Bolt hard to open

[greenron15]

Every once in a while I find it hard to open the bolt after firing.
I have been using the same load for awhile. Sierra 168 match king. Reloader 15/ 44.5 grains/Federal case/cci 200 primer/trimmed to 2.005. in a 308 Winchester. Any ideas what causes this to happen

 

[bigedp51]

What type-brand rifle?

What weight bullet?

Savage rifles sometimes have poor primary extraction.

 

[Terry]

Common suspects...

Brass not sized enough, too long.

Brass fired with a hot load, base expansion.

 

[fdshuster]

Need more information. Does the hard bolt lift occur with only the first 2 to 4 firings, then it's normal? Or does it happen at any and all times throughout firing? Has all the brass been fired the same numer of times or are they mixed between "old" and "new"? Has all the brass been fired in your chamber only?

 

[dreever]

What bullet? That would be a pretty hefty load for 175's on up.

 

[M-61]

All of the above plus: Is the ambient temperature higher than what you had been shooting at? I have RE 15 to be very temp sensitive to the extremes in NY.

 

[greenron15]

168 sierra match king .
GA Precision crusader rifle
Happens infrequently
Used the same load for 2 years in this model rifle.This one is brand new 111 rounds fired through it.
All brass has been fired 2 times

 

[jonbearman]

Sounds like you need to bump the shoulder alittle to me.

 

[6BRinNZ]

Is it hard to open at the initial opening or at the top of the movement?

 

[Old Navy]

Sounds like you need to bump the shoulder a little to me.

This solved the same problem for me. Later! Frank

 

[fdshuster]

And if bumping the shoulder(s) back does not fix the problem, then you may have to consider a small base die to reduce the case head diameter a few thousandths.

 

[BoydAllen]

Try trimming all of your cases, and make sure that you measure your shoulder bump. Beyond that, are you weighing charges? If a case is too long, and the shoulder set back too far, it can be forced into a position, during firing, such that the mouth of the case is jammed into the bullet, which will raise pressure, and can result in a hard bolt lift.

 

[amlevin]

Recently had that problem with some "more experienced" brass. A real close look at the case showed a faint case head separation line (a crack that hadn't leaked gas yet).

I now pay even more close attention to inspection of the inside of the case.

 

[BoydAllen]

It is pretty much a given that incipient separations (what you found) are caused by not paying sufficient attention when setting up one's FL die, and repeatedly bumping back shoulders too far.(or)They can also happen when light loads are shot repeatedly followed by a relatively hot load. The clue to this is seeing primer protrusion after firing one of the light loads. The case was forced forward into the chamber during firing, but there was not enough pressure to bring the head back to the bolt face. If this is repeated several times, the datum line to head measurement is incrementally reduced, and even though cases are within OAL spec. , their short "headspace" can allow the end of their necks to be forced into the bullet, increasing pressure. These are the two situations that cause what you have found.

 

[amlevin]

It is pretty much a given that incipient separations (what you found) are caused by not paying sufficient attention when setting up one's FL die, and repeatedly bumping back shoulders too far.

Thanks Boyd. I knew the "why" Can actually trace some of these cases back to a die I "thought" I had set properly

Complacency to be avoided.

 

[BoydAllen]

I always set up my shoulder bump every time that I start a reloading session, for the very reason that you mentioned. It is also important to keep brass in batches that are fired pretty much in rotation within the batch. The reason that I started to do a setup every time that I load is that one time I forgot that my 6PPC die was set for old hard brass, and started sizing a fairly fresh batch. Luckily I checked the bump after only 3-4 had been sized. Instead of .001 bump, I had .0035. Since then I have taken the die out of the press at the end of every session. I use a Lee lock ring, that starts to make contact when the die is a little high, and will not go metal to metal to metal with the top of the press within the range of adjustments that I use. To keep it where I want on the die, I put a Hornady lock ring above it, and screwed it down to touch the Lee once it was set where I wanted it, tightened the Hornady lock screw, which spread it into the Lee ring, locking it it securely in place on the die. I also think that I am getting some benefit as far as sized case concentricity goes with the die floating a little on the O ring. As far as the explanation of where the separation goes, it was much for those reading the thread as anything else. Your point about checking cases is a good one.

 

[searcher]

I'll add support for the gent who suggested a check on your brass trim length. As your brass stretches and gets closer to your chamber length, you will first see a "high pressure" firing only occasionally unless your brass is all trimmed exactly the same length. There are a few that are always just a bit longer and are the first ones to jam into the bullet when they become too long. Subsequent reloadings without a neck trim will increase the frequency as you have more longer necks.... Shoulder bumps can also help as others have pointed out but typically are not as random when needed. In either case, you should be able to feel something is amiss when carefully closing the bolt on your loaded cartridge. If there is slightly more resistance from one round versus another - the brass is likely the issue - or at least a contributor. If the bolt drops nicely on all loaded cartridges prior to firing, the problem may be elsewhere such as improper powder charge, enlarged flashholes on just the few cases that create the hard bolt lift, etc. Next time you encounter this, measure the length of that cartridge versus the others and check the flashhole to begin ruling out items.