Head space or bolt face??

jed

Regular
Super GunNutz
Rating - 100%
126   0   0
Location
BC
I have a problem with a Remington 700. I purchased the rifle off this site last year and never had time till now to really play with it. It is a SA, originaly it was 22-250 and then rebarreled to 243. The problem I have is that on some rounds I cannot close the bolt. When I first received the rifle I scrounged around the bench and found 30 pieces of new brass which I loaded up and fired fine. I then ordered a bag of brass and next went to the range with 80 rounds. Only 50 odd of which I could fire. I thought maybe the problem was a bad batch of brass, or maybe the full length resizing. I ordered a neck sizer and ran all the brass through. Even with no slug I still could not close the bolt on all the resized rounds. Plan B...I bought a box of factory loads, seventeen of the factory rounds closed fine. Three would not close at all. Not being the sharpest knife in the drawer I only then took the bolt out of my other SA 700 and tried it. (nice to be a nut and have a spare) Of course all the rounds chambered fine. I am reluctant to actually shoot the rifle with the other bolt I can't explain why but I don't want to. I am guessing that something is a couple thou out of whack but I don't know what. Anyone have any similar experience or thoughts. I don't have any use for another unreliable rifle and I can't afford to turn it into a heavy barreled swift so I have to fix it. Thanks in advance for all the input. Jed
 
It could be a tight necked chamber or the chamber could be a little short. Have a gunsmith tickle the chamber with a reamer. Or you may be faced with having to neck turn all your brass. The neck size die will only neck size, you may need to full length re-size to bump the shoulder back. Seing that you have tried factory ammo, my bet would be a tight necked chamber.
 
If you want to know if the headspace is correct, a steel headspace gauge is required.

Take it to someone with a steel headspace go - gauge and have the headspaced checked with the bolt stripped apart. If the bolt will close without resistance on a go - gauge and it will not close on the go gauge with one piece of masking tape on the rear of the gauge - the headspace is minimum and perfectly acceptable.

I have seen barrels fitted by "gunsmiths" who use a factory case and their resizing die to set the headspace "really tight" thinking they are solving a future headspace problem, when in fact they are often creating one.

Trying to "size" all the cases with a neck sizer did nothing.... it only sizes necks...

A gunsmith can diagnose this in a few minutes.
 
Last edited:
Sounds like the headspacing wasn't done properly when the .243 barrel was installed. Especially when factory ammo won't chamber. That other bolt may be causing excessive headspace.
"...took the bolt out of my other..." You cannot just change bolts without testing the headspace with proper guages. Bits of tape on guages mean nothing.
New brass must be checked for length, trimmed to the same length, chamfered on the inside of the mouth, then full length resized. Cases used in two rifles of the same chambering must be full length resized every time.
The dies should be set up so the shell holder just kisses the bottom of the die when the ram is all the way up.
Neck sizing is fine if you use the brass in one bolt action rifle only.
 
sunray said:
Bits of tape on guages mean nothing

Well please correct me if I'm wrong because I really would like to know about this. So if I wanted to stay with a saami spec chamber but wanted to keep it on the tight side of the specs for accuracy etc knowing that the go gauge does close and the no-go doesn't close won't tell me where I'm at. But if I make the "go" longer by X thou and it doesn't close I believe I'll know exactly where I'm at. Yes?
 
Last edited:
sunray said:
You cannot just change bolts without testing the headspace with proper guages. Bits of tape on guages mean nothing.

A piece of masking tape on the back of a steel go gauge adds exactly 3 thou to your measurement, which is less than the difference to a no go gauge.

I guarantee if you close a bolt on a go gauge and feel it engage at the bottom of the bolt closing, if you add a piece of tape on the rear of the gauge, the bolt will not close. The tolerance will be set for a true minimum saami specification.

Tape on a gauge means a lot if you know how to interpret the measurements.
 
be careful with the masking tape, different brands can vary wildly in thickness. just went and measured three different brands and they varied from .007 thick to .013". That could get you into trouble.
 
Last edited:
Oscar Makonka said:
be careful with the masking tape, different brands can vary wildly in thickness. just went and measured three different brands and they varied from .007 thick to .013". That could get you into trouble.

A good point... I have not experienced tape that thick...

I have always found that on first contact with the sticky side of the tape on the anvil, the tape measures 5 thou, but when on the back of the headspace gauge and compressed by the bolt closing, and then measured again, it measures 3 thou after the glue compresses.

The difference between a go gauge and a no go gauge is 6 thousands of an inch. What ever make of tape you use, just make sure your compressed tape is less than 6 thou thick. It is preferable to just feel the go gauge at the bottom of the stripped bolt closing...
 
Jed, take your FL sizing die to a lathe or grinder. Take 5 to 10thou off the bottom.

Size some brass and see if that chambers. If not, keep taking a bit off the bottom of the die till it does.

I bet that after you take off the first bit of die, the brass will chamber just fine.

My guess is that the chamber is 2 to 4 thou SHORTER then your FL sizer can size.

The chamber has been cut using a sized case as the headspace guage. The die used pushed the brass to min spec, maybe even a little below.

Factory brass is sized to fit within the rules of SAAMI and the very generous factory chambers. The size variance is huge so it doesn't surprise me that some factory ammo will not chamber in min spec chambers.

Also, remember that reloading dies are made to a variety of specs so some dies are 'bigger/longer' then others. Even from the same company!

Big reason why I don't like bolt swaps in M305's but that is another story...

A two minute job will solve your problem. Once you have sized ALL of your brass to fit, you can go to the neck sizer for future reloading.

Just have the decency to include the 'custom' die with that rifle so the next owner doesn't have to post this same question.

Jerry
 
I have a custom 22-250 with a very tight chamber [length]. My FL sizing die would not size brass shot in any other rifle sufficiently to get it to chamber. Like Jerry, I took the easy route, chucked the die in a valve refacer and machined .006" off the bottom of the die. Eureka! perfect sizing every time now, and a really nice tight chamber. Regards, Eagleye.
 
Back
Top Bottom