I have already publicly stated I couldn't be a ammo MFG :o have had a couple of different rounds suffer some odd happenings. Most I ever got was some powder to the face but if you shoot enough I think it's when, not if.
Many say it is Boutique that worries most but I have also had big factory ammo fail as well. Handloaders don't get off the hook either because I have seen first hand issues there. I just feel I couldn't tell anyone that if they shoot X bran of ammo they will never experience an issue.
The only time I worry is when I am pursuing MAX 10mm velocities. In those cases it doesn't matter if it is handloads, major mfg or boutique mfg. Those loads are on the limits of what 10mm brass can handle and beyond the limits for some gun platforms (looking at you Delta Elite).
I don't worry in my Glock 29 or my Witness. But my Para 16-40 I think lead a previous life as an IPSC gun before I bought it. While the barrel is still good, the chamber has been modified for feeding I am pretty sure. It delivers a nice glock smile with MAX loads.
This weekend I was testing some 205 grain WFN hard cast with Longshot. The top end load, (I am at work and don't recall the load) produced smiles such that the brass will be thrown out.
In general I don't feel the need to make 1250 fps with a 210 grain bullet though. I can't see a real difference between that load's performance and the same bullet at 1190 fps, and I can make 1190 fps with no pressure signs at all, and often with quite a bit less powder.
I guess what I am saying is I have grown quite comfortable with ammo that lives up to 96% of the 10mm's max performance, and don't expect to spend much time pursuing that last 4%. I exclusively handload and am rather meticulous about checking charges. So, no, I don't expect to be bitten by a head rupture of catastrophic failure.
I most always shoot my handloads and have done so for 33+ years. As you can tell I liked the challenge of the commercial pull downs, this helps dispell the myths that it is not anything really special, except pushing the boundarys in most instances. Some of the major commercial ammo maker may use what is considered "non canister" powders, where as the boutique loaders may use the off the shelf canister grade stuff. Commercial manufactures do not check each and every component like some handloaders do. (Flash holes NOT being drilled, damaged components, etc. with eyes on quality control) the stuff runs thru the machines like clock work, so therefore things can go out the door. Liabilities for ammo, do rest with the manufacture and the end product user...it all comes down to money in the end.
A balance of particular componets and load development that fits the SAAMI specifications for given pressure MAP. The other thing as mentioned, is the guns themselves, not all are created equal (chamber support, recoil systems, barrels, etc.), people can set them up differently than the factory original which all serve to accomedate various degrees of impulse with the chosen ammunition.
While there are some velocity junkies that want the fastest velocity rounds, I actually look for a balance of 100% reliability performance vs, accuracy and velocity for a particular application, like hunting, target and self defense. Handloading was to provide all of this and more with the satisfaction of "Doing It Yourself"! Not to mention cost savings over the years building custom ammo at target prices or less! ;D
Quote from: sqlbullet on November 27 2012 08:33:15 AM MSTThe only time I worry is when I am pursuing MAX 10mm velocities. In those cases it doesn't matter if it is handloads, major mfg or boutique mfg. Those loads are on the limits of what 10mm brass can handle and beyond the limits for some gun platforms (looking at you Delta Elite).
And of course the brass case itself is only capable of handling well under 5000 PSI. The only reason issues arrise are chambers that don't support the whole case, at least to the rim. 10mm proof loads are suggested by SAAMI to be at a minimum average of 50,500 PSI, up to a maximum average of 54,000 PSI. Clearly Glock doesn't care, and Colt cares even less, faaaaaaaaaaaaar less!
The issue of 10mm loads blowing out their brass cases in some platforms at 37,500 PSI and HIGHER has nothing to do with the brass case. Rather it has everything to do with 10mm semi-auto firearm manufacturers manufacturing barrels with chambers that do not fully support the cartridge case, period.
Any 10mm platform, if based on SAAMI guidelines, should handle SAAMI's listed Maximum Probable Sample Mean of 40,500 PSI for the 10mm Auto without any problem whatsoever. If anyone chooses to use a platform that can't handle that without a case blowout or worse, that's up to them. But in no way is it a fault of the 10mm brass case in relation to SAAMI specifications.
Jump to T/C Contenders and Revolvers and all of a sudden +40,000 PSI is no issue whatsoever. Who'ld have thunk it?
Sorry for the rant.....firearm manufacturers are just getting to me. >:( Seems Kimber is the only one who cares in a mass produced semi-auto platform. Kudos to them. 8)
Quote from: The_Shadow on November 27 2012 10:00:35 AM MSTAs you can tell I liked the challenge of the commercial pull downs, this helps dispell the myths that it is not anything really special, except pushing the boundarys in most instances.
Well said, and great work that you did there! 8)
Without disagreeing with you Redline, there is another factor at play here.
Kimber makes 1911's for guys who want 1911's and are willing to live with whatever that means. I have had good luck feeding my 1911 10mm, but it is more finicky than my EAA's or my Glock, both of which eat anything. Kimber can tighten up the chamber on their gun and know it won't cost them customers if there is the occasional gun that won't digest a certain type of ammo.
Glock on the other hand has built it's empire on "Glock Perfection" of simplicity and reliability. They have to compromise the opposite direction from Kimber. They make the chamber oversize and risk the occasional Ka-Boom in order to achieve that reliability. Guys who move to after market barrels for their Glocks occasionally decreased reliability with certain makes or loads as a result of the tight chamber.
There is no free lunch. At least not that I have found.
And I got smileys with a LW barrel with loads that didn't in a stock Glock barrel.
I may buy a Kimber yet. ;D
I have read a few posts here recently with people having issues with Kevin's 9 and 10mm ammos. It's been real hard to figure out what is happening although blame the ammo is the first course.
Quote from: sqlbullet on November 27 2012 02:30:22 PM MST
Without disagreeing with you Redline, there is another factor at play here.
Kimber makes 1911's for guys who want 1911's and are willing to live with whatever that means. I have had good luck feeding my 1911 10mm, but it is more finicky than my EAA's or my Glock, both of which eat anything. Kimber can tighten up the chamber on their gun and know it won't cost them customers if there is the occasional gun that won't digest a certain type of ammo.
Glock on the other hand has built it's empire on "Glock Perfection" of simplicity and reliability. They have to compromise the opposite direction from Kimber. They make the chamber oversize and risk the occasional Ka-Boom in order to achieve that reliability. Guys who move to after market barrels for their Glocks occasionally decreased reliability with certain makes or loads as a result of the tight chamber.
There is no free lunch. At least not that I have found.
Agreed in general.
But I wouldn't jump the gun on what the two Kimber 10mms will or won't feed reliably. Who's to say? Certainly isn't anyone around here speaking up on them regarding what issues they may or may not have. The only feedback we have on any Kimber that I'm aware of is the barrel pic intercooler posted and the ones I posted for someone else.
Also, I feel it's important to differentiate between a loose chamber and lack of some amount of actual case support. That's a big difference in my mind. We don't know if Kimber 10mm barrel chambers are especially tight or loose or somewhere in between, but only that is would appear their barrels support more of the case than any other manufacturer's barrel does.
We also know that 1911s in general probably require more tweaking toward feed reliability than any other semi-auto pistol platform overall, when they need it. Still, there are sure a lot of folks out there that love'em and are willing to tweak. That's just part of the devil in the details regarding 1911s in my mind.
Not trying to make a stink here. I just think some of the details/semantics are worth noting. Your hunch could be 100% correct specifically regarding the Kimber 10mm platforms, but then again it may not be. I'm not seeing enough information to make that judgement one way or the other yet.
I'ld also add that we don't know if Glock 10mm reliability would suffer with more case support (not looseness or tightness of the chamber overall, but actual support or lack thereof) or not. We only know what they settled on. Not what they necessarily all tested before going with what they settled on. And true, some aftermarket barrels for the Glocks give some owners feed issues, but it's also true that some don't while having much better case support.
Quote from: EdMc on November 27 2012 02:35:09 PM MSTAnd I got smileys with a LW barrel with loads that didn't in a stock Glock barrel.
That's the thing about LW barrels and why I'll never touch one. One guy gets a sweet one that handles any halfway reasonable load with ease, and reliably. Then the next guy gets one that should have never left the factory. Now they've gone to their "new and improved" design with less case support, and time will tell if there's any consistency with them either. Then there are the ones people get that have a chamber so tight they have to send it back to the factory to get it rereamed. They only reason they are as popular as they are is their relatively low cost compared to others. But in my mind this is a classic example of getting what you pay for, even though some people get lucky and get one that's worth owning.
QuoteI may buy a Kimber yet. ;D
If you do I expect you'll get all questions on everything Kimber regarding 10mm on this forum. Kimber doesn't seem to get much love around here. The question is whether it's deserved or not. Sure wish someone in the position to do so would take the plunge and fill in the rest of us. I'm not suggesting what anyone should or shouldn't do, just that it would be cool if they did. ;D It's not like Kimber just came out with these 10mm models. They've existed for quite a few years already.
I can only comment on the LW I have.....it's chamber is tight, and they leave about the same amount of casing unsupported as a std Glock barrel. Since I bought it used I can't send it back. The taper is far less than a Glock chamber and the bore slightly smaller. I need to take the time and look closer at the Smith 1006 and std Delta chambers to compare.
The Colt has the smallest bore.....with one load, that did cause smileys in the Delta, it ran about 60 fps + faster than the same load in the std barrel Glock. Avg of 1198 in the G20 and 1262 in the Delta. This was only one small sample so take it as you will.
Sometime back I asked in a post about Kimbers and several replied with positive comments about them. Whether they reload their own or have used any of the UW stronger loads I have no idea. My attempts at loading N-350 was the result of a magazine article that used a Kimber Target II as the test piece.Well below the max load of the article I forced smileys in the G20, but at an even lower loading at least broke 1200 fps with a 180 gr bullet in my G20.
So.....perhaps I need to spend more time with the Smith and a chrono? I do like 1911s, maybe a Kimber is in the future. :-\
Quote from: REDLINE on November 27 2012 04:55:51 PM MST
Agreed in general.
But I wouldn't jump the gun on what the two Kimber 10mms will or won't feed reliably. Who's to say? Certainly isn't anyone around here speaking up on them regarding what issues they may or may not have. The only feedback we have on any Kimber that I'm aware of is the barrel pic intercooler posted and the ones I posted for someone else.
Also, I feel it's important to differentiate between a loose chamber and lack of some amount of actual case support. That's a big difference in my mind. We don't know if Kimber 10mm barrel chambers are especially tight or loose or somewhere in between, but only that is would appear their barrels support more of the case than any other manufacturer's barrel does.
We also know that 1911s in general probably require more tweaking toward feed reliability than any other semi-auto pistol platform overall, when they need it. Still, there are sure a lot of folks out there that love'em and are willing to tweak. That's just part of the devil in the details regarding 1911s in my mind.
Not trying to make a stink here. I just think some of the details/semantics are worth noting. Your hunch could be 100% correct specifically regarding the Kimber 10mm platforms, but then again it may not be. I'm not seeing enough information to make that judgement one way or the other yet.
I'ld also add that we don't know if Glock 10mm reliability would suffer with more case support (not looseness or tightness of the chamber overall, but actual support or lack thereof) or not. We only know what they settled on. Not what they necessarily all tested before going with what they settled on. And true, some aftermarket barrels for the Glocks give some owners feed issues, but it's also true that some don't while having much better case support.
We are on the same page. I am not saying that Kimber 10mm's won't work with any ammo. I am just saying that criteria is not on the top of the Kimber list. It is on the top of the Glock list.
If a mfg wants to ensure every gun will feed well, they have to put more slop in the specs, or that have to spend lots of time hand fitting all the components. In the price range of the Glock and Kimber offering, option two is off the table.
In that case you may get a Glock like my 29. Haven't seen a smile out of it yet. And you may get a Kimber with a tight chamber that feeds anything. But, you shouldn't be surprised if a Kimber with a tight chamber doesn't like semi-wadcutters, or if a Glock smiles the brass when shooting Underwood.
Well said. Maybe someday we'll find out if a Kimber can run or not, and with what.
They do. I have read reports saying no problems!
Well that's some postitive Kimber news. I wonder if what you've heard included any UW ammo loads.
I see on the Kimber website they use a 16# recoil spring. I wonder how that works out with UW ammo. Seems kinda light. I suppose heavier poundage springs are available for them though, so I suppose it's not an issue then anyway, even though it would require going aftermarket.
One thing I don't get about the Kimber 10mm platforms, the Eclipse Custom II and the Stainless Target II, is the Target model comes with an adjustable rear sight and whatnot, but then they put their better trigger in the Eclipse model and left the Target model with the standard trigger. Shouldn't the better trigger be in the Target model? I don't know, just seemed odd to me. Regardless of which trigger the gun comes with from Kimber, they say trigger pull is 4.0-5.0 lbs. Is that a standard pull weight on 1911s in general?
Okay, one more question; Are the Kimber 10mms SA or DA? Does it really matter? And why? Okay, it was more than one more question. ;D
The Kimber is SA so can be carried 'cocked & locked'........some like this, others don't. I'd think the avg trigger pull would be 4.5-6 lbs on most 1911s. You don't want too light of a trigger on a carry pistol. I could be wrong on that... ;D
The Eclipse has a different finish and grips along with 'night sites'. Very pretty pistols....I looked at one once in 45 ACP. Personally I don't care to pay extra for night sites but that's just my preference.
I found a used Target II within reasonable driving range.......may go after it Friday if I decide I really want another 10mm. :-\ Damn sure don't 'need' another one. LOL Been thinking about a Colt LW Commander in 38 Super...something I'd wanted to try for awhile so still undecided.
I don't see any functional difference between the triggers personally. Of the parts in the firing group on a 1911, the trigger itself has little to do with pull weight, when properly fit and polished. Far more concerned with sear, disconnector and hammer.
And, lest anyone think my previous comments were in any way questioning the reliability of a Kimber, they are not. I would gladly take one if the right deal came along. Very high quality guns.
And yes...4-5 lbs is about standard for a 1911. My Para 16 is right at 5.0 lbs. The Para 12 is about 3.5 lbs. Both snap like glass and have no over-travel at all. Both have a little take up due to the firing pin block parts and truth be told, the 16-40 can be a little creepy from time to time.
My Match is now a 2.5lb pull... on it's own which really feels too light!
Quote from: Intercooler on November 29 2012 08:32:19 AM MST
My Match is now a 2.5lb pull... on it's own which really feels too light!
My Kimber Eclipse Custom II is currently at a local gunsmith's. He previously reduced the pull from 4.5 lbs to about 3.5 lbs. Still seemed heavier than I'd like. I took it back and asked for about 2 lbs.
I'm accustomed to a very light trigger on my scandium/titanium snubby (when cocked, of course) ... never been measured, but it's extremely light, and a delight to shoot. So as long as the 2 lb trigger doesn't give me inadvertent doubletaps (or tripletaps ...), I'll be happy.
In a 1911 that may be okay due to straight back pull. Henning who makes gun parts for Witness pistols actually shot himself in the leg due to the play left to right in the trigger. In a Witness 2-2.5lbs is teetering on a hair trigger from what I have seen. Tap it wrong and it could go off!
Quote from: Mike_Fontenot on November 29 2012 10:05:33 AM MSTMy Kimber Eclipse Custom II is currently at a local gunsmith's. He previously reduced the pull from 4.5 lbs to about 3.5 lbs. Still seemed heavier than I'd like. I took it back and asked for about 2 lbs.
Have you run any Underwood Ammo or Buffalo Bore loads through it?...if so, how did it handle them?
Has your's been reliable with all ammo you've run through it, or have you tweaked a little here and a little there for reliability sake?
How do you like the 16# recoil spring? Is the slide heavy enough that that works okay, or do you feel it could use a step up in spring weight?
Did you aquire yours brand new? If so, did it end up requiring some break-in time, or did it shoot well from the git-go?
Sorry for so many questions, it's just that we haven't had many Kimber 10mm owners around to ask before. Seems like you certainly enjoy yours, because if not, I couldn't imagine you'ld care about sticking more money into with trigger jobs and whatnot.
Anyway, really appreciate all your insight with your Kimber. Thanks for chiming in! 8)
Quote from: REDLINE on November 29 2012 01:58:18 PM MST
Have you run any Underwood Ammo or Buffalo Bore loads through it?
Yeah, almost all my shooting (after break-in) has been with full-power rounds: BuffaloBore (BB), DoubleTap (DT), and Underwood (UW-GD and UW-XTP).
Quote
Has your's been reliable with all ammo you've run through it [...]?
I think the design decisions that Kimber made for the Eclipse Custom II 10mm were EXACTLY right ... it's the ONLY 1911 and caliber that I want. But their EXECUTION of the assembly process has been disappointing ... I sent it back four times during the first year I had it. Problems were: premature lockback (fixed with a new/different slidelock), plunger tube got loose (re-staked), failure to manually eject (fixed by shortening the ejector), battering of the link lug at the "knee" from hits by the slidelock pin (pin isn't supposed to touch the lug) (they replaced barrel, but it had same problem), and (finally) failures to manually chamber a round from a full mag. They failed to fix that last problem, so I took it to a local 1911 gunsmith, who said the primary problem was that the extractor was a 9mm extractor, not a 10mm extractor, and was slightly too short (making it too hard for the rear of the case to slide up under the extractor during chambering). It seems to be running well now, but I haven't put a lot of rounds through it yet since that fix.
To Kimber's credit, they always DID pay shipping both ways, and they replaced a lot of parts, but they just may not have enough really good gunsmiths to handle their returned guns properly, and to monitor their assembly processes.
Since it IS the only 1911 (actually, the only semiauto) that I want, for me it will be worth the pain of getting it right.
Quote
How do you like the 16# recoil spring? Is the slide heavy enough that that works okay, or do you feel it could use a step up in spring weight?
Stock 10mm spring is 18.5lbs. I've had several gunsmiths tell me that it needs more than that, but my current gunsmith seemed to think the stock spring is fine. He DID reduce the mainspring strength, though. I also asked him to replace the firing-pin stop with a short-radius one, to try to slow the initial slide movement (I've been seeing what looks to me like a distorted primer crater that I think is due to the case being pulled downward before the firing-pin can retract ... but the new firing-pin stop didn't seem to affect that). I also have asked my gunsmith to slightly shorten the tip of the firing-pin, because it protrudes very slightly past the firewall when stopped by the firing-pin safety ... if I'm going to have that safety (and I DO want that grip-lever-controlled safety ... in fact, it's a requirement for me), I don't want the firing-pin touching the primer AT ALL if the grip lever isn't depressed.
Quote
Did you acquire yours brand new? If so, did it end up requiring some break-in time [...]?
I DID buy it new (September, 2011). And I DID follow their break-in instructions: about 400 rounds of low-power American Eagle 180gr. But since then, I've fired almost all full-power rounds, mostly 180gr, but lately some lighter bullets (~150gr) also ... if the feeding reliability is good, I may end up alternating the two bullet weights in my carry mags.
I shot my Razorback 10mm yesterday many rounds and bullet types up to 220gr. Zero issues! It's been just a great piece after the initial day of wanting to throw it down the range.
At the range I have shot someone's Eclipse .45ACP and it functioned great. Yesterday though I talked to the shooter next to me who had the real short barrel 1911 style .45ACP. He was also telling me how it was sent back several times and still wasn't right (he had jamming issues yesterday still). They did replace out almost all the pieces including giving him free night sights. Still doesn't make up for a pistol you can't have confidence in.
Quote from: Mike_Fontenot on November 30 2012 09:18:52 AM MST
Quote from: REDLINE on November 29 2012 01:58:18 PM MST
Have you run any Underwood Ammo or Buffalo Bore loads through it?
Yeah, almost all my shooting (after break-in) has been with full-power rounds: BuffaloBore (BB), DoubleTap (DT), and Underwood (UW-GD and UW-XTP).
Quote
Has your's been reliable with all ammo you've run through it [...]?
I think the design decisions that Kimber made for the Eclipse Custom II 10mm were EXACTLY right ... it's the ONLY 1911 and caliber that I want. But their EXECUTION of the assembly process has been disappointing ... I sent it back four times during the first year I had it. Problems were: premature lockback (fixed with a new/different slidelock), plunger tube got loose (re-staked), failure to manually eject (fixed by shortening the ejector), battering of the link lug at the "knee" from hits by the slidelock pin (pin isn't supposed to touch the lug) (they replaced barrel, but it had same problem), and (finally) failures to manually chamber a round from a full mag. They failed to fix that last problem, so I took it to a local 1911 gunsmith, who said the primary problem was that the extractor was a 9mm extractor, not a 10mm extractor, and was slightly too short (making it too hard for the rear of the case to slide up under the extractor during chambering). It seems to be running well now, but I haven't put a lot of rounds through it yet since that fix.
To Kimber's credit, they always DID pay shipping both ways, and they replaced a lot of parts, but they just may not have enough really good gunsmiths to handle their returned guns properly, and to monitor their assembly processes.
Since it IS the only 1911 (actually, the only semiauto) that I want, for me it will be worth the pain of getting it right.
Quote
How do you like the 16# recoil spring? Is the slide heavy enough that that works okay, or do you feel it could use a step up in spring weight?
Stock 10mm spring is 18.5lbs. I've had several gunsmiths tell me that it needs more than that, but my current gunsmith seemed to think the stock spring is fine. He DID reduce the mainspring strength, though. I also asked him to replace the firing-pin stop with a short-radius one, to try to slow the initial slide movement (I've been seeing what looks to me like a distorted primer crater that I think is due to the case being pulled downward before the firing-pin can retract ... but the new firing-pin stop didn't seem to affect that). I also have asked my gunsmith to slightly shorten the tip of the firing-pin, because it protrudes very slightly past the firewall when stopped by the firing-pin safety ... if I'm going to have that safety (and I DO want that grip-lever-controlled safety ... in fact, it's a requirement for me), I don't want the firing-pin touching the primer AT ALL if the grip lever isn't depressed.
Quote
Did you acquire yours brand new? If so, did it end up requiring some break-in time [...]?
I DID buy it new (September, 2011). And I DID follow their break-in instructions: about 400 rounds of low-power American Eagle 180gr. But since then, I've fired almost all full-power rounds, mostly 180gr, but lately some lighter bullets (~150gr) also ... if the feeding reliability is good, I may end up alternating the two bullet weights in my carry mags.
Thanks for taking the time to spell it all out. Much appreciated. Overall, about the issues you've had, yeah it sucks to have any issues, but I'm quite impressed they paid shipping both ways. Also, none of the issues you came across would be deal breakers in my opinion. Sounds like a solid firearm overall. Plus, from what I've seen you can't beat the chamber support on the Kimber barrel, and for full power loads that's awesome.
Mike I am glad that your smith worked all that out.
I personally have a different view on the mainspring. Ned Christensen of Michiguns pretty well proved that a 10mm 1911 should have a flat bottom firing pin stop with a slight break to the radius along with a 25 lb main spring. This set-up will properly delay unlock and will eat up enough of the 10mm slide momentum to match 45 acp slide velocity/momentum.
That is not to say that your set-up won't serve you very well. Just saying the frame is most likely being subjected to forces outside it's original design envelope. That may work great for your platform with it's overbuild forged frame.
Quote from: sqlbullet on December 02 2012 08:17:33 AM MST
[...]
Ned Christensen of Michiguns pretty well proved that a 10mm 1911 should have a flat bottom firing pin stop with a slight break to the radius along with a 25 lb main spring. This set-up will properly delay unlock and will eat up enough of the 10mm slide momentum to match 45 acp slide velocity/momentum.
That is not to say that your set-up won't serve you very well. Just saying the frame is most likely being subjected to forces outside it's original design envelope. That may work great for your platform with it's overbuild forged frame.
I DO have some concerns about that. I DID get my gunsmith to install a flat-bottomed firing-pin stop (and he DID put a very small radius on it). I did it primarily because I was seeing what I thought (and still think) was a deformation in the primer craters caused by the firing pin not being retracted before the slide starts to move back. But I haven't seen any improvement in the primer crater deformation with the new fps, possibly because that effect may have been counteracted by the weaker mainspring that the smith put in.
I THINK his reason for reducing the mainspring strength MAY have been because it might be necessary to get a light trigger pull ... if so, I'll need the weaker mainspring, because a very light trigger is important to me.
I'm struggling with the thought that I should increase my recoil spring to 20lbs (up from the stock 18.5lb recoil spring in the 10mm Kimber), to compensate for the weaker mainspring, but I don't want to risk getting damage during the return-to-battery ... in that direction, the stronger recoil spring ISN'T offset by the weaker mainspring. An alternative would be to leave the recoil spring at 18.5 lbs, and start using a Wilson "shock buffer" to prevent recoil damage. Any advice?
(I actually DID increase my recoil spring to a 20lb variable, during most of the 700 rounds or so that I've fired, and my current smith told be (in response to my direct question) that he wasn't seeing any signs of damage anywhere. The spring was a "variable" one by accident ... I hadn't noticed that detail when I ordered it ... if I decide to switch to a 20lb from the current 18.5lb spring, it'll be a "conventional" spring.)
[addendum:] I'm possibly going to use light bullets (~150gr), and that results in less recoil for a given muzzle energy than with heavier bullets. So it's possible that the recoil forces may not actually be much if any greater than for a .45ACP with 230gr bullets, even though I'm using full-spec 10mm loads, with much higher muzzle energy than .45ACP loads.
Reports of others here that have measured as the increased the mainspring weight is that it's effect on pull weight is pretty negligible. I havent tested myself.