Kimber 1911 question .... is there sufficient case support here?

[MCMXI]

First, the question:

Does this chamber have sufficient case support?

Next, the "story":

I bought a Kimber Tactical Entry II a couple of years ago to use in USPSA matches. There were two in my LGS but I didn't know much, if anything, about the 1911 platform at that time, so I chose the one that didn't have the scratch on the frame . It seemed to be reliable out of the box with factory 230gr ammunition from four different manufacturers, but wouldn't reliably feed my 185gr LSWC reloads with the factory magazine or Wilson Combat magazines. Sometimes I could run through a magazine with no issues, and then have two or three failures to chamber on the next magazine. I figured it was the nature of the beast and that this was "normal" for a match barrel and moved on. My SIGs run through those reloads so no big deal ... right?

I decided that I wanted a very reliable match/class 1911 so changed all of the MIM parts to Ed Brown parts and as long as I stick with 230gr FMJ or 200gr LRNFP bullets, all is good. I've shot a bunch of matches with zero issues and am close to 1,500 rounds in matches without a single failure. I tried to shoot my 185gr reloads recently and it ran ok but still with feeding issues ... typically on the last few rounds in the magazine. So this past weekend I did some research, and after reading excellent articles by 1911Tuner and others, I decided to try to figure it out once and for all. After reading lots of information about the feedramp and the barrel ramp, I took a good look at the feedramp in the Kimber and noticed that it's not centered on the frame. Also, I noticed an odd wear pattern on the bottom right of the feedramp which could be from the bullet hitting the frame in that area (not sure though).

Kimber feedramp as it came from the factory.

I decided to leave the left side of the feedramp alone and match the right side to the left side as best as I could using some Grobet files and emery paper, ending with a fine diamond polishing compound (you can see the reflection of one of my dogs).

Feedramp before polishing.

Feedramp after polishing.

The next thing I looked at was the barrel ramp and compared it to the barrel ramp in my Ed Brown Special Forces Carry. The Ed Brown barrel ramp is more "aggressive" so I matched the ramp in the Kimber barrel to the EB barrel and finished it off by polishing.

Ed Brown barrel and Kimber barrel after working on the barrel ramp but before polishing.

I haven't been to the range yet but I assembled some dummy rounds using the 185gr bullet and empty sized cases (no powder/primer) and can run through a whole magazine (many, many times) just by pulling back on the slide and releasing it as quickly as possible to simulate the firing cycle. I couldn't do this with the Kimber as it came from the factory due to feeding issues. I feel encouraged at this point but am concerned about case support. I've ordered an Ed Brown barrel just in case and will fit that without touching the barrel ramp. It's an upgrade to the Kimber anyway. I'd like to test out my work this weekend but safety is a concern. Any thoughts?

Finished feedramp and barrel ramp.

 

[MCMXI]

So no thoughts yet but I should add one caveat. I stated that I "matched" the Kimber barrel ramp to the Ed Brown barrel ramp. That's a stretch and it's the reason for my question. If I had half a brain, I would have dropped a cartridge into the EB barrel, marked the case where the ramp ended, and then matched the Kimber barrel to that. I didn't think of this until after the fact and so I ended up with slightly less barrel support compared to EB i.e. slightly more aggressive barrel ramp. If EB is on the ragged edge of reliability and safety, then this barrel is probably toast. However, if EB is playing it safe, then I'm probably ok. I can't find any information giving the maximum distance from the case head to where the barrel ramp ends (when a round is chambered). If I had this value, I could scribe a line on the case, drop it into the chamber and see if it's sufficiently supported.

Also, I have one possible explanation as to why those 185gr SWC bullets weren't feeding correctly. With the ramp shifted to the left of the centerline of the frame, the bullet meplat would strike the feedramp with the right side making contact before the left side. This would cause the cartridge to rotate to the right as it's pushed up the feedramp. A RN bullet wouldn't have this problem even with the feedramp as it was. Only the tip of the bullet would make contact with the feedramp with no rotation of the cartridge.

 

[243winxb]

Does this chamber have sufficient case support?

No IMO. Fire some factory ammo. If you get case bulge you will have your answer. With hand loads you will bulge the brass if you load hot enough. Fight the bulge with Starline +P brass.

The 45 Auto+P is a strengthened version of the 45 Auto with the same external dimensions. A thicker web and heavier sidewall at base strengthens the case in potentially unsupported areas. This case has approximately 2 grains less internal water capacity than the standard 45 Auto.

 

[MCMXI]

243winxb, thanks for the advice. I took some photos this morning comparing my Ed Brown SFC barrel (left) to the Kimber barrel (right). The barrel ramps are close but I may have screwed up the Kimber barrel. The new Ed Brown barrel didn't come in yet so I plan to shoot Sunday's match with a SIG P220 Combat in the "limited 10" division and after the match I'll test the Kimber barrel with my reloads and the new Ed Brown barrel if it comes in tomorrow.

 

[rcmodel]

I'd suggest you cut a case in two lengthwise and put a sectioned case in the chamber.

That way, you can see exactly where the thick case web ends in relation to the feed ramp cut.

It looks like it should be O.K. to me, but what do I know about photographs on the internet.

rc

 

[Jim Watson]

The .45 is pretty tolerant of overthroating. I have one about like that done by no less authority than Pachmayr. It won't get +P loads but is ok with ball and fine with my 90% loads.
If it worries you, shoot it the first time in the left hand with face averted. Or maybe tied to a fence post and a string to the trigger.

 

[rcmodel]

Just take the mag out before you try it.
If it blows a case, the shrapnel/gas will blow out the mag well without hurting anything much.

Especially if you have rubber or hard plastic grips.

rc

 

[243winxb]

Test firing is the only way to know for sure.

I would start with 3.8gr of bullseye/200gr lswc, then increase the powder charge, till i hit maximum. Watching for a bulge as i go. If the brass is going to bulge it will take a +P loading @ 23,000 PSI. I got a better look at the first photo after down loading & enlarging it. This is why i think it may bulge With +P

 

[MCMXI]

I'd suggest you cut a case in two lengthwise and put a sectioned case in the chamber. That way, you can see exactly where the thick case web ends in relation to the feed ramp cut.

Excellent suggestion ... thanks!!


IMI case in Ed Brown SFC chamber.

IMI case in Kimber chamber.

The .45 is pretty tolerant of overthroating. I have one about like that done by no less authority than Pachmayr.

That makes me feel a little better. I don't like screwing things up but the new EB barrel wasn't that expensive and I learned a lot from this experience which will come in handy when I start messing with a Kimber Stainless Pro Raptor. Thanks for the tip re firing the pistol. rcmodel's "remove the magazine" is a very good idea. I have G10 grips which are very hard so if there is any shrapnel, they'll do a good job of directing the debris away from my hand.

I would start with 3.8gr of bullseye/200gr lswc, then increase the powder charge, till i hit maximum. Watching for a bulge as i go. If the brass is going to bulge it will take a +P loading @ 23,000 PSI. I got a better look at the first photo after down loading & enlarging it. This is why i think it may bulge With +P

My two loads are 185gr LSWC with 6.0gr W231 and 200gr LRNFP with 5.5gr W231. Both loads are around 17,000 CUP and near the maximum listed but nowhere near +P. In fact, I can't find any loads that are +P, not even jacketed bullet loads.

 

[jluther820]

What I dont understand is why you didnt just polish the ramp on the frame first and leave the barrel alone? I suspect that alone might have solved your problem. Also have you checked your crimp and OAL?

 

[MCMXI]

What I dont understand is why you didnt just polish the ramp on the frame first and leave the barrel alone? I suspect that alone might have solved your problem. Also have you checked your crimp and OAL?

Crimp and overall length are fine. I've been shooting this particular load since 1992 and have shot tens of thousands of rounds through various SIGs over the years without any issues. Your point about the feedramp is well taken and I have no logical explanation.

Well, after yesterday's range session, it turns out that the Kimber still won't feed those 185gr loads. On the bright side, nor will my Ed Brown Special Forces either!! I took rcmodel's advice and removed the magazine for the first couple of rounds of each load. I shot three different loads through the Kimber yesterday using the factory barrel and didn't see any obvious case bulges, so at least the barrel is ok. These are the loads that I tried.

A. 185gr LSWC, 6.0gr W231, WLP primer, Federal cases
B. 200gr LRNFP 5.5gr W231, WLP primer, PMC cases
C. 200gr LRNFP 6.0gr W231, WLP primer, Federal cases

The photos below show all four sides of ten cases of load C after I cleaned them. This load should generate something on the order of 18,000 CUP and is the max load listed in Lyman's 49th Edition. Basically, I didn't improve anything. The Kimber still runs perfectly with 200gr LRNFP and 230gr FMJ but still isn't reliable with the 185gr LSWC bullet from Western Nevada. The humor here is that I made a note months ago that the WN bullets weren't reliable in the Ed Brown. If I'd bothered to read through the logs for the Ed Brown, I wouldn't have tried to match the Kimber barrel ramp to the Ed Brown barrel ramp. I would have resigned myself to the idea that this is a poor bullet choice for 1911s and not wasted my time trying to get the Kimber to shoot this particular bullet. I have five SIG P220's and every single one of them has no problem with the 185gr LSWC.

This has been a good lesson. Struggling to get a 1911 to feed a particular bullet may be an exercise in futility. Even though I like the idea that a pistol will function 100% reliably with every bullet available, it's just not a realistic expectation, particularly for 1911s. Find bullets that work and stick with them. I'll be sticking with bullets that have ogives similar to the standard 230gr FMJ ... they seem to work exceptionally well.

 

[edwardware]

Firing with mag removed. . .

So, when you let the slide slam home over an empty mag well, did you ruin the sear and hammer hooks?

My Kimber Ultra Carry had to take a trip back to the factory for a trigger job; the hammer would slide right off the sear. The cause, they say, was my performance of a tradition 1911 function check (dropping the slide home, from the stop, over an empty mag well).

They were quite snippy while pointing out that, while this may be good practice with a 'stock' 1911, it will ruin a 'fine target sear' like the one in my 3" Kimber.

Seriously!

 

[MCMXI]

So, when you let the slide slam home over an empty mag well, did you ruin the sear and hammer hooks?

No, the trigger feels the same ... but I only did this six times (less to be honest). Also, I fitted an Ed Brown hammer and sear in the Kimber so they're not MIM parts. I always ride the slide and don't let the slide slam forward on any of my pistols unless there's a round in the magazine.

As for this whole fiasco, 1911Tuner makes the point that ammunition with a C.O.L. less than 1.200" may not feed reliably in a 1911. The 185gr LSWC reloads have a C.O.L. of 1.146" ...

 

[hey_poolboy]

I know my SA won't run SWC's unless they are at least 1.22, but my standard load's OAL is 1.25 on a 185gr. LSWC. They run fine.

 

[Walkalong]

My 1911's, including my CDP Ultra, feed the Berrys 185 Gr (bottom right) just fine. It is similar to that bullet. I do not remember any of my 1911s being "throated" that aggressively. I know most are not.

 

[nalioth]

So, when you let the slide slam home over an empty mag well, did you ruin the sear and hammer hooks?

My Kimber Ultra Carry had to take a trip back to the factory for a trigger job; the hammer would slide right off the sear. The cause, they say, was my performance of a tradition 1911 function check (dropping the slide home, from the stop, over an empty mag well).

They were quite snippy while pointing out that, while this may be good practice with a 'stock' 1911, it will ruin a 'fine target sear' like the one in my 3" Kimber.

Seriously!

What has the old warhorse been reduced to? A persnickety prima donna?

Reading the above saddens me.

 

[MCMXI]

My 1911's, including my CDP Ultra, feed the Berrys 185 Gr (bottom right) just fine. It is similar to that bullet.

That's a nice photo right there! Your C.O.L. for the that Berry 185gr is 1.190" whereas my 185gr is at 1.146". 0.044" doesn't sound like much but it's possible that there are other factors involved. I tried increasing the C.O.L. a little but but the bullet made contact with the lands in the barrel which caused chambering issues. Also, the C.O.L. is limited by the location of the wax groove. Here's a closeup of the Western Nevada 185gr LSWC. I can extend the same offer to you if you'd like to try 100 of these bullets in your 1911s. I'd be interested to see how you get along with them.

As for the barrel, it seems to work fine with my reloads (not the 185gr obviously). But it's redundant now since I installed an Ed Brown barrel last week. The EB barrel is definitely an upgrade to the Kimber factory barrel so I'm looking forward to trying it out after Saturday's match. In truth, I always planned on upgrading the barrel but probably not this early in the game. Now that I've done it, I have no regrets and this Kimber is officially finished for the next 50,000 rounds.

 

[rcmodel]

We used to modify GI mags to feed 185 wad-cutter when I smithed for 5th. Army AMU.
The mod consists of making a round follower out of the flat one with a hammer and rounded punch.
Next, 3/8" half-circles are ground out of the feed lips 1/2" ahead of the back of the mag to allow earlier release of the cartridge rim.

The same thing is being accomplished with a different feed lip bend today by some mag manufactures.
Brownell's sells a swaging tool for modifying mags.
http://www.brownells.com/1/1/39641-...forming-tools-lip-forming-yoke-brownells.html

And here is a good read on the various types of magazine feed lips you can run into today.
http://how-i-did-it.org/magazines/index.html

At any rate, I am pretty convinced your problem is related to your magazines feed lips.
We built the soft-ball national match guns so they would feed empty cases.
After that, wad-cutter didn't stand a chance of hanging up!!

rc

 

[243winxb]

[QUOTEC. 200gr LRNFP 6.0gr W231, WLP primer, Federal cases

][/QUOTE] Glad to see it held up, no bulge. Nice photo of the sectioned brass.

 

[MCMXI]

rcmodel, thanks for the link to that interesting article on 1911 magazines and maybe it is a magazine issue after all. I was disappointed to learn that the Wilson Combat 47D magazines don't control the cartridge in the same way many other magazines do e.g. Colt. I have ten of the WC ETMs and those are what I've been using. I've been using them in the EB too.

Walkalong, I'm sending you 100+ 185gr bullets. Let's see how they work for you.

243winxb, thanks.

 

[Busyhands94]

i would not say that 25,000 PSI in a millimeter of brass is the best option, i would have to say that is not the best case support there.

 

[243winxb]

Load- .45 ACP 200g cast SW 5.9g 231 CCI LP

Bullet setback or Double charge? Full story here > http://forums.gunbroker.com/topic.asp?TOPIC_ID=506938

 

[Walkalong]

I was disappointed to learn that the Wilson Combat 47D magazines don't control the cartridge in the same way many other magazines do e.g. Colt

Check Mate mags have worked great for me. I put the small bumpers on them to help slam them home.

http://www.topgunsupply.com/check-mate-.45acp-7rd-ss-gi-full-size-1911-magazine.html

http://www.topgunsupply.com/check_mate-1911-stainless-45acp-magazine.html

http://www.checkmatemagazines.com/cart/pc/viewPrd.asp?idcategory=12&idproduct=112

http://www.checkmatemagazines.com/cart/pc/viewCategories.asp?idCategory=2

They make mags with "Wadcutter" feed lips as well.

 

[Walkalong]

Some pics of some mags I am using. The pics are not as nice as 1858's I am afraid, but do show the feed lips well enough to see the differences. I forgot to add one of the Wilson Officers mags I use in my 3" Kimber. I use the aluminum base pads.

These are what I will be trying 1858's 158 Gr bullets in. I will try them in different mags in different guns at different O.A.L.'s.

 

[MCMXI]

Walkalong, you're way too modest ... those photos are outstanding and should be in a 1911 sticky. Here are the three magazines that I have. Ed Brown (left), Kimber (middle) and Wilson Combat ETM (right) ... I have 10 of the WCs but only one each of the other two. The difference in the feed lips is very obvious. The EB and Kimber are fairly similar. I'll need to study your photos and do some research but I'm leaning towards the Check-Mate magazines since they have the tapered feed lips that some call "hybrid".