400 CorBon & Fitting a 1911 barrel

[MikeS]

Hi All.

I have a couple of questions both concerning a new 1911 barrel I bought recently. First off, am I wrong in assuming that with the 400CorBon cartridge it's a matter of replacing the barrel (and stuff around it, bushing, link, etc.) from a 45ACP 1911? Would I use the same magazines as for 45ACP or do I need to get different magazines for it? Also is the stock spring from the 45 (it's a Taurus PT1911) strong enough, or do I need to get a stronger spring? If I need a different spring, what weight spring should I get?

Next, are there any truly drop in 1911 barrels? If not, what is involved in fitting a brand new barrel/bushing/link into my existing frame? Thanks in advance!

[ReloaderFred]

I can't speak to your Taurus, but my Colt 1991-A1 was just a drop-in for the .400 Cor-Bon barrel, including using the same barrel bushing. I did add a Sprinco Recoil Reducer to the .400 Cor-Bon conversion, though.

It uses regular .45 acp magazines, since the .400 Cor-Bon is simply the .45 acp case necked down to .400". When making the brass, I prefer to use once fired Winchester or Federal .45 acp brass to neck down. Those two are thicker and last longer when necked down. I also get fewer wrinkled necks with those two brands when necking them down to .400". It's important to size the brass in the .45 acp dies prior to necking them down in the .400 Cor-Bon dies. If there are any irregularities in the case mouths, they'll wrinkle and ruin the brass.

Hope this helps.

Fred

[jmsj]

MikeS,
There are three kinds of replacement barrels, drop in, semi drop in and gunsmith fit. Sometimes the drop in fit and semi drop in fit will work as is but they can both require some fitting. Obviously the gunsmith fit requires the most fitting.
The first two usually require checking the hood and getting the the upper lock up right. The gunsmith fit requires not only the upper lock up but cutting the lower lugs and installing the correct barrel link.
I would reccomend getting the Jerry Kuhnhausen book on the 1911. It gives all the specs and procedures for working on the 1911 pistols. I would also reccomend getting a barrel with a pre-fit bushing. The barrel to bushing fit is already done and the lock up angle is already cut in. Fitting the barrel to the bushing is easy but getting the lock up angle right is a little trickier.
I would think that the Taurus PT1911 would be strong enough as it has a forged frame, if in doubt check with CorBon. Same for the spring rate, I would contact CorBon and see what they reccomend.
Good luck, jmsj

[MikeS]

The barrel I bought has both a pre-fit bushing, and comes with the link pre-installed. How tight (or loose) is the bushing to barrel fit supposed to be? On both the factory barrel/bushing as well as on a commander length 41ae barrel I have here the bushings seem pretty loose on the barrel, is that right? Am I correct that one of the steps in accurizing a 1911 would be having a bushing the fit much closer to the barrel?

[ReloaderFred]

Your best bet is to fire the gun and find out how accurate it is before you mess with anything. Some guns just defy logic. You won't find out about yours until you test it on paper.

Hope this helps.

Fred

[Moonie]

I have a 6" drop in 400 corbon barrel for my PT1911, works great with all other stock parts. Do remember that 400 corbon brass is made from +p brass that has a thicker web. I do use reformed standard 45 brass as well but load them light.

[Blackwater]

My Olympic Arms barrel fit my old bushing quite well, and even the sights shot to the same POI at 25 yds. Maybe I got lucky? Try it, and make any adjustments as they prove necessary, but do NOT carry it for defense unless and UNTIL you've proven it thouroughly. Feeding was never a problem. As someone said, it's a lot easier to get a .40 cal bullet in a .45 cal hole than it is to get a .45 cal. bullet in there. I polished the feed ramp with my Dremel tool and that's it. As with .45 parts of all kinds, and probably especially with barrels and bushings, you just have to try it, and then fit it as indications identify necessities.

BTW, If you stick with it, I think you'll like everything about it, except maybe that very short neck, but .... that's not an insurmountable problem at all. It's just a point of caution when you're loading it.

It may be worth noting that I shot an armadillo with mine and it was the 2nd animal that I've shot that went down like a sack of wet sand and didn't even quiver - just kinda' bounced a little when it hit the dirt. I hit it going almost directly away from me at about 12 yds. and hit it in almost the exact dead center of the right ham, with the bullet exiting just to the left of the center of the chest. I'm not entirely sure whether it was a 135 gr. Cor Bon factory load, or the 150, but whichever, it blew out the entrails in front of the chest where they lay for about 16" or so, stretched out in front of the chest when I got to the carcass. Quite an impressive kill. However, I swore off the 135's thereafter for defensive use since I just MIGHT need some significant penetration.

Another thing you'll like is the considerably flatter trajectory of the .400 vs. the .45. Not long after I got it, I was out shooting with friends and there was a plow share at 100 yds. I shot at it 8 times, and hit it all 8 times with a dead on hold. It was sighted @ 2" high at 25, and was center of the plate at 100. Being used to significant holdover with the .45 at that distance, I was pretty impressed.

I guess you could say that I like the .400. It's been pretty good to me, and very utilitarian afield. It works very well, and keeps the frame that I've shot most over the years, and have become conditioned to. Not a bad combo.

[softpoint]

Start out with your stock recoil spring. It will probably be fine. The .400 appears to be inherently accurate,out of several that my friends and I played with ,they all shot well. Standard .45 ACP magazines are fine. One note, loading can be a bit tricky,the cartridge has a very short neck, and you need to keep tight neck tension to keep from bullet setback. especially in the 1911 platform., factory Cor Bon loads have cannelured bullets, and I'm not aware of any over-the counter .40 bullets that have cannelures. If I were to use cast, I'd look for a boolit with a crimp groove. The cartridge headspaces on the shoulder, so crimping is no problem. We had better luck with Starline .400 brass than re-formed .45 brass,but both will work.
If your barrel and bushing will install in the gun and the slide will go all the way forward,and lock up, I'd shoot it. I have a mis-matched .45 made from assorted parts that shoots inch groups at 25 yards, and has had no special fitup work done. This isn't always the case, of course.

[MikeS]

I was mainly concerned about fitting the barrel because several years ago I had a gov issue 1911A1 that had a 16" barrel in it when I bought it, and I replaced the barrel with a generic stock length, and it shot fine for me, but the guy I sold it to told me that it wasn't fitted properly. I didn't know if he was telling me this to try and get a lower price on the gun or not. He said that not all of the ribs were making contact with the slide, and he would have to do some fitting before it was safe to shoot. Is something like that possible, having the barrel lock up all the way, but still need some fitting?

[jmsj]

Sounds like he was saying the ribs or upper lugs were not making full engagement. It is possible for the slide to come all the way forward and look like the gun is in full lock up but the lugs not fully engaged. The quick easy way (not the best) to check is to look at the wear on the upper lugs on the barrel and in the slide and see if the shined up areas are showing adequate lock up. The best way is to use modeling clay or lay out fluid in the lugs and cycle the action and measure the lock up.
There are a few reasons why the lugs don't fully engage, the hood is not fitted correctly, it is too long or wide and interfering with breech face. The link is too short and not raising the barrel high enough. The bottom lug is too large and interfering with the slide stop before the barrel but usually this won't allow the slide to come all the way forward or the upper lug dimensions are to large or not square and are interfering and not allowing full lock up.
I am sure I may have overlooked an issue but these have been my experience
Good luck, jmsj

[BigSkol]

One note, loading can be a bit tricky,the cartridge has a very short neck, and you need to keep tight neck tension to keep from bullet setback. especially in the 1911 platform., factory Cor Bon loads have cannelured bullets, and I'm not aware of any over-the counter .40 bullets that have cannelures. If I were to use cast, I'd look for a boolit with a crimp groove. The cartridge headspaces on the shoulder, so crimping is no problem. We had better luck with Starline .400 brass than re-formed .45 brass,but both will work.

Can you tell me please, what dies are you using and what type of crimp - do you have a measurement e.g. 0.419"? I see Lee does a 3-die set, but I don't see a 4-die set; do you need a Factory Crimp die or is a good enough crimp achievable with the Seating Die? Thank you in advance.

[Moonie]

Can you tell me please, what dies are you using and what type of crimp - do you have a measurement e.g. 0.419"? I see Lee does a 3-die set, but I don't see a 4-die set; do you need a Factory Crimp die or is a good enough crimp achievable with the Seating Die? Thank you in advance.

Because this is a bottle necked pistol round Lee doesn't make a FCD. I've not had an issue with crimping with the seating die.

[MikeS]

Moonie, actually Lee does make an FCD for the 400 Corbon. It's the rifle style collet crimp, not the one with the carbide ring, so that makes it one of the 'good' FCD's to have. I don't have my dies yet, but I ordered Lee dies, and unfortunately I didn't see the 4 die set, so I ordered the FCD separately. For the time being I ordered a Lee boolit mould, one of their TL designs, as it was the only boolit mould I could see with a crimp groove. Once I get the barrel in (it's in UPS's hands at the moment) I plan to slug the barrel, then get Tom @ Accurate Molds make me a 4 cavity brass mould to cast the proper size, and it will contain a crimp groove. One thing I still need to get is sizing die for my Star sizer, but that too is going to wait until I have the barrel in hand so I can slug it, and get the right size. One thing I plan on doing before I order a mould from Tom is to take one of the TL boolits (the ones with all the crimp grooves, and no lube grooves :) ) and put it in a fired casing and gently push it into the barrel, and basically let the barrel seat the boolit, then check to make sure it will fit in the magazine at that length. This will tell me how long a nose the boolit I order from Tom can safely have. Does doing this make any sense? I would think that I would probably end up with a boolit with a longer nose than driving band area if I make the boolit to stay within the neck of the cartridge.

[GL49]

Who do you recommend for a barrel manufacturer for the the 400 Corbon? I've seen them at Sarco for less than $50, but wonder about the quality. I've got two 1911's, I thought about getting a 400 Corbon barrel for my Norinco. For a brass choice, I have a couple thousand empty cases of 45 military match brass, I suppose that would be a good choice? My other options are Remington, PMC, or Winchester. Suggestions?

[Moonie]

Moonie, actually Lee does make an FCD for the 400 Corbon. It's the rifle style collet crimp, not the one with the carbide ring, so that makes it one of the 'good' FCD's to have.

This is great to hear, will have to pick one up.

[mktacop]

FWIW, I just picked up a 400 Corbon barrel and Lee dies (including the 400 Corbon FCD). I also contacted Tom at Accurate molds and had him modify a bullet to use with this barrel. The mold number is 40-175C in case anyone is interested. I had to order a new Star die too since this barrel slugged at .401

[MikeS]

mktacop, I looked at the 40-175C, and thought it would be a good boolit for the 400! I also like the 40-135B, but made with a bevel base rather than gas check base. I figure I would rather go with a light weight boolit, rather than a boolit that's a weight that's also available in 45. I would also see if he would make it to drop a .411 boolit so I could also shoot it from my 41AE Tanfoglio. In another message thread I said that I couldn't get a .411 sized boolit to size down to .401 using a Lee sizing die, but I was wrong. I was trying to size a .411 170gr boolit, and it was the first boolit I tried to size in the die which of course I bought new. Then I resized 50 boolits a friend gave me that were .403 so I ran them thru to bring them down to .401. After running those boolits thru the sizer I decided to try sizing a .411 boolit, and it went right thru! So now I've resized 50 more of them, and they're going to be the next 50 rounds I'm going to load in 400. I figure as long as I can size down .411 boolits to .401 I might as well get the mould to drop .411 so I can use the boolits in either cartridge. Does that make any sense?

[mktacop]

mktacop, I looked at the 40-175C, and thought it would be a good boolit for the 400! I also like the 40-135B, but made with a bevel base rather than gas check base. I figure I would rather go with a light weight boolit, rather than a boolit that's a weight that's also available in 45. I would also see if he would make it to drop a .411 boolit so I could also shoot it from my 41AE Tanfoglio. In another message thread I said that I couldn't get a .411 sized boolit to size down to .401 using a Lee sizing die, but I was wrong. I was trying to size a .411 170gr boolit, and it was the first boolit I tried to size in the die which of course I bought new. Then I resized 50 boolits a friend gave me that were .403 so I ran them thru to bring them down to .401. After running those boolits thru the sizer I decided to try sizing a .411 boolit, and it went right thru! So now I've resized 50 more of them, and they're going to be the next 50 rounds I'm going to load in 400. I figure as long as I can size down .411 boolits to .401 I might as well get the mould to drop .411 so I can use the boolits in either cartridge. Does that make any sense?

Makes sense to me! At the risk of hijacking your thread, here is my range report from today. This was my first outing with the 400 CorBon barrel and loads.

All rounds were loaded using .45ACP Large Primer brass. Brass was first run through a standard .45ACP sizing die, then through the Lee 400 CorBon sizing die to neck it down. Powder used was HS-6. Bullets were .401 150gr LSWC and .401 180gr LRNFP. Primers were CCI Large Pistol Primers. Lee FCD used for a nice tight crimp.

Load 1:
150gr LSWC
9.4gr HS-6 (Sierra 5th Edition load manual gave estimated velocity of 1050 fps)
1. 1113
2. 1118
3. 1157
4. 1130
5. 1159
6. 1130
Avg Velocity: 1134.5
SD: 19.39

Load 2:
150gr LSWC
9.8gr HS-6 (Sierra manual estimated 1100 fps)
1. 1183
2. 1176
3. 1178
4. 1193
5. 1177
6. 1192
Avg Velocity: 1183
SD: 7.62

Load 3
180gr LRNFP
7.3gr HS-6 (Sierra manual estimated 850 fps)
1. 920.1
2. 905.5
3. 914.8
4. 919.2
5. 872.4
6. 946.9
Avg Velocity: 913
SD: 24.27

Accuracy at 25yds was best with the 9.8gr load, but recoil was significant. I definitely want a heavier recoil spring if shooting this load. CorBon recommends a 22lb spring and I'm running a 18lb spring right now.
I'm going to go lighter on the powder next time and see if I can get a lighter load that is more accurate.
I checked all the cases and saw no primers pushed back or other signs of over-pressure. Had light to moderate leading in the rifling grooves. I've ordered a .402 sizing die to help with that since the barrel slugged at .401.

I still have a lot of experimenting to do with this caliber, but my initial results look very promising.

[BigSkol]

Who do you recommend for a barrel manufacturer for the the 400 Corbon?

LoneWolf were selling some NOS AccuMatch barrels (5" and 5-1/2" with compensator) on Ebay and GunBroker. They may still have some left, so it may be worth a call to Don on 208.448.0600 x104. Nice barrel IMHO.

My Federal and Blazer small primer 45 ACP brass sized nicely with the Lee steel die (sized with 45 ACP carbide die first).

[MikeS]

BigSkol, that's the barrel I bought. It dropped right into my PT1911 and so far the action functions properly (the action cycles, goes completely into battery, etc.) I haven't fired it yet as I just got in the last die in my reloading die set (I bought a set of Lee dies, but forgot to buy an FCD which I did the next day). Accumatch wasn't real big on putting their name, or any other markings (like caliber) on the barrel! Of course there's no way I could accidentally try and fire 45ACP thru it. This barrel, like all the rest of my guns, will be cast only, no jacketed bullets for me! I know you don't need to use case lube IF you do as you did, and run the brass thru a 45ACP carbide die first, but for the initial case forming I still used some case lube. I have another 50 Federal SP brass to resize, I'm going to try it without the lube and see if it works, as I hate having to deal with it!

mktacop, regarding hijacking 'my' thread, no worries. I don't know how anyone else feels about it, but as far as I'm concerned, nobody 'owns' a thread, other than in the S&S forum, they're different, there a person starts a thread to sell their stuff, so IMHO they sort of own the thread. I think either Ken, or the software developers that wrote this softwear, or both agree, as it's the only area where the thread originator can close the post.

As is always my problem, my timing is off! I think I'll run out of money before Oct is over, I just bought a rifle, then found out that group buys for 3 moulds are closing within the month! I guess I'll have to wait til Nov before I can order a mould for the 400, but as soon as I can I want to get a lightweight boolit mould for it. Till then, now that I found out that I CAN resize down .411 boolits to .401 I can still reload it with the 170gr SWC, and possibly even try a 200gr SWC to see if it'll work, although I doubt it, as the entire lube groove would be below the case neck. I also have a Lee 6 cavity 175gr TL mould for it, so I guess even if it takes me longer til I can get mould I want. I think because of how much boolit is below the case neck, I'm going to tumble lube the boolits after I size and lube them conventionally, as I think it would stand a better chance of not getting damaged from the heat of being fired. (or blown out of the lube groove by the fast moving gasses)

[mktacop]

MikeS, When you are ready for a mold, check Accurate's site again. I contacted them yesterday with another design and this morning it was up on their site. This one is 40-145C, a SWC with a crimp groove. They said it should cast 143gr in WW. I would have ordered one already, but I had an unexpected big expense last night when the heating element in my Master Caster burned out. :(

[Moonie]

The only mold I have for my 400 barrel is a 2 cav Lee 145gr SWC. It seems to work perfectly, one of my sons recently purchased a 40 S&W pistol and I'm trying to get him to purchase a 170 TC 6 cavity.

[MikeS]

Mktacop, you beat me to it! That's exactly the boolit I want! I was originally thinking of getting a mould like that, but that drops a boolit large enough (.411) so I could use it in both the 41AE & 400Corbon, but I think I'll get that mould as it is, to drop a .401 boolit. So thanks to both you & Tom for designing that boolit so fast.

[mktacop]

Mktacop, you beat me to it! That's exactly the boolit I want! I was originally thinking of getting a mould like that, but that drops a boolit large enough (.411) so I could use it in both the 41AE & 400Corbon, but I think I'll get that mould as it is, to drop a .401 boolit. So thanks to both you & Tom for designing that boolit so fast.

[smilie=w:

[2wheelDuke]

Mike, I'm interested to see how that mold works out. My 175gr TC's are shooting well, but it's kind of a long boolit in that case.

[MikeS]

Duke, I'm curious how it's going to work out too. I so far have loaded 50 400 rounds using the boolits I got from you, and I've already resized down some of my 170gr .411 boolits, so those will be the next 50 I load, just as soon as I pull 50 more 45ACP loads down that are in sm brass cases. October is turning into mould month for me, 2 different group buys have come due, and one of them I'm in for 2 moulds, then add the couple of Lee moulds I bought, and I'm up to 6 moulds so far! Of course the 2 buys, one is with NOE, the other Mihec, and then the Accurate order, I'm curious which mould will come in first!

How accurate are the 175's shooting? Have you tried shooting any of them into the berm, and tried to recover it? I'd be curious is the bases are getting harmed by being loaded so deeply into the case.

[BigSkol]

I still have a lot of experimenting to do with this caliber, but my initial results look very promising.

So given the overall dearth of data (or at best the wide distribution of it), I thought I'd add a brief range report too. Firstly a caveat: I did this off my own back and accepted all risk. I effectively made up the load based on what stock I had and knowing fully that the powder I used was not in the appropriate burn rate bracket (too fast). So yes I may have been irresponsible, to a degree, but I did so with an exploratory heart and because I really wanted to check out my new .400 CorBon barrel!

Parent cases were previously fired 45 ACP and 45 ACP+P of at least 0.892" length (my Lee die stretches cases by 3/1000" and I read that the trim length of .400 CorBon is 0.895"). +P were large pistol primer (Speer) and the others were once fired small pistol primer (Federal and Blazer). All cases re-sized just fine after being sized in a 45 ACP die. Bullets were .400" Montana Gold 180gr CMJ (flat point) and the powder was TiteGroup - yes TiteGroup! I did an extrapolation of .40 S&W, 45ACP and 10mm Auto, some math and a great deal of supposition before coming to the load that I thought would be safe enough to try. Yes I do understand the differences between pressure specs of each caliber.

Bullet: MG 180gr CMJ
Charge: 5.0gr TiteGroup
OAL: 1.220"
Pistol: PT1911
Barrel: Accumatch
Temp: 75degF

Velocities (fps): 882.5 (-3.8), 865.3 (-21.0), 908.1 (21.8), 894.5 (8.2), 880.8 (-5.5), 899.4 (13.1), 870.0 (-16.3), 894.0 (7.7), 883.9 (-2.4), 884.0 (-2.3).
High: 908.1; Low: 865.3; Average: 886.3
E.S.: 42.8
S.D.: 12.4
95%: ±9.9

25yd target and case images at: http://imageshack.us/g/1/9806834/

Note the primers of the fired cases - signs of flow. So the lesson here is that a safe 45 ACP load or a below minimum 10mm load does NOT guarantee a safe .400 CorBon load - but we all knew that already, right? Does anyone wish to comment?

I have a 22lb spring, some Starline 45 Super cases, 155gr XTPs and more suitable powder (AA7 and Universal Clays) en-route to do some proper testing soon - so fear not those who gasped with me using TiteGroup!

[mktacop]

Nice write-up BigSkol. A little outside-the-box thinking is good sometimes!

I've got some test loads ready with the 175gr bullet I cast for this load using both Unique and AA #7 powders. I'm hoping to get to the range this weekend and give them some testing.

[Moonie]

Nice write-up BigSkol. A little outside-the-box thinking is good sometimes!

I've got some test loads ready with the 175gr bullet I cast for this load using both Unique and AA #7 powders. I'm hoping to get to the range this weekend and give them some testing.

Looking forward to hearing the outcome.

[MikeS]

Well, I finally got to the range a couple of days ago. Duke (2WheelDuke) was also there, and we were both shooting our 400 Corbon loads. My load was 6gr of HP-38 and Duke's load was 5gr of a slower burning powder, possibly Unique, but I don't remember exactly what powder he was using. Well both of our loads shot well in our guns, but looking at the primers just now after seeing what BigSkol's looked like, and my loads had primers that look similar, but not quite as severe. Dukes load left the primers looking like normally fired primers look, so his load was the better load of the two. Interestingly my loads functioned flawlessly in my Taurus PT1911, but when shot in Duke's 1911 (again, I don't remember what brand it was) he had a couple of rounds that failed to eject properly, and instead they stovepiped. I don't know what springs are in Duke's gun, or mine for that matter, it's whatever is the stock spring for Taurus. I only shot 15 of the 50 rounds I've already loaded, so I'm debating if I should just shoot the rest of them, or if I should pull them, and reload them with a different load.

On a different note, this heart failure thing I'm dealing with now isn't fun. I only shot 15 rounds because by the time I had shot that many I was worn out. Just holding my arm straight out for a few seconds makes my arm start to 'fall asleep', and even tho I held my 1911 with both hands the effort of holding it for those 15 shots got me out of breath. I recently bought an old rolling block rifle in 45-70, I'm hoping the fact that when I get to the range, the fact that I'll be shooting from a seated position at a bench will allow me to shoot it more than a couple of times!

[mktacop]

Made it to the range today to do some testing of the 400 CorBon loads. I started with a 24lb spring in my 1911, and figured I could go to the 22lb spring if needed. As it turned out, the 24lb spring worked just fine with all but one load.

I wasn't really able to do any accuracy testing since the range was very busy today and I was on a 50 yard bay, so I mainly concentrated on velocity testing.

Temp at the range was 81 degrees. All bullets were sized to .402 and initial look down the barrel showed no obvious leading.

Load 1:
175gr Cast TC
6.5gr Unique
High Velocity: 1066
Low Velocity: 998.9
Avg Velocity: 1044.7
SD: 23.7
IDPA PF: 183

Load 2:
175gr Cast TC
9.0gr AA #7
High Velocity: 1008
Low Velocity: 953.5
Avg Velocity: 982.6
SD: 13.87
IDPA PF: 172

Load 3:
145gr Cast SWC
10.5gr AA #7
High Velocity: 1162
Low Velocity: 1100
Avg Velocity: 1135.1
SD: 22.07
IDPA PF: 164.5 (Not quite)

Load 4:
145gr Cast SWC
7.0gr Unique
High Velocity: 1128
Low Velocity: 1002
Avg Velocity: 1070.5
SD: 40.08
IDPA PF: 155

Load 5:
150gr Cast SWC
4.5gr Red Dot
High Velocity: 946.8
Low Velocity: 897
Avg Velocity: 915.07
SD: 17.39
IDPA PF: 137

With the 24lb recoil spring, only the Red Dot load had any issues. I had 1 stove-pipe and the brass was falling at my feet. This load was definitely under-powered.

The remainder of the loads had good ejection and grouping with the brass about 5-6 feet to my right and about 2-3 feet behind me. Perceived recoil on all loads was light to moderate. I think the heavier spring REALLY helped with that.

All brass was picked up and inspected between loads. None showed any signs of primer smear or over-pressure.

[35remington]

BigSkol, whatever you're seeing, I have my doubts that it's primer flow.

Given that your velocities are little different than a rather mild 45 ACP load with the same weight bullet, I think what you're seeing has less to do with primer flow and more to do with a rough firing pin hole or something else related to the shearing of primer material on the breechface.

A 180 at barely 900 fps shouldn't be that much pressure in a 400 case.

Please consider dropping the 22 lb. spring as unnecessary and liable to increase the damage to the gun, as well as increasing the odds the gun will malfunction. Try instead as a much better option with equal or better slide speed reduction capability and less damage to the gun an 18.5 lb. spring with a small radius firing pin stop.

The small radius stop is much much better as a solution to heavy loads than a heavy spring. The super heavy spring is obsolete and ill advised in a 1911 as a heavy load "improvement."

Mktacop's 24 lb. spring is an especially bad idea, and for loads of the power level he is shooting a 16 to 18.5 spring with regular stop or small radius stop would have sufficed.

Really!

Enough with the heavy spring business. Not a gentle way for me to say it, admittedly, but heavy springs are not good.

[2wheelDuke]

I did some more testing with my Springfield 1911-a1 with the .400 barrel.

I'm using the Lee micrometer charge bar set to .73cc of Unique. I believe it's dropping at about 5.5 grains of Unique. I'm using the Lee 175gr tc cadt of water dropped isotope lead, and sized .401, lubed with speed green.

I'm going easy since I only have the stock recoil spring. I'm getting good accuracy and function.

My chrony showed a low of 809 and a high of 868, with an average of 834.36.

So it looks like I'm right around .40s&w level from what I can see. I'm pushing this boolit a good bit faster in 10mm. I'll have to pick up a spring kit and look into working my load up a bit. I just don't want to beat up my gun.

[35remington]

If you don't want to beat up your gun, do not install a heavier spring kit. Try the small radius stop instead. Heavy springs beat up the gun, despite what is believed.

There is a much better way.

[mktacop]

For those that might be interested, I’ve completed another round of testing 400 CorBon loads and cast bullets.

I changed out the 24lb spring used last time and substituted an 18lb spring and a flat firing pin stop (no radius). Perceived recoil was very manageable with this new combination. Recoil actually seemed less than previous loads, even though these were hotter. All loads were fired from an American Classic II 1911 with the listed modifications. All loads were made with re-formed .45ACP brass and CCI Large Pistol primers. 10 rounds per load were fired over the chronograph. I was only able to do a good accuracy check on a couple of loads and those results will be listed where available.

Load 1:
150gr LSWC, sized .402
11.0 gr AA #7
Avg Velocity: 1149.3
High Velocity: 1183
Low Velocity: 1129
SD : 16.69
Extreme Spread: 54

Load 2:
150gr LSWC, sized .402
11.5 gr AA #7
Avg Velocity: 1199.3
High Velocity: 1232
Low Velocity: 1177
SD : 21.24
Extreme Spread: 55

I made another load using 12.0 gr AA#7, but it proved to be too hot of a load. Primers were flattened and a few showed signs of near-pucture.

Load 3:
150gr LSWC, sized .402
5.0 gr Red Dot
Avg Velocity: 983.4
High Velocity: 1007
Low Velocity: 958.4
SD : 15.39
Extreme Spread: 48.6
This load showed poor accuracy.

Load 4:
150gr LSWC, sized .402
5.5 gr Red Dot
Avg Velocity: 1070.9
High Velocity: 1097
Low Velocity: 1036
SD : 19.18
Extreme Spread: 61
This load showed VERY GOOD accuracy.

Load 5:
175gr LTC, sized .402
9.5 gr AA#7
Avg Velocity: 1018
High Velocity: 1054
Low Velocity: 994
SD : 19.69
Extreme Spread: 60

Load 6:
175gr LTC, sized .402
10.0 gr AA #7
Avg Velocity: 1068.3
High Velocity: 1091
Low Velocity: 1039
SD : 15.18
Extreme Spread: 52

[35remington]

Now we're doing better. Keep the 24 lb. spring for tensioning your tomato stakes.