New thread on hard to open bolt on Rem 700

R

Roy Allain

Guest
I am starting a new thread on this topic because I don't want to hijack the Model14 post any longer and am sorry I did.

I resize 30 pcs. of fired brass. Before sizing the web measured .4395 and measured .4395 after sizing.

Obviously the die isn't sizing the web. I have 2 Harrell's bump dies. I thought they also bumped the web, but I guess not. Maybe I didn't specify that when I bought them from Lynwood.

Short of having a too tight chamber at the web area, could this be the origin of my hard to open bolt? Possibly?
 
Is the bolt hard opening on the sized brass? If it is, the "web" area is the problem.

If a case is long at the shoulder it still extracts easily, if it is too large in diameter on the body or "web" it sticks quite hard...
 
The "web" is solid brass, I don`t believe any sizer works there. A small base die will take out the pressure ring just above it if you need reduction there. If the web is showing expansion and needs to be knocked down your load is wayyyyyy past OK......
 
From what I have gleaned here

when one has a situation like this, the easiest thing to do is to have the chamber polished out a couple of thou in the back. Apparently this cures the problem.
 
web sizing..

What happen to small base dies and body sizing dies?

If my instruction were correct the web is "from the .200" line to the case head".

If memory serves me correctly the minimum SAAMI spec on a .308Win case is .468".

I see 308s chambered from .468 to .472 in the web all the time. I consider a chamber out of SAAMI spec to be sloppy. But it ususlly does not effect the accuracy. Just ones brass life.

Nat Lambeth
 
You can cut the bottom off of a die and dril out the upper part of the die with a drill a little largerthan the shoulder. It allows the die to size down to the base.
Butch
 
In the page linked below read down to the section titled -Custom Dies Work Best- In the next to the last paragraph pay attention to the last few sentences about a rough way to check and see if your die suits your chamber .

http://www.6mmbr.com/6PPC.html
 
That's a possiblilty Butch

Butch Lambert said:
You can cut the bottom off of a die and dril out the upper part of the die with a drill a little largerthan the shoulder. It allows the die to size down to the base.Butch
Click to expand...

When I see Don later this week, I'll talk to him about that.

Thanks

Roy
 
Hey Pete

Pete Wass said:
when one has a situation like this, the easiest thing to do is to have the chamber polished out a couple of thou in the back. Apparently this cures the problem.
Click to expand...

Geraci talked about that last Sunday, and I plan on going over that and a few other options. He wants to measure the chamber and see what can be done.

Rooah
 
I'm not sure if this will cause the hard bolt lift, but

I measured a bunch of brass necks and found this.

4 pcs. - .0088 w/66 gr. Knights @ .2435 = .2611 at pressure ring
32 pcs. - .0090 w/66 gr. Knights @ .2435 = .2615 at pressure ring
12 pcs. - .0091 w/66 gr. knights @ .2435 = .2617 at pressure ring
2 pcs. - .0092 w/66 gr. Knights @ .2435 = .2619 at pressure ring

Would this cause the case to stick in chamber as opposed to oversized web or undersized chamber at web???

Roy
 
Roy,

Has the brass ever been fired in another chamber?

Before you fired it in this chamber was it hard to close the bolt?

After firing in this chamber was the bolt hard to open?

After sizing does the empty brass go in the chamber tight? Loose?

Does the empty sized brass want to stick in the chamber?
 
Roy Allain said:
I measured a bunch of brass necks and found this.

4 pcs. - .0088 w/66 gr. Knights @ .2435 = .2611 at pressure ring
32 pcs. - .0090 w/66 gr. Knights @ .2435 = .2615 at pressure ring
12 pcs. - .0091 w/66 gr. knights @ .2435 = .2617 at pressure ring
2 pcs. - .0092 w/66 gr. Knights @ .2435 = .2619 at pressure ring

Would this cause the case to stick in chamber as opposed to oversized web or undersized chamber at web???

Roy
Click to expand...

No, it would not cause the case to stick in the chamber upon bolt openning, once the bullet leaves the case upon firing and the neck area of the case adjacent to the pressure springs back, it will spring back the same regardless of previous bullet pressure ring dimensions...............Don
 
Reply to Dennis

Dennis Sorensen said:
Roy,

Has the brass ever been fired in another chamber?

Before you fired it in this chamber was it hard to close the bolt?

After firing in this chamber was the bolt hard to open?

After sizing does the empty brass go in the chamber tight? Loose?

Does the empty sized brass want to stick in the chamber?
Click to expand...

#1 - NO
#2 - No, the bolt has never been hard to close
#3 - Yes
#4 - Loose
#5 - This is what I'm trying to find out. I assume it is sticking, because the bolt is hard to open when I begin to push up on the bolt handle. But then again, what the heck do I know.

Thanks

Roy
 
Roy Allain said:
#1 - NO
#2 - No, the bolt has never been hard to close
#3 - Yes
#4 - Loose
#5 - This is what I'm trying to find out. I assume it is sticking, because the bolt is hard to open when I begin to push up on the bolt handle. But then again, what the heck do I know.

Thanks

Roy
Click to expand...

If the bolt closes easily on sized brass but then is hard to open on the same brass, I believe the rear of the chamber is a thou or 2 too tight.

Take that same brass that closes easily but makes the bolt click on opening and smoke the rear of the case with a match, lighter, candle, whatever and chamber and extract it again. It should show you exactly where it binds. You can confirm this by then filing that diameter of the case smaller. Measure before and after and test it... My bet is two thou will fix it. The easiest is to polish the rear of the chamber out until the brass no longer "clicks"...
 
Dang. Dennis. Why didn't I think of that

I'll try that today Dennis and get back with the results.

Thanks

Roy
 
Bump dies are designed to size the neck, and, when adjusted to do so, bump the shoulder, nothing else. I didn't know that Lynwood still made them. His FL dies do size the diameter of the body.

The problem with trying to size the web. with any die that is designed to work with a shell holder is that between the thickness of the top lip of the shell holder, and a slight radius at the mouth of the die, it cannot be reliably reached. What you can size, is the area just above web, and that should show a slight reduction after FL sizing, if the die and chamber are matched. I should add that the definition of the web that I understand to be correct is that part of the case that is solid from side to side across the diameter, not including any of the side wall of the case.

There can be problems if the chamber is too close to the web diameter (the diameter that adjoins the top of the extractor groove). Under the pressure of hot loads, the web is smashed between the bolt face and the pressure of combustion, and will increase in diameter. A FL die can reduce the diameter of the case immediately in front of the web, allowing it to be chambered without interference, but when the case is fired, that area will pop back out to its pre-sized diameter, causing a "click" at the top of the bolt lift. I once took a clicking case and carefully polished it down a couple of thousandths, parallel to its centerline, just in front of the extractor groove. That removed the click, as determined by subsequent firing. The answer to the problem, as has been stated, is proper reamer design, relative to the case head diameter, allowing just enough clearance to allow for web growth, as produced by hot loads. In an existing chamber, again, as has been stated, the only remedy is to polish out the back of the chamber a couple of thousandths, after careful setup in a lathe.
 
It is possible that your bolt face is misalligned, or does not have enough
radial clearance. It is also possible that the cocking ramp is gauled and or
not shaped right, maybe even unlubed.
There is sufficient force in the cam in ramps to make it difficult to feel
a tight web area going in. By removing the firing pin assbly, you can
get a better feel of any resistance there. The area of a case just above
the web, refered to as the expansion line, is thicker and much better
supported by the solid brass in the web. It is quite elastic, untill the
plastic limits of the brass have been exceeded.Once exceeded, cases get
sticky as in bolt click. Even when sized down in dia. they seem to have a memory,and find there way back to bolt click fast. Polishing chambers is
a quick solution, and works when a usable die cannot be found, or when the chamber is actually to small. It can produce out of round and football
shaped chambers (big in the middle).If overdone. Recutting the chamber with a good reamer might be advisable.
 
Last edited:
Dennis, I did that today

Dennis Sorensen said:
If the bolt closes easily on sized brass but then is hard to open on the same brass, I believe the rear of the chamber is a thou or 2 too tight.

Take that same brass that closes easily but makes the bolt click on opening and smoke the rear of the case with a match, lighter, candle, whatever and chamber and extract it again. It should show you exactly where it binds. You can confirm this by then filing that diameter of the case smaller. Measure before and after and test it... My bet is two thou will fix it. The easiest is to polish the rear of the chamber out until the brass no longer "clicks"...
Click to expand...

Execpt I didn't smoke the brass. I removed the firing pin assembly and put the stripped bolt back in the action. Then I tried 50 pieces and they went in and extracted without any bind. None.

It is only after firing that I will have a hard extraction. I think you guys are correct in that the chamber is too small at the web area. Most of my loads are 28.6 to 29.2 grs. of N133. Not too hot, but maybe it is for this barrel. A Krieger LV.

I'll start another thread when I get this problem resolved, hopefully within the next 2 weeks.

Thanks for all your help guys.

Roy
 
Roy Allain said:
Execpt I didn't smoke the brass. I removed the firing pin assembly and put the stripped bolt back in the action. Then I tried 50 pieces and they went in and extracted without any bind. None.

It is only after firing that I will have a hard extraction. I think you guys are correct in that the chamber is too small at the web area. Most of my loads are 28.6 to 29.2 grs. of N133. Not too hot, but maybe it is for this barrel. A Krieger LV.

I'll start another thread when I get this problem resolved, hopefully within the next 2 weeks.

Thanks for all your help guys.

Roy
Click to expand...

My experience --> If it is hard extraction after firing it is usually excessive pressure.
 
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