Freebore, free-bore, throat

Could anybody tell me how much freeborn should I expect to have on a 38 special mid-range barrel?
Thanks in advance...

I'm guessing, but since they're only intended to be used with flush-seated wadcutters, I'd say almost none.

Not sure if Colt used this but this is the “Match” chamber listed in SAAMI.  I doubt it was used as this is clearly a revolver chamber, but remove the .358 free bore and I bet it’s close.  

Wobbley wrote:Not sure if Colt used this but this is the “Match” chamber listed in SAAMI.  I doubt it was used as this is clearly a revolver chamber, but remove the .358 free bore and I bet it’s close.  

Thank you so much for taking the time to look into that. Yes, unfortunately SAAMI does not have specs for 38 Special MidRange semi-auto. 
I have a Colt 38 Special Mid Range that has 0.6" of freebore! You can see the matte area in the picture I posted earlier. 
I would love to know how that compares with any other Colt 38 Special Mid Range 1911s.

Greetings,

Your barrel appears to be an early version. A photo of the stamping on the hood will verify this.

The last version of the Colt National Match 38 Mid-Range barrels are marked **MK III**.

The MK III barrels have what looks like a threaded chamber.

Did you buy the gun brand new? If not, it is possible someone modified the chamber with a 38 AMU ream that does indeed have a long leade.

This is a CIP drawing of a 38 Special Match. It is very similar to the SAAMI.

Last, what is your concern? Does the barrel not shoot well?

Cheers,

Dave

fc60 wrote:Greetings,

Your barrel appears to be an early version. A photo of the stamping on the hood will verify this.

The last version of the Colt National Match 38 Mid-Range barrels are marked **MK III**.

The MK III barrels have what looks like a threaded chamber.

Did you buy the gun brand new? If not, it is possible someone modified the chamber with a 38 AMU ream that does indeed have a long leade.

This is a CIP drawing of a 38 Special Match. It is very similar to the SAAMI.

Last, what is your concern? Does the barrel not shoot well?

Cheers,

Dave

Greetings Dave,

You are right, the Colt 38 Special Mid Range I have is one of the earlier versions. I just recently bought it and I don't know the history. 
The pistol doesn't shoot as well as it "should". I am trying to figure out if the barrel has been modified, or if it has some other problems. According to what I could find on the internet, the early version was plagued with inaccuracies.  I have tried different ammo, and used a Ransom Rest as well.

Thank you for taking time to reply.

I just dug through a box of old 38 special barrels and barrels in functioning pistols.
NM mkiii, Colt Kit Gun, Clark 5" one piece, Clark two piece (Douglas 10 twist), Aikman two piece, and 38 AMU.
I can only visually inspect the barrel chambers from the chamber, I do not have a bore scope. All the barrels were similar in chamber depth and lead angle length. It was difficult to eyeball if any freebore was present. 
The only barrel that was different was one of the 38 AMU barrels from a 1961 Clark 38 AMU. There is no visible end of the chamber. The chamber diameter goes straight into the rifling but has a lead approximately 1.25" long. The lead angle has no rifling for the majority of the lead angle. Hopefully that makes sense. 
So the bullet can travel a distance before engraving into the tapered smooth lead before sizing down to eventually engage the rifling.
The attached photo does not accurately poetry the long length of the lead. 
So to summarize,  it looks like most 38 barrels do not have a true freebore. 
Jon

Jon Eulette wrote:I just dug through a box of old 38 special barrels and barrels in functioning pistols.
NM mkiii, Colt Kit Gun, Clark 5" one piece, Clark two piece (Douglas 10 twist), Aikman two piece, and 38 AMU.
I can only visually inspect the barrel chambers from the chamber, I do not have a bore scope. All the barrels were similar in chamber depth and lead angle length. It was difficult to eyeball if any freebore was present. 
The only barrel that was different was one of the 38 AMU barrels from a 1961 Clark 38 AMU. There is no visible end of the chamber. The chamber diameter goes straight into the rifling but has a lead approximately 1.25" long. The lead angle has no rifling for the majority of the lead angle. Hopefully that makes sense. 
So the bullet can travel a distance before engraving into the tapered smooth lead before sizing down to eventually engage the rifling.
The attached photo does not accurately poetry the long length of the lead. 
So to summarize,  it looks like most 38 barrels do not have a true freebore. 
Jon

Thank you for going through all that trouble Jon. What a collection you have!
Is the picture you shared from a 38 AMU barrel? It looks very similar to mine, although mine does not say 38 AMU. The rifling starts at 1.7" on my barrel.
I appreciate all the feedback

Yes it’s the 38 AMU barrel. Rifling starts at approximately 2.4”. The photo makes it look like an end to the chamber, but it’s only 0.003-0.005” of a step of that much. When using an instrument to try and feel it, it is almost unnoticeable. I looked at them because this post got my curiosity going.
Jon

Jon Eulette wrote:Yes it’s the 38 AMU barrel. Rifling starts at approximately 2.4”. The photo makes it look like an end to the chamber, but it’s only 0.003-0.005” of a step of that much. When using an instrument to try and feel it, it is almost unnoticeable. I looked at them because this post got my curiosity going.
Jon

Thank you for checking it and letting me know

Greetings,

You should research on a Colt Collectors website.

Colt may have reamed the early 38 Gold Cup barrels with the long leade.

I have never seen any early barrels to compare to.

I do know that the initial Colt 38 AMU had the long leade. When the 38 KIT barrels and 38 MTU barrels came out they had a "traditional" leade angle. Similar to the SAAMI 38 WadCutter profile.

I would very much doubt that cast bullets will shoot well in your barrel. I believe Lead fouling will plague your efforts.

The best offering I can think of would be the Speer 148 HBWC or the ZERO 148 HBWC propelled with 2.7 (two-point-seven) grains of Winchester WST.

Try to source a box of old Remington or Western 38 HBWC manufactured in the 1960's. This vintage generally shot X-Ring at 50 yards.

Clark's guns built on the 38 AMU shot two inches at 50 yards.

Cheers,

Dave

fc60 wrote:Greetings,

You should research on a Colt Collectors website.

Colt may have reamed the early 38 Gold Cup barrels with the long leade.

I have never seen any early barrels to compare to.

I do know that the initial Colt 38 AMU had the long leade. When the 38 KIT barrels and 38 MTU barrels came out they had a "traditional" leade angle. Similar to the SAAMI 38 WadCutter profile.

I would very much doubt that cast bullets will shoot well in your barrel. I believe Lead fouling will plague your efforts.

The best offering I can think of would be the Speer 148 HBWC or the ZERO 148 HBWC propelled with 2.7 (two-point-seven) grains of Winchester WST.

Try to source a box of old Remington or Western 38 HBWC manufactured in the 1960's. This vintage generally shot X-Ring at 50 yards.

Clark's guns built on the 38 AMU shot two inches at 50 yards.

Cheers,

Dave

Greetings Dave,
Thank you very much for the invaluable information. I got some Zero 148 HBWC but have not gotten to reload it yet.
Thank you for taking the time to share