Return to Reloading 9mm after decades ...

S

Stirling

Inactive
New here, as of today. Not new to handguns or reloading 9mm. I got a call from a young friend right after the shootings telling me he wanted to rush out and buy a gun. This started me looking at the whole business again after decades of pursuing other things.

That's all intro, I do have a very specific question. I have pet load I worked up 30 years ago while trying to solve a reliability issue with the Styer GB. After fussing with it for 18 months I just sold the gun. The pet load was Sierra 115 JHP seated to 1.10 with 8.5gr Blue Dot, WW factory primed Brass. This load turned out to be usable in virtually every 9mm I tried it in with the exception of the Styer GB which had multiple issues (magazine issues, copper wafers blowing out the gas ports and jamming the slide).

When I tested this load in a HK P7 PSP if functioned flawlessly shot tight groups and produced good velocity (~1250fps p7 G19). It also worked fine in a Glock 17 1st Gen, Baretta M92, Sig P225. I discovered early on that the HK P7 was "different" from all the others in that the OL of 1.10 combined with the shape of Sierra 115 JHP caused the bullet to snug into the lands. So I backed off on the load and reduced OL to 27.5mm aprox. 1.08 and worked back up to 8.5 Blue Dot without any notable problems. Shot lots of these without any sort of problem.

Now 20 years later, I discover people getting excited about seating bullets back away from touching the lands. I loaded a few dummies and see that the 27.5 MM OL still touches the lands in the P7. No signs of pressure issues. Cases look like and measure like factory ammo, for example 115 Gr Silver tips. There are no fluting indentations from the P7 Chamber.

On the other hand switching to powder to 7.0,7.2, 7.4 Grains of VV 3n37 all other things kept equal produced significant fluting marks (p7 chamber) in the brass, not just powder marks. You clean off all the powder and magnify the image and you see a fluting stamp that gets heavier as you work up 7.0,7.2, 7.4 VV 3n37. I have subsequently abandoned VV 3n37 for this particular application.

I am wondering how important it is to actually have set back from the lands in the p7. The gun functions flawlessly. No pressure issues. There no marks on the dummy loads after they are extracted. This can possibly be explained by the shape of the forcing cone or the leading edge on the twisted "polygon" (not really a polygon, more like a rotating oval).
 
Last edited:
Welcome to the forum.

In rifle cartridges, touching the lands can raise pressure 20% or so as compared to being 0.030" off the lands or so. Dr. Lloyd Brownell figured out a long time ago that this had to do with gas bypass around the bullet while it found its way into the throat. The bypass flow prevent pressure from rising as early. However, when you seat a bullet enough deeper, the loss of powder space catches up with to you and pressure starts to rise again.

Pistols are a bit different in that they operate at lower pressure to start with and they have much bigger expansion ratios. I seat cast lead bullets out to headspace on the bullet (a 1911, in my case, in .45 Auto), as I noted groups shrank about 40% and leading essentially ceased when I did this (outside of a few traces). I've not seen any similar improvement headspacing on the bullet with jacketed bullets.

If these guy's are seating deep to insure the cartridge headspaces on the case mouth instead of on the bullet, I'm not convinced that's a gain. If they are doing it because they are afraid of a pressure rise, in theory, if touching the lands raises pressure in your gun, seating a little deeper will let you use a little more powder and get a little more velocity, if you need it, but seating too much deeper will raise pressure again and should be avoided. Because pistol powder spaces are small, you don't need to seat much deeper to take up a fairly significant additional percentage of the powder space, and that can raise pressure. Pistol bullets (but especially lead) are known to be unseated or to start unseating under primer pressure alone, so I suspect many of the actually are in contact with the lands when the pressure build-up gets serious, and this is one reason you don't hear of more accidents from bullets being pushed deep into a case during feeding.

Whatever way you seat, the trick is to adjust the load to suit the gun with the bullet seated that way. If the guys interested in deeper seating are seating deeper because they believe there's a feed reliability improvement that results, the same thing applies: adjust the charge for how you are loading the bullet.
 
pistol loads

I back off of touching the rifling in my 9mm and 45 ACP because if some should seat just a little long it may prevent the slide from closing fully. For home defense reliability is number one. For target work, get as close to touching as you like.
 
From the numbers you stated it seems to me that your OAL is on the short side. Which could very well cause feeding problems, function problems
 
Pressures and OL ... etc

Thank you for the helpful replies. Yes 27mm seems kind of short until you look at the the shape of Sierra *8110 115JHP which is an old style truncated cone with a high shoulder which gets you into the lands quickly. Compare it to most recent 9mm 115JHP shapes which have a long pointed curve with no abrupt shoulder. That shape will always create a longer OL which is good news for feeding. The early published data from Sierra *8110 115JHP gave a minimal OL 1.015. I always assumed that was a misprint.

I tested the OL of 27mm in a Glock 19 and the velocity at 10 ft was 1280fps which is in the same ball park with the tests I did before at the old OL of 27.5 mm. I get about 50fps spread using Bluedot with the Sierra *8110 115JHP 9mm. That's carefully measuring each load with a powder trickler.

Decades ago Speer's Handbook #9 and #10 had some frightening data for 9mm Blue Dot. I tried working up to some of their max loads with Speer 100gr Round Nose HP and never got very close to the max which was 10.2. I was shooting a Colt Gov MKIV 9mm back then. Later on I worked up to 10.2 Blue dot with Sierra 90gr HP seated to 1.01 but that was shooting in a PB92. With that load there were extreme spreads which were unacceptable, over 100fps. I shot a lot of Sierra 90gr loaded over 8.1 Herco which was much more tame than Blue Dot and gave tight groups. Don't shoot Sierra 90gr any more, I have about 1200 bullets left sitting in boxes. The Sierra 90gr doesn't feed well in some pistols. The Glock 19 and P7 will digest it but they are very tolerant compared to other pistols I have used.

I have used the early data (1st ed) for VV 3N37 which also had some kind of marginal top end loads. Their reported velocities are out of minimal spec. test barrel which means nothing like any pistol you will ever shoot. Anyway I tried working up a usable load 3N37 Sierra *8110 115JHP and ran into trouble at 7.4 Grains. Just to find out I tested 3N37 with Sierra 90gr up to 8.0 Grains which gave ~1450 out of a Glock 19. It was very stable, some tests had a spread as low as 20fps. If I ever decide to shoot the Sierra 90gr again 3N37 would be my choice. Much more stable than Blue Dot, which doesn't like bullets of that weight.


Back to the P7 overall length issue, I was little worried at the 27.5 mm OL with the Sierra *8110 115JHP that it might not go all the way into battery after the gun gets dirty from firing a few rounds. I have never shot more than 50 rounds between cleanings so that scenario isn't a problem but you like to think your ammo will be reliable under all scenarios. I tested the P7 to see if striker would fall with the slide back less than a millimeter and was horrified to discover that the striker will fall. I haven't thoroughly evaluated this scenario.
 
Last edited:
That is a lot of detail. i sugest a crono. 9mm is the lowest margin to reload, it may not be worth it. i load for several 9mm guns and do not worry COAL to lands.
 
Owning multiple 9mm and .45 ACP handguns, therefore not loading specific lots for any. In bullet seating and OAL (and bullet style) each has different quirks. As such reloads are as much for reliable feeding as for accuracy, at 25yds on the targets I shoot with a good load, its all good. YMMV
 
When I started handloading ~2000, I started overloading work ups to failure with every powder and 9mm bullet combination I could find.

One memorable experiment was putting a 9mm handgun in an ammo can, burying the ammo can with a hole for the bullet pointing down and a hole for the trigger string pointing up. The gas rounded out the can like a football. The can breathed in dirt and sand so I could barely get the Kel-Tec action open to clean it. I gave up on underground testing.
 
i sugest a crono.
Click to expand...

Oh yes, I use a chronograph. After extensive research and reviewing all my records from the work I did 20 years ago including a close study of all the brass samples from the tests in several pistols, i recently tested 115gr Sierra JHP PowerJacket over hand measured 8.9 Gr Blue Dot seated seated in new WW factory primed brass to OL 27mm. Test pistol was HK P7 PSP (1981). At ten feet from Pro Chrono it averaged 1302 fps. First round out of clean barrel was 1323fps. In the P7 and others the clean lightly lubed barrel produces a spike in velocity on the first round. I have no intention of loading any more 1300fps loads. An extra 50fps isn't worth the risk.

The cases looked virtually like factory SilverTips at 1100fps. I tested the same load with 7.4 grains of VV 3N37 which gave av 1265fps and noted more damage to brass with fluting markes in the metal. Discontinued use of 3n37. I did find that powder worked well with Sierra 90gr JHPs which I no longer use due to feeding unreliabiity.

I am NOT recommending this loading to anyone else. I saw records of other people shooting this in other guns. My powder lot and primed brass are all from the late 1990s so none of this data is current. The BlueDot is in a paper canister from Hercules.
 
Last edited:
I haven't reloaded much recently but I have reloaded extensively and tried a bunch of different powders in 9mm. Universal Clays is my choice for factory level 9mm loads. Blue dot works but it doesn't meter well and has higher deviation. Universal Clays is clean at the pressures generated by 9mm and 40. If you load 45, Clays which is a different faster powder is the better choice for factory equivalent loads. It's similar to bullseye. Blue dot is one I like for 32 mag. Blue dot is also fine in medium 357 and 38 super and 40 and 10mm. It's just not optimum in my opinion for 9mm luger.
 
"...touching the lands..." Doesn't apply to handgun cartridges and is a load tweaking technique in rifle.
8.5 grains of Blue Dot is the current Max load for a jacketed 115. 1.10" is kind of short too. Alliant gives 1.125" as the OAL they used. Only ever used 1.169" for any 9mm bullet myself. Very much doubt it'd ever be an issue. SAAMI minimum OAL is 1.000".
In any case, do not start at the Max load with your buddy's pistol. You need to work up a load for his pistol.
 
measure factory ammo. 1.169 is often too long for many magazines. A factory round is often loaded to 1.120 to 1.135. This is particularly true for hollow points. If you load something like a 124xtp to 1.169 you will not be able to chamber the round because the bullet sides will hit the rifling before the round can chamber.
 
I'm loading the same bullet, Sierra 115gr JHP. Sierra's min OAL is 1.050". Doing this however still has it jamming into the lands in some pistols. Which in an semi auto is not good for 2 reasons actually.
1) slide may not fully close
2) if you don't actually shoot it the slide may not open by hand. Ask me how i found this out...

Also i have since switched powders from Blue Dot. Burns too slow and get a lot of unburned powder out of the muzzle.
I've since switched over to Silhouette and True Blue.
 
You must log in or register to reply here.
Back
Top