Ruger GP100 in 44 S&W Special!

**Tokarev** · 01-01-17, 16:54

It sounds like "thread choke" is common on barrels with a thin forcing cone wall.

Just a quess but I believe that the bullets are swaged slightly undersize as they pass through the constriction.

Jacketed bullets swage down to a diameter that's too small to recover while a lead bullet may be able to obturate enough to recover and be more accurate.

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**Coal Dragger** · 01-01-17, 17:22

I've heard theories either way on jacketed vs lead bullets and whether or not they will spring back a bit and slug up to size.

The barrel in my Freedom Arms M83 has a very slight constriction as felt with a lead ball slugging the bore. Doesn't keep it from chewing out ridiculously small groups, even with the auxiliary .45 ACP cylinder with the bullets dealing with over 1/2" of cylinder throat to jump before the forcing cone. I've shot seated bench rested groups with a Trijicon RMR on top out of the .45 ACP cylinder that were a ragged hole at 25 yards. The original .454 Casull cylinder is a bit more accurate when I can do my part, although I will admit I'm not man enough to shoot it sitting down with full power loads. Tried it once, and split my forehead open for my troubles. Backed off to non nuclear powered loads it is very accurate with up to 360gr bullets, and really likes 300-335gr pills. Not much you can't flatten with a 335gr hard cast LFNGC bullet trundling along at 1250fps, and they don't beat the shit out of you on the other end.

**Tokarev** · 01-02-17, 10:51

I'm afraid I'll have to initiate a return.

Here is a 6" bullseye target at 25 yards. I fired 5 rounds of 200gr plated "FMJ" along with 5 rounds of Remington 240 JHP and 5 rounds of 180 XTP. Last was my 220cast load with 11gr of Blue Dot.

200gr stuff

180gr XTP's

240 JHP

200gr cast. Note two bullet holes were from previous group with 240 JHP. Still all five rounds of cast are in the black.

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**Tokarev** · 01-02-17, 11:01

Another series. Targets 3, 4 and 5 were with the 200gr plated. Targets 1 and 2 are the 220gr cast. 25 yards.

What appears to be another keyhole

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**Coal Dragger** · 01-02-17, 13:15

There is something wrong with that wheel gun.

**williejc** · 01-02-17, 14:33

Tokarev, my reply addresses your post #31. The constriction is in the very forward section of the forcing cone continuing into the rear of the barrel. It negatively affects lead bullets, not jacketed ones. Furthermore, only lead bullets obturate or bump up in size in response to pressure, and it's the bullet's base that increases in size. At revolver pressures, jacketed bullets don't obturate.

Obturation takes place in cylinder chambers. The forcing cone then swages the "bumped up" bullet down to fit barrel in such way that it forms a gas seal and also grips the rifling sufficiently. Only lead bullets undergo this being bumped up and then swaged down. Softer bullets require less pressure to obturate. For this reason, softer bullets will frequently lead less and shoot more accurately than will harder ones at lower velocities. Harder alloy is not always desirable, especially for non magnum velocity loads. Why is this constriction undesirable? Because the narrow section squeezes down a perfectly sized bullet into a smaller diameter projectile that does not fit the bore. The undersized bullet will not form a gas seal or properly grip the rifling. Hot gas can blow past its sides and cause leading.

At least two factors can ruin lead bullet accuracy. One is undersized chambers, and the other is the constriction at the barrel's rear. So, a revolver could have one or the other or both. With respect to Ruger and your feelings, my opinion is that Ruger and you may have different ideas about accuracy. You are an advanced shooter and may have to hire a specialist to ream the chambers to an appropriate diameter, Taylor throat the forcing cone to remove any constriction, and cut a target crown on the muzzle. The result would be a revolver producing 1 inch groups at 25 yards. I'm guessing now, but I think Ruger would be satisfied with 3 inch groups at 25 yards. Let us know what the folks at Ruger tell you.

**Tokarev** · 01-02-17, 16:04

The revolver shoots lead bullets well but does not appear to like jacketed.

**G woody** · 01-02-17, 16:35

I love the .44 special. In fact I have an original Charter Bulldog Pug. I've had great success with cast bullets & Bullseye powder. I own, & have owned lots of Rugers. Sadly, now they design Firearms to be assembled by non skilled workers!! I have wonderful memories of New Mexico, & visit whenever I can.