Where's the failure?
Quote from Reloader on May 7, 2012, 2:27 amSo here's the issue;
I've been reloading .308 in my 650XL for a little. I've done 30 rounds between the starting recommended charge of Varget for 41 grains to mid-rage at 43 grains. In both instances I had a failure to feed/extract to the point where one time (at 41 grain) the bullet only traveled halfway down the barrel and I had to disassemble the rifle to get it out. The other failures seemed that the shell failed to feed or extract from the bolt getting lodged in the chamber and I had to really pull on the charging handle to get the shell out.
Any idea on what's going on? I was thinking these are all signs that the charge I'm using is too small or that some of the brass may have bulge at the cartridge's base. I do a light crimp so it shouldn't be that influencing it.
Thoughts?
So here's the issue;
I've been reloading .308 in my 650XL for a little. I've done 30 rounds between the starting recommended charge of Varget for 41 grains to mid-rage at 43 grains. In both instances I had a failure to feed/extract to the point where one time (at 41 grain) the bullet only traveled halfway down the barrel and I had to disassemble the rifle to get it out. The other failures seemed that the shell failed to feed or extract from the bolt getting lodged in the chamber and I had to really pull on the charging handle to get the shell out.
Any idea on what's going on? I was thinking these are all signs that the charge I'm using is too small or that some of the brass may have bulge at the cartridge's base. I do a light crimp so it shouldn't be that influencing it.
Thoughts?
Quote from Reloader on May 7, 2012, 3:34 pmWhat projectile are you loading? Feeding and extraction issues are not necesasrily related? Do loaded cartridges freely manually extract from the chamber? Are you using a headspace case gage to help set the size die?
What projectile are you loading? Feeding and extraction issues are not necesasrily related? Do loaded cartridges freely manually extract from the chamber? Are you using a headspace case gage to help set the size die?
Quote from Reloader on May 7, 2012, 11:40 pmUsing Winchester brass with Hornady 168 grain Match bullet and Winchester primer out of a 16" barrel. I started the charge at the recommended 41 grain with a light crimp and had one fail to feed (out of 20 rounds) that jammed the bolt denting the cartridge, and another where the bullet failed to exit the barrel (thankfully I caught that before disaster). I then went up to 43 grains and had one round (again out of another 20) with similar results, jamming the bolt. When I got it out the bullet was partially forward in the cartridge (which is why I assume it failed to feed/eject). So wasn't sure if the 650 was either not metering the Varget well and I was getting a low charge, or something was keeping the cartridge from feeding/ejecting properly. I check all rounds twice with calipers and thru a case gauge and it all checks out so not sure where the problem is (aside from just low pressure). The fail to fire and ejection problems are all indicative of low powder but just want to make sure so I don't risk damage to the rifle.
Using Winchester brass with Hornady 168 grain Match bullet and Winchester primer out of a 16" barrel. I started the charge at the recommended 41 grain with a light crimp and had one fail to feed (out of 20 rounds) that jammed the bolt denting the cartridge, and another where the bullet failed to exit the barrel (thankfully I caught that before disaster). I then went up to 43 grains and had one round (again out of another 20) with similar results, jamming the bolt. When I got it out the bullet was partially forward in the cartridge (which is why I assume it failed to feed/eject). So wasn't sure if the 650 was either not metering the Varget well and I was getting a low charge, or something was keeping the cartridge from feeding/ejecting properly. I check all rounds twice with calipers and thru a case gauge and it all checks out so not sure where the problem is (aside from just low pressure). The fail to fire and ejection problems are all indicative of low powder but just want to make sure so I don't risk damage to the rifle.
Quote from Reloader on May 8, 2012, 3:00 amAs I'm sitting here late at night (thinking only of reloading), I'm also wondering that some of the problem may be from some brass having bulge near the base. I'm reloading once-fired brass (Winchester 165 grain BTHP) I've previously purchased and fired myself and noticed some of the brass has a great deal of difficulty getting thru the resizing die. Almost to the point of getting stuck (as I've seen other people on YouTube lamenting on). Again I can only attribute that behavior to bulge in the brass itself near the base. If the brass can get thru the resizing die and case gage, the bulge may still be present enough to cause the bolt to fail in properly feeding the round forward into the chamber. I'm meaning to reload another 20 rounds at 44 grains and I'll have to pay close attention when processing them and throw out any brass that gives me hesitation.
Thoughts?
As I'm sitting here late at night (thinking only of reloading), I'm also wondering that some of the problem may be from some brass having bulge near the base. I'm reloading once-fired brass (Winchester 165 grain BTHP) I've previously purchased and fired myself and noticed some of the brass has a great deal of difficulty getting thru the resizing die. Almost to the point of getting stuck (as I've seen other people on YouTube lamenting on). Again I can only attribute that behavior to bulge in the brass itself near the base. If the brass can get thru the resizing die and case gage, the bulge may still be present enough to cause the bolt to fail in properly feeding the round forward into the chamber. I'm meaning to reload another 20 rounds at 44 grains and I'll have to pay close attention when processing them and throw out any brass that gives me hesitation.
Thoughts?
Quote from Reloader on May 8, 2012, 2:33 pmA few more questions-1) does the bottom of the size die contact the top of the shellplate? Do sized, lube-free cases drop in flush with the bottom step of the case gage, and freely fall out? What case lube are you using? Is the blue wing nut at the bottom of the failsafe rod tight enough that when you push the handle forward to seat a primer, does the coil spring above the blue wing nut become partially collapsed? On the rounds that failed to feed, how far into the chamber did they go?Does the bolt push on the base of the case, or up the body of the case?
A few more questions-1) does the bottom of the size die contact the top of the shellplate? Do sized, lube-free cases drop in flush with the bottom step of the case gage, and freely fall out? What case lube are you using? Is the blue wing nut at the bottom of the failsafe rod tight enough that when you push the handle forward to seat a primer, does the coil spring above the blue wing nut become partially collapsed? On the rounds that failed to feed, how far into the chamber did they go?Does the bolt push on the base of the case, or up the body of the case?
Quote from Reloader on May 9, 2012, 12:32 amAnswers;
1- No, the bottom of the shellplate stops 1/8" (the width of a dime) from the bottom of the resizing die. I've noticed that some shells have a hard stop halfway or 2/3s down the length of the cartridge sometimes requiring a little more force to complete the movement. Now I attribute this to case bulge and will limit those shells. Recognizing that resizing the brass should have a gradual resistance and not a hard stop.
2- Yes, using a .308 case gage the shells fall freely, and flush (top and bottom). I also re-check them once the bullet is assembled.
3- I use Dillon Case Lube, however clean each round after assembly
4- Yes, when pressing the handle fully upward the priming peg comes completely up seating the primer. When this happens the spring is compressed.
5- The rounds that failed to feed seem to get 2/3 or a 3/4 into the chamber, but I only notice this when I pull the trigger, hear the pin drop, and get no detonation. The primers are dented but not sufficiently to fire the bullet. Then I have to jam the charging handle down to get the shell to extract. Once the bullet fired but had insufficient pressure to leave the barrel and only went 1" down before stopping (thankfully the following round contacted the bullet and failed to feed.
6- The shells are pushed by the bolt from the base.
Answers;
1- No, the bottom of the shellplate stops 1/8" (the width of a dime) from the bottom of the resizing die. I've noticed that some shells have a hard stop halfway or 2/3s down the length of the cartridge sometimes requiring a little more force to complete the movement. Now I attribute this to case bulge and will limit those shells. Recognizing that resizing the brass should have a gradual resistance and not a hard stop.
2- Yes, using a .308 case gage the shells fall freely, and flush (top and bottom). I also re-check them once the bullet is assembled.
3- I use Dillon Case Lube, however clean each round after assembly
4- Yes, when pressing the handle fully upward the priming peg comes completely up seating the primer. When this happens the spring is compressed.
5- The rounds that failed to feed seem to get 2/3 or a 3/4 into the chamber, but I only notice this when I pull the trigger, hear the pin drop, and get no detonation. The primers are dented but not sufficiently to fire the bullet. Then I have to jam the charging handle down to get the shell to extract. Once the bullet fired but had insufficient pressure to leave the barrel and only went 1" down before stopping (thankfully the following round contacted the bullet and failed to feed.
6- The shells are pushed by the bolt from the base.
Quote from Reloader on May 10, 2012, 2:37 pmReadjust the size die until it makes firm contact with the top of the shellplate, then see if the sized brass easily chambers.
Readjust the size die until it makes firm contact with the top of the shellplate, then see if the sized brass easily chambers.
Quote from Reloader on May 11, 2012, 12:20 amIs there any risk of damage to the shellplate given the repetitive contact with the sizing die?
Is there any risk of damage to the shellplate given the repetitive contact with the sizing die?
Quote from Reloader on May 11, 2012, 2:24 pmNo risk of damage at all. Do a few cases, then see if they freely chamber, allow the bolt to close, and extract.
No risk of damage at all. Do a few cases, then see if they freely chamber, allow the bolt to close, and extract.
Quote from Reloader on May 14, 2012, 11:35 amok so I made a batch of 20 rounds and cycled them through my AR-10 (chambered for 7.62 NATO) starting from the closed-bolt position before inserting the magazine. Out of the 20, five rounds failed to allow the bolt to completely move forward the final 1/2" into the locked position jamming the both itself. I had to bang the stock on the desk to get the bolt to finally eject the round. I checked those five rounds through the case gauge and the chambering was fine. I measured the length of each round with a caliper and it was at 2.810" (give or take .005"). I then cycled the five rounds again starting from the open-bolt position before inserting the magazine and they cycled through.
So what gives? I've moved the sizing die down to the shellplate, and lightened the crimp to almost none. Not to belabor this, but it's not instilling a great deal of confidence here. Is the sizing die just not shaping the brass correctly, or perhaps I need to reduce the .308 length below 2.810"?
Load Data:
Federal brass
Winchester large rifle primer
43.5 grain of Varget powder
168 grain Hornady Match bulletRifle:
AR-10 chambered for 7.62 NATO with 16" barrel
ok so I made a batch of 20 rounds and cycled them through my AR-10 (chambered for 7.62 NATO) starting from the closed-bolt position before inserting the magazine. Out of the 20, five rounds failed to allow the bolt to completely move forward the final 1/2" into the locked position jamming the both itself. I had to bang the stock on the desk to get the bolt to finally eject the round. I checked those five rounds through the case gauge and the chambering was fine. I measured the length of each round with a caliper and it was at 2.810" (give or take .005"). I then cycled the five rounds again starting from the open-bolt position before inserting the magazine and they cycled through.
So what gives? I've moved the sizing die down to the shellplate, and lightened the crimp to almost none. Not to belabor this, but it's not instilling a great deal of confidence here. Is the sizing die just not shaping the brass correctly, or perhaps I need to reduce the .308 length below 2.810"?
Load Data:
Federal brass
Winchester large rifle primer
43.5 grain of Varget powder
168 grain Hornady Match bullet
Rifle:
AR-10 chambered for 7.62 NATO with 16" barrel