expander ball down one or two thousandths to increase neck tension. If all your cases aren't exactly the same length, the crimp can vary wildly in how much it is applied. Shorter cases may even have no crimp applied.
As with all reloading, consistency is the key. If you trim everything to exactly the same length, it probably won't matter whether you use a crimp, or smaller expander ball to get the proper neck tension.
Some people feel that crimping increases accuracy. My experience is the opposite of that. Every time I try a crimp on precisely trimmed cases, my accuracy decreases, even when powder capacity is changed to make up for the increased pressure of the crimp. When I went to the turned down expander ball method, my accuracy improved.
The military has to use a crimp because the ammo is often used in full auto firearms. My ammo is for matches.
However, I will admit that at the last match, I did have one failure to chamber when a bullet got pushed back into the case. There is always a first. Out of the last 10,000 rounds I have fired, this is the first one where the bullet was pushed back into the case. Clearing the malfunction cost me 5-10 seconds more on the stage.
Re: Crimp or no crimp?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: m_gale</div><div class="ubbcode-body">Match bullets (no cannelure) and taper crimps are for game guns.</div></div>
Damn. Sure are a lot of "game guns" killing badguys around the world.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: m_gale</div><div class="ubbcode-body">Match bullets (no cannelure) and taper crimps are for game guns.</div></div>
Damn. Sure are a lot of "game guns" killing badguys around the world.
Re: Crimp or no crimp?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LoneWolfUSMC</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: m_gale</div><div class="ubbcode-body">Match bullets (no cannelure) and taper crimps are for game guns.</div></div>
Damn. Sure are a lot of "game guns" killing badguys around the world. </div></div>
Probably lots of "not" badguys too.
Just sayin'.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LoneWolfUSMC</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: m_gale</div><div class="ubbcode-body">Match bullets (no cannelure) and taper crimps are for game guns.</div></div>
Damn. Sure are a lot of "game guns" killing badguys around the world. </div></div>
Probably lots of "not" badguys too.
Just sayin'.
Re: Crimp or no crimp?
Most of the SR shooters are not crimping the 69 grSMK or the 80gr SMK. Now the 77gr SMK almost seem to need a very light crimp. I do not crimp the 69gr bullets I shoot but I crimp all of my 75gr and 77gr ammo. I was reading that when BH was testing the 77gr bullets they did not shoot well until they were crimped. They crimped them and they shot much better. They do in my rifle but the 69gr and 80’s it does not help and it hurts accuracy on one of them. I do not have my old log books here so I can not remember what one shoots worse with the crimp.
Most of the SR shooters are not crimping the 69 grSMK or the 80gr SMK. Now the 77gr SMK almost seem to need a very light crimp. I do not crimp the 69gr bullets I shoot but I crimp all of my 75gr and 77gr ammo. I was reading that when BH was testing the 77gr bullets they did not shoot well until they were crimped. They crimped them and they shot much better. They do in my rifle but the 69gr and 80’s it does not help and it hurts accuracy on one of them. I do not have my old log books here so I can not remember what one shoots worse with the crimp.
Re: Crimp or no crimp?
I have a Rock River/Varmint that I am shooting Hornady 68 Grn bullets over Varget with. I am crimping with a Lee crimping die because I am loaded with 24grns of Varget and the bullets will want to come out of the case because it is such a compressed load.
I like the piece of mind that crimping gives me, I don't have to worry if my bullets are going to move from rough handling.
SScott
I have a Rock River/Varmint that I am shooting Hornady 68 Grn bullets over Varget with. I am crimping with a Lee crimping die because I am loaded with 24grns of Varget and the bullets will want to come out of the case because it is such a compressed load.
I like the piece of mind that crimping gives me, I don't have to worry if my bullets are going to move from rough handling.
SScott
Re: Crimp or no crimp?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: m_gale</div><div class="ubbcode-body">There is a reason military grade cartridges used in auto loading rifles are ROLL crimped into a bullet with a cannelure.
Match bullets (no cannelure) and taper crimps are for game guns.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wyosniper</div><div class="ubbcode-body">I would lite crimp, cause it could shove that bullet back deeper and cause more pressure. When it slams the next round in. </div></div>
This is a patently false statement. Seating a bullet deeper, whether by choice or during the counter recoil phase (loading), increases free bore which DECREASES pressure. </div></div>
You are wrong sir.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: m_gale</div><div class="ubbcode-body">There is a reason military grade cartridges used in auto loading rifles are ROLL crimped into a bullet with a cannelure.
Match bullets (no cannelure) and taper crimps are for game guns.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wyosniper</div><div class="ubbcode-body">I would lite crimp, cause it could shove that bullet back deeper and cause more pressure. When it slams the next round in. </div></div>
This is a patently false statement. Seating a bullet deeper, whether by choice or during the counter recoil phase (loading), increases free bore which DECREASES pressure. </div></div>
You are wrong sir.
Re: Crimp or no crimp?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hamilton</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: m_gale</div><div class="ubbcode-body">There is a reason military grade cartridges used in auto loading rifles are ROLL crimped into a bullet with a cannelure.
Match bullets (no cannelure) and taper crimps are for game guns.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wyosniper</div><div class="ubbcode-body">I would lite crimp, cause it could shove that bullet back deeper and cause more pressure. When it slams the next round in. </div></div>
This is a patently false statement. Seating a bullet deeper, whether by choice or during the counter recoil phase (loading), increases free bore which DECREASES pressure. </div></div>
You are wrong sir.</div></div>
+1. Pressure should follow an inverse parabolic curve, starting high when the bullet is at the lands, decreasing as you move back, then increasing again as you move further back, starting to compress the load.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hamilton</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: m_gale</div><div class="ubbcode-body">There is a reason military grade cartridges used in auto loading rifles are ROLL crimped into a bullet with a cannelure.
Match bullets (no cannelure) and taper crimps are for game guns.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wyosniper</div><div class="ubbcode-body">I would lite crimp, cause it could shove that bullet back deeper and cause more pressure. When it slams the next round in. </div></div>
This is a patently false statement. Seating a bullet deeper, whether by choice or during the counter recoil phase (loading), increases free bore which DECREASES pressure. </div></div>
You are wrong sir.</div></div>
+1. Pressure should follow an inverse parabolic curve, starting high when the bullet is at the lands, decreasing as you move back, then increasing again as you move further back, starting to compress the load.
Re: Crimp or no crimp?
I have loaded and shot quite a few 75 gr hornadys without crimp. Results have been favorable, no signs of setback after multiple chamberings in an AR15.
I have loaded and shot quite a few 75 gr hornadys without crimp. Results have been favorable, no signs of setback after multiple chamberings in an AR15.
Re: Crimp or no crimp?
i did a test with my ar-15 in .223 and dpms lr-308.ar-15 with 69mk and lr-308 with 168mk .i shot 20 rounds each with no crimp and 20 with a light crimp using the lee crimp die.
the crimped loads grouped tighter, but not by much.
these were run thru the magazine.when i single loaded them i did not see any difference.the only way you will know for sure is to try it yourself.
i did a test with my ar-15 in .223 and dpms lr-308.ar-15 with 69mk and lr-308 with 168mk .i shot 20 rounds each with no crimp and 20 with a light crimp using the lee crimp die.
the crimped loads grouped tighter, but not by much.
these were run thru the magazine.when i single loaded them i did not see any difference.the only way you will know for sure is to try it yourself.
Re: Crimp or no crimp?
My non-crimped autoloading ammunition ends up with a longer OAL after chambering, whenever I've checked.
My non-crimped autoloading ammunition ends up with a longer OAL after chambering, whenever I've checked.
Re: Crimp or no crimp?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hamilton</div><div class="ubbcode-body">My non-crimped autoloading ammunition ends up with a longer OAL after chambering, whenever I've checked. </div></div>
If you nearer or touching the lands and not getting pressure signs isn't that contributing to accuracy?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hamilton</div><div class="ubbcode-body">My non-crimped autoloading ammunition ends up with a longer OAL after chambering, whenever I've checked. </div></div>
If you nearer or touching the lands and not getting pressure signs isn't that contributing to accuracy?
Re: Crimp or no crimp?
When loading for accuracy, I load up a few powderless primerless rounds into a mag, pull the charging handle all the way back then let fly, extract carefully, repeat. At least two cycles of this per round, then measure. Significant change in oal: light crimp. Otherwise no crimp.
When loading for accuracy, I load up a few powderless primerless rounds into a mag, pull the charging handle all the way back then let fly, extract carefully, repeat. At least two cycles of this per round, then measure. Significant change in oal: light crimp. Otherwise no crimp.
Re: Crimp or no crimp?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hamilton</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: m_gale</div><div class="ubbcode-body">There is a reason military grade cartridges used in auto loading rifles are ROLL crimped into a bullet with a cannelure.
Match bullets (no cannelure) and taper crimps are for game guns.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wyosniper</div><div class="ubbcode-body">I would lite crimp, cause it could shove that bullet back deeper and cause more pressure. When it slams the next round in. </div></div>
This is a patently false statement. Seating a bullet deeper, whether by choice or during the counter recoil phase (loading), increases free bore which DECREASES pressure. </div></div>
You are wrong sir. </div></div>
I'll play along. Is it possible you can point to one verifiable source to back your position?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hamilton</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: m_gale</div><div class="ubbcode-body">There is a reason military grade cartridges used in auto loading rifles are ROLL crimped into a bullet with a cannelure.
Match bullets (no cannelure) and taper crimps are for game guns.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wyosniper</div><div class="ubbcode-body">I would lite crimp, cause it could shove that bullet back deeper and cause more pressure. When it slams the next round in. </div></div>
This is a patently false statement. Seating a bullet deeper, whether by choice or during the counter recoil phase (loading), increases free bore which DECREASES pressure. </div></div>
You are wrong sir. </div></div>
I'll play along. Is it possible you can point to one verifiable source to back your position?
Re: Crimp or no crimp?
Precision military ammunition (both match and long range) are (generally) not crimped.
US Army Ammunition Drawing Number C-8597555, Cartridge, 7.62mm NATO, Special Ball, M118 Long Range.
Precision military ammunition (both match and long range) are (generally) not crimped.
US Army Ammunition Drawing Number C-8597555, Cartridge, 7.62mm NATO, Special Ball, M118 Long Range.
Re: Crimp or no crimp?
Doesn't the MK262 Mod 1 have a crimp on the cannelure?
I don't crimp my AR reloads. I have only reloaded 77gr SMK and 77gr Noslers shot out of service rifle barrels. I have read that people have had success with a light crimp on the 77 grain bullets as the person stated above, but I never tried it and to be truthful I don't plan on trying it. The consensus among match shooters seems to be no crimp. That many million rounds down range they can't all be wrong.
YMMV
Doesn't the MK262 Mod 1 have a crimp on the cannelure?
I don't crimp my AR reloads. I have only reloaded 77gr SMK and 77gr Noslers shot out of service rifle barrels. I have read that people have had success with a light crimp on the 77 grain bullets as the person stated above, but I never tried it and to be truthful I don't plan on trying it. The consensus among match shooters seems to be no crimp. That many million rounds down range they can't all be wrong.
YMMV
Re: Crimp or no crimp?
The 77-grain Sierra Match King used in Mark 262 Mod 1 has crenellations, not a cannelure. This was Sierra's way of meeting what the customer specified without ruining accuracy.
The 77-grain Sierra Match King used in Mark 262 Mod 1 has crenellations, not a cannelure. This was Sierra's way of meeting what the customer specified without ruining accuracy.
Re: Crimp or no crimp?
great info, but does anyone have an opinion on crimping .204 Ruger rounds for an R15? I threw the charging handle on a few powderless rounds as suggested by someone on here and there was a slight change in OAL, but I haven't tried playing with the expander yet. crimp dies are hard to find unless special ordered so I wanted some more opinions...
great info, but does anyone have an opinion on crimping .204 Ruger rounds for an R15? I threw the charging handle on a few powderless rounds as suggested by someone on here and there was a slight change in OAL, but I haven't tried playing with the expander yet. crimp dies are hard to find unless special ordered so I wanted some more opinions...
Re: Crimp or no crimp?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DPontius</div><div class="ubbcode-body">great info, but does anyone have an opinion on crimping .204 Ruger rounds for an R15? I threw the charging handle on a few powderless rounds as suggested by someone on here and there was a slight change in OAL, but I haven't tried playing with the expander yet. crimp dies are hard to find unless special ordered so I wanted some more opinions... </div></div>
If it's shooting how you want it to I wouldn't bother.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DPontius</div><div class="ubbcode-body">great info, but does anyone have an opinion on crimping .204 Ruger rounds for an R15? I threw the charging handle on a few powderless rounds as suggested by someone on here and there was a slight change in OAL, but I haven't tried playing with the expander yet. crimp dies are hard to find unless special ordered so I wanted some more opinions... </div></div>
If it's shooting how you want it to I wouldn't bother.
Re: Crimp or no crimp?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: m_gale</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hamilton</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: m_gale</div><div class="ubbcode-body">There is a reason military grade cartridges used in auto loading rifles are ROLL crimped into a bullet with a cannelure.
Match bullets (no cannelure) and taper crimps are for game guns.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wyosniper</div><div class="ubbcode-body">I would lite crimp, cause it could shove that bullet back deeper and cause more pressure. When it slams the next round in. </div></div>
This is a patently false statement. Seating a bullet deeper, whether by choice or during the counter recoil phase (loading), increases free bore which DECREASES pressure. </div></div>
You are wrong sir. </div></div>
I'll play along. Is it possible you can point to one verifiable source to back your position? </div></div>
Don't take our word for it, try it yourself. Get yourself a nice high pressure load (might as well make it interesting) and shove the bullet as far back into the case as you can and then fire it. Let us know how it goes.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: m_gale</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hamilton</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: m_gale</div><div class="ubbcode-body">There is a reason military grade cartridges used in auto loading rifles are ROLL crimped into a bullet with a cannelure.
Match bullets (no cannelure) and taper crimps are for game guns.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wyosniper</div><div class="ubbcode-body">I would lite crimp, cause it could shove that bullet back deeper and cause more pressure. When it slams the next round in. </div></div>
This is a patently false statement. Seating a bullet deeper, whether by choice or during the counter recoil phase (loading), increases free bore which DECREASES pressure. </div></div>
You are wrong sir. </div></div>
I'll play along. Is it possible you can point to one verifiable source to back your position? </div></div>
Don't take our word for it, try it yourself. Get yourself a nice high pressure load (might as well make it interesting) and shove the bullet as far back into the case as you can and then fire it. Let us know how it goes.
Re: Crimp or no crimp?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hamilton</div><div class="ubbcode-body">My non-crimped autoloading ammunition ends up with a longer OAL after chambering, whenever I've checked. </div></div>
After reading this thread I chambered a 168gr FGMM round 10 times in my POF to see what would happen. The bullet started to creep out of the case to the point it wouldn't fit in the magazine! Objects in motion remain in motion.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hamilton</div><div class="ubbcode-body">My non-crimped autoloading ammunition ends up with a longer OAL after chambering, whenever I've checked. </div></div>
After reading this thread I chambered a 168gr FGMM round 10 times in my POF to see what would happen. The bullet started to creep out of the case to the point it wouldn't fit in the magazine! Objects in motion remain in motion.
Re: Crimp or no crimp?
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Don't take our word for it, try it yourself. Get yourself a nice high pressure load (might as well make it interesting) and shove the bullet as far back into the case as you can and then fire it. Let us know how it goes.
</div></div>
Hey that's crossing the line. We don't want anyone getting hurt. Your sarcasm won't be so funny when someone loses a body part.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Don't take our word for it, try it yourself. Get yourself a nice high pressure load (might as well make it interesting) and shove the bullet as far back into the case as you can and then fire it. Let us know how it goes.
Hey that's crossing the line. We don't want anyone getting hurt. Your sarcasm won't be so funny when someone loses a body part.
Re: Crimp or no crimp?
All reloading books have a Minimum Overall Length (MOAL) for every load. The reason for this is pressure. You can make the cartridges longer, allowing the bullet to leave the casing faster and decreasing pressure, but pushing the bullet in further increases the pressure because it takes longer to push the bullet out.
I've personally tested this theory accidentally, and had a case rupture, ejecting my magazine from the bottom of the weapon.
Picture a jar with a small charge in it, put a cork in it partially, and the cork will be popped off when the charge goes off. Take the same jar and charge, and shove the cork in as far as you can and the charge will break the glass.
All reloading books have a Minimum Overall Length (MOAL) for every load. The reason for this is pressure. You can make the cartridges longer, allowing the bullet to leave the casing faster and decreasing pressure, but pushing the bullet in further increases the pressure because it takes longer to push the bullet out.
I've personally tested this theory accidentally, and had a case rupture, ejecting my magazine from the bottom of the weapon.
Picture a jar with a small charge in it, put a cork in it partially, and the cork will be popped off when the charge goes off. Take the same jar and charge, and shove the cork in as far as you can and the charge will break the glass.
Re: Crimp or no crimp?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sebben</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Don't take our word for it, try it yourself. Get yourself a nice high pressure load (might as well make it interesting) and shove the bullet as far back into the case as you can and then fire it. Let us know how it goes.
</div></div>
Hey that's crossing the line. We don't want anyone getting hurt. Your sarcasm won't be so funny when someone loses a body part. </div></div>
If you don't know that shoving the bullet deeper into the case can increase pressure dangerously then you probably don't know what end of the gun the bullet comes out of either. My advice would be to play it safe and look into a different hobby.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sebben</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Don't take our word for it, try it yourself. Get yourself a nice high pressure load (might as well make it interesting) and shove the bullet as far back into the case as you can and then fire it. Let us know how it goes.
Hey that's crossing the line. We don't want anyone getting hurt. Your sarcasm won't be so funny when someone loses a body part. </div></div>
If you don't know that shoving the bullet deeper into the case can increase pressure dangerously then you probably don't know what end of the gun the bullet comes out of either. My advice would be to play it safe and look into a different hobby.
Re: Crimp or no crimp?
This is one of those trick questions. Whether you will need to crimp or not is largely dependent upon the components that you are using.
As far as safety goes, you do not want the bullet being jammed farther into the case. This will raise pressures to a dangerous level. I wouldn't worry so much about the bullets moving forward a bit when the round is being chambered. This isn't uncommon and usually only moves a couple of 1/1000ths of an inch. If the bullet does move enough to rest on the lands, this isn't a big deal either.
Safety issues aside, some ammo/rifle combos like a good crimp. I've taken to using a Lee Factory Crimp die. In some cases it increased accuracy, but I've never seen it degrade accuracy; so to be on the safe side, I do crimp.
This is one of those trick questions. Whether you will need to crimp or not is largely dependent upon the components that you are using.
As far as safety goes, you do not want the bullet being jammed farther into the case. This will raise pressures to a dangerous level. I wouldn't worry so much about the bullets moving forward a bit when the round is being chambered. This isn't uncommon and usually only moves a couple of 1/1000ths of an inch. If the bullet does move enough to rest on the lands, this isn't a big deal either.
Safety issues aside, some ammo/rifle combos like a good crimp. I've taken to using a Lee Factory Crimp die. In some cases it increased accuracy, but I've never seen it degrade accuracy; so to be on the safe side, I do crimp.
Re: Crimp or no crimp?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TonyAngel</div><div class="ubbcode-body">I've taken to using a Lee Factory Crimp die. In some cases it increased accuracy, but I've never seen it degrade accuracy; so to be on the safe side, I do crimp.</div></div>
Same here.
In this particular case, a crimp definitely made a difference regarding accuracy:
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TonyAngel</div><div class="ubbcode-body">I've taken to using a Lee Factory Crimp die. In some cases it increased accuracy, but I've never seen it degrade accuracy; so to be on the safe side, I do crimp.</div></div>
Same here.
In this particular case, a crimp definitely made a difference regarding accuracy:
Re: Crimp or no crimp?
i have recently been working up loads for my DPMS 260 and i have a dummy round with no crimp that i use so after my 3rd shot it chambers that dummy round to keep vibrations the same on the last shot. Anyway what i am basically saying is that the dummy round has been chambered 25 or so times and has not been pushed back at all and i am getting 3 round groups of .450"-.660" @100yds so i will stick with no crimp.
i have recently been working up loads for my DPMS 260 and i have a dummy round with no crimp that i use so after my 3rd shot it chambers that dummy round to keep vibrations the same on the last shot. Anyway what i am basically saying is that the dummy round has been chambered 25 or so times and has not been pushed back at all and i am getting 3 round groups of .450"-.660" @100yds so i will stick with no crimp.
Re: Crimp or no crimp?
I do not crimp in my AR 15 nor my new MA-TEN 308 everyhting feed fine ans shoots well. I also do not crimp for the bolt gun
I do not crimp in my AR 15 nor my new MA-TEN 308 everyhting feed fine ans shoots well. I also do not crimp for the bolt gun
Re: Crimp or no crimp?
If you are target or varmint shooting a light crimp is ok but if you are using reloads for tactical competitions or drills i would definitley crimp to prevent bullet movement during recoil and rapid fire.
If you are target or varmint shooting a light crimp is ok but if you are using reloads for tactical competitions or drills i would definitley crimp to prevent bullet movement during recoil and rapid fire.
Re: Crimp or no crimp?
I am wondering the same thing....i just got an AR 15 and would like to get set up to reload. I have a 16 inch with a 1in7 twist I am thinking about 77ga Sierra hpbt with 748 powder, I have lots of this that I use with my PSS 308. Anyhone have any ideas on this powder. Well sorry I guess that would be for another post.
I am wondering the same thing....i just got an AR 15 and would like to get set up to reload. I have a 16 inch with a 1in7 twist I am thinking about 77ga Sierra hpbt with 748 powder, I have lots of this that I use with my PSS 308. Anyhone have any ideas on this powder. Well sorry I guess that would be for another post.
Re: Crimp or no crimp?
I lightly crimp my hand loaded 77gr cannelured SMKs using a Dillon die. Current 5-shot groups are as good as .460 MOA out of my custom SPR.
I lightly crimp my hand loaded 77gr cannelured SMKs using a Dillon die. Current 5-shot groups are as good as .460 MOA out of my custom SPR.
Re: Crimp or no crimp?
I use neck sizing as the means to control neck tension rather than crimping. I make the case necks for my auto-loaders 2-3 thou smaller in ID than those for bolt guns so they get a better grip on the bullet It's as easy as choosing the right bushing if you're using something like the Redding S dies, or honing down the diameter of your expander ball in a standard die. It works for me even in my M1As which have more violent actions than the ARs. I should note that keeping your cases annealed is important here. A work-hardened neck won't hold a bullet like a recently annealed neck.
As mentioned earlier, if your case lengths are not identical, then the amount of crimp will vary from round to round. Not a good thing for accuracy. I learned this the hard way many years ago. The cases that were a tad longer not only got more crimp, some actually bulged at the shoulder and wouldn't even chamber. The bulge was so slight it wasn't noticeable unless I put a mic on them. I had to go through and inspect about 1,000 rounds. That was the last time I crimped a bottleneck case - 30 years ago.
I use neck sizing as the means to control neck tension rather than crimping. I make the case necks for my auto-loaders 2-3 thou smaller in ID than those for bolt guns so they get a better grip on the bullet It's as easy as choosing the right bushing if you're using something like the Redding S dies, or honing down the diameter of your expander ball in a standard die. It works for me even in my M1As which have more violent actions than the ARs. I should note that keeping your cases annealed is important here. A work-hardened neck won't hold a bullet like a recently annealed neck.
As mentioned earlier, if your case lengths are not identical, then the amount of crimp will vary from round to round. Not a good thing for accuracy. I learned this the hard way many years ago. The cases that were a tad longer not only got more crimp, some actually bulged at the shoulder and wouldn't even chamber. The bulge was so slight it wasn't noticeable unless I put a mic on them. I had to go through and inspect about 1,000 rounds. That was the last time I crimped a bottleneck case - 30 years ago.
