Need advise with hard to open bolt.

[308Cajun]

46.0 Varget 45.0 RL 15 47-39 CFE 223
I had a first time experience at the range. I had trouble opening the bolt after firing rounds. I fired 3 loads: 1, 45.0 gr RL 15, 168 AMAX; 2, 46.0 Gr Varget, 168 AMAX; 2, CFE 223 47.0 - 49.0 in .5 increments. All cases were once fired Federal, all primers were Fed 210. Cases in loads 1 & 2 were full length resized. Load 3 cases were once fired in my rifle, so were necked sized using Lee Collet die. Temp was 90 degrees. I had difficulty opening the bolt for all loads fired. The worst load was the RL 15 load, which is a max load. The Varget load is also am max load, but 1 I have been shooting for years, both in this rifle ( Marlin X7 308) and a Remington 700, with no problems. CFE 223 is a new load which I was working up. I figure it's 1 of 3 things too much pressure, bumping the shoulder too much in full length resizing, or a dirty chamber. cleaned the chamber while shooting Varget and it helped. I stopped shooting RL 15 after 3 rounds. Photos of the fired primers are attached. Any thoughts?

 

[LHSmith]

Wet chamber or seat depth changed- out to far into rifling or rounds got heated in sun.

 

[M-61]

My thoughts are the pictures do not really show, to my eyes, anything to be alarmed about.
HOWEVER, in this case words may speak more than pictures. Your 2nd sentence is the key. "I had trouble opening the bolt after firing rounds".
That's something. How much trouble? Real stiff or you had to get a mallet? Either way there is a problem. I see small cratering around the pin strike, but for me that's normal and would not concern me. Maybe I'm missing something in the pics but that hard bolt opening is a clear sign of something wrong.

Is that leakage around the primers??
An ejector mark on center round, center pic? (08)?

 

[Webster]

View attachment 985003 View attachment 985004 View attachment 985005
46.0 Varget 45.0 RL 15 47-39 CFE 223
I had a first time experience at the range. I had trouble opening the bolt after firing rounds. I fired 3 loads: 1, 45.0 gr RL 15, 168 AMAX; 2, 46.0 Gr Varget, 168 AMAX; 2, CFE 223 47.0 - 49.0 in .5 increments. All cases were once fired Federal, all primers were Fed 210. Cases in loads 1 & 2 were full length resized. Load 3 cases were once fired in my rifle, so were necked sized using Lee Collet die. Temp was 90 degrees. I had difficulty opening the bolt for all loads fired. The worst load was the RL 15 load, which is a max load. The Varget load is also am max load, but 1 I have been shooting for years, both in this rifle ( Marlin X7 308) and a Remington 700, with no problems. CFE 223 is a new load which I was working up. I figure it's 1 of 3 things too much pressure, bumping the shoulder too much in full length resizing, or a dirty chamber. cleaned the chamber while shooting Varget and it helped. I stopped shooting RL 15 after 3 rounds. Photos of the fired primers are attached. Any thoughts?

The Berger manual list 43.8 grains of Varget as a max load for their 168 gr bullet. Resize the cases and see if the bolt closes easily on an unloaded case, then try lighter loads. Your loading 45 & 46 grains. Back off 1 to 1.5 grains of RE15 and see if the problem goes away. Why do you think you have to shoot near max loads? Maybe it's a lot difference for the powder?

 

[Sniper338]

I dont have a book in fromt of me but it sounds like hot loads... add ambient heat and sun on the ammo and you get more pressure spikes

 

[dickn52]

I had a local SWAT team hand me about 500 cases of Fed Match that they used. They must have fire formed or something as I never got them into my Tikka. Ended up dismantling them and tossing them to a friend.

 

[ShootDots]

There are a few things to look at: 1.) Powder charge. I believe that they are a tad on the hot side. 2.) If you do not bump the shoulder back from 1.5 to 3.0 thousandths, you can, and in many cases, CAUSE pressure signs, even with loads not at max. 3.) various lots of powder, especially with Varget, can run W-A-Y slow, or at times, very fast, compared to most, for lack of better terminology, "Normal" lots. This is what I call a "stealth problem".. H4831 (Both regular and SC) along with Varget are prime candidates for this "hard to detect" problem..

 

[308Cajun]

My thoughts are the pictures do not really show, to my eyes, anything to be alarmed about.
HOWEVER, in this case words may speak more than pictures. Your 2nd sentence is the key. "I had trouble opening the bolt after firing rounds".
That's something. How much trouble? Real stiff or you had to get a mallet? Either way there is a problem. I see small cratering around the pin strike, but for me that's normal and would not concern me. Maybe I'm missing something in the pics but that hard bolt opening is a clear sign of something wrong.

Is that leakage around the primers??
An ejector mark on center round, center pic? (08)?

I didn't notice any leakage. A couple of the cases showed a very light " shiny spot, nothing definite. I quit shooting the RL 15 after 5 rounds. after the last RL shot, I had to let the gun sit, and was able to get it open.

PS. Velocities were about what I expected with both Varget (2680 - 2700 FPS), and CFe(2720 - 2750FPS). Surprisingly, the few rounds I shot with RL 15, which showed the most evidence of over pressure, were almost 100 FPS below the expected velocity with a 22" barrel- about 2600 FPS.

 

[308Cajun]

The Berger manual list 43.8 grains of Varget as a max load for their 168 gr bullet. Resize the cases and see if the bolt closes easily on an unloaded case, then try lighter loads. Your loading 45 & 46 grains. Back off 1 to 1.5 grains of RE15 and see if the problem goes away. Why do you think you have to shoot near max loads? Maybe it's a lot difference for the powder?

46.0 is the max in both the Hodgdon and Nosler data with cup and core bullets.. I would not be shooting this load with a Berger or any other monolithic bullet. i checked,and the bolt already closes easily on the UN sized cases that i fired yesterday. i think I will back don .5 - 1 grain on the Varget at least for the summer. I'm still working up the CFE 223. I'm through with RL 15. can't get any form anyone within 100 miles anyway.

 

[Webster]

46.0 is the max in both the Hodgdon and Nosler data with cup and core bullets.. I would not be shooting this load with a Berger or any other monolithic bullet. i checked,and the bolt already closes easily on the UN sized cases that i fired yesterday. i think I will back don .5 - 1 grain on the Varget at least for the summer. I'm still working up the CFE 223. I'm through with RL 15. can't get any form anyone within 100 miles anyway.

The ejector mark is a sure sign of over pressure, plus primer leakage. Backing down is the easiest thing to try before trying 5 other possible causes mentioned by others.

 

[GeorgeSpringer]

43 grains of either Varget or RL15 are max loads for me with 175 SMK's.

 

[fguffey]

bumping the shoulder too much in full length resizing,

How can returning a case to minimum length cause high pressure?

F. Guffey

 

[aloreman]

it doesnt cause pressure. it will cause extremely flat primers people read as pressure. the primer starts to come out just alittle and then the case moves back to the bolt smashing it flat

 

[fguffey]

it doesnt cause pressure. it will cause extremely flat primers people read as pressure. the primer starts to come out just alittle and then the case moves back to the bolt smashing it flat

the primer starts to come out just a little and then the case moves back to the bolt smashing it flat

There is this very pro·lif·ic poster that claims the firing pin strikes the primer and then the case, bullet and powder take off for the front of the chamber; and I disagreed and he has not been civil since, to me. And, now you are telling me the case moves back 'alittle' and smashes something. To avoid the risk having someone being uncivil to me I will try and say something about what I think. If the primer is driven back because it is not supported by the bolt face I would think the pressure inside the primer when it was not supported by the primer pocket caused the primer to expand. And now I wonder if there is anyone here that can imagine how fast this stuff happens.

And then there is all that case travel that seems impossible to keep up for most reladers, no me; I am the fan of cutting down on all that case travel.

F. Guffey

 

[Jose_Luis_G]

I agree with aloreman to what the shoulder is concerned.
I haven't read anyone asking for the lenght of the case.
Have you ever trimmed them? An abnormal extra long case can make the neck to get into the free bore, -or just come too close to it- so it will not allow the neck to expand properly, causing pressure signs and bolt blocking as well.

 

[Ned Ludd]

From what I can see in the pictures, it looks like you have some primer cratering and a few ejector marks. My guess is your load is on the hot side, how hot is hard to say without knowing more detail about your chamber/load specifics, the relative burn rate of your lot of Varget, etc. Knowing your velocity would give you a much better idea of where the load is, and also provide a good baseline for comparison of loads in the future. One other question is where in the bolt cycle did you feel difficulty with it? If it is near the end of the upstroke (i.e. above halfway up), that can sometimes mean the base of your cases isn't being sized back down sufficiently. In that case, a small base die may help alleviate the issue. However, I think in your case the most likely issue your load is simply too hot for the conditions.

 

[XBBR Shooter]

46.0 is the max in both the Hodgdon and Nosler data with cup and core bullets.. I would not be shooting this load with a Berger or any other monolithic bullet. i checked,and the bolt already closes easily on the UN sized cases that i fired yesterday. i think I will back don .5 - 1 grain on the Varget at least for the summer. I'm still working up the CFE 223. I'm through with RL 15. can't get any form anyone within 100 miles anyway.

There is this very pro·lif·ic poster that claims the firing pin strikes the primer and then the case, bullet and powder take off for the front of the chamber; and I disagreed and he has not been civil since, to me. And, now you are telling me the case moves back 'alittle' and smashes something. To avoid the risk having someone being uncivil to me I will try and say something about what I think. If the primer is driven back because it is not supported by the bolt face I would think the pressure inside the primer when it was not supported by the primer pocket caused the primer to expand. And now I wonder if there is anyone here that can imagine how fast this stuff happens.

And then there is all that case travel that seems impossible to keep up for most reladers, no me; I am the fan of cutting down on all that case travel.

F. Guffey

Sorry Mr. Guffey, but you are WRONG.

I was speaking to Richard Diaz (Chief Engineer at Remington) about some other topics some years back, and the subject of chamber dynamics came up - and with that, the force of primers.

He said that the force the primer exerts on the case (pushing the case forward) is approximately 700 pounds (NOT PSI, but real pounds).

i had a hard time believing that, so, I took a primed case and stood it in a stainless pot and put in on the stove - and lit the burner. I went into the next room until I heard an expected "BANG".

The result was a very deep dent in the 1/12th inch thick pot floor, and the case was embedded in the ceiling.
The primer does force the case/powder/and bullet forward, if there is any space in the chamber.
Once the pressure gets high enough, the case either stretches at the web (dry chamber), or the whole case slides back (if the chamber is wet), and squishes the extruded primer flat - that is why you can have flattened primers at the edge with low pressure, and without cratering.

 

[M-61]

From 308CAJUN:
"cleaned the chamber while shooting Varget and it helped."

Helped how? The bolt opened normally? Flattened primers and cratering are not definitive signs of 'too' high pressure. IMO the hard to open bolt is!
In your pic with Varget it looks like a good amount of cratering and since some above responses point to your load being on the high side you would expect it. But that hard to lift bolt is the killer for me.
Have you de-primed a case and tried to install a new primer to see if indeed the primer pocket has enlarged?

You said, " bumping the shoulder too much in full length resizing..."
Did these cases require to have the shoulder 'bumped?' As fguffey stated above about being a fan of cutting down on the case travel...well me too.
Arbitrarily 'bumping' the shoulder from one unknown length to another serves no purpose other than working the brass more and more.
In a bolt action target rifle I can see no reason to move that shoulder at all if the bolt closes nicely on a fired case. It is a perfect fit (thanks to 50,000+ psi) for MY chamber. Then again I am one who will neck size and neck size only enough to secure the particular bullet i am using.
The above is my opinion and what works for me in MY rifles.
Interesting that after you let the rifle cool the bolt functioned to your satisfaction. Bottom line there is a pressure problem that many have covered above.

 

[fguffey]

I was speaking to Richard Diaz (Chief Engineer at Remington) about some other topics some years back, and the subject of chamber dynamics came up - and with that, the force of primers.

I had no ideal you were going to be name dropping on me, Richard Diaz! Again he said the firing pin drove the case, powder and bullet to the front of the chamber and I said "I disagree". And no one spoke up; all they did was spread this 'repeat after me' on all forums. Again, I said I had killer firing pins, I said my firing pins crushed the primer before the case, bullet and powder knew their little buddy, the primer had been crushed. And then there is the assumption the case stretches and I always ask: How can a reloader determine of the case ran to the front of the chamber and back again as you describe?




And then at the end you added the part about the case being wet. So; it is not likely the case takes off for the rear of the chamber and smashes the primer and if the primer backs out it is more likely the appearance of the primer is caused by the primer not being supported in the primer pocket because it backed out and then someone should wonder why the primer is not being supported by the bolt face.
Once the pressure gets high enough, the case either stretches at the web (dry chamber), or the whole case slides back


Click to expand...

Once the pressure gets high enough, the case either stretches at the web (dry chamber), or the whole case slides back (if the chamber is wet), and squishes the extruded primer flat.

I would suggest your call Richard Diaz (Chief Engineer at Remington) and ask him if he can think of another option. I said I disagreed with the firing pin thing driving the case forward, I could never get the
pro·lif·ic poster on many forums to consider the primer, it was always the firing pin and nothing happened until the shoulder of the case contacted the shoulder of the chamber and that put the shoulder of the case at the shoulder of the chamber ever time and that left clearance between the case head and bolt face and that does not happen ever time but when it does the case has no choice but to stretch between the case body and case head; unless someone greased their bullets.

Sorry Mr. Guffey, but you are WRONG.

I disagree.

F. Guffey

 

[LHSmith]

Are you sure the engineer was not Richard Dietz, who took over after Jim Stekl who took over after Mike Walker?