9mm and 1.15 quandry


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Jeff H
November 4, 2009, 10:31 PM
So I just got the 9mm dies and am setting them up with lead 125g bullets. Every reloading source I have sets the min OAL at around 1.15" and the max at 1.169ish, but the thing that seems strange to me is that at 1.15, the grease ring is barely covered by the brass and no other round I have loaded has had the bullet out so far, not to mention that some factory rounds I have are shorter. Is there any advice from the masses on the OAL of this load?

Planning on 4.9g of Bullseye after I work up to it in my gun. Thinking about starting with 4.5ish.

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Beelzy
November 4, 2009, 10:35 PM
Those bullets should have a crimping groove right above the top lube ring. Is the crimp
in this groove??

rfwobbly
November 4, 2009, 11:04 PM
Jeff -
Welcome aboard, hope I can help.

• On lead bullets you DO want to completely cover the grease groove. On most lead RN there is a slight step on the nose and that's what they want you to run the case up to. Maybe a little less with some shoulder showing, but NO further in than lining the step up with the case mouth.

• The SAAMI max length is 1.169" (29.7mm), but it can be anything shorter that will feed reliably in your magazines and gun. Personally, I find on my guns that once I get below 1.080" I have to start watching out for FTFs. So whenever I reload a new bullet, I try to choose a length in excess of 1.100" because I know I'll be trouble-free in that department. Saying all that, I must ad that I do have a 115gr Hornady HAP load that calls for an OAL of 1.040" and functions great. But there's only one way to find out and that's to load it and shoot it.

• As I said there is no minimum length, except that set by your gun's feeding mechanism. However, the 9mm case is so tiny inside that as you reduce the OAL, you also have to reduce your powder. This because it's a set volume of powder burned in a set internal case volume that to a large extent determines chamber pressure. Generally speaking, if you reduce the OAL you are reducing the volume inside the case, so you have to make a like reduction in powder. Obviously, you can reduce the OAL by .010" with no problems, but a reduction by .100" is serious stuff in 9mm.

Bottom line, don't use a load that shows an OAL of 1.160" if you intend to load at 1.000". Follow?

• So for your case, you'll seat a test bullet up to the shoulder or until it looks right to you. Measure it with calipers. Then try to find a load for that OAL with a 115gr bullet using Bullseye. This is why experienced reloaders keep so many reloading manuals around. You might have to look in 2 or 7 sources to find something.

I have a load listed in an old book for the Lyman 115gr FP using an OAL of 0.997 and 3.8 to 4.9gr Bullseye.

Hope this helps!

Jeff H
November 4, 2009, 11:13 PM
Those bullets should have a crimping groove right above the top lube ring. Is the crimp in this groove??

No crimp groove, this is a RN bullet not a SWC, sorry if I misled anyone.



Oh and on the crimp topic, I am crimping around .375ish, what do other people use?

rfwobbly
November 4, 2009, 11:41 PM
Jeff -
On 9x19, the crimp is only to remove the belling. You don't want to crimp so much that you reduce the dia of the bullet. You are not trying to hold the bullet in as on a 38 Spcl. I generally aim for .002" under SAAMI, or .378".

I've found that at that dia, if I'm loading plated bullets, there's no breaking of the copper plate, and they hop right into the chamber.

Hope this helps!

chris in va
November 4, 2009, 11:44 PM
Look at it this way. The maximum oal my 9mm TC's will run in my HiPoint carbine and CZ 75BD is 1.04". No that not a misprint. 4.0gr Universal under the 124gr TC bullet, runs perfectly in both.

I haven't loaded LRN yet, just some FMJ at 1.15. You just have to make a dummy round and find what the bullet will chamber reliably in your individual firearms and go from there.

But I'm new at this, having made only 1500 rounds so far, take it at face value.

Aristodemus
November 5, 2009, 04:22 AM
Chris, DUDE!

About a year ago you liked something I put in a flame-war on DKos.com: __________________
There are two kinds of people in the world: (1) the free; and (2) food animals.

-Aristodemus

You advised you might use my quote as part of your sig line but I didn't expect attribution. Muchas gracias; I am quite honored.

Keep a look out for more RKBA cross-postings from DKos. There's a cadre of 2A supporters who aim to publish one diary per week, on narrow topics, and see how many fence-sitters we can get to reconsider. Will it turn Coke to Pepsi? No, but it just might find my car keys, so to speak, and that's all positive ROI and consistent with Oleg's stated purpose of gaining adherents, not pissing people off.

--Aristodemus

Deus Machina
November 5, 2009, 07:52 AM
I've noticed CZ's have a really short throat, too, but 1.04"? Eesh!

Anyway, to the OP, the Lee manual suggests 1.15" for only some of the powders, and gets down pretty short for some of the slower ones.

I've taken to setting all my lead to 1.125", since that's 1) the same as some of the factory FMJ I shoot, and 2) gives a little leeway either way for it to feed in my CZ 75D PCR.

The min. OAL listed in the reloading manual for the powder I use is 1.15", so I know I'm seating it further than I'm supposed to, but no sign of problems on my end yet and I took an extra step down from max. Be careful.

Also, in my case, my LRN does not have a step, and has a slightly wider ogive. So there is more weight up front than the common stepped ones, so I may not be pushing the base any farther back into the case than the author figured. It's not like he had specifics for certain molds.

Really wish they would include both OAL and seating depth. And I should buy a tumble-lube style mold to help out with the throat depth and hopefully cut back on the leading I'm still getting from this one with its scant single groove.

Okay, ranting over. :o

rcmodel
November 5, 2009, 12:14 PM
The single grease groove is plenty if the bullet size matches your barrel, the alloy or hardness is correct, and the lube you use is any good.

Thay made bullets that way for 100+ years for a reason. They work.
If they didn't work, they would have changed them by now.

rc

F_L
November 5, 2009, 01:28 PM
Jeff,
I load 124 gr LRN for my P6 at 1.065 and 3.8 gr Bulleye. Anything longer than that will not chamber in the P6. See what will chamber and work to that length. Also, after about 200 rounds I get enough lead in the lands that it won't chamber at 1.065.
Fred

Jeff H
November 5, 2009, 04:54 PM
I load 124 gr LRN for my P6 at 1.065 and 3.8 gr Bulleye.

Interesting. That load is below the minimum for both the OAL and powder...IIRC I thought that Bullseye was 4.6-4.9g for 125g LRN.

Anyway, I see that there is enough variation that I shouldn't be concerned about being shorter than 1.15. I'll just find a measurement that works with my gun and work up a load. Probably just use the same measurement as the FMJ that I have been using since I know that cycles fine. I think that was around 1.1 but I'll verify tonight.

rfwobbly
November 6, 2009, 09:27 PM
Interesting. That load is below the minimum for both the OAL and powder.

Read my post again. The pressure comes from 1) the space inside the case, and 2) the powder. In order to remain near the same pressure, if you reduce the OAL you must reduce the powder.

You didn't mention what pistol you were loading for. As previously mentioned, some bullet nose shapes make a huge difference in OAL in some pistols simply due to the chamber and rifling configuration.

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