OAL and chambering issues in RARR

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Contender44
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OAL and chambering issues in RARR

Post by Contender44 » Mon Apr 09, 2018 6:27 pm

I'm having to pull a bunch of bullets because, when loaded to max OAL or anywhere close to it, they will not chamber in my RARR. This has occurred with 110 grain Lehighs, 190 grain HPBT, and 150 grain SBPTs. If I go to load them deep enough to chamber, the pressure, per QuickLoad, goes out of sight with loads in the supersonic range. Has anyone else had this issue? Does the RARR have a short leade? I'm going to reload them all subsonic (at least with the heavier ones) and seat them deep enough to chamber. Perhaps with the 150 and 190 grains I shouldn't be surprised by with the 110 grains I would think they could be loaded supersonic, near mag length, and still chamber.

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dellet
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Re: OAL and chambering issues in RARR

Post by dellet » Mon Apr 09, 2018 7:34 pm

SAAMI max length never, ever, has anything to do with if any bullet will fit in a particular chamber at that length.

There are many bullets that can not be loaded to 2.260", that is max length that will fit in the magazine.

Not sure on the other bullets since you did not mention the manufacturer, but I am guessing there is a reason that Lehigh has their length at 2.110" for the 110 Controlled Chaos.

Never hurts to check with the manufacturer, since quickload can not tell you how long a certain bullet can be loaded in any chamber.

https://cdn.shopify.com/s/files/1/0711/ ... 2266762681

I would suggest an investment in a comparator

https://www.hornady.com/reloading/preci ... comparator#!/

Then again the problem could also be thick brass. And this would be a handy tool to help determine that.
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Contender44
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Re: OAL and chambering issues in RARR

Post by Contender44 » Mon Apr 09, 2018 8:40 pm

Thanks very much. I understand (before, and very clearly now) that OAL is different from what a chamber will accept. It looks like that Lehigh will need to be loaded a lot shorter than even 2.1. I reckon I'll have to invest in the Sheridan Gauge. I do think that Ruger chamber (leade) is very short. I don't think it's the brass as it's Hornady 300 blk brass, properly resized, trimmed, and chamfered. I am going to take the firing pin out of my AR and see if any of these will chamber in it. Either way it will be a stark and memorable lesson as I will end up pulling 100 bullets which ain't exactly fun. From now on I'll make sure they chamber, the adjust my seating depth and charge accordingly. I think I was spoiled in reloading for a single shot 7.62x25 Tokarev (Contender) that accepts very long bullets without complaint. Edit: OK I checked to see if I was using the word "leade" correctly but having researched it now I think I meant "throat" or "freebore," i.e., the area before rifling begins. I'm wondering if my RARR has a short throat. "Leade" is apparently the area while rifling begins, gradually.
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Re: OAL and chambering issues in RARR

Post by mr.revolverguy » Mon Apr 09, 2018 9:00 pm

Please get a comparator set as Dellet called out. That along with a Sheridan Gauge is well worth the investment. Though in your case since you believe your RARR has a short length chamber you might also think about
https://www.hornady.com/reloading/preci ... fied-cases#!/

This will help you measure your specific chamber length. If your chamber is short it will be the total opposite of most others reports, and I would be totally shocked. I recently completed a little experiment to work out the specifics to make my RaRR 100% no matter what primer I load with you can read about it here.

viewtopic.php?f=137&t=101761&p=981264#p981264
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dellet
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Re: OAL and chambering issues in RARR

Post by dellet » Mon Apr 09, 2018 9:12 pm

What are the other bullets you have?

Is the Lehigh the controlled chaos or a different bullet?

The controlled chaos, at least the ones I have, in Theory can be loaded to 2.300". The problem with that is that you only have one driving band in the neck of the case and it's impossible to keep the bullet straight. You need to at least get that second band in the neck.
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Contender44
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Re: OAL and chambering issues in RARR

Post by Contender44 » Tue Apr 10, 2018 7:46 am

Yes, the Lehigh is the controlled chaos. I loaded it per Lehigh specs and it ran into the rifling big time. Looks like I'm going to need to "shell" out big time for all these tools and gauges to figure out BLK is going on.

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Re: OAL and chambering issues in RARR

Post by Contender44 » Tue Apr 10, 2018 8:43 am

OK now I'm really stumped. I decided to take a fired case, put in a Lehigh CC "long", mark it with magic marker, and slowly push it in to the chamber to see how far the rifling pushed it back. Well of course it got stuck hard and I had to take a rubber hammer to open the bolt. So I knew the bullet was not the hang up as it would have just pulled out and let the case come out. Then I took an empty fired case and chambered that. Also stuck. Then I took an resized, trimmed case (one I pulled a bullet from) and it stuck too. All of these have a hard bolt close and then need to be hammered open with rubber hammer. Keep in mind that a bunch of my handloads chamber fine. So now I see I have not a chamber problem but a brass sizing problem. I use Lee dies, and have successfully loaded many hundreds of other rifle rounds without such problems. Why do some of my 300 blk reloads chamber and some don't? Most if not all of these are 300 blk brass, not made from 556 brass so I don't think it's a neck thickness issue. No doubt now that I will get a case gauge. I may have to pull the decapping pin and full length size a couple again and see if that helps, maybe I did not have the die adjusted right on a couple of runs. The mystery continues .... I will report if and when I get it figured out!

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dellet
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Re: OAL and chambering issues in RARR

Post by dellet » Tue Apr 10, 2018 9:12 am

Try a freshly sized case, not one you loaded and pulled a bullet from and try it in the chamber before seating a bullet.

What is your exact, complete load data.

Both what the fired rounds were that you got the brass from, and what you are trying to load.
Last edited by dellet on Tue Apr 10, 2018 10:20 am, edited 1 time in total.
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Re: OAL and chambering issues in RARR

Post by Whole Bunches » Tue Apr 10, 2018 10:14 am

I had a similar problem with another Blackout rifle. Turned out that when I started measuring the loaded rounds vs comparing the measurement to SAAMI specs https://www.pinterest.com/pin/204069426 ... login=true that the case neck wall thickness of some cases was too thick resulting in the loaded neck diameter that was greater than SAAMI specs leading to cartridges not fully chambering.

That lead to the realization that some brass lead to too great of a loaded neck diameter. That lead to a list of bad brass to use for forming Blackout brass from that lead to a long post about same a few years ago in 300BlkTalk.

I'd start with measuring the neck diameter of loaded rounds that stick and comparing to SAAMI specs. Even if 1/1000" over diameter, they will normally chamber OK, but get much larger than that and there are problems. I have also found that even with "good" head stamped brass that occasionally one will have a thicker neck than normal.

Let us know please.

Contender44
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Re: OAL and chambering issues in RARR

Post by Contender44 » Tue Apr 10, 2018 2:01 pm

This morning before leaving for work I measured the neck diameter of a factory round (Hornady Black which chambers easily) and one of my reloads with bullet not yet pulled. The measured EXACTLY the same (I think .330 going from memory). The diameter at the base was exactly the same also. Trying to eyeball with the caliper pointers, the distance from the rim to the top of the shoulder looked the same also. Confusion continues, but I've ordered the Sheridan slotted gauge for starters. When I figure it out I'll be sure and advise of the answer to this mystery ...

And I will try to re-size a fresh, dedicated 300 blk fired case (trimmed) and see if it chambers empty ...

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