FTF problem

[bozo699]

Yeah, I wondered if maybe the problem with short cases wasn't that they were pushing the round in without the extractor popping over the rim.

But would 450s make a difference?

They have a harder cup, the firing pin drives the case forward and with to much headspace the round doesn’t go off.
Wayne

 

[KY_Windage]

What I meant was, if you pressed 450's into one of 243win's sawed-off cases, and held them by the extractor only, would "every one of them" go off, as in his experiment. I suspect they would.

 

[bozo699]

What I meant was, if you pressed 450's into one of 243win's sawed-off cases, and held them by the extractor only, would "every one of them" go off, as in his experiment. I suspect they would.

I can’t answer that as I’ve never done it. In a bench rest rifle with a custom br action fire forming 6 br cases to brx or dasher with .100 headspace NO you will get FTF occasionally with 450s using a softer cup like a 205 using a false shoulder or heavy jam or a combo of both you rarely get a FTF or at least that’s been my experience ff a few thousand cases over the years.
Wayne

 

[Webster]

I’m reasonably sure I know what caused this problem, but I want to run this past all of you anyhow.

Here as a little background on the problem. The rifle is a Kelbly BB Panda action with a 1-10 twist 308 barrel. I bought the barrel as a blank and had it chambered up by a well-known gunsmith late in the season of 2018.

I started break-in/load development with new Alpha brass that had been neck sized only and only about 30% of the rounds loaded would fire using CCI 450 primers.

I didn’t mess with this rifle until a few weeks ago and bought 200 pieces of new Peterson brass. (Couldn’t seem to locate the Alpha brass) Again, neck sized only and the same issue appeared again. I took measurements from fired brass, as opposed to new and the new brass is .007 shorter as measured to the datum line of the shoulder.

Well that explains the FTF, but the “why” is the question.

My solution:

I started to do a little load development with the Berger 200-20x bulled jammed .010 but the results were poor. So rather than burn up components and bbl. life, I gave a modified COW method a try.

I put 15 gr. of VV 3N37 in a case with a small wad of paper towel and lit it up with a small pistol mag. primer. (I’m reasoning that the pistol primer would light up easier that the hard cup #450 primer.)

SUCCESS!! Now all the brass measures the same.

Your thoughts as to what caused this issue are welcomed.
Thanks,

Lloyd

Many talk about dissembling the bolt and cleaning it but no-one mentions putting oil on the bolt shroud. The firing pin assembly slides thru the shroud. It is the only source of friction to slow down the FP movement. In Tony Boyers book he says he drills out part of the shroud to reduce friction.

 

[dkhunt14]

Many talk about dissembling the bolt and cleaning it but no-one mentions putting oil on the bolt shroud. The firing pin assembly slides thru the shroud. It is the only source of friction to slow down the FP movement. In Tony Boyers book he says he drills out part of the shroud to reduce friction.

Actually BAT has a video on replacing firing pin spring and shows a special grease he uses on the sliding part inside the shroud. Matt

 

[243winxb]

special grease

Should increase pin speed.

https://www.batmachine.com/videos/firing-pin-removal-grease-installation/

 

[KY_Windage]

What I meant was, if you pressed 450's into one of 243win's sawed-off cases, and held them by the extractor only, would "every one of them" go off, as in his experiment. I suspect they would.

I did this test with Small 450's in a sawed-off 204 case in a Rem 700. The primer fired, but it was a very light hit and the strike knocked the case out of the extractor. 450's can't be that tough if that very light strike fires one.

But anyway, the answer is simple -- don't use cases with excessively short measurement to the shoulder and make sure your FP is long enough, has a strong enough spring and is sliding freely.

 

[1shot]

I did this test with Small 450's in a sawed-off 204 case in a Rem 700. The primer fired, but it was a very light hit and the strike knocked the case out of the extractor. 450's can't be that tough if that very light strike fires one.

But anyway, the answer is simple -- don't use cases with excessively short measurement to the shoulder and make sure your FP is long enough, has a strong enough spring and is sliding freely.

What is your definition of excessively short? In my case, the chamber was .007 long to virgin brass. The 450’s FTF 66% of the time, while Wolf SR-M fired every time.
Lloyd

 

[bozo699]

What is your definition of excessively short? In my case, the chamber was .007 long to virgin brass. The 450’s FTF 66% of the time, while Wolf SR-M fired every time.
Lloyd

Lloyd
Your wasting your breath!.... have the best day.
Wayne

 

[KY_Windage]

What is your definition of excessively short? In my case, the chamber was .007 long to virgin brass. The 450’s FTF 66% of the time, while Wolf SR-M fired every time.
Lloyd

What is "excessive" is going to varying depending on a lot of factors and have to be determined for each rifle. If you are happy shooting the Wolfs, problem solved. But if you want to shoot 450's, then .007 is "excessively" short for your particular rifle, even though it would not be in mine, due to my longer FP, or whatever.

I suggested to you that you quit seating your primers so deeply but you apparently do not want to do that. That's fine, CCI and nearly everyone else says to seat below flush. But you obviously have a short FP (or a weak spring), and that combined with seating your primers so deep is creating FTF's.

With (any) primers seated flush I can shoot brass that is .010 too short all day long and get no FTF's. You simply need to change something. You decide what it will be.

 

[bozo699]

Lloyd
Your wasting your breath!.... have the best day.
Wayne

You see what I mean!?....
Wayne

 

[Webster]

Yeah, that's prolly why I can't get any good 5-shot groups with my 204 at 100 yds -- primers are too high.



And why my 7-08 won't shoot at 800 yards:



My RCBS hand-primer tool won't even seat below flush. But what do they know about shooting?

When I shoot groups and get a nice group and 1 out. I always wonder if it's my shooting ability or mass produced bullets (58 gr VMax usually). I don't sort bullets it's a varmint hunting rifle. I only use flags if someone else puts them up. I staple a ribbon to the bottom of the target board. The 1 out can be in any direction so it's probably not the wind. The rifle is more accurate than I can shoot. I have shot a few groups in the 1's and a couple every year below .250". I see big improvement shooting Sierra 60 gr Varminters over 58 VMax. The 60 Gr is my new hunting and target bullet.

 

[KY_Windage]

If the crosshair wasn't where it was supposed to be when the gun went off, I know it. If the bullet does not go where I aimed, the first suspect is my rest/position, next my reloading technique. The latter is where the real bugaboos lie.

 

[Webster]

If the crosshair wasn't where it was supposed to be when the gun went off, I know it. If the bullet does not go where I aimed, the first suspect is my rest/position, next my reloading technique. The latter is where the real bugaboos lie.

Always a question, is the group size due to the rifle, reloading, bench skiles or crappy bullets.

 

[dkhunt14]

Always a question, is the group size due to the rifle, reloading, bench skiles or crappy bullets.

Or CONDITION. Matt

 

[dkhunt14]

What is "excessive" is going to varying depending on a lot of factors and have to be determined for each rifle. If you are happy shooting the Wolfs, problem solved. But if you want to shoot 450's, then .007 is "excessively" short for your particular rifle, even though it would not be in mine, due to my longer FP, or whatever.

I suggested to you that you quit seating your primers so deeply but you apparently do not want to do that. That's fine, CCI and nearly everyone else says to seat below flush. But you obviously have a short FP (or a weak spring), and that combined with seating your primers so deep is creating FTF's.

With (any) primers seated flush I can shoot brass that is .010 too short all day long and get no FTF's. You simply need to change something. You decide what it will be.

The anvil has to crush the pellet to go off. For the anvil to crush the pellet it must go against the bottom of the pocket. Whether it is driven there or seated against. Matt

 

[KY_Windage]

The anvil has to crush the pellet to go off. For the anvil to crush the pellet it must go against the bottom of the pocket. Whether it is driven there or seated against. Matt

Mine go off just fine w/o ever getting anywhere near the bottom of the pocket. The FP drives the pellet onto the anvil, I guess. Anyway, they go off just fine and with all the consistency one could ask for.

 

[KY_Windage]

Or CONDITION. Matt

We have to exclude varying wind conditions or we will never get anywhere.

 

[dkhunt14]

Mine go off just fine w/o ever getting anywhere near the bottom of the pocket. The FP drives the pellet onto the anvil, I guess. Anyway, they go off just fine and with all the consistency one could ask for.

I would almost bet the firing pin is driving them forward and pressure is pushing them back against the bolt face. Matt

 

[KY_Windage]

I would almost bet the firing pin is driving them forward and pressure is pushing them back against the bolt face. Matt

Nope, I tested for that. I put a deadened primer in a case with no powder or bullet and "fired" it. It was flush when I put in and flush when I took it out.