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).
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).
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