KKM 6" G20 barrel. What spring weight should I buy? [Archive] - Glock Talk

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SolidBrass
12-22-2011, 22:41
Six Inch match grade hunting barrel. I would be using Underwood ammo with her and some hard cast.

They offer 20 lbs, 22, 24 or stock 17 lbs springs. Also stainless guide rod or tungsten (for 2x the cash of stainless) What do the 10mm guru's advise?

For the 6" version and pretty hot ammo I was guessing 22 lbs, but maybe the 20 is enough.?

PS I've been waiting 4 months for a lone wolf, I can't wan't to increase my killing power any longer.

I've a stock weight stainless guide rod already if that is enough.

arushus
12-22-2011, 23:03
Personally, Id go with the 22lb spring. Whether the barrel is stock length, 5.15" or 6", shouldnt have much, if any, bearing on what spring weight you choose.

ModGlock17
12-23-2011, 07:52
Check gun spring.com for a Recoil Calibration package that has several springs of different weights. When starting out, I would get a variety of weights to see what fits my style, with option to change them in less than a minute.

Remember that they do wear out after thousands of rounds. You'll like shooting so much that thousands of rounds come sooner than you think.:cool:

alwaysshootin
12-23-2011, 08:36
Personally, I wouldn't pay 2x for tungsten, the stainless guide rod works just fine. I have used the 20, and 22lb springs, and, they work great with my hottest loads, and lighter target loads. The variety pack sounds like a great idea. That way you can find the one that works best with your set up.

SolidBrass
12-23-2011, 17:05
Is stock weight on tungsten rod usable for the 6" barrel?

arushus
12-23-2011, 19:53
I dont see why not

alwaysshootin
12-23-2011, 20:07
Is stock weight on tungsten rod usable for the 6" barrel?

Yes, but I'm guessing your brass will eject out around 20 feet. If you prefer it in the 6-10' range, get a 20 or 22 lb spring.

gofastman
12-27-2011, 21:14
Personally, Id go with the 22lb spring. Whether the barrel is stock length, 5.15" or 6", shouldnt have much, if any, bearing on what spring weight you choose.

yes it absolutely should!

24lb+ only for warm/hot ammo out of a 6" tube

SolidBrass
12-27-2011, 22:12
I should add that this G20 doesn't have a lot of rounds threw her. Shot first with weak JHP with some FTF's. I striped of the mag ext. and put the stock GRA in place, only a few rounds since. Mail order ammo slowed me down this fall. Meanwhile I've stocked up on ammo. As soon as it's warm enough for open range use I'll finally break her in with some high power underwood 180 FMJ's before I try more JHP.

Still think I want to upgrade string with stock barrel now?

arushus
12-27-2011, 22:14
yes it absolutely should!

24lb+ only for warm/hot ammo out of a 6" tube

Please enlighten me as to how? It doesnt increase the slide weight at all. All it does that would even affect the speed of the slide at all is slightly increase the speed of the bullet. This slight increase does not warrant a heavier spring weight. So tell me, what about a longer barrel would necessitate a heavier spring?

inspectorjj
12-27-2011, 23:31
Personally, Id go with the 22lb spring. Whether the barrel is stock length, 5.15" or 6", shouldnt have much, if any, bearing on what spring weight you choose.

I totally agree. That is what I used on my 6", LWD ported 5.15 barrel, and my Glock factory barrel with 0, nada, none, zilch issues.

Please enlighten me as to how? It doesnt increase the slide weight at all. All it does that would even affect the speed of the slide at all is slightly increase the speed of the bullet. This slight increase does not warrant a heavier spring weight. So tell me, what about a longer barrel would necessitate a heavier spring?

arushus, your common sense is showing. The barrel makes no difference on the spring weight. The only thing that would make a difference is the slide being different in weight or length.

arushus
12-27-2011, 23:46
I totally agree. That is what I used on my 6", LWD ported 5.15 barrel, and my Glock factory barrel with 0, nada, none, zilch issues.



arushus, your common sense is showing. The barrel makes no difference on the spring weight. The only thing that would make a difference is the slide being different in weight or length.


Thank you JJ! I was waiting on another 10-ringer with a lil common sense to back me up!

21Carrier
12-27-2011, 23:49
yes it absolutely should!

24lb+ only for warm/hot ammo out of a 6" tube

You shouldn't need a 24lb spring. I would suggest a 20lb or 22lb. The longer barrel will be slightly heavier (and increase recoiling mass, reducing recoil), but it should also increase the overall energy transmitted to the slide. Since it increases bullet velocity, and thus projectile energy, it will also increase recoil energy. But only on the order of about 7% (depending on the load). Remember, every action causes an equal but opposite reaction. If you increase the forward velocity and energy of the bullet, you increase the rearward reaction (recoil). Overall, you shouldn't need a new spring just because of the barrel. I think a heavier spring is a good idea for range use with hot loads anyway, but only to keep your brass closer, and MAYBE slow down unlocking (debatable).

IMPORTANT!!! Don't forget that increasing barrel length will effectively increase the pressure of a given round! Mudrush (the late Mike Willard of SwampFox) was VERY clear about this, and I've seen it in my guns as well. His full power ammo was NOT SAFE in 6" barrels, and that very well might apply to Underwood as well! A longer barrel means the bullet is in the tube longer. That increases the amount of time the brass is under pressure, and increases the overall pressure and work done on the brass. That could take a simple Glocksmile into KB territory. If you don't believe me, I almost learned this the hard way.

Right after completing my G20LS (with 6" LWD barrel), I chronographed a load that was totally safe in my G29's STOCK barrel. I had shot HUNDREDS of this load (135gr Nosler JHP @ 1575fps, sounds familiar, huh?), without a single smile. Then, I fired a string of 10 in my G20LS. I got 1800fps, but HUGE Glocksmiles. It came DAMN close to blowing up my gun! Be careful guys! Do NOT assume a load that's safe in a 4.6" barrel is also safe in a 6" barrel. To be fair, my LWD barrel seems to have been opened up a bit, and lacks "full support" like most, but then again, yours might be the same.

SolidBrass
12-29-2011, 22:24
Kevin,

I was thinking about picking up a 6” barrel for my Glock 20sf 10mm. Your ammo is nice and hot. Is it too hot for a 6” barrel?

Any plans for a 10mm TMJ, FMJ, or hard cast in something 200gr or over?

SolidBrass

Not, not too hot for a 6” barrel. We want our ammo to be as hot as possible while still staying within the realm of safety for all barrel lengths.

And we are looking to expand the 10mms, just no firm dates as of yet. Things have been incredibly busy (which is a very good thing!)

Thanks, and Happy New Year!

Kevin Underwood

That is a happy new year. My Underwood stock hit the 1000+ something rounds with this latest arrival!! Guess I should shoot more.

glock20c10mm
12-29-2011, 23:43
I think a heavier spring is a good idea for range use with hot loads anyway...MAYBE slow down unlocking (debatable).
That possibility is currently being debated here -

http://www.glocktalk.com/forums/showthread.php?t=1390590

21Carrier
12-30-2011, 03:56
Oh yeah, OP, I forgot to add this: Don't waste your money on tungsten. It's a waste of money, in my opinion. There's no need for exotic metals.

SolidBrass
01-02-2012, 19:54
Happy daze. I got a holiday surprise that Lone Wolf has "low stock" on the G20 6". So I hopped on it, picked up a couple extra stock magazines and I decided (without much reason) to by a 20lbs spring. I'll swap it with my current stainless GRA that has a stock spring. I didn't even realize I could remove the screw and simply swap springs until recently. Are they under high stress or is it pretty straight forward?