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Posted: 3/12/2016 10:25:41 PM EDT
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I am loading 124gr fmj rn 9mm with 5.9grs of HS6. I have my col at 1.140-1.141". Based on the slight bulge of my case where the bullet was seated, I estimated the bullet is seated at 0.202 or less.
I am just not sure how deep I should be seating them because the deeper you seat it, the higher the pressure is going to be depending on the load as I am pretty sure the base of the bullet is touching top of the powder. Most research I did ended up with the commenters saying just follow the COL. This doesn't help me when brass cases that I am loading vary from .751 - .748". I know there are varying COLs and that mine is within the range, but how deep is too deep where it will blow up my Glock? The way I look at it, I could meet the COL let's say 1.135, but I could be seating a bullet deeper than the rest of my loads to get a particular round to match the COL of 1.135" In a nutshell, am I being to conservative with my bullet seating of 1.140" with the 5.9grs of powder in a case that varies from .751" to .748" My Speer manual shows about 1.135 for COL with 124gr 6.0 gr HS6. but Hodgdons shows 6 grs to a max of 6.6 grs with a 1.150" COL. Hope someone here can help clear up my confusion. |
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They fit in my mags and I tested them in my barrel and no issues. I just concerned about the pressure. As I look through my book, I see HS6 is 7.4 grs as a max with 115gr with 1.135" COL.
So do you think I could actually seat my load a little bit deeper than I already have and still be safe as you mentioned with your 147s? |
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If your real concern is .003" difference in case lengths causing seating depth differences I'd say you are over reacting.
Let me put it this way. If you were to load a safe load at the recommended C.O.L. and your casings varied as much as the SAMMI case length limits you would still be very much in the safe zone. I hope this helps. Motor |
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Quoted:
Yeah, I guess 3 thousandths of an inch ins't that much when you think about it. Just a few threads about pressure and seating the bullets deeply kinda worried me. I understand. One thing you have to remember is that if you fallow the manual you will be OK over 99.9% of the time. So if you are loading a published load and loading it according to the dimensions given in the manual you should be safe. Some times (probably many times) its hard to find data that is for your specific bullet but often if you search enough you can. If you can't then you have to start cross referencing and comparing bullets to come up with a good COL. Another factor is the load level. If you are loading start level or mid level loads (as compared to top end) you have more safety margin. If you take your time and look at the information in those threads about deep seating and high pressure you will see that it takes more than "normal" differences to create those situations. |
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Yeah, that is what happened. Not sure why the Lyman manual doesn't have a 124gr load. Basically I was reading Hoggdons website and other websites to try and supplement the lack of information in my manuals.
Thanks for your input. If the weather is nice tomorrow, I'll test them at the range. |
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Welcome to Arfcom and the Reloading Forum. Either of those are close enough if you follow the data and work up from the start load. Start load=lowest charge shown. The start load is a reloaders best friend. At this level it fine to substitute like but different components or bullet they weigh within 5 grs of the data. BTW, most of my 9mm loads are right around 1.10 OAL. |
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Quoted: Welcome to Arfcom and the Reloading Forum. Lyman 49 has loading data for 125 gr JHP and 120 gr cast. Either of those are close enough if you follow the data and work up from the start load. Start load=lowest charge shown. The start load is a reloaders best friend. At this level it fine to substitute like but different components or bullet that weigh within 5 grs of the data. BTW, most of my 9mm loads are right around 1.10 OAL. |
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My experience with HS6 is at the starting end of the powder range, you may see a lot of unburnt flakes. It does clean up somewhat as you approach max.
Also the data listed on hodgdon website lists 124gr data for berry's which is a plated bullet. 125gr Sierra FMJ lists 6.4 as start and 6.9 as max with a COL of 1.090 Hope the weather holds up tomorrow and you get to shoot! |
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Quoted:
Variance in case length will give you inconsistent crimps but shouldn't affect the overall length. Sometimes I think we all "think" too much. AJE. You are absolutely correct but what the OP was worried about was that a casing that was short would be seated not as deeply. This is true but only in the sense if measured from the case mouth. Which actually has nothing to do with altering pressure except for as AJE pointed out it has the potential to slightly change neck tension. The thing that matters most on seating depth is the space between the bottom of the bullet and the inside bottom of casing. This will not change as long as the OAL is maintained no matter how much the casing length difference is. Should have thought of this before. Oh well. 
Motor |
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Most all the 9mm empties I find run from 0.743 to 0.748" depending on head stamp.. I load all mine in batch by headstamp, and with 124 or 147 FMJ, I go 1.150" and call it a day
Only OAL adjust I have to fudge is if I am loading HP or lead, then it bullet maker OAL for HP, or drive band placement for cast lead that pretty much dictate your OAL |
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OP - your OAL of 1.14 to 1.15 is correct for most 9mm loading. Many manuals list the max length at 1.169" for 9mm - but as others pointed out, that length may cause problems in some magazines.
Yes, 1.150" may seem "long" to some. But loading longer: -is safer since the pressure is lower -brass lasts longer due to lower pressure -gun lasts longer due to lower pressure -longer gernerally feeds better - longer is gernerally more accurate because the bullets closer to the lands There's just no good reason to load 9mm short! With one exception: certain CZ handguns. I love CZ s and own a few. They are very accurate. But some of them have very short throats; the longer loaded 9mm can even touch the rifling if you are not careful. |
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I run 124gr RN (round nose) and HS-6 at 6.4 gr, COL 1.150 (no Glock), they run at 1050 - 1090 FPS depending on all the variables you talked about.
Bullets that are longer, where more of the round is seated into the case I charge less, exactly as you say, but as long as you aren't going too fast/exceeding pressure its kosher. Do you have a (or access to a) chronograph? Knowing the velocity of your projectile would allow you to calculate barrel pressure (and answer your question about how conservative your load is). Calculating barrel pressure |
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I am actually probably going to pick up a chronograph next payday. I figure with my 5.9 grs of HS6 and COL of 1.140 around 950 to 1000fps for a guess based on my book.
I can also tell the bullet isn't touching the powder as I can shake them an hear the powder moving around. Hopefully this weekend I can try and test since the weather didn't cooperate yesterday. |
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Quoted:
By plunk, do you mean that is fits in the barrel and chambers? Drop assembled cartridge in the chamber,, it should fall in freely and set proper.. in general, the sound it make when it drop in properly is kinda "plunk"... turn barrel over and cartridge should "ideally fall out freely |
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I agree with previous reply that HS-6 will leave unburned powder flakes at lower charge levels.
HS-6 is my "go to" 9mm powder, it's all I'll use in SD loads. FWIW- I only use CCI 550 Small Pistol Magnum primers in HS-6/124gr XTP loads. Get a much cleaner burn, no pressure concerns at mid level charges, and no noticeable difference in recoil. Accuracy improved a bit going from CCI 500 to CCI 550 also. |
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