primer only case locks up cylinder?

[rfd]

after firing off 50 handloads successfully last week with the new S&W 642, today i wanted to test out a different primer with sized and primer-only brass. loaded the cylinder with the 5 primer-only cases and the first one fired off and locked up the cylinder. i had to rap the cylinder with a rubber mallet to free it. put back the snap caps and no problem. no clue what's happening ... ?

[M-Tecs]

The pressure of the primer back it out and without the pressure in the case to reseat the primer it locks revolvers up. The wax bullet shooters drill out the flashholes to prevent this.

[rfd]

thanx - after i created this thread i blew off another primer and with a light i could see the blown primer pushed back on the firing pin.

[gwpercle]

Drop a rod down the barrel , small enough to go into the case , tap the rod to reseat the primer.
Easier on revolver than rapping the cylinder with the rubber mallet .

[rfd]

thanx - that's a better/easier solution. 238985

[osteodoc08]

If you drill out the primer flash hole, please mark them somehow so they don't get mixed with regular brass.

[Petrol & Powder]

Yep, already been stated but I'll second it, The primer backed out. It will occur every time with a primer in an empty casing.

Drilling the flash hole is the solution when you wish to fire primed but otherwise unloaded casings. Once the flash hole is drilled to a larger diameter the casing becomes permanently unsuitable for conventional reloading - So if you drill out the flash holes on a few casings, MARK those casings and never use them for reloading ! Or better yet, destroy them after you use them to test primers.

[Petrol & Powder]

And just for reference, and I welcome others to chime in here:

Federal primers are typically the easiest primers to reliably set off with light firing pin strikes and CCI tend to be the most stubborn.

An unmodified S&W 642 will reliably ignite any brand of primer that I know of, assuming the primer is properly seated.

[JBinMN]

http://castboolits.gunloads.com/showthread.php?377629-Is-drilling-out-flash-holes-dangerous

http://castboolits.gunloads.com/showthread.php?9837-Opened-up-flash-holes-a-test

[farmerjim]

If you worry about full charges with drilled out flash holes read this:

http://castboolits.gunloads.com/showthread.php?377629-Is-drilling-out-flash-holes-dangerous

[osteodoc08]

certainly rifles to revolvers is apples to oranges. I’d be willing to see data of a revolver and issues with pressure if someone wanted to do the test.

And it’s not always about pressure e at the muzzle end and resulting accuracy. There is also pressure at the primer end too which is why we see stretched primer pockets and if you get leaking of gas, you can get cutting of the breech face as well.

[bmortell]

ya even if a test or two showed it don't matter I still wouldn't intentionally mix modified brass with regular, even if just for consistency sake.

I keep 5 revolver cases with big flash holes marked red all over, I load em unsized with a magnum primer and push a roundball down in incase I need a slingshot

[JBinMN]

I would like to see data from testing from pistols/revolvers with opened flashholes using normal load data as well, if there has been any.

Including the interest in seeing where the idea that opening up flash holes in handgun cartridges would be of any danger when used in normal loads.

I can understand what they do when opened up in wax/soap/glue boolits since I make them myself & shoot them. I am curious why they would be a problem in normal loading.

I could see where some would say that it pushes the projectile out of the case before it is desired might be an issue, but then again, perhaps it is not.

Certainly worth knowing more about , IMO, anyway...

Anyone got a link or links to help out?

I don't consider this a furthering of a sidetrack, as it is worth knowing. Unless someone wants to go start a topic about it for handguns...

[farmerjim]

Larry Gibson's testing has shown that there is no problem with using full loads in bottleneck cartridges. This defied conventional wisdom. It would be nice to see a test on a straight wall case to see if it is the same or not.
I do make light loads for 223 and 308, but no pistol cartridges.

[Baltimoreed]

Only time that I drilled out my primer holes was when I loaded up some primer powered .45 acp rubber bullets to play around with. I kept these nickled brass segregated from my regular .45acp brass. Pretty accurate too. You would need to drill them for wax bullets I’m thinking.

[Larry Gibson]

Larry Gibson's testing has shown that there is no problem with using full loads in bottleneck cartridges. This defied conventional wisdom. It would be nice to see a test on a straight wall case to see if it is the same or not.
I do make light loads for 223 and 308, but no pistol cartridges.

357 magnum, 44 magnum, 45 ACP or 45 Colt?

[M-Tecs]

The 44 mag is the highest pressure of the bunch and the 45 Colt is the lowest. Testing both would address both ends of the spectrum.

[osteodoc08]

I’d be more interested in the pressures within the primer pocket, how long until gasses leak around the primer and the resulting breech face issues. I don’t think there will be any meaningful end point differences as far as terminal ballistics. That’s my theory/guess/hypothesis.

[onelight]

I have had pierced primers mainly from Winchester small pistol on medium pressure loads in 32 H&R and 9mm no signs of excess pressure firing pins check out good just a little black hole in the primer. In this situation would a case with a drilled flash hole cause flame cutting or damage on the fireing pin or recoil shield/bolt . The primers that did this were all from the same carton.

[Larry Gibson]

The 44 mag is the highest pressure of the bunch and the 45 Colt is the lowest. Testing both would address both ends of the spectrum.

Sounds like a plan.

[osteodoc08]

Larry, do you have any way to measure primer pocket dimensions over x amount of firings?

[Larry Gibson]

Prepped the cases and loaded them today. I'll use my "standard" load as of late for the 45 Colt which is 7 gr bullets under a 234 gr Lee 452-230-TC. The 44s are loaded with Keith's 22 gr Alliant 2400 under a Lyman 242 gr 429360 SWC. Have 10 rounds each with standard flash holes (just the way they came) and 10 rounds each with the flash holes drill out with a #28 drill.

239235

[osteodoc08]

Which primers did you use? Look forward to your testing.

[Larry Gibson]

Larry, do you have any way to measure primer pocket dimensions over x amount of firings?

Yes, I can measure diameter. However, keep in mind it takes 70,000 psi +/- (usually more of a + psi) to enlarge primer pockets. I would really like some to explain to me how the psi can be any higher in the primer pocket because the flash hole is larger than is the peak psi measured? As I understand it the pressure is "equal in all directions". Thus I can't get my mind wrapped around how, because of the size of the flash hole, how the psi could be any higher?

[osteodoc08]

Yes, I can measure diameter. However, keep in mind it takes 70,000 psi +/- (usually more of a + psi) to enlarge primer pockets. I would really like some to explain to me how the psi can be any higher in the primer pocket because the flash hole is larger than is the peak psi measured? As I understand it the pressure is "equal in all directions". Thus I can't get my mind wrapped around how, because of the size of the flash hole, how the psi could be any higher?

It is in essence an orifice. The pressure should be lower on the outgoing side when there is a smaller orifice as opposed to unobstructed. I believe it’s in the realm of the bournouli principle or equation. If it was a completely contained explosion, like in a bore obstruction, I imagine the pressure would be the same, but in a normal state, the cylinder of gas is always expanding from ignition of powder. With the orifice in place, the pressure should be less with the greater constriction separating the primer side. I’m not a physicist and could be completely wrong.

[M-Tecs]

Not really applicable in this case since the internal volume of a primer is very small compared to the volume case and the inch or two of the barrel when the pressure is at it's peak. The duration of peak pressure is greater than the orifice restrictions on gas expanding into the primer. It may be true in the case of a pierced primer, however, when the primer is not pierced or leaking the case and primer are a closed system. Pressure drops due to the bore obstruction (bullet) moving and increasing the volume more than the expanding gasses can fill. Depending on case size and at what point the pressure is at it's peak the volume of the primer may be a couple of thousand times less.

https://www.encyclopedia.com/science-and-technology/physics/physics/bernoullis-principle

[osteodoc08]

Then what would be the purpose of Palma brass, using SRP as opposed to LRP, and using a smaller primer hole? Supposedly it’s greater brass life (due to less primer pocket stretch) and lower SD leading to greater accuracy. What stretches primer pockets? Why is it reported that there is less brass stretch with Palma brass in the primer pocket before the primer pocket becomes loose? If there is no difference in pressure at the primer pocket, why go away from balloon head cases? I’m all for advancement of knowledge in our sport. I imagine the manufacturers with their fancy equipment have figured this out a long time ago.

So if we determine it doesn’t effect pressure at the primer pocket and there is no difference in terminal performance, how are we going to determine the optimal size for accuracy? That would be an interesting secondary. Larry, do you have a ransom rest?

[farmerjim]

I anxiously await the results of this test. I believe that it will go exactly as the bottle neck case tests. But I could be wrong, that is why we test our theories.

[M-Tecs]

Then what would be the purpose of Palma brass, using SRP as opposed to LRP, and using a smaller primer hole? Supposedly it’s greater brass life (due to less primer pocket stretch) and lower SD leading to greater accuracy. What stretches primer pockets? Why is it reported that there is less brass stretch with Palma brass in the primer pocket before the primer pocket becomes loose? If there is no difference in pressure at the primer pocket, why go away from balloon head cases? I’m all for advancement of knowledge in our sport. I imagine the manufacturers with their fancy equipment have figured this out a long time ago.

So if we determine it doesn’t effect pressure at the primer pocket and there is no difference in terminal performance, how are we going to determine the optimal size for accuracy? That would be an interesting secondary. Larry, do you have a ransom rest?

Longer brass life was not the reason for the SRP 308. I have some experience with SRP in 308. For me the brass life claims are inconclusive.

http://bulletin.accurateshooter.com/2013/05/large-vs-small-flash-holes-in-308-win-brass/

https://rifleshooter.com/2018/05/does-primer-size-matter-6-5-creedmoor-small-v-large-primer-brass-comparisons/

http://forum.accurateshooter.com/threads/primers-small-vs-large-fact-vs-theory.3906793/

https://www.accurateshooter.com/cartridge-guides/6xc/

Norma 6XC Brass — Now Available

Norma Precision AB S0670 40, ?matfors, Sweden and David Tubb of Superior Shooting Systems Inc., Canadian, Texas USA announce their collaboration to make and import 6XC brass in the U.S. and European markets.

This follows more than two years of developmental work on the 6XC cartridge by Norma. Case head hardness of the new 6XC brass will be on par with the best and hardest commercially-manufactured cartridge brass. Hardness is important for best use in a repeating rifle, especially one used for NRA High Power and Long Range competition. The Norma standard for body wall runout is .002 inches or less at the base of the case.
The new brass features a large rifle sized primer pocket. A detailed study of large and small rifle primers showed that large rifle primers worked best when the propellant charge exceeds 35 grains as is the case with the 6XC.


https://www.starlinebrass.com/brass-cases/308-Match/

The .308 Match is our small primer version of the .308 Winchester case. Many competitive shooters prefer the consistent velocities produced by small rifle primers. Like all of our other small primer rifle cases, we utilize our standard .080" flash hole diameter, as we feel it gives better ignition with slower burning and harder to ignite powders, making it more user friendly than many of the small primer/small flash hole versions of this caliber*.

[osteodoc08]

Interesting M-Tecs. Thanks for the good reads. Hopefully at the end we can debunk some common held beliefs, again.

[Larry Gibson]

.......So if we determine it doesn’t effect pressure at the primer pocket and there is no difference in terminal performance, how are we going to determine the optimal size for accuracy? That would be an interesting secondary. Larry, do you have a ransom rest?

No I do not have a Ransom Rest at this time nor access to one. As to what size flash hole gives "optimum accuracy" was not a consideration for drilling flash holes larger. The reason was to prevent cases used for "squib, cat's sneeze or mouse fart" loads from developing shoulder set back in push feed actions using rimless cases after a few firings. That's it. Getting better accuracy with such loads along with less powder position sensitivity in larger cases was a secondary benefit.

I have some 30-06 and 308W cases that had the flash holes drilled out back in the early '90s. hey have been fires a bajillion times with 3.2 gr Bullseye under 90 - 118 gr cast bullets. The primer pockets are still "tight". The question here was if the flash holes were drilled and the cases were inadvertently used with full power loads is it "dangerous". My testing with the 308W using full power jacketed bullet loads at a measured 55 - 56,000 psi demonstrates it is not....... I will find out with straight walled pistol cartridges (44 magnum and 45 Colt) soon .......

[ReloaderFred]

My unscientific test of large flash holes versus regular size flash holes involved the Winchester NT cases in .45 acp that came from the factory with a 1/8" flash hole to alleviate the faster brisance of the DDNP priming compound before they switched to small pistol primers for NT loadings. I decided to load some up and just test for accuracy with a known load, and at 15 yards and 25 yards, I found no difference between the two in accuracy. There were also no visual differences in the cases I used, but this was a relatively small test sample of 25 rounds of each size flash hole, compared side by side.

My conclusion, which only applies to myself, was there was no danger in using drilled out flash holes for regular loading in the .45 acp, using Bullseye powder. I had intended to also test with Winchester 231, but it never happened, as life got in the way and I forgot about it until I read this thread.

Hope this helps.

Fred

[Larry Gibson]

As to accuracy based on size of the flash hole back in the day when I was shooting High Power I got wrapped around the axel over flash hole size and centered flash holes when I was an Expert aspiring to make Master. I had fully prepped a bunch of cases, uniformed the flash holes and eliminated those with off center flash holes. At the next match which was a "Leg" match a couple members of the AMU from Fort Benning showed. Both were using borrowed match M14s using Federal Match ammunition. Both zeroed the M14s while shooting the 200 yard off hand match (200 yards) shooting High Master scores doing it and in all the other matches (200 RF, 300 RF & 600 SF). Even with all my "perfect" ammo I still shot my usual high end Expert score (won my classification) . The two AMU shooters took 1st and 2nd with very high scores and were separated only by X count. One gave a talk at the end of the match. He said the Federal ammo and the match M14 he borrowed were both excellent but the real key to high scores was learning to really focus on the front sight and proper trigger pull. Privately he told me all I was doing to make "perfect ammo" was to no avail because there were too many other variables. He was correct as I just did a simple match prep to my cases after that and learned to focus on the front sight and pull the trigger correctly. I went from Expert to Master in short order and then to shooting High Master scores at long range.

Since then I have several times attempted to prove, to myself at least, that centered flash holes and flash holes of a certain size mattered for the best accuracy. Even with the very accurate match and varmint rifles I have and even with a 40X bench rest rifle I was never able to prove either really mattered. I was able to prove to my own satisfaction that uniforming the cases flash holes to one size seemed to matter......... I no longer get wrapped around the axel over such...........

[Larry Gibson]

Drilled Flash Hole Test; 44 Magnum and 45 Colt

Completed the test yesterday 29 April, 2019. Test firearm was a Contender with a 8.4” barrel in 44 Magnum and a 10” barrel in 45 Colt. A 2.5X scope is on the Contender. All measured data except group size (ctc widest shots) was obtained via the Oehler M43 PBL. I had prepared 10 cases, as previously posted, for each test string; 10 with standard flash holes and 10 with the flash holes drilled out with a #28 drill. Winchester WLPs were used in all cases for both cartridges.

Testing was conducted from the bench with a Hoppe’s Pistol Rest with the target at 50 yards.
Temperature was 80 degrees.
Humidity was 30%
Barometric Pressure was 29.63

44 Magnum;
Bullet was a 429360 cast of COWW +2% tin, AC’d and aged 10+ days before sizing .430 and lubed with BAC.
Cases were Remington R-Ps sized and loaded in RCBS dies.
Powder charge; 22 gr of Alliant 2400
OAL; 1.638

With Standard flash holes;
Velocity; 1622 fps (muzzle)
SD/ES; 13/41 fps
Pressure; 35,800 psi(M43)
Pressure SD/ES; 500/1,700 psi
Group; 3.1”

With flash holes drilled;
Velocity; 1599 fps (muzzle)
SD/ES; 17/47 fps
Pressure; 34,500 psi(M43)
Pressure SD/ES; 1,400/3.900 psi
Group; 3.2”

45 Colt:
Bullet was a 452-230-TC cast of COWW +2% tin, AC’d and aged 10+ days before sizing .454 and lubed with BAC.
Cases were CBC 45 Colt sized in RCBS steel FL sizer and loaded in Hornady dies.
Powder charge; 7.3 gr 700X
OAL; 1.598”

With Standard flash holes;
Velocity; 1060 fps (muzzle)
SD/ES; 7/23 fps
Pressure; 16,300 psi(M43)
Pressure SD/ES; 400/1,500 psi
Group; 2.9”

With flash holes drilled;
Velocity; 1059 fps (muzzle)
SD/ES; 4/15 fps
Pressure; 16,000 psi(M43)
Pressure SD/ES; 400/1,100 psi
Group; 3.15”

From the measured data we see there is essentially no difference. Again the sky did not fall, California did not slide off into the Pacific and still no Trump collusion with Russians……

Here’s the fired primers…..no difference in “flattening”…….

240800

[M-Tecs]

Awesome ---- Thanks for doing the tests.

[mjwcaster]

Larry could you post your test as its own thread to be easier to find in the future?
Very valuable info, I wouldn’t want it to be lost.
And thanks for all your testing you do.
Matt


Sent from my iPhone using Tapatalk

[osteodoc08]

Once again. Thank you for your diligence.

Conclusion- Drilled primer pockets mean no nevermind when it comes to pressures over standard flash hole sizes. Questionably worse variation in ES/SD and accuracy?