tts said:
I've read that the manufacturing process of JHPs lends to more accuracy. What are your thoughts?
For the same weight bullets, due to the hollow space in the nose, JHP bullet will have longer base (bearing surface) to engage the rifling and stabilize the bullet. Although this may help, this factor alone won't necessarily translate to greater accuracy as shot group accuracy is the result of several reloading variables.
Ultimately, accuracy will benefit from more consistent muzzle velocities. More consistent muzzle velocities will result from more consistent chamber pressures. For me in theory, more consistent chamber pressures will result from (and taking into consideration the use of mixed head stamp range brass resized with slight variations in case lengths and condition of brass by manufacture and usage/work hardening):
1. Consistent bullet weight
2. Consistent powder charge
3. Consistent primer ignition
4. Consistent neck tension
5. Minimized high pressure gas leakage
1. Bullet weight. For me, accuracy is everything and have spent my early years of match shooting hand weighing bullets to sort by exact weight. Not anymore, as I learned other reloading variables like powder charge variations trump slight variations in bullet weight.
Montana Gold (and many other quality/premium jacketed/plated) bullets will vary less than 1 grain bullet-to-bullet and I have used this as my standard for consistency in jacketed/plated bullets.
2. Powder charge. I use 1/10 grain variation or less for charge-to-charge consistency and most small ball/flake powders like Bullseye/Titegroup/WST/W231/HP-38/Universal/WSF/AutoComp will produce this level of consistency.
3. Primer ignition. I have used Winchester SP/LP exclusively over the years but tried Magtech/PMC SP and Wolf/Tula LP primers (bronze/brass colored cups) during "primer shortage" in recent years with happy results (exception being silver/nickel colored lot of Tula SP primers I am currently
having ignition issues with).
4. Neck tension. This is where the length of bullet base may come into play as longer JHP bullet base will be seated deeper in the case neck resulting in greater neck tension and producing slightly higher chamber pressures/muzzle velocities using the same powder charge/OAL as FMJ bullet. Some USPSA match shooters I have shot with, in pursuit of absolute economy of reloading, will often use Titegroup/JHP bullet combination, but not necessarily for accuracy as long as the load met power factor minimums (most match shooters simply developed/adjusted their load's OAL/powder/charges until they achieved a certain level of acceptable accuracy/PF regardless of bullet types used).
5. High pressure gas leakage. Longest OAL that will reliably feed/chamber in your pistol/barrel/magazine will reduce gas leakage along with the use of .355" (for 9mm, .400" for 40S&W) groove diameter barrels with shorter leade/start of rifling for more consistent chamber pressures.
Keep in mind that many shooters also prefer the use of JHP bullets for the purposes of reduced smoke and/or lead exposure issues. So if you have these concerns, it will affect your bullet selection.
In the end, it will probably come down to your barrel's groove diameter, leade length and start of rifling as to whether you would benefit more from FMJ's exposed lead base's ability to expand to seal with the barrel vs deeper seated JHP to produce more consistent chamber pressures (so slug your barrel to find out what the groove diameter is). For me,
holes on target speak volumes. It would be nice to range test both bullet types in your pistol before you made a large purchase. Perhaps you could call Montana Gold and ask if you can obtain a bullet sample?