View Full Version : Bolt hard to pull back
Cookie91/38
10-05-2014, 2:46 PM
Hello,
Ive been reloading 308 for about a month or two now, and i just made a few batches with 175SMK's. I trim the brass to 2.008, and the OAL Is 2.8 with the SMK. When I close the bolt its smooth, but about 50% of the time the bolt lifts up easily, but "locks up" and you really have to tug at it to pull it back. Im getting great groupings, but was wondering what is causing this? And my weapon is a remington 700 sps tactical with a usually very smooth bolt. Thanks a lot, Evan
Ahhnother8
10-05-2014, 2:55 PM
Overpressure OR brass fired in another gun needs to be small-base sized one time only, then will work fine in this gun.
Cookie91/38
10-05-2014, 3:03 PM
This brass has only been fired in this gun. It is PPU brass. My load is 42.2 so I don't think overpressure would be an issue? It was doing this with a 41.7 load too
If the brass goes in easily, it should come out easily, unless you are over pressure—assuming the bolt can be easily pulled back with factory ammo.
Does this happen with factory loads?
What powder are you using?
Did you work up the load from the start load and did the start loads extract easily?
I hope you aren't just jumping into what you THINK is a safe load.
This used to be the way rifle loads were all tested—until hard bolt lift or sticky extraction and then charge weight was reduced by 0.5-1.0gn. Many of these pet loads were found to be running about 70-75,000 psi (after dropping the 0.5-1.0gn) and had been used for decades.
Any marks/shiny areas on the case heads?
If not over pressure, then possibly improper annealing has weakened the whole case or there is a problem with your bolt (improper heat treating or such).
You can try to cover the whole case with black Magic Marker, fire the round, and, upon extraction, see where the "hang up" is.
Your manual may say it is a safe load, but your rifle is telling you it is over-pressure.
Cookie91/38
10-05-2014, 3:33 PM
If the brass goes in easily, it should come out easily, unless you are over pressure—assuming the bolt can be easily pulled back with factory ammo.
Does this happen with factory loads?
What powder are you using?
Did you work up the load from the start load and did the start loads extract easily?
I hope you aren't just jumping into what you THINK is a safe load.
This used to be the way rifle loads were all tested—until hard bolt lift or sticky extraction and then charge weight was reduced by 0.5-1.0gn. Many of these pet loads were found to be running about 70-75,000 psi (after dropping the 0.5-1.0gn) and had been used for decades.
Any marks/shiny areas on the case heads?
If not over pressure, then possibly improper annealing has weakened the whole case or there is a problem with your bolt (improper heat treating or such).
You can try to cover the whole case with black Magic Marker, fire the round, and, upon extraction, see where the "hang up" is.
Your manual may say it is a safe load, but your rifle is telling you it is over-pressure.
Yes factory rounds go in and out easily. Im using 4046 powder, and I started out at 41.7. Ill look when I can for any marks on the case heads. If they were over pressured, wouldn't all the rounds be sticking? Or can it vary? Because some ejected smooth and some didn't.
I show 41.3gn of 4064 as max and 34.0gn being start. I see references to 4046 on the 'net, but I don't show it in any reloading manual or on the IMR site.
Load some at 34gn and work up and see if there is some sticking at all loads or if it suddenly appears at some charge weight. Could be some bad cases, could be high pressure in YOUR rifle (small match chamber or such that doesn't apply to the test barrel used by the manual's test lab).
Call Remington and discuss it with them.
rsrocket1
10-05-2014, 3:51 PM
As mentioned, take one of your "really tight" fired brass cases and color it with a magic marker. Try and chamber it again and look for where the ink rubs. It will probably be on the shoulder which means you need to bump it back a couple of mils. If you neck size only, every few firings you may need to bump the shoulder back a little.
You can do a "partial full length resize" by starting with a full length dies and screwing it out a couple of turns from touching the shell holder. Then screw it in until it pushes the shoulder back to where the shoulder will no longer rub the chamber of your rifle. Mark the spots on the die and retaining nut so you can reference the spot in the future when you have some more cases that need the shoulder bumped back.
A headspace gauge (http://www.hornady.com/store/Lock-N-Load-Headspace-Kit-With-Body-1-Each/) can tell you whether you need to bump.
Cookie91/38
10-05-2014, 4:02 PM
As mentioned, take one of your "really tight" fired brass cases and color it with a magic marker. Try and chamber it again and look for where the ink rubs. It will probably be on the shoulder which means you need to bump it back a couple of mils. If you neck size only, every few firings you may need to bump the shoulder back a little.
You can do a "partial full length resize" by starting with a full length dies and screwing it out a couple of turns from touching the shell holder. Then screw it in until it pushes the shoulder back to where the shoulder will no longer rub the chamber of your rifle. Mark the spots on the die and retaining nut so you can reference the spot in the future when you have some more cases that need the shoulder bumped back.
A headspace gauge (http://www.hornady.com/store/Lock-N-Load-Headspace-Kit-With-Body-1-Each/) can tell you whether you need to bump.
I actually full length resize every time right now, so does this still apply?
jdmstuff
10-05-2014, 4:20 PM
I show 41.3gn of 4064 as max and 34.0gn being start. I see references to 4046 on the 'net, but I don't show it in any reloading manual or on the IMR site.
Load some at 34gn and work up and see if there is some sticking at all loads or if it suddenly appears at some charge weight. Could be some bad cases, could be high pressure in YOUR rifle (small match chamber or such that doesn't apply to the test barrel used by the manual's test lab).
Call Remington and discuss it with them.
Where are you getting your load data from? The Hodgdon site shows the starting load at 41.5 with a max at 45.6 compressed.
rsrocket1
10-05-2014, 4:22 PM
I actually full length resize every time right now, so does this still apply?
No, if you full length resize you should not have a headspace problem unless your die is not screwed down all the way and you cannot slip a piece of paper between the die and the shell holder with a case being resized. I've read of folks thinking they are fully resizing their brass only to find out that they were short stroking the press or that they didn't check that the die touched the shellplate with the case in the die, only without the case.
I would still try the magic marker test to see where the cases are binding in your chamber.
Cookie91/38
10-05-2014, 4:28 PM
No, if you full length resize you should not have a headspace problem unless your die is not screwed down all the way and you cannot slip a piece of paper between the die and the shell holder with a case being resized. I've read of folks thinking they are fully resizing their brass only to find out that they were short stroking the press or that they didn't check that the die touched the shellplate with the case in the die, only without the case.
I would still try the magic marker test to see where the cases are binding in your chamber.
Il try the magic marker thing in a bit here. So should the die not touch the shell plate?
Ah, yes, and your source is more accurate than my source. My source was Hornady.
Remember, no lab has your gun, your exact lot number of bullets, or your exact lot numbers of powder or primers, and probably not your brand or lot number of cases. A manual is a guideline only.
Believe me, a start load in one manual can be max or over max in another or in your gun.
This is why I start at the lowest starting load I can find (referencing several sources) and work up looking for pressure signs (with hard extraction at the top of the list).
Call Hodgdon or Rem and ask them what they think.
If your sizing die is NOT screwed down all the way, you may not be able to chamber the case, but the head space would not be problem (with the case pushed all the way forward, there would not be excessive space between the case head and the breech, which to me is excessive head space). Head space issues, to me, come from pushing the shoulder back too far. Thus, I screw the sizing die down just until the cases easily chamber.
Cookie91/38
10-05-2014, 4:37 PM
Ah, yes, and your source is more accurate than my source. My source was Hornady.
Remember, no lab has your gun, your exact lot number of bullets, or your exact lot numbers of powder or primers, and probably not your brand or lot number of cases. A manual is a guideline only.
Believe me, a start load in one manual can be max or over max in another or in your gun.
This is why I start at the lowest starting load I can find (referencing several sources) and work up looking for pressure signs (with hard extraction at the top of the list).
Call Hodgdon or Rem and ask them what they think.
If your sizing die is NOT screwed down all the way, you may not be able to chamber the case, but the head space would not be problem (with the case pushed all the way forward, there would not be excessive space between the case head and the breech, which to me is excessive head space). Head space issues, to me, come from pushing the shoulder back too far. Thus, I screw the sizing die down just until the cases easily chamber.
I screw the sizer die down until it touches the shell plate, per the instructions in the manual. I guess Il reduce my load down a few grains and see what happens?
maxx03
10-05-2014, 5:11 PM
I screw the sizer die down until it touches the shell plate, per the instructions in the manual. I guess Il reduce my load down a few grains and see what happens?
The shoulder might need to get bumped back a little more. Screw the die in 1/8 to 1/4 turn so it cams over when you're at the top of the press stroke.
Divernhunter
10-05-2014, 6:24 PM
Sounds like you are just on the edge. Drop the charge 1 gr and try it.
Also if you are using a single stage press screw the die down until it touches THEN 1/4 more turn and lock it. The handle should cam-over when there is no shell in the press. It is easier to feel without a shell in the press.
Ahhnother8
10-05-2014, 6:33 PM
The friction point will be just above the extractor groove in the brass. That is why you can lift the bolt but not pull it back. If the case was too long, it would force the bolt open once the lugs cleared. Even if an unfired round is too long, you can typically use the camming power of the bolt to close it, and after firing, the case will be shorter and eject easily.
Overpressure OR need to small-base size the brass.
Cookie91/38
10-05-2014, 7:02 PM
Thanks a lot guys. I will try camming over, and if that doesn't work then drop the charge or buy a small base die.
dave225
10-05-2014, 7:07 PM
whats the primer look like
maybe a picture of the case after marking and a picture of the primer would help
agreed overpressure sounds about right
baih777
10-05-2014, 7:14 PM
You don't need a small base die for PPU brass. I have been using it all year. Reloaded the same brass about 8 times now. F/L die is OK. I think overcamming is your answer. I do that to mine. Spend your money on a Dillion case gauge. Saves you a lot of headaches.
krwada
10-05-2014, 8:56 PM
Did you trim your brass? Did you measure the trim length?
Improper trimming will do this with rifle loads.
Full length sizing will inevitably work the brass to longer lengths ... then when you fire some ... the case length being too long will cause this symptom. The problem is it will not be consistent ... some will extract OK ... some will be difficult to extract.
Proper trimming is essential for safe rifle rounds.
My PPU loads with IMR 4064 is 40.6. With Federal brass I do 42.2. The PPU was over pressured for me at that same load with sticking bolts as well.
Cookie91/38
10-05-2014, 9:53 PM
My PPU loads with IMR 4064 is 40.6. With Federal brass I do 42.2. The PPU was over pressured for me at that same load with sticking bolts as well.
Oh wow thats really helpful. Was the lift hard to or just the pull? Was it on every round?
Cookie91/38
10-05-2014, 9:54 PM
Did you trim your brass? Did you measure the trim length?
Improper trimming will do this with rifle loads.
Full length sizing will inevitably work the brass to longer lengths ... then when you fire some ... the case length being too long will cause this symptom. The problem is it will not be consistent ... some will extract OK ... some will be difficult to extract.
Proper trimming is essential for safe rifle rounds.
Im using a LE Wilson case trimmer and they are all coming out evenly in length, and seem even. Is it easy to trim unevenly? And is 2.008 a good trim length? Or do I have to trim to 2.005?
+1 on camming over. I experienced the same issues in my early reloading days and had to bump the shoulders back. Also do you have a 308 case gage? If not, I would invest in one.
baih777
10-05-2014, 10:29 PM
this is what I was referring to. 308 case guage.
http://www.midwayusa.com/product/880646/le-wilson-case-length-headspace-gage-308-winchester
I use a Dillon but it measures at the shoulder.
Maybe he shod first figure out where the case is sticking? It cold be his sizer die is not sizing the diameter of the casehead enough. I had a sticky case issue after 5x with Winchester brass. I measured the case head. It was springing back too much. Got a small base die. Problem solved.
Don't tell him to cam over. If his shoulder position was the problem he would have a hard time chambering a round, not extracting the round.
Measure a sized case and compare it to a fired case. See where it is sticking. I bet it's somewhere on the case wall near the extractor groove.
krwada
10-06-2014, 8:51 AM
Im using a LE Wilson case trimmer and they are all coming out evenly in length, and seem even. Is it easy to trim unevenly? And is 2.008 a good trim length? Or do I have to trim to 2.005?
If you are using the Wilson case trimmer ... then trim length is not a problem for you. 2.008" for Win .308 is fine.
The only thing I can think that can do this is overpressure. Do you get the bolt extraction problem when you use the lower charge weights? This is an indication of overpressure.
Overpressure will be different with different brass ... as others on this forum have pointed out.
This is one of the reasons why it is good to test rifle loads using the same headstamp and to work up accordingly ... especially for rifle.
popeye4
10-06-2014, 10:16 AM
If the cartridges are chambering without effort, it most likely isn't a sizing/headspace problem.
I'm guessing this is an overpressure issue. I don't know how the case capacity of PPU brass compares to the baseline case used in developing the load recipe, but perhaps measuring the water volume of the case might shed some light. Weigh an empty case (with spent primer still intact) and then fill with water and weigh again. This will give you the internal volume of the case in grains of water (I know, that's mass and not volume, but one is directly proportional to the other). Smaller case capacity will lead to higher pressures with the same powder charge.
This thread provides some baseline info. http://www.700rifle.com/forum/20-handloading-techniques/871-brass-capacity-308-win-brass-laupa-federal-brass.html
Bottom line: if you're seeing evidence of excessive pressure (sticky bolt on extraction is pretty classic), back off your load a bit.
Cookie91/38
10-06-2014, 10:52 AM
I will try and back the load to 40.6 like the above poster, because even at 41.7 it was still sticking.
bigedp51
10-06-2014, 12:36 PM
Cookie91/38
What make rifle are you having this problem with?
1. Lifting the bolt straight up is called "primary extraction" and should break the case free from the chamber and move the case slightly to the rear.
2. Secondary extraction is then pulling the bolt all the way to the rear.
If the primary extraction is not timed correctly it does not totally break the cartridge free from the chamber walls. And this makes secondary extraction difficult.
This happens a lot with Savage rifles, so if you have a Savage rifle your load may have nothing to do with your extraction problem.
spamsucker
10-06-2014, 1:28 PM
on thick brass (military, LC, etc..) for me 41.5 IMR 4064 and a 168gn Hornady is all I get before showing pressure signs, including sticky bolt lift (which was at a similar charge weight to yours). I've had up to 44gn in remington brass without pressure signs. I'm betting overpressure. Back it down and use as little powder as necessary to get the grouping and velocity you need. Don't race the chronograph man.
sbmunshi
10-06-2014, 2:41 PM
I experienced the same with PPU brass fireformed. This did not happen using winchester or Lapua brass. With the PPU it went in smooth and the extraction was a little tight. Lower your powder load and you should see a difference.
Oh wow thats really helpful. Was the lift hard to or just the pull? Was it on every round?
Both lift and the pull. Here is the thread http://www.calguns.net/calgunforum/showthread.php?t=919372
Ahhnother8
10-08-2014, 2:52 PM
So, was it overpressure or was the case head not sized down enough?
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