Springs, bullet weight-whats up with all that

[Rainman48314]

Does bullet weight matter in terms of malfunctions, ejecting away from the shooters head, felt recoil? Am I better off using only 124 gr as opposed to 115 or 147gr? What are the trade-offs?

Should I buy a heavier weight recoil spring for my new slide PM9...is one even available yet? What's the impact of going from a 9# to 12# spring.

Do I try to optimize for a carry load and let the range performance fall where it may?

I guess I need clarification of how these variables play out.

[jocko]

no such thing as a 9 or 12# jsrping for the jpm9, UR KAHR COMES WITH AN 18# RECOIL SPRING, WOLFFS OFFERS THE 20.5# recoil spring which I hav ein my PM9 and have used almost since day one. It will last longer for sure, my guess is that it shold direct the casing somewhere else to. The grain of the bullet I am not sure should make alot of difference, as it is the load of the round that cold be mor eimportant. i. e. +P ammo and regular standard ammo should eject some hwaqt differently.

Look at the wolffs listing, now if u have the new style beveled front slide then none of those springs from woplffs will work in ur gun, as they are for the blunt noxe version, so right now u are stuck with the 18# factory springs, which should be OK. Most defense loads of 124 grain hp are what most PM9 owners carry and shoot. Some do shoot the 147 grain but by far the 124 grain is the most popular defense load. My range fodder is 115 grain fmj wwb about 99% of the time.

so without knowing which model PM9 u have some of the above will not hold true.

eventually wolffs will offer the heavier recoil springs for the beveled longer PM9 slides.

[OldLincoln]

I just resprung my PM9 with Wolf 20.5 (Corrected from 22.5). It states that the stronger spring is only meant for full power rounds. The experts can say for sure but I would guess that commercial and standard reloads qualify, but if loading light target rounds they may not.

As for ejecting casings, it makes sense (to me) that a stiffer recoil spring would tame the wild casing flights, in that the slide is slowed more before hitting the stop. I haven't shot my new springs yet but expect the recoil to be easier also.

[jocko]

I don't think wolffs makes a 22.5 recoil spring for the pM9. I think u mean 20.5 srping and it will work with anything. I have shot wwb 115 wal mart ammo in it since day one and no issues. Once u get a 100 rounds out of that 20.5 sprngs it will settle down somewhat to. U might see some felt recoil reduction. Some report that, some aren't sure. With my ported pM9 is is hard to talk about felt recoil as mine is just so so pleasant

[TheTman]

I'm only going to address the performance of 115-124 grain bullets vs. the 147 gr. When reloading our own 9mm, my friend and I found that the 147 gr bullets were the least accurate, using a Berretta 92F, and a Star Model 30. I've also have a couple sources that say to stay away from the 147 gr bullet, that the 9mm was designed for a 115-125 grain bullet and people should use those weight bullets. When reloading those proved to be quite a bit more accurate than the 147 grain bullets. However, many folks have good results and like the 147 gr ammo and swear by it. I'd choose the weight that proved most accurate with my weapon. I think the reason the 147 gr bullet had some success was that the extra mass helped it penetrate barriers and some agencies adopted it for that reason.
I'd guesstimate that with the short barrel on the PM9, that the lighter weight bullets would be the way to go. Much like 185 gr bullets have been suggested as a better bullet than the 230 gr offerings for 3.5" barrel .45's. They accelerate faster and seem to give better performance than the 230gr bullets do. I would think the same would be true with the 115-124 gr 9's vs the 147 gr. I think one place where those 147 gr bullets might really shine is in those 9mm "camp carbines" or in longer barrelled weapons.
I'm sure many will say I'm full of chicken puckey and the 147 gr is a great bullet, and that 230gr bullets are great no matter what barrel length .45 you have. I'm just repeating what I've been told by those that know a lot more about these matters than I do.

[CJB]

Its a balancing act. The lighter bullets can be propelled faster, regardless of the barrel length, but short barrels have an advantage. Everything must be kept within the pressure limits as well. The 115's can move faster than 124's, which move faster than 147's.

They move the slide at different speeds.

http://www.youtube.com/watch?v=VKCdq6X08Sw

Therefore... different springs will be optimal for correct operation. In practice, there is some good deal of leeway (or hopefully so), or we'd need to change springs with every different load.

[jocko]

heavier springs by wolffs are not normally TOO heavy to work with even standard rounds at least inb kahrs, I have found the K9 22# wolffs springs work perfect with wwb in a ported K9. Most people don't shoot for range fodder +P ammo ALOT due to cost and felt recoil is in the minds of the beholder. These guns are not like precision time peaces , guns can take a pretty good amount of abuse, if u want to call it that

If one is ever in doubt, probably the best thing to do is stick with factory poundage springs and u won't go wrong.

[Rainman48314]

no such thing as a 9 or 12# jsrping for the jpm9, UR KAHR COMES WITH AN 18# RECOIL SPRING, WOLFFS OFFERS THE 20.5# recoil spring which I hav ein my PM9 and have used almost since day one. It will last longer for sure, my guess is that it shold direct the casing somewhere else to. The grain of the bullet I am not sure should make alot of difference, as it is the load of the round that cold be mor eimportant. i. e. +P ammo and regular standard ammo should eject some hwaqt differently.

Look at the wolffs listing, now if u have the new style beveled front slide then none of those springs from woplffs will work in ur gun, as they are for the blunt noxe version, so right now u are stuck with the 18# factory springs, which should be OK. Most defense loads of 124 grain hp are what most PM9 owners carry and shoot. Some do shoot the 147 grain but by far the 124 grain is the most popular defense load. My range fodder is 115 grain fmj wwb about 99% of the time.

so without knowing which model PM9 u have some of the above will not hold true.

eventually wolffs will offer the heavier recoil springs for the beveled longer PM9 slides.

I have the newer PM9 slide and recoil assembly. I'll be shooting some 124 gr American Eagle FMJ ammo this week. For some reason it was about $2 /box of 50 less than the 115 gr I usually shoot. I also have some of the original hydra-shok (Fed 9BP) in 115 gr I plan to try. In 50 rd boxes, it was priced much better than the common box of 20.

Thanks for the correct spring parameters, Jocko. I just threw out the other numbers to put the question out there.

[Rainman48314]

I shot some Remmington 124 gr, some American Eagle 124 gr (by Federal) and some Federal 9BP HP in 115 gr. I was hard to feel any difference in recoil between these three. Toward the end of my session, I had two or three issues with the AE 124s. I'm planning to carry the Federal HPs and use two or three brands at the range. The Federal is cheap enough, $17.99 / 50 rds to my door, that I can shoot some regularly.