Firing pin spring pressure in Bat Neuvo

jackie schmidt

jackie schmidt

New member
I built a HV on a Bat Neuvo. It shoots quite well.

One thing I checked was the firing pin drop and spring static pressure. The firing pin drop is fine, around .220 inch. The spring pressure seems a tad light, I checked it at 18 pounds.

On a whim, I stripped the firing pin assy, and machined a thick enough spacer to get it between 23/24 pounds.

It sure sounds better. Before it had a clanky sound, after a nice crisp snap. I am going to test it this week end.

The best way I found to get the two small set screws that lock the firing pin in the cocking piece is to soak the shroud assembly in penetrating oil, then warm it with a air heat gun. They are put in tight with locking compound.

By the way, it took a .190 inch thick spacer to get the fall from 18 to 24 pounds.
 
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tim said:
Maybe.....you want to call Chris or Dwight on that perhaps.
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Every action I have ever had shot better with at least 22 pounds of static pressure. If it shoots worse, I can simply take the spacer out.

One thing I thing they should do with the Neuvo is make one for a true HV or Rail Gun by doing away with the lightning scallops on the side and the cut away on the bottom. I understand that all of this is performed on a CNC program, it would be difficult to do it for a single ordered action.

I’m thinking of ordering one for my rail in drop port.
 
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jackie schmidt said:
Every action I have ever had shot better with at least 22 pounds of static pressure. If it shoots worse, I can simply take the spacer out.
Click to expand...

Only reason I mentioned it is that if you believe all the info on it, much of the concept seemed directed at ignition. Is it possible an iffy spring slipped under the radar ?
Like you said, not tough to swap back.
 
seems like i read a post from Chris Harris where they were testing pretty light springs with good results
im talkin 5lbs ive searched and cant find it now
 
Tim Singleton said:
seems like i read a post from Chris Harris where they were testing pretty light springs with good results
im talkin 5lbs ive searched and cant find it now
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5 lbs? I'm not sure that would fire a primer.

i have cured more than one erratic shooting Rifle by increasing the pin travel and giving it no less than 22 lbs of static pressure. Early Farleys were some of the worst.

Years ago, a good friend had a brand new Farley Rifle built. The first time he brought it to the range, it was super smooth and slick, you could just flip that bolt open with your finger. Everybody marveled at the workmanship.

The problem was you could not make two bullets touch. He was convinced the barrel was bad. We took the Rifle to my shop where I offset drilled the trigger hanger and bushed it back for the 1/8 hanger pins. This moved the trigger back to give the firing pin at least .220 inch travel. I then machined a spacer to give it at least 22 lbs of static spring pressure, which will be about 28 pounds in cocked position.

The first group he fired after these mods was a mid "one", the Rifle suddenly became a real shooter.

In my opinion, one of the reasons Pandas shoot so well out of the box is Kelbly builds them with a substantial firing pin travel and 23+ pounds of static spring pressure.
 
jackie schmidt said:
5 lbs? I'm not sure that would fire a primer.

i have cured more than one erratic shooting Rifle by increasing the pin travel and giving it no less than 22 lbs of static pressure. Early Farleys were some of the worst.

Years ago, a good friend had a brand new Farley Rifle built. The first time he brought it to the range, it was super smooth and slick, you could just flip that bolt open with your finger. Everybody marveled at the workmanship.

The problem was you could not make two bullets touch. He was convinced the barrel was bad. We took the Rifle to my shop where I offset drilled the trigger hanger and bushed it back for the 1/8 hanger pins. This moved the trigger back to give the firing pin at least .220 inch travel. I then machined a spacer to give it at least 22 lbs of static spring pressure, which will be about 28 pounds in cocked position.

The first group he fired after these mods was a mid "one", the Rifle suddenly became a real shooter.

In my opinion, one of the reasons Pandas shoot so well out of the box is Kelbly builds them with a substantial firing pin travel and 23+ pounds of static spring pressure.
Click to expand...
finally found it
actually it was in a reply to one of your posts
http://benchrest.com/showthread.php?98087-Bat-Nuevo-BR-PPC-Boltface-Extraction-Ejection-Question
 
jackie schmidt said:
By static, I mean the spring in the uncocked position.

Here is a picture. It's not as exact as having a dedicated instrument, but with practice, you can get things pretty close. At the very least, you can tell how much you increased, or decreased the spring.
Click to expand...

So, the "weight" at which the spring starts to compress is the approximate static pressure?
 
Hunter said:
So, the "weight" at which the spring starts to compress is the approximate static pressure?
Click to expand...


I wouldn't call it "weight" nor is it very approximate....... altho Jackie's measuring method is a liddle approximate, it's still brilliant. And an accurate description.

Picture a spring.....

it's got a foot of travel an it takes 50lb to fully compress it, bottom it out.

Now put a 25lb weight on it.

Where the weight stops is "25lb static pressure"

Turning the apparatus sidewise doesn't change any of the descriptors IMO.
 
Wayne Shaw said:
Jackie, did that create any cock on close?
Click to expand...

Not on the Neuvo. In fact, it just feels a tad stiffer. The stiffer spring did not affect the Bix and Andy trigger either.

My Farley HV 30 BR is on the verge. You can feel the cocking piece catch at almost the same moment the bolt starts to turn. When I did the hanger on it, it ended up with .270 firing pin fall.

It’s just a early R/L, I don’t shoot in very fast in the Score format. But it shoots pretty darned good.
 
jackie schmidt said:
I built a HV on a Bat Neuvo. It shoots quite well.

One thing I checked was the firing pin drop and spring static pressure. The firing pin drop is fine, around .220 inch. The spring pressure seems a tad light, I checked it at 18 pounds.

On a whim, I stripped the firing pin assy, and machined a thick enough spacer to get it between 23/24 pounds.

It sure sounds better. Before it had a clanky sound, after a nice crisp snap. I am going to test it this week end.

The best way I found to get the two small set screws that lock the firing pin in the cocking piece is to soak the shroud assembly in penetrating oil, then warm it with a air heat gun. They are put in tight with locking compound.

By the way, it took a .190 inch thick spacer to get the fall from 18 to 24 pounds.
Click to expand...

Hi Jackie, I use a lot of these actions. I have about a dozen in the shop now Id guess. They should have about .245" pin fall with no cock on close. Id get a different trigger hanger. Your spring also seems light, from memory the ones I have checked are about 21lb is the cocked position. An excellent ignition design in my opinion. Alex Wheeler
 
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zfastmalibu said:
Hi Jackie, I use a lot of these actions. I have about a dozen in the shop now Id guess. They should have about .245" pin fall with no cock on close. Id get a different trigger hanger. Your spring also seems light, from memory the ones I have checked are about 21lb is the cocked position. An excellent ignition design in my opinion. Alex Wheeler
Click to expand...

+ one on the ignition system. Instead if the lug style bayonet assembly, it features an interrupted thread. The shroud has a generous diameter fit that allows for perfect alignment.

I went to the range yesterday, and the Rifle shot great.
 
jackie schmidt said:
+ one on the ignition system. Instead if the lug style bayonet assembly, it features an interrupted thread. The shroud has a generous diameter fit that allows for perfect alignment.

I went to the range yesterday, and the Rifle shot great.
Click to expand...
Jackie- do you feel the changes made a improvement in the way it shot or did it just shoot as good as it did before?
 
Bat neuvo

The BAT NEUVO is a very fine action and should not need any corrections to the ignition system unless
it is done by Dwight or someone with his knowledge. I would call BAT, Dwight or Chris Harris if you think their
is a problem. It does not sound like you have started to tune the rifle/action. In my experience, the ignition
system is very sensitive to any changes(firing pin fall etc.). The rig with a new barrel should be capable of
shooting sub one groups at 100 yard at a selective seating depth and three different powder loads. I would also review
the latest info with regard to lighter firing pin weights.
 
tunermi said:
The BAT NEUVO is a very fine action and should not need any corrections to the ignition system unless
it is done by Dwight or someone with his knowledge. I would call BAT, Dwight or Chris Harris if you think their
is a problem. It does not sound like you have started to tune the rifle/action. In my experience, the ignition
system is very sensitive to any changes(firing pin fall etc.). The rig with a new barrel should be capable of
shooting sub one groups at 100 yard at a selective seating depth and three different powder loads. I would also review
the latest info with regard to lighter firing pin weights.
Click to expand...

Well, when I took this action to the range the first time, The extractor would not catch one out of every three cases, forcing me to push the case out with a cleaning rod.The Sako extractor was either installed too far back in the bolt body, or the part of the extractor that hooks on the case was too thick. The distance between the inner face of the extractor hook and the bolt face was too tight. I tried dressing the inner face of the extractor hook with small Emory files, but could not get enough off. I finally mounted the extractor in my tool grinder and dressed the inside face to where the extractor had about .003 clearance, allowing it to snap over the case every time. Problem solved.

Also, Bat knows the primary purpose of this action is a short range Benchrest Rifle. So why does it come with an ejector spring that throws the case 5 feet. That’s not a problem for someone like me, I can remove the ejector and tune the spring to where it pitches the case right next to Rifle on the bench. But for others, it could be a problem if they don’t feel comfortable working on it.

By the way, after increasing the firing spring pressure, I installed my favorite 6PPC HV barrel and shot the best groups I have shot with the Rifle to date. I then put my 1-12 twist barrel shooting the Bart’s 80 grn on and won the next 200 yard VFS Match at Tomball.

Also, Bat should offer this action without all of the lightening cut aways and side scalloping on the action body. They are assuming everyone wants this action to build a LV. They could leave the action in it’s round form, increasing stiffness for applications such as a HV or Rail Gun where minimum weight is not much of a factor.

I am aware this might be prohibitive, since most of these operations are done on a CNC setup.

All in all, the Bat Neuvo features some of the best innovations in action design we have seen in several decades. I plan on getting another in the near future in drop port.
 
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I don't know why

some folks seem to think others who have professional capabilities should seek permission to do simple alterations to suit their own likes and dislikes. Not everyone is mindless and without mechanical skills. It makes me want to puke sometimes, the things that are said on here. Mindless people are boring. Tinkerers are interesting and what Benchrest use to be all about. I don't know about anyone else but I decided a long time ago I don't have to call the king my uncle if I don't want to.There are a few of us left. If we bust it, by god we'll eat it or fix it.

Pete
 
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