Anyone use the roller bearing on their 2 lug BAT bolt?
- Thread starter DSM
- Start date
Bill Gammon
New member
I have a roller bearing Bat DS action and have "NOT" a bit of a problem with it. Advantages, I don't know, disadvantages, I don't know, problems, none. Hope this helps!
DSM,
I have nine BAT model M two-lug actions. None have the rolling-bearing on the cocking piece. They still are all smoother than any other action that I have used (several over the past 16 years).
It is my understanding that the roller bearing modification started out as a way to make the three-lug actions open with less effort. When the three-lug first came out there was much discussion about doing the same bolt-lift effort with 2/3 of the travel. The roller-bearing seemed to alleviate that issue. They were being put on the two-lugs at customer (and Dwight's) request.
I believe what makes the two-lug work smoother is having the action timed correctly so that there isn't excessive cocking on closing: along with having your dies properly match the chambering. This comes from having the firing pin travel somewhere around .220. More gives you cocking on closing of the bolt and less smooth bolt opening. Less than this gives you inconsistent ignition. I just had a new 1.370 Model M built that wouldn't shoot until I replaced the trigger hanger to give me 2.19 of travel and it now becomes a barrel-tuning exercise rather than a gun-fixing exercise. I believe that having the action correctly timed and having your dies properly fit the chamber make these actions the smoothest on the planet; with or without the roller bearing. Before you take your rifle out of service to have the cocking piece replaced, you may wish to try the timing on the action first. (I would also have a very competent gunsmith install the tungsten firing pin weight to remove any doubt about good ignition.)
The BAT DS and the newer model M's that are the 1.370 diameter come with two trigger hangers that can be used to adjust the firing pin travel. The older M's or those with a fatter action body can only be adjusted by moving the cocking piece on the firing pin body (somewhat tricky) or locating a trigger that gives you near .220 of travel (an adventure in trigger hunting). All of my BATs are either 1.470 or 1.550 diameter, thus my constant search for the older Jewel triggers
I have nine BAT model M two-lug actions. None have the rolling-bearing on the cocking piece. They still are all smoother than any other action that I have used (several over the past 16 years).
It is my understanding that the roller bearing modification started out as a way to make the three-lug actions open with less effort. When the three-lug first came out there was much discussion about doing the same bolt-lift effort with 2/3 of the travel. The roller-bearing seemed to alleviate that issue. They were being put on the two-lugs at customer (and Dwight's) request.
I believe what makes the two-lug work smoother is having the action timed correctly so that there isn't excessive cocking on closing: along with having your dies properly match the chambering. This comes from having the firing pin travel somewhere around .220. More gives you cocking on closing of the bolt and less smooth bolt opening. Less than this gives you inconsistent ignition. I just had a new 1.370 Model M built that wouldn't shoot until I replaced the trigger hanger to give me 2.19 of travel and it now becomes a barrel-tuning exercise rather than a gun-fixing exercise. I believe that having the action correctly timed and having your dies properly fit the chamber make these actions the smoothest on the planet; with or without the roller bearing. Before you take your rifle out of service to have the cocking piece replaced, you may wish to try the timing on the action first. (I would also have a very competent gunsmith install the tungsten firing pin weight to remove any doubt about good ignition.)
The BAT DS and the newer model M's that are the 1.370 diameter come with two trigger hangers that can be used to adjust the firing pin travel. The older M's or those with a fatter action body can only be adjusted by moving the cocking piece on the firing pin body (somewhat tricky) or locating a trigger that gives you near .220 of travel (an adventure in trigger hunting). All of my BATs are either 1.470 or 1.550 diameter, thus my constant search for the older Jewel triggers
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I know I'm hijacking the thread a bit, but...
Thanks, Joe. A couple questions: The extra smoothness you're getting is just from not having any cock-on-close, right? Or does the .220 fall affect the rotational effort in opening the bolt? Just because I can't see how doesn't mean it isn't there.
That means, if I were willing to give up a bit of "bolt close smoothness," I could use cock-on-close for a bit more ignition. You seem to have everything working well, and at one level, that's all one needs.
But as I remember, Phil Bower (4Mesh) got his best results with a little more pin travel, achieved by a little more cock-on-close. This was with a big BAT, I believe a 10-inch.
I, for one, still don't have all the compromises for improved ignition straight in my head, in part because even the engineers can't seem to tell us just which formula best expresses what we're after. Seems you can't just substitute amongst weight, fall, and spring pressure all that easily.
Makes me remember those hand-cocking .22s we had when I was a kid. Bolt action. After you closed the bolt, you just pulled back on the cocking piece. Yeah, one more hand motion & takes time, but cheap, & if you cared, easily adjustable for just about everything.
Anyway, does the timing you're taking about just affect closing effort?
Thanks, Joe. A couple questions: The extra smoothness you're getting is just from not having any cock-on-close, right? Or does the .220 fall affect the rotational effort in opening the bolt? Just because I can't see how doesn't mean it isn't there.
That means, if I were willing to give up a bit of "bolt close smoothness," I could use cock-on-close for a bit more ignition. You seem to have everything working well, and at one level, that's all one needs.
But as I remember, Phil Bower (4Mesh) got his best results with a little more pin travel, achieved by a little more cock-on-close. This was with a big BAT, I believe a 10-inch.
I, for one, still don't have all the compromises for improved ignition straight in my head, in part because even the engineers can't seem to tell us just which formula best expresses what we're after. Seems you can't just substitute amongst weight, fall, and spring pressure all that easily.
Makes me remember those hand-cocking .22s we had when I was a kid. Bolt action. After you closed the bolt, you just pulled back on the cocking piece. Yeah, one more hand motion & takes time, but cheap, & if you cared, easily adjustable for just about everything.
Anyway, does the timing you're taking about just affect closing effort?
Charles E.
My newly-acquired under-acheiver was throwing shots at .239 of pin fall. It had noticeable cocking on close and was more resistant when opeing the bolt than when it got moved to the .219 fall. It had the Jewel trigger in the hagger with the .030 showing on the front of the left side of the hanger. I put the .010 hanger in showing the number on the front left side of the hanger and the gun started to shoot with no shot-pitching and the bolt lift was more smooth and much like my other well-performing rifles. It seems like the correct setting is with no cock on close for my rifles, which have the 7 1/2 bolt. Can't speak for the engineering behind it. What I see on the target is what guides my thought process. (I'm too mentally slow for all that engineering.)
I had other BAT rifles not shoot well with .195 to .210 of fall and became performers when it went to the .220 mark. That being said, other actions seem to also have a "relevent range" where the correct fall gives the best compromise of performance and bolt lift. The Pandas that I had worked best at .230 of fall. I once had one that was schizophrenic with another brand of trigger that showed .280 of fall. When I put a Jewel into the rifle and it showed .230 of fall, alll of a sudden it looked like the gun was on the correct amount of Prozac; go figure.
My newly-acquired under-acheiver was throwing shots at .239 of pin fall. It had noticeable cocking on close and was more resistant when opeing the bolt than when it got moved to the .219 fall. It had the Jewel trigger in the hagger with the .030 showing on the front of the left side of the hanger. I put the .010 hanger in showing the number on the front left side of the hanger and the gun started to shoot with no shot-pitching and the bolt lift was more smooth and much like my other well-performing rifles. It seems like the correct setting is with no cock on close for my rifles, which have the 7 1/2 bolt. Can't speak for the engineering behind it. What I see on the target is what guides my thought process. (I'm too mentally slow for all that engineering.)
I had other BAT rifles not shoot well with .195 to .210 of fall and became performers when it went to the .220 mark. That being said, other actions seem to also have a "relevent range" where the correct fall gives the best compromise of performance and bolt lift. The Pandas that I had worked best at .230 of fall. I once had one that was schizophrenic with another brand of trigger that showed .280 of fall. When I put a Jewel into the rifle and it showed .230 of fall, alll of a sudden it looked like the gun was on the correct amount of Prozac; go figure.
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I concur with Joe after what I witnessed at my last match at Holton. Joe took it upon himself to approach me and take a look at my gun. It wasn't shooting real poor but had me scratching my head saturday and sunday morning with the missing shot every group. We went from the .030 to .020 hanger and the rifle came alive. Sure wished he would have caught that saturday morning.
Thanks again Joe.
Hovis
Thanks again Joe.
Hovis
Steelhead1
G Vanlier
Now you guys have got my attention I need some help with this particular issue! I have a Bat 3 Lug Sv Multi flat that since it was built in 07 just never seems to do well and I have often wondered about bolt timing and how it affects accuracy. I have not had the opportunity to have a really good mentor and rely on a try it and see if it works methodology. My rifle was built by a top notch shooter in Phoenix and I never complained to him or asked him about whether or not he times the bolt, so thats my fault. But how do I go about timing the bolt or is this something best left to someone like Dwight Scott, who built the Teddy heavy gun I have with no problems. Can this roller bearing be installed on my 3 lug because that is another issue I have with it is hard bolt lift, I also occasionally have problems with the bolt during closing in that it seems like the round cant's a little and hangs up, so you have to pull the biolt back a bit push the roumd up a little bit and then the bolt closes ok!
Sorry Skeet I am not trying to steal your thread but this is something I feel needs to be corrected! I also chamber and thread my own barrels so I do have some skills if someone would explain the sequence of how timing is accomplished.
Sorry Skeet I am not trying to steal your thread but this is something I feel needs to be corrected! I also chamber and thread my own barrels so I do have some skills if someone would explain the sequence of how timing is accomplished.
I will post one in about two weeks when I receive my action.
mark roper
Member
Joe, when you say older Jewell, how old?
I think the round hanging up as it feeds into the chamber causing you to pull the bolt back slightly is caused by the ejector being a wee bit long and the rim of the case is catching on the ejector. I had this problem with my Bat B..........Ian
I like the M's for two reasons: 1) my first BAT/Scoville (which may have been THE first BAT/Scoville by my discussions with Bob Scoville), was an 1.470 M with the 7 1/2 bolt. It still shots better than I can. I think that Bob used that action because he was able to take quite a bit of weight out of the stock and not loose rigidity. And 2) I do believe that a rigid action is better. Even if it is simply in my head, it is MY head that I'm using during shooting and not some other guys' ideas that I haven't witnessed on a target.
Mark, I am a trigger collector. And the reason is that I do change guns a lot and my belief is that ignition (both timing and firing pin momentum) have a great impact on how these animals work. I have some older ones that Arnold made early on and some other ones that were made in the mid 1990's. I also think that the ones today, when properly worked on, are as good as any out there when the timing is good. They are like the HR department at work: they can't help you, but they sure can hurt you.
One thing to be very careful of: If you don't really know your gunsmith well (not a good thing in Benchrest), be very careful of sending your gun to someone with a valued trigger in it. I have seen guns come back with a different trigger in it. And then the gunsmith doesn't know what you are talking about. I trust the couple of guys who I use for smithing, but you just don't know what goes through some guys' heads.
I think that checking for cocking on close is as simple as watching closely if the cocking piece drops (not enough fall) or moves backwards (too much fall) as the bolt handle is closed. This is adjusted with either a trigger hanger or a different trigger. I check the amount of fall with a coarse measurement using a dial caliper (the skinny rod that comes out the end away from the dial) against the cocking piece and indexed against the back of the action. Zero the measurement when it is cocked and then see what the measurement is after you pull the trigger (on a EMPTY chamber). There are other aspects of action timing like how does the fired round get out of a microport (or IF it does), but that is more to do with the type of extractor, the ejector plunger extension and tension and even as simple as where the port is located. Too much technology for this thread (and my meager engineering knowledge).
I don't know much about SV's and three-lugs. I've had both and have seen them shoot. Bukys uses three-lugs and his record speaks for itself. Tony started (or restarted) the craze in trying to duplicate his old Wichita action a few years ago, but I believe that he is shooting a two-lug today along with his many-times reworked Hart HV and a Stiller action on his rail gun. I do believe that firing pin momentum is important and the 6 1/2's don't have the same momentum as the 7 1/2's. And you can't do as much with springs and harmonics as you can with shear mass. Again, this is just my opinion; but, I am not an experimenter and I try and use what works in my system more so than what some guys who overthink some of this stuff may be trying to sell you. I use what the Big Boys use and spend my time tuning the gun and reading the flags.
I would rather just get the gun working without overthinking it and let it alone. Simple is often better than "latest and greatest". Then I can spend what limited time I have on the variables that seem to make us shoot better.
Mark, I am a trigger collector. And the reason is that I do change guns a lot and my belief is that ignition (both timing and firing pin momentum) have a great impact on how these animals work. I have some older ones that Arnold made early on and some other ones that were made in the mid 1990's. I also think that the ones today, when properly worked on, are as good as any out there when the timing is good. They are like the HR department at work: they can't help you, but they sure can hurt you.
One thing to be very careful of: If you don't really know your gunsmith well (not a good thing in Benchrest), be very careful of sending your gun to someone with a valued trigger in it. I have seen guns come back with a different trigger in it. And then the gunsmith doesn't know what you are talking about. I trust the couple of guys who I use for smithing, but you just don't know what goes through some guys' heads.
I think that checking for cocking on close is as simple as watching closely if the cocking piece drops (not enough fall) or moves backwards (too much fall) as the bolt handle is closed. This is adjusted with either a trigger hanger or a different trigger. I check the amount of fall with a coarse measurement using a dial caliper (the skinny rod that comes out the end away from the dial) against the cocking piece and indexed against the back of the action. Zero the measurement when it is cocked and then see what the measurement is after you pull the trigger (on a EMPTY chamber). There are other aspects of action timing like how does the fired round get out of a microport (or IF it does), but that is more to do with the type of extractor, the ejector plunger extension and tension and even as simple as where the port is located. Too much technology for this thread (and my meager engineering knowledge).
I don't know much about SV's and three-lugs. I've had both and have seen them shoot. Bukys uses three-lugs and his record speaks for itself. Tony started (or restarted) the craze in trying to duplicate his old Wichita action a few years ago, but I believe that he is shooting a two-lug today along with his many-times reworked Hart HV and a Stiller action on his rail gun. I do believe that firing pin momentum is important and the 6 1/2's don't have the same momentum as the 7 1/2's. And you can't do as much with springs and harmonics as you can with shear mass. Again, this is just my opinion; but, I am not an experimenter and I try and use what works in my system more so than what some guys who overthink some of this stuff may be trying to sell you. I use what the Big Boys use and spend my time tuning the gun and reading the flags.
I would rather just get the gun working without overthinking it and let it alone. Simple is often better than "latest and greatest". Then I can spend what limited time I have on the variables that seem to make us shoot better.
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Boldface added.
Hmm. Remember Jerry Hensler's post a while back? We need both experimenters and competitors. One kind discovers, one kind proves out. Hard to find both in one person, but boy, when you do... The boldface is for "don't be so cynical, just be selective." Anyhow, that's my sales pitch.
Personally, I'd try anything Jerry (among others) thought worth doing, whether the big boys had picked up on it or not.
Speaking of the big boys--
Another hmmm. I case you've not looked recently, you're one of 'em. HOF, WBC, etc.
Cheers,
Charles
Don't get me wrong, we need experimenters. Without them, we don't have carbon fiber stocks, advances in optics, Heck even the PPC. I'm not one; I'm what we call here in the automotive industry a "Fast Follower". Actually, most of the Big Boys are fast followers. But, they are also not going to continue down a path that doesn't get them to shoot better, quicker than the competition. I call it "riding a slow horse into mediocrity".
I haven't been at one rifle match ever where everyone there wasn't trying to shoot better. I get 20 questions every match about what could help them shoot better. And I get offers to buy my equipment darn near every week. My biggest concern is that when somebody who doesn't have your best interest at heart tells you how the latest and greatest is kicking ass, and then you throw YOUR time, energy and money to follow an idea that hasn't been tested in the crucible of competition, who ends up taking the beating if it doesn't work?
As far as being one of the Big Boys, that is ancient history. When I chased points, there was quite a cost in terms of time, energy, money and my family. And I have a basement full of unusable "science projects". If I can shed some small ray of light from that experience on a problem that keeps someone from going down the wrong path, that is more important to me today.
That being said, I would set the trigger timing so that your BAT doesn't cock on close, or loose fall on close. I'd do it before I'd send a bolt to someone or back to BAT to install a roller bearing. If that doesn't make things smoother, then you have a next step to try.
I haven't been at one rifle match ever where everyone there wasn't trying to shoot better. I get 20 questions every match about what could help them shoot better. And I get offers to buy my equipment darn near every week. My biggest concern is that when somebody who doesn't have your best interest at heart tells you how the latest and greatest is kicking ass, and then you throw YOUR time, energy and money to follow an idea that hasn't been tested in the crucible of competition, who ends up taking the beating if it doesn't work?
As far as being one of the Big Boys, that is ancient history. When I chased points, there was quite a cost in terms of time, energy, money and my family. And I have a basement full of unusable "science projects". If I can shed some small ray of light from that experience on a problem that keeps someone from going down the wrong path, that is more important to me today.
That being said, I would set the trigger timing so that your BAT doesn't cock on close, or loose fall on close. I'd do it before I'd send a bolt to someone or back to BAT to install a roller bearing. If that doesn't make things smoother, then you have a next step to try.
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