Increase D. W. CBOB recoil spring wt. from 20 to 22 lbs.?

[WyoBob]

My new CBOB launches empties much farther than either of my stock SA 1911's. Over 20 feet. My somewhat new STI Trojan 9mm deposited empties about 3 feet away and in a nice little pile when it was new. When my STI started flinging empties quite far after 2,000 rounds, I replaced the spring and it started ejecting much closer.

I'm wondering if I should increase the spring weight on the CBOB from the factory 20 lbs. One thing's for sure. I want this pistol to last forever as it's a great shooter and I don't want to take a chance on battering the frame due to an incorrect recoil spring wt. Any thoughts or comments? Can I go to a 22 lb. recoil spring without taking a chance on doing harm?

WyoBob

[niemi24s]

I'm wondering if I should increase the spring weight on the CBOB from the factory 20 lbs.Is this 20lb spring what's supposed to be in the gun, or is it the tested weight of the spring that's actually installed in the gun?

[WyoBob]

Is this 20lb spring what's supposed to be in the gun, or is it the tested weight of the spring that's actually installed in the gun?

The factory spring is supposed to be 20#. I think it tested 19.5 when I tested it with my improvised tester on a digital bathroom scale. A few other new springs I tested were within .5# of spec except the ISMI 12.5# recoil spring I ordered for my 9mm Trojan. It tested 10#. The 10# ISMI tested 10 lbs. and both springs tossed the brass to the same location. So, I think my spring tests are fairly accurate. I'll retest the factory spring later tonight and double check. The CBOB only has just over 200 rounds though it with this spring.

* The spring now tests 18.5 lbs.

Thanks,

WyoBob

[Hawkmoon]

A CBob is a Commander-length pistol. A standard Colt Combat Commander uses an 18-pound recoil spring, so if the CBob has a 20-pounder, it's already heavier than what the Commander platform was designed for. 22 pounds is the standard recoil spring for a 3-1/2" Officers ACP. I don't think you should go heavier than 20 in your pistol.

[niemi24s]

The spring now tests 18.5 lbs.I know recoil springs for 5" 1911's are tested at a compressed length of 1 5/8", which is very, very close to their length when the slide is all the way back.

Knowing nothing about the shorter 1911's, I have no idea about their in-the-gun compressed lengths or what length they're tested at.

But, perhaps you already know that stuff. If not, it might be something to look into. In other words, Hawkmoon & Wolff say the factory standard is 18lbs - but at what compressed length? - and was your 18.5lb reading at this same length (whatever it might be)?

Regards

[DuckRyder]

As a point of clarification,

Is this a 10mm CBOB or a .45?

[WyoBob]

As a point of clarification,

Is this a 10mm CBOB or a .45?

Sorry, it's a 45.

Yes, from what I've read, "commander" factory springs are 18 lbs. I have no idea why the D.W. CBOB is 20 lbs.

Tell me if I'm thinking about this in the right way. A higher than factory spec recoil spring will "hammer" the slide stop and lower barrel lugs. I don't want to do that. With a weaker spring that ejects the brass quite far, the recoil is taken by the VIS. If you had to choose between the two, you'd choose the latter.

In various places, I've read that one way to tell the recoil spring is due for a change is when the brass starts landing farther away. So, I'm shooting for a "happy medium". I am going to fit an OS EGW firing pin stop with a small radius even though I didn't see much difference in distance in ejected brass when I switched back and forth between the EGW stop I fit on my S.A. Champion and the CBOB factory stop. Recoil characteristics did change for the best, IMO, with the EGW small radius stop was fitted.

Thanks, everybody.

WyoBob

[niemi24s]

I have no idea why the D.W. CBOB is 20 lbs.Is the slide on this gun a carbon/stainless steel or is it an aluminum alloy?

[WyoBob]

Is the slide on this gun a carbon/stainless steel or is it an aluminum alloy?

Its' stainless steel.

WyoBob

[niemi24s]

Well, that idea for why DW says 20lb vs. 18lb just flew out the window! :p

Cheers

[ga16de6669]

Just a thought, but perhaps your DW has a lighter mainspring. Thumb cock one of your other 1911 and compare it to your DW. Its just an idea but i suspect that may have a thing to do with it. Also, shorter 1911 have higher slide velocity and might have a longer ejector. How does your extractor do on the tension test?

[WyoBob]

Just a thought, but perhaps your DW has a lighter mainspring. Thumb cock one of your other 1911 and compare it to your DW. Its just an idea but i suspect that may have a thing to do with it. Also, shorter 1911 have higher slide velocity and might have a longer ejector. How does your extractor do on the tension test?

Hard to compare. I have a 9mm STI Trojan which cocks very easily and two Springfield's that cock quite a bit harder than the CBOB. I don't own a 45 cal 1911 without an ILS with a heavier mainspring.

I'll call Dan Wesson if I ever get off my methane well, weirdo, 12 hours shifts in the sticks and can get to an area where I can get cell coverage :(

WyoBob

[Frank]

I seem to recall that some higher grade 1911s use a slightly lighter than standard mainspring (say around 19 pounds compared with the standard 23 pounds) for a lighter trigger pull. They then use a heavier recoil spring to compensate. Remember that the weight of the mainspring affects the slide velocity in recoil since it has to work against the mainspring to cock the hammer.

Personally, I prefer the standard set up: 23 pound mainspring and 18 pound recoil spring on a Commander size gun (16 pounds on five inch gun).

You might want to try swapping out the mainspring for one you know is 23 pounds, and trying both the 20 pound recoil spring and an 18 pound one.

DVC

[WyoBob]

Personally, I prefer the standard set up: 23 pound mainspring and 18 pound recoil spring on a Commander size gun (16 pounds on five inch gun).

You might want to try swapping out the mainspring for one you know is 23 pounds, and trying both the 20 pound recoil spring and an 18 pound one.
DVC

Thanks, Frank. I think the CBOB uses an officer's spring due to the bobtailed mainspring housing. I'll look into it when I get off my present gas well job.

Thanks, WyoBob

[Frank]

The CBOB does indeed use an officer length mainspring, but that size is also available at 23 pounds.

DVC

[NordicRX8]

Well, that idea for why DW says 20lb vs. 18lb just flew out the window! :p

Cheers

I've always heard that Stainless (slide) on Stainless (frame) has higher friction resistance and that heavier springs are suggested. This was many years ago when galling was an issue with all stainless guns. Metallurgy has changed in the last 20 years, so that may have changed as well but it did fall in line with my theory. ;)

? for the OP: Is this a new gun fresh from the factory or dealer or just new to you? Shooting 200 rounds and having the spring weight change (based on your measurements- assuming you performed them the same) sounds like a weak (failing) spring.

[John]

Listen to Frank, 16 for 5", 18 for 4.25" is the way to go, with a 23 lbs main spring.