Dry fired rifle

W

wisconsin

Guest
One of the guys at my club has offered a BR50 rifle up for sale to me. He says its at the gunsmith for repair because it was having a hard time extracting and or going into battery with the .22 rd. He then goes on to say that it has a double fring pin system and was dry fired. Well I'm not an expert by any means but what I do recall in all the years of owning firearms is that if you dry fire some firearms you will destroy its accuracy. If this is the real reason it went in for repairs. My question is this can it be repaired and still maintain its accuracy or should I run away from this sale. Jeff
 
With a rimfire its not uncommon for the striker to peen the breech opening on the barrel. In fact it's quite common. Over time this will create a surface inclusion that distorts the inside of the chamber right at the breech face. When you attempt to chamber a bullet it galls the bearing surface of the bullet. Now you essentially have the same thing as sticking weights to the outside of a football and then attempting to throw it properly. It will "jump rope" because the CG of the projectile has changed. Same thing happens with the bullet. It also fusses with the cartridge rim because now it'll try to stand off the breech a little. This fuggers the headspace too and it creates a condition that makes the gun prone to inconsistent ignition. On a rimfire this is pure poison for accuracy because the initial spark is so very, very important.

There is no reason to get all nervous about the gun though. It just needs to be literally ironed out. A chamber iron is all that's required. It's a small tool that is tapered a bit. It has three sides that are round and smooth. You cram it up the arse of the barrel and then rotate it via the handle. It'll "iron" the inclusions right back where they came from and life goes on.

Easy fix.

Cheers!

Chad
 
Sounds like a Time Precision RF action. They had dual firing pins.

Carp
 
There is no reason to get all nervous about the gun though. It just needs to be literally ironed out. A chamber iron is all that's required. It's a small tool that is tapered a bit. It has three sides that are round and smooth. You cram it up the arse of the barrel and then rotate it via the handle. It'll "iron" the inclusions right back where they came from and life goes on.

Easy fix.

Cheers!

Thanks Chad
 
Wisconsin,
I'm no expert with a Time Precision action other than it has dual firing pins.....and I think it had no extractors and adjustable headspace. Sounds like all the things I think I know about it would explain the issues that gun has. Now other than that I know in the past that there were some incredible shooting Time's. I cannot and will not tell you to run from a sale. I'd let it be fixed and test fire it if I could and then decide.

Carp
 
For the life of me, I can not see a down side to the dual firing pin of a time action, in fact I wish more manufacture with have them in there design.

As said before, the proof of the pudding is in the shooting. Let the owner of the rifle supply the ammo for testing, he will want to show the rifle at it best, I hope you will know if you can get the same ammo before you think of buying.:D
 
Big Al is onto something. . .

Kinda off topic and I hope the OP doesn't mind.

The striker's clock position on a rimfire DOES in deed matter. Lets pick this apart a little piece by piece.

We have the lowly 22LR; a rim fire cartridge which means the priming mixture is squished between the folds of the rim of the cartridge case.

We have barely enough powder to accelerate the bullet past the speed of sound.

Now, what happens when the case is positioned horizontally in the loading tray/magazine and then shoved forward into the chamber? (By either a finger in case of a single shot (if your doing it right) or by the bolt stripping the round off the feed lips in the case of a repeater)

The powder is disturbed and one can only speculate it's condition as it sits in the case. There is however one constant that doesn't change and that is gravity. Gravity is going to virtually guarantee that the powder is resting at the 6 o clock position. So wouldn't it be better to have the striker hit the rim at this position? Wouldn't that feature be compelling to more consistent ignition because there is a greater chance of "spark saturation" when the whole process starts?

I think it would.

I'll back up by saying that some very impressive groups are shot every week with actions that ignore this train of thought so perhaps there isn't as much to it as I'd like to hope, but I do know of a very, very, very, very sharp old man down in Raton, NM who's been fiddling with guns since the 50's who feels the same way.

I have a very rare (he's only made a few) Mark Chanlynn rimfire barrel contoured for "mini Palma". I started on a rimfire action years ago and when I get around to finishing it I'm planning on testing this little theory out with two bolts. One with the striker at 12 and the other at 6.

It'll be interesting to see what happens.


Have a great day all.


Cheers,

C
 
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Chad,
I have one of my 40X rimfire BR rifles with a bolt set up for a 6 oclock firing pin and another with the 12 oclock firing pin. From accuracy testing I've done, I could tell no difference in the accuracy. I could alternate bolts during shooting a group and notice no difference, shooting 5 shot groups in the mid .1 range and using Eley Tenex ammo. Who knows, it might make a difference with other lesser grade ammo but this is a competition rifle and lesser grade ammo is of no interest to me.
Most people's school of thought is that the powder is laying in the bottom of the case with an assumption that the case is only half full of powder. On rounds I've pulled bullets from using Tenex the powder filled the case to the base of the bullet. I'm wondering if they're using some type of filler t increase load density. The bench I test rifles on is about 6' X 8' and after shooting a couple of boxes of ammo there will be a lot of unburned flakes/ chunks of little gray/green stuff that don't appear to be powder on the bench in front of the muzzle of a 24" barrel and a 24" barrel should burn up all of that little powder charge.
One thing about it though, the 6 oclock firing pin setup sure didn't decrease the accuracy. I just didn't see any improvement.
 
I found out today that this is indeed a Time Precision Rifle. It has a bull or a 1" barrell. He is using Ely black. What lot number I'm not sure. I was not really impressed with his groups. But I didn't ask what yardage he was at. I will shoot it next week. He is asking $1400. for it. I not sure if thats priced right. Since the company is now out of business. The more I get into this sport the more my head begins to hurt. I just want to make the right move the first time. Jeff
 
Tell me about all the rimfire shooters you know who never had a misfire in all there shooting of rimfire ammo? Big number is it? I do not mean the folks you naturally think of shooting from a bench, but all rimfire shooters. Why are there misfired ctg with rimfire ammo? When you think of the answer of why we have misfires, hang fires you come to the inevitable conclusion that the best way to get around the potential problem is with a two firing pin bolt.

I guess that I'm not the only one that was instructed as a kid to re index the ctg in the chamber and try again.

Yes there are other reasons for the two firing pin bolt, I leave it to the really smart action builders like Bill Calfee to explain the reasoning. Is a hang fire disruptive two a shooter? How about a hang fire? Well heck yes, it shifts your concentration from shooting ti dealing with a different problem.
 
I can say that the few cases of TENNEX that I've shot over the years has yet to result in a hang fire. I do get them more often than I'd like with the cheap crap I run through my 10/22 though.

As a former gun plumber for the Anschutz national service center that dealt with every marquee trigger puller (to include Mat Emmons) at the US Olympic Training Center from 2000 to 2003 I can say with great certainty that no one was/is using a dual striker fire control system.

I am being speculative here but I venture to guess its due to lock time.

Every Olympic event involving a rifle is fired from position with a maximum of two hands and one shoulder being in contact with the rifle at any given moment. Slings are allowed but artificial support is not.

You have a projectile traveling at roughly 1/3rd the speed of any modern high performance centerfire cartridge and you are physically holding the rifle while trying to hit a target the size of a #2 pencil eraser while using iron sights. This means EVERYTHING counts. The trends go back and forth with different length barrels but lock time is always kept to a minimum and that means a single striker fire control.

Bench rest is an animal all its own (I realize) but I can't help but think that lock time is also very important. I've built quite a few rimfire and centerfire bag guns over the last ten years and to date no one has ever asked for a dual striker system.

Enjoyable conversation!!

Cheers,

C
 
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Try as I may, I'm unable to come up with a reason why both strikers should not hit the case rim at the same time, taking into a count already well established machining practices? If a single spring is used for the means of launching the same strikers at the same release time and one sear is used to release the firing pins, the pins are the same length? What am I missing in this?
 
NesickaChad and Big Al,
The lowly rimfire .22 case in Benchrest is the craziest animal you can chase. Please do not demean those that spend so much time and money to pursue their sport. I promise you that it would drive you crazy to score well in that sport.

I do not support or dismiss the building of a two firing pin system for rimfire but want to explain to those of you who do not understand the...what seems to me as common sense part of a rimfire case. You both seem to have centerfire backgrounds. A rimfire case, as NesikaChad says "We have the lowly 22LR; a rim fire cartridge which means the priming mixture is squished between the folds of the rim of the cartridge case." Very close to the reality but not precise. The priming compound is not squished or squeazed or smashed between anything. It is precisely placed in the rim if a quality BR rimfire cartridge of a couple of manufacturers. The idea of Time Precision....along with the "common sense" fact of rimfire priming and ignition is that the primer cound ingnites AROUND the rim (after the firing pin strike) at a rate that it takes the compound to burn......if two firing pins hit at the same exact time......then the rimfire priming compound burns at least twice as fast......lock time....maybe.....?????? It seems to be their (Time Precision) most important engineering development of this action. But I've heard of actions with 4 firing pins.......never seen one but heard of the concept. It would take the "lock time" or ignition to .250 of the norm.

Carp
 
Lock time as I've always understood it is the time on a watch it takes from the moment the trigger sear releases the fire control to the moment the propellant begins forward motion of the projectile.

Assuming I define that accurately then I fail to see how four, five, a dozen strikers are going to out perform one. Reason being is mass/inertia. We all can agree it takes more effort to push a dump truck than it does to push a chevette. Maybe not a fair comparison but we get the point.

There has to be something to it because if there was a clear cut better way then these type of actions would be popping up all over the competitive shooting events. I don't think that is the case nor ever has been.

Regarding priming compounds. I apologize for my poor/innaccurate definition earlier. Regarding the spark and how it travels. My understanding is that priming compounds are an RDX based explosive. From my days as a Combat Engineer in the Marine Corps I can tell you that RDX has a detonating velocity of right around 64,000 feet per second. It'd take about 7 minutes to get from San Diego to New York if you poured a trail of it across the states. A 22RF rim has a circumference of a little more than .87" inches.

I may have done this math wrong, so sharp guys feel free to help:

64,000 / 12 gives us inches (768000)
768,000 inches divided by .877 (circumference of the case rim) tells us that you could ignite 875,712 twenty two long rifle cases in a second if they were all laid out. (I said that correctly right?)

Well, were just interested in one of those 875 thousand cases. So chop up one second by 875,712 and I guess (think?) this is how long on a watch it takes to get that spark all the way around that single case. My calculator goes into arrest when I try it. If I did this right I think it illustrates that one pin vs two pins, four, five, six, becomes a bit silly at some point.

Or maybe I'm just full of S__t too.:D

Cheers!

C
 
Then the idea of liquid priming and the use of centrifugal spinning is not correct. the reason I was told for the rims to hold the largest amount of the priming compound.

I do know that in some of my CB cap ammo (acorn brand) their appears to be a white cap inside the base of the case.
 
Hey, Al, I was always told the...........

priming compound was applied the same way as you. The REAL reason for .22 RF misfires is the K/Wal-Mart mentality, the big-box STORES dictate the sale price of the ammo, so they TELL the ammo companies what they want to sell it for, and what they'll BUY IT FOR. So, the ammo companies make the necessary cuts, and that's what we are handed.:mad: The same way Detroit used to build cars. When I was a kid, I really can't remember more than six or eight misfires IN MY YOUTH!!! But since 1980 or so, they've been more frequent, with anything less than target:(.


I know of one RF rifle that won't get an eggy chamber......the lowly english Martini! I have an old beat-up club gun I've yet to shoot, and there is a groove machined where the FP would strike at twelve, just for dry-fire practice.;)
 
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