Action Strength
- Thread starter jackie schmidt
- Start date
jackie schmidt
New member
Heat Treat
That is the last place I wanted to go. Is the action simply not as strong as other actions??. Stiff bolt lift from the get go is usually a sign that the action is stretching further than the brass spring back. Of course, we all know that the first response by many is, "you should not be shooting the 6PPC at 3400 fps".
This is the first Chrome Moly Benchrest Action I have owned. (not counting my old originol 40x). I am sure that there are multitudes out there who have the exact same action and are experiencing no problems.
But, I called Cecil Tucker, and he told me that a very good friend, and prominant shooter, had the exact same problem, with the same action. What they finally did was apply fine lapping compound to the bolt, and lap the darned thing untill it had a little more clearance. (these actions are known for their very close bolt to action body fit). The problem was cured, and as a plus, the thing stopped spitting shots.
His theory was that the entire action sort of "bound up" when fired, not allowing things to work as they should. Or, at least, that is his best guess.
When I get back from the Bluebonnet, I will probably try that.
That all being said, I can't believe I am the only Benchrest Shooter who is having this problem. As I said before, none of my other actions do this, and all of my friends, who shoot the exact same combination in other brands, have no problems.
That is one reason I openned this discussion. Are there others who are having the same problems?? ..........jackie
That is the last place I wanted to go. Is the action simply not as strong as other actions??. Stiff bolt lift from the get go is usually a sign that the action is stretching further than the brass spring back. Of course, we all know that the first response by many is, "you should not be shooting the 6PPC at 3400 fps".
This is the first Chrome Moly Benchrest Action I have owned. (not counting my old originol 40x). I am sure that there are multitudes out there who have the exact same action and are experiencing no problems.
But, I called Cecil Tucker, and he told me that a very good friend, and prominant shooter, had the exact same problem, with the same action. What they finally did was apply fine lapping compound to the bolt, and lap the darned thing untill it had a little more clearance. (these actions are known for their very close bolt to action body fit). The problem was cured, and as a plus, the thing stopped spitting shots.
His theory was that the entire action sort of "bound up" when fired, not allowing things to work as they should. Or, at least, that is his best guess.
When I get back from the Bluebonnet, I will probably try that.
That all being said, I can't believe I am the only Benchrest Shooter who is having this problem. As I said before, none of my other actions do this, and all of my friends, who shoot the exact same combination in other brands, have no problems.
That is one reason I openned this discussion. Are there others who are having the same problems?? ..........jackie
That's interesting Jackie. Heck, I think I had that exact same problem and didn't know it. I had one that seemed to be very hard to open and didn't shoot well HOT. I had a 22-.100 short barrel on it. Now that you mention it, I polished the bolt body because after coming back from a match that it had rained, I either forgot or didn't get enough oil on the bolt body and it has a very fine surface rust. After polishing, the first thing I noticed was the bolt sliding easier but never put 2 and 2 together because I never had problems after that with going HOT with other barrels, I just figured that the one barrrel (first one on the action) was a little tighter in the bore and caused higher pressures. Maybe it was exactly what your saying. Hmmmm
Hovis
Hovis
Boyd Allen
Active member
Jackie,
It might be a good idea to measure the bolt clearance of both actions before you do anything.
Boyd
It might be a good idea to measure the bolt clearance of both actions before you do anything.
Boyd
JerrySharrett
Senile Member
Remember, Chrome Moly steels (SAE 4140, 4150, etc) in certain heat treated conditions make a great spring. That is another feature I feel makes the Stolle Panda is the superior benchrest action. Its body is aluminum, a material that absorbs and deadens vibrations. In the benchrest platform any vibration induced and not attenuated is just another contributor to inaccuracy.
D
Donald
Guest
The Viper Actions are also aluminum. The drop port is the best thing since sliced bread.
Donald
Donald
J
j mckinnie
Guest
And
the inserts in the alloy actions are WHAT???
the inserts in the alloy actions are WHAT???
jackie schmidt
New member
McKinnie
They are either Stailess Steel, probably 17-4 or 416, or Chrome Moly, probably 4140, tempered at a suitable level of hardness..........jackie
They are either Stailess Steel, probably 17-4 or 416, or Chrome Moly, probably 4140, tempered at a suitable level of hardness..........jackie
I
IndianaJames
Guest
Jackie: I know of an action identical to yours that had similar issues. It was remedied by recutting the barrel threads for more clearance. After doing this, the bolt lift was easy up until the primer pockets rattled loose.
Not sure where you're at with thread loading, etc. so this may or may not be applicable. I know you're a proponent of loading the barrels tight against the shoulder. On the action I'm speaking about, the other change was from around 125-135 lb/ft. torque to just a firm 'snap' with the action wrench. Both these things were done at the same time.
For what it's worth........ -Al
Not sure where you're at with thread loading, etc. so this may or may not be applicable. I know you're a proponent of loading the barrels tight against the shoulder. On the action I'm speaking about, the other change was from around 125-135 lb/ft. torque to just a firm 'snap' with the action wrench. Both these things were done at the same time.
For what it's worth........ -Al
Interesting fix.
C'mon Stan, tell us why.
Anyone have any idea WHY this would work? What it would remedy/change? I'm having trouble imagining the reason. And all my visualizations that do work are detrimental to accuracy.....
al
M
mks
Guest
Interesting fix.
C'mon Stan, tell us why.
Anyone have any idea WHY this would work? What it would remedy/change? I'm having trouble imagining the reason. And all my visualizations that do work are detrimental to accuracy.....
al
Some wild ideas. First, maybe the recut barrel threads caused the chamber to be better aligned with the bolt. This might happen if the new threads were more coaxial with the chamber than the original ones. Second, if the original threads were very tight, it could cause some compression of the chamber diameter that cutting looser threads would relieve.
Third, the lighter barrel tension might reduce asymmetrical stresses in the action. Say the action was glued into the stock without the barrel attached, or attached with low torque. Then the glue/stock would resist the compression of torque-up on the bottom of the action, but not on the top, resulting in bending of the action. Less torque = less bending.
I'm not sure how likely any of these is. But, hey, you didn't say you wanted GOOD ideas!
Cheers,
Keith
Bob Kingsbury
New member
If recutting the threads and installing it with a snap solved the
problems, The barrel was not installed right to begin with. I have seen
more than one where the barrel was not shouldered up right
problems, The barrel was not installed right to begin with. I have seen
more than one where the barrel was not shouldered up right
Last edited:
Bob, the person that did the 'remedy' wasn't the original barrel fitter...so I don't know the particulars of the original installation. The chamber wasn't recut during the fix. My gut tells me the install torque wasn't a factor. I simply mentioned it because these two things were the only changes made.
I'm not a professional machinist, not advocating this as a fix, not going to put forth my own theory on why it worked. It's a sample of one and that's a darn poor number for anyone to draw conclusions from.
End of story on my part.
-AlDavid Halblom
Flying Fish Fundamentals
Jackie, if
you try the fix, please post results. If it is a "fix" that is one to keep in the "if all else fails" file
Bob, the person that did the 'remedy' wasn't the original barrel fitter...so I don't know the particulars of the original installation. The chamber wasn't recut during the fix. My gut tells me the install torque wasn't a factor. I simply mentioned it because these two things were the only changes made.
I'm not a professional machinist, not advocating this as a fix, not going to put forth my own theory on why it worked. It's a sample of one and that's a darn poor number for anyone to draw conclusions from.
End of story on my part.
you try the fix, please post results. If it is a "fix" that is one to keep in the "if all else fails" file
For what this is worth: Based on the thread thus far, which has not identified the OEM, I suspect that the best route for resolution, should you run into this problem, is to PM Jackie or one of the other poster's who indicated they had knowledge of the problem or a solution. I highly doubt that the OEM will be named on a public forum that is indexed by Google.
-- Stephen
Jackie
I'm certain that I can tell you what's going on, and unfortunatley, it's more of a design flaw. Something that most people don't understand is modules of elasticity. The hardness of steel does not change this, nor does the alloy have much effect. When steel is hardened, it simply will bend further without taking a set. Soft steel bends with the same force as hardened steel, but can't bend as far as hardened steel without staying bent. That said, a soft action WILL stretch the same amount as a hardened action under bolt thrust, and they will both contract the same. The soft action will develope headspace only from wear. If the soft action developes headspace by stretching, it will do so with each shot, and the headspace will become excessive very fast. This is NOT the problem you are having. Your problem is NOT from the alloy used or from it's hardness, because I doubt you have had an increase in headspace.
Now I know everybody may want to jump on me and argue this point. You want to tell me that a 1/4" drill blank at hardness of 64C will be stiffer than a piece of 1/4" cold rolled steel. This is false. It is not. The harder steel only has the better ability to return to straight than the softer steel after both have been deflected by the same amount. An example would be this. Hardened steel bent to far will break, and soft steel bent to far will stay bent.
Problems arise when the sectional area of the locking lugs and front receiver ring have been reduced. By this I mean the sectional area of the steel that stretches under bolt thrust. This would be locking lug deflection on the bolt, and receiver ring stretch that occurres in the section between the lug area and the back of the barrel.
An example would be a Remington action has a diameter of 1.350". This is the diameter of the insert in a Stolle action, so strenght is similar. Any action that has a reduced diameter cannot handle as much thrust without bolt loading. Many actions have diameters that have been reduced. This is okay as long as the pressures are along the lines of factory loaded ammo, or the case head diameter is reduced. Obviously a .223 has much less thrust than a PPC for two reasons. One is the increased area inside the case head of the PPC. The other is the much higher pressures that can be obtained with the PPC brass over the .223.
Several measurements are required to determine how much stretch is going on when bolt thrust occurres at firing. The more stretch that occurres, the stiffer the bolt lift.
Michael
I'm certain that I can tell you what's going on, and unfortunatley, it's more of a design flaw. Something that most people don't understand is modules of elasticity. The hardness of steel does not change this, nor does the alloy have much effect. When steel is hardened, it simply will bend further without taking a set. Soft steel bends with the same force as hardened steel, but can't bend as far as hardened steel without staying bent. That said, a soft action WILL stretch the same amount as a hardened action under bolt thrust, and they will both contract the same. The soft action will develope headspace only from wear. If the soft action developes headspace by stretching, it will do so with each shot, and the headspace will become excessive very fast. This is NOT the problem you are having. Your problem is NOT from the alloy used or from it's hardness, because I doubt you have had an increase in headspace.
Now I know everybody may want to jump on me and argue this point. You want to tell me that a 1/4" drill blank at hardness of 64C will be stiffer than a piece of 1/4" cold rolled steel. This is false. It is not. The harder steel only has the better ability to return to straight than the softer steel after both have been deflected by the same amount. An example would be this. Hardened steel bent to far will break, and soft steel bent to far will stay bent.
Problems arise when the sectional area of the locking lugs and front receiver ring have been reduced. By this I mean the sectional area of the steel that stretches under bolt thrust. This would be locking lug deflection on the bolt, and receiver ring stretch that occurres in the section between the lug area and the back of the barrel.
An example would be a Remington action has a diameter of 1.350". This is the diameter of the insert in a Stolle action, so strenght is similar. Any action that has a reduced diameter cannot handle as much thrust without bolt loading. Many actions have diameters that have been reduced. This is okay as long as the pressures are along the lines of factory loaded ammo, or the case head diameter is reduced. Obviously a .223 has much less thrust than a PPC for two reasons. One is the increased area inside the case head of the PPC. The other is the much higher pressures that can be obtained with the PPC brass over the .223.
Several measurements are required to determine how much stretch is going on when bolt thrust occurres at firing. The more stretch that occurres, the stiffer the bolt lift.
Michael
jackie schmidt
New member
Michael
I have a feeling that this is exactly what is going on, mainly because I have quite a few e-mails from shooters who are having the exact same problem, with this same action.
The main problem is "why". This action shares the same basic "1 3/8" body diameter that seems to be the industry standard in round, 2-lug Benchrest Actions. It is manufactured from some type of Chrome Moly steel, while it might have a few proprietary alloy features, I feel safe in saying that it has about the same properties as a piece of 4140 at about 32-34 RC.
This is all standard fare. Nothing special. Nothing out of the ordinary. So why is there a bolt openning problem in this particular action when there are thousands out there of the same basic design that have no problems to speak of??
Some of the "fixes" that have been suggested are solutions to a problem that should not exist. Let's face it, if you have to resort to doing "special" things to a particular piece of equipment just to get it to function as it should, then the piece of equipment probably isn't worth messing with.
Michael, if you get a moment, give me a call at (832) 689-4157.......jackie
I have a feeling that this is exactly what is going on, mainly because I have quite a few e-mails from shooters who are having the exact same problem, with this same action.
The main problem is "why". This action shares the same basic "1 3/8" body diameter that seems to be the industry standard in round, 2-lug Benchrest Actions. It is manufactured from some type of Chrome Moly steel, while it might have a few proprietary alloy features, I feel safe in saying that it has about the same properties as a piece of 4140 at about 32-34 RC.
This is all standard fare. Nothing special. Nothing out of the ordinary. So why is there a bolt openning problem in this particular action when there are thousands out there of the same basic design that have no problems to speak of??
Some of the "fixes" that have been suggested are solutions to a problem that should not exist. Let's face it, if you have to resort to doing "special" things to a particular piece of equipment just to get it to function as it should, then the piece of equipment probably isn't worth messing with.
Michael, if you get a moment, give me a call at (832) 689-4157.......jackie
M
MarkR
Guest
"Hardness"...as in Rockwell hardness and modulous of elasticity are two quite different animals.
D
Donald
Guest
Sure would be nice to know what the brand name of the suspect action is, but I suspect that is not going to happen.
Donald
Donald