Restriction On Changing Springs In Product Guns?

[mcb]

So I shot my first practical pistol match a few weeks ago and I am really looking forward to the next one in two weeks. I have a Springfield Armory XD-40 Service and have been shooting a stiffer recoil spring and one piece guide rod in it. Am I allow to shoot this spring/guide rod in the production class or does it have to be the stock weight recoil spring and captive guide rod. I have read the rule book but have not found anything the specially prohibited or allowed that type of internal change.

Thanks

mcb

[BSeevers]

Any internal change is ok as long as you don't alter weight by more than 2 oz in USPSA. Its in the rule book. External change are not allowed except sights and grip tape/sock

Now a using a more heavy spring will cause more recoil but that's a different story.

[Flexmoney]

As Uncle Bill stated, in USPSA Production, you can change the spring (most want a lower weight spring).

In IPSC Productin (outside the USA), I think you have to stick with the stock parts.

[mcb]

Thanks guys I did not want to break the rules.

Now I know I'm new around here and should probably not start and argument on my second post but I would like to explore the spring stiffness idea.

First the choice of spring can't increase or decrease the total recoil impulse, darn laws of physics, namely that whole conservation of momentum thingy. Now the spring stiffness can change the length of time and peak accelerations of the impulse but the total impulse does not change unless the projectiles mass or exit velocity change.

Now given I'm shooting an XD that does not have a recoil buffer of any type I would think a stiffer spring would lengthen the impulse and reduce the peak acceleration spike you get as the slide hit the stops at the full rearward position. The stiffer spring would make the slide hit the stops at a lower velocity. In my experience shooting both the 18 lbs stock spring and the 22 lbs after market spring I do notice that I have noticeably less muzzle climb with the stiffer spring.

I though the reason for using lighter springs was to decrease cycle time by increasing the reward velocity of the slide?

mcb

[Flexmoney]

mcb,

You can debate this with guys until your face turns blue (many have done so). Most all the conmpetition shooters like a lighter spring. Quite a few have even experimented with different weight springs. Most of them will tell you, with little doubt, that they like how the gun handles with a lighter spring. (I always ask them to prove that they can actually get better hits and times. )

Probably, what you will hear (and I am sure we have past threads on this very subject if you want to search for them) is that a heavier spring will give more of a rolling recoil, whereas a lighter spring will make the recoil a bit more snappy...getting the gun back on target faster

And, a heavier spring will hit a bit harder as the slide closes...perhaps, dipping the front sight. (All a timing issue, really.)

[DougCarden]

As far as the XD goes, I replaced the factory 9x19 spring with a 15lb Wolff conventional, and with my reloads at 10yds the rounds almost touch shooting a pair. I cannot do that with the heavier factory spring. FWIW Flex summed it up pretty well.

DougC

[mcb]

mcb,

You can debate this with guys until your face turns blue (many have done so).  Most all the conmpetition shooters like a lighter spring.  Quite a few have even experimented with different weight springs.  Most of them will tell you, with little doubt, that they like how the gun handles with a lighter spring.  (I always ask them to prove that they can actually get better hits and times. )

Probably, what you will hear (and I am sure we have past threads on this very subject if you want to search for them) is that a heavier spring will give more of a rolling recoil, whereas a lighter spring will make the recoil a bit more snappy...getting the gun back on target faster 

And, a heavier spring will hit a bit harder as the slide closes...perhaps, dipping the front sight.  (All a timing issue, really.)

<{POST_SNAPBACK}>

Your explanation makes sense Flexmoney I guess I just thought the rolling recoil would be easier to control and less fatiguing then the snappy recoil. With my limited experimenting between the 18lbs stock spring and the 22 lbs aftermarket I thought the heavier spring help muzzle climb. Maybe I will have to see if I can find a spring softer then the original 18 lbs spring; might have to try the 15lbs spring that DougC suggested. The guys over at http://www.hs2000talk.com almost unanimously suggest either a 22 or 24 lbs spring for the XD-40. Hmmm... I still have a lot to learn.

Thanks

mcb

[BSeevers]

Without being too negative, I submit that the guys here wear guns out. I personally have shot somewhere around 500K rds in my life. Man I really should be a better shooter. Most with lighter springs. I know I can learn from anybody though.

[Flexmoney]

mcb

You will hear the "go heavier" arguement from the guys over on GlockTalk as well. The difference is, the guys and gals here shoot at Mach-10 with their hair on fire...and they do so accurately.

To tell you the truth, I can't recall the last time somebody brought up the term "muzzle climb". The major concern around here is getting the gun back to the (next or same) target for the next shot.

Regardless, you have to go with what works for you. I still use a stock spring in my Glock 35 (40 caliber at Major power factor). It works for me because that is what I have shot tens and tens of thousands of times.

If I were shooting Minor full-time, I would likley go to a lighter recoil spring to get the slide speed up and get better ejection (my minor loads just dribble brass out of the gun on ejection).

[mcb]

Thanks again guys,

This IPSC style shooting is very new to me and I am completely addicted even though I have only shot one match. I have been a shooter and hunter my entire life but my XD-40 Service was my first center fire semi-auto handgun. I have had the gun about three month and have nearly 1800 rounds through it and have since picked up an XD-40 Tactical to go with my original XD-40 Service. The Tactical was what I really wanted originally but I could not find one at the time and got a good deal on the Service model. A few months later I found a Tactical. I figure I will shoot both this summer and maybe sell the one I shoot less this fall.

I have shot a lot of 50ft indoor target, trap, skeet and sporting clays but was always disappointed that these sports don't require timely reloads. Practical pistol does require timely reloads and this was a big allure for me to give the sport a try.

I know we are a little off my original topic but does it make sense for me to shoot Limited-10 instead of Production since I am shooting major with the 40S&W and factory ammunition. With using an XD-40 which division makes more sense? I am still learning some of the more subtitle differences between the divisions.

Thank

mcb

[ima45dv8]

mcb,

Welcome to the forums.

Give the lighter springs a try, at speed, and then decide for yourself. I think you may be pleasantly surprised.

As for division, maybe you should give Limited10 a try. In Production, you're scored Minor regardless of caliber which is why most folks you'll see shooting Production are using 9mm. But if you load soft .40s, Production may be OK for you. In Limited10, .with a .40, you will scored Major (provided your ammo make the power factor threshold of 165).

...Mark

[Flexmoney]

Limited-10 is perfect if you are shooting full power ammo. No worries.

If you reload, then a Minor power factor load in 40 is great for Production.