Home Forums Hunting & Shooting Gunsmithing 45acp throat length max

SAAMI specs the throat (to start of rifling) as about 0.110" or thereabouts. My question is: how much freebore is too much? I'm using "throat" and "freebore" hear interchangeably because SAAMI doesn't really break them out.

Let's say I reamed the "throat" to 0.220" - is that too much? Does accuracy fall off past a certain point?

I know that this must've been examined/tested in the last 60 years.

I'm asking because I've got the itch to run WFN-style bullets out to a COL limited only by the magazines.

dla,
you are basically limited to 1.275" oal depending on platform & magazine.

seat your L-WFN projectiles to a jam.

Taper Crimp

The simplest velocity gain that you could achieve.

Nope.

I mean you're right about the magazine limit, but wrong about my question.

dla-
Nope.

I mean you're right about the magazine limit, but wrong about my question.


Depending on the platform-

1911 mag body front face is a radius to feed ball ammo.

SIG P220 mag body max OAL is 1.260"

S&W 645,745,945,4506 mag body are the most generous for various meplat designs.

GLUCK/TupperWare-good luck.


Load one of your L-WFN projectiles into a 45ACP case to 1.270" OAL.

The exposed projectile drive bands forward of the grease groove would be your required freebore/leade requirement.

Load 45 SUPER brass w/ appropriate recoil spring to gain more velocity.

I guess you want to talk at me - sigh.

You should read my question first. I know how to find my max COL for my chosen bullet - but that wasn't my question.

By the way, you do not need 45 super brass - been there, done that many years ago. A poster "clarkm" tested 45acp brass to beyond 40k psi without issue probably 30 years ago.

Wide Flat Nose bullets penetrate better than any other profile I've tried, but they are nearly impossible to use in a standard 45acp due to inadequate "throat".

There is another profile called "ogive wad cutter" (an swc with a really wide & long nose) but it is a bit unstable because it is a long ways to the driving bands (a lot of bullet before the driving bands engage the rifling). I can buy a 215gr version from Missouri Bullet Company.

But the limitation, other than magazine, is the throat which was sized for starting 230gr round nose bullets. Lots of folks have reamed their throats - used to be a common upgrade.

I'm wondering how much you can ream (i.e. lengthen the throat) before accuracy gets really bad. I would like to lengthen the 0.452" portion of the "throat" (i.e. freebore) by 0.100" or more.

I can't find a 1911 gunsmith either.

Dedicate & Throat the barrel for the projectile that you want to shoot.
1911 barrels are cheap.

A 45 Win Mag platform would be an option.
A Freedom Arms Model 83 454 Casull would shoot rings around any 1911 platform.
A S&W 460 would up the velocity 2X of any 45ACP/Super load.

0) 45 acp.reduced........... 185 gr 07.6 gr AA#5 jams w/stock Patriot spring
1) 45 acp........................185 gr 10.2 gr AA#5 1100 fps 18,000psi
2) 45 acp +P...................185 gr 10.8 gr AA#5 1200 fps 21,700 psi
3) 45 Super.....................185 gr 12.4 gr AA#5 1312 fps 28,000 cup
4) 460 Rowland............... 185 gr 14.5 gr AA#5 1500 fps 38,800 cup
5) Easy extraction ...........185 gr 15.0 gr AA#5 Mauser rifle
6) Case starts to stretch...185 gr 15.2 gr AA#5 *rifle
7) difficult extraction ........185 gr 16.0 gr AA#5 *rifle
8) primer falls out ............185 gr 16.5 gr AA#5 *rifle 61,927 psi per Quickload

I don't see you posting any "pushing the engineering limits" info anymore - did you quit blowing things up?

7mmRM 140gr H4350

Hodgdon says 59 gr max

My hunting load 72 gr

No brass was harmed.