Robert Westcott
Member
Looking for a good load for my Ruger PC9 at 100 yards with 124g JRN. Suggestions?
This is great info, and should help cut my process time in half or better. I’m planning 9mm PCC loads with coated RN bullets from Acme. I’ve got a 9mm Hi-Point carbine to try them out in.Welcome to THR.
When I did load development for carbine loads at 50/100 yards, I found following with 124 gr vs 115/100 gr loads:
- Bullet drop (Vertical stringing) is more significant at 100 yards dependent on your muzzle velocity variance
- Lighter faster bullet will produce less bullet drop at 100 yards
- 115 gr bullet around 1300 fps at muzzle of 16" carbine barrel will drop about 10 inches at 100 yards (Heavier 124 gr bullet will drop even more)
- So smaller muzzle velocity variance will produce smaller groups (Or shotgun pattern) at 100 yards
- If your muzzle velocity is close to supersonic, your bullet will travel through transonic speed wobble down to subsonic which can affect bullet trajectory
- Bullet speed will decrease around 100 fps for each 50 yards of travel
- To get smaller groups at 100 yards, work on identifying loads that produce smallest 50 yard groups first
There are some who posted ridiculously small groups at 100 yards with Pistol Caliber Carbines and I am skeptical as "routinely", I do not get such small groups. My 10 round group sizes are more like 5 inches with smaller being around 3 inches.
Speed of sound is 1125 fps. To reduce bullet drop and transonic tumble, I prefer to use lighter 115 gr bullet or even lighter 95/100 gr bullets with higher muzzle velocities so they could remain supersonic all the way to 100 yard target as you will lose about 200 fps to 100 yard target. My 100 gr load's muzzle velocities are just below 1500 fps (1478-1475-1480-1471-1467 fps). Another option is to use subsonic load at muzzle to avoid the transonic wobble issue.
My reference benchmark for 9mm accuracy is Atlanta Arms 115 gr FMJ AMU (1.130" OAL, 1150 fps) with accuracy requirement of ten-shot groups at 50 yards with an average group size not to exceed 1.5 inches that are "designed for extreme accuracy at 50 yards and is used by the Army Marksmanship Unit and the Marine Service Pistol team for service pistol matches." - https://atlantaarms.com/products/9mm-115gr-fmj-match-amu.html
http://www.gunsandammo.com/reviews/jr-american-flag-carbine-review/
My 50 yard 10 shot groups with RMR 100 gr HM RN (Yes, with MIXED range brass) - https://www.thehighroad.org/index.p...n-9mm-40s-w-45acp.799231/page-3#post-10245856
Which is on par with what Guns & Ammo produced with their JR carbine at 50 yards (1.2"-1.7" shot groups).
Promo load produced less muzzle velocity variance than HP-38 load and smaller 100 yard group. (1478-1475-1480-1471-1467 fps)
This makes complete sense. The only reason the bullet drops is gravity. Gravity's pull is the same on all objects. Therefore, a bullet traveling faster is able to go father down range before it drops a given distance.When I did load development for carbine loads at 50/100 yards, I found following with 124gr vs 115/100gr loads:
- Bullet drop (Vertical stringing) is more significant at 100 yards dependent on your muzzle velocity variance
- Lighter faster bullet will produce less bullet drop at 100 yards
- 115gr bullet around 1300 fps at muzzle of 16" carbine barrel will drop about 10 inches at 100 yards (Heavier 124gr bullet will drop even more)
Exactly and this idea was first suggested to me by Walkalong and he was correct.This makes complete sense. The only reason the bullet drops is gravity. Gravity's pull is the same on all objects. Therefore, a bullet traveling faster is able to go father down range before it drops a given distance.
That being the case, maybe you should look at 95 and 100gr bullets originally intended for the 380Auto, which also fit 9x19 Luger.
With retirement upon me, I hope to continue range testing where I left off, especially using a DIY hybrid pistol/carbine optical machine rest (Once finished building). One of these is testing RMR's 95 gr FMJ along with 115 gr JHP/FP Match Winner.
I'd go full-power, which in 9mm is very well served by Hodgdon CFE Pistol or Alliant BE86. Both have websites with extensive load data.Looking for a good load for my Ruger PC9 at 100 yards with 124g JRN. Suggestions?
Yes, I have already done Berry's 115 gr HBRN-TP vs 124 gr HBRN-TP and like both of them - https://www.thehighroad.org/index.php?threads/9mm-and-herco-for-jacketed-lead-plated-bullets.745656/An interesting addition to your testing would be the Berry Mfg 115gr Hollow Base RN. I don't usually nominate plated bullets for the long distance accuracy column, but these are thicker plated and have the longer bearing area which might help stability.
I have actually done fast vs slow burning powders, including BE-86 and was disappointed it didn't produce smaller groups than faster burning powders.I'd go full-power, which in 9mm is very well served by Hodgdon CFE Pistol or Alliant BE86. Both have websites with extensive load data.
I would try both routes also - Sport Pistol would be my first stop for a 'fast' option - but would be more confident of staying supersonic to 100 yards with a 124 with BE86. Rightly or wrongly.I have actually done fast vs slow burning powders, including BE-86 and was disappointed it didn't produce smaller groups than faster burning powders.
Agree on Sport Pistol as I now consider Sport Pistol replacement for W231/HP-38 that meters better, cleaner burning and less temperature sensitive.I would try both routes also (Sport Pistol would be my first stop for the 'fast' option) but would be more confident of staying supersonic to 100 yards with a 124 with BE86. Rightly or wrongly.
Yes, independence from work and goal of my retirement is to conduct more objective factual load testing and myth busting to the benefit of THR members and guests.I hope that's retirement from a steady paycheck, and not retirement from this board. I enjoy your thorough posts.
I agree that less ES in velocity will produce smaller groups regardless of the bullet drop.Drop is more than full powered but as long as drop is consistent (Small ES) then it isn't hard to get the range and make consistent hits.
Right. And of course we need to have a consistent hold, we can induce vertical stringing with our gun handling with pistol just like we can with inconsistent shoulder pressure with rifle.Since I suspected this vertical stringing was likely from variation in velocities,
My 50/100 yard groups were shot with carbine on bipod with firm push forward. I agree on the consistent hold hence why I am building the machine rest for carbine testing.Right. And of course we need to have a consistent hold, we can induce vertical stringing with our gun handling with pistol just like we can with inconsistent shoulder pressure with rifle.
I am also using Lyman #49 and yes, I do agree on accuracy of Power Pistol for 9mm as BE-86 at almost the same burn rate shattered all of my previous reference loads for accuracy except WST.Lyman's #49 recommends Power Pistol as the starting point for 9mm carbine loads.
It's the most accurate powder listed for 5 of their 6 loads tested in a Ruger PC-9. Top velocities too.