RMR 9mm 147gr Copper plated RNFP jams

[RikSors]

A chamber checker is a very helpful tool. I had countless hours burning candles just to pass the plunk test until a friend recommended the chamber checker. It used to be that I have to plunk test a new load for every pistol. This takes out the guess work especially when loading lead projectiles. It is a plunk test and more (crimp, coal, etc...).

 

[Crazy Horse]

fxvr5,
I try to stay within a range that gives me some room error.

As a rule (for me) I don't load near minimums or maximums on powder charges or OAL.

I ran into cycling issues some time ago using 45 acp LSWC. I was able to finally get a useable cartridge, but it took some time to develop cartridges for testing. The major difference in that instance was the use of 200gr bullets vs the standard 230gr RN bullets. That situation called for heavier powder loads. In the end I used a lower powder amount per bullet. It was safe, but the load was slightly less than Speer manual posted. It worked very well though-in all my 45's. A member (Slamfire) helped out and I was very appreciative of all the support.

https://www.thehighroad.org/index.php?threads/shield-45-best-bullet.858968/#post-11321125

In the case of 9mm, I'm using a heavier round which calls for lighter powder loads vs higher powder loads for lighter bullets. COALs are also lower in both cases. It is good to know that I can go to as low as 1.00. Thank you

My goal is to get the RNFP to function reliably in all my 9mm firearms. I suspect it will take the same amount of testing. I still have 200 bullets, so I will continue to test. If it gets too cumbersome (I get tired of having to reset dies, crimps, and weights), I'll just use them on my Canik until I run out and look at trying the 147gr RN FMJ option.

Thanks again for the the help.

 

[LiveLife]

You not have said that any of these problems were caused by compressed powder charges.

In how many instances were the 'blown' guns were caused by compressed powder charges? How many of the blown guns were caused by excess powder charge, bad brass?

Look, if you want to discuss the virtues of case fill calculation, start a new thread and I will happily show you my calculations.

I don't want to be rude and detract from OP which is helping identify a working OAL.

 

[Crazy Horse]

A chamber checker is a very helpful tool. I had countless hours burning candles just to pass the plunk test until a friend recommended the chamber checker. It used to be that I have to plunk test a new load for every pistol. This takes out the guess work especially when loading lead projectiles. It is a plunk test and more (crimp, coal, etc...).

View attachment 895805

I have one, but doesn't that just verify if the bullet is too long or wide. I don't think it verifies if the bullet is shorter than published mins?

 

[fxvr5]

Look, if you want to discuss the virtues of case fill calculation, start a new thread and I will happily show you my calculations.

I don't want to be rude and detract from OP which is helping identify a working OAL.

I'm not interested in your calculations. I would only be interested in positively identified instances in 9mm Luger when compressed charges caused a massive and dangerous spike in pressure. That would require pressure measurements. Can you direct me to a resource with that information? Thanks.

 

[fxvr5]

I have one, but doesn't that just verify if the bullet is too long or wide. I don't think it verifies if the bullet is shorter than published mins?

Chamber checkers are only useful if they are EXACT copies of your barrel's chamber. Otherwise, the barrel chamber is the best tool for determining cartridge fit.

 

[LiveLife]

I'm not interested in your calculations. I would only be interested in positively identified instances in 9mm Luger when compressed charges caused a massive and dangerous spike in pressure. That would require pressure measurements. Can you direct me to a resource with that information? Thanks.

Sorry, I could only offer you my calculations and that my preference is not to use compressed charges.

But you go ahead and use compressed charges if you like. It's your pistol and your hands. I like to keep mine.

 

[fxvr5]

Sorry, I could only offer you my calculations and that my preference is not to use compressed charges.

But you go ahead and use compressed charges if you like. It's your pistol and your hands. I like to keep mine.

I've shot many thousands of them. One nice thing about compressed powder charges - they prevent bullet setback. Non-compressed loads permit setback, so if you really don't want setback to increase pressure, use a load that is already compressed.

 

[RikSors]

What about duplicating the “ogive” measurement and the crimp from a factory round (say WWB)? Then do the ladder test from minimum til the gun cycles. Obviously, the 124RNFP will be shorter. Unless of a bullet design flaw, the gun should cycle fine.

 

[LiveLife]

I've shot many thousands of them

Over 600,000 for me.

One nice thing about compressed powder charges - they prevent bullet setback. Non-compressed loads permit setback

I prevent bullet setback from sufficient neck tension.

If you want to use powder compression to prevent bullet setback, you go.

Wow.