929 at 50 yards

[9146gt]

Anyone shot a 929 in a Ransom rest at 50 yards? Not much luck here so far. 3.5" groups with factory Winchester 147 TCMC and 5.2 gn of Autucomp, Zero 115,Fed match primers and Remington brass.

Tom

[MWP]

3.5" is bad from a factory gun?

[PatJones]

3.5" is bad from a factory gun?

+1

[toothguy]

I have had good accuracy results using a 125 gr XTP or Zero .357 bullet with .355 and 1 in 10 twist barrels. Recut the crown and forcing cone to make sure they are concentric.

[9146gt]

3.5" is bad from a factory gun?

+1

686-3 1986 1.5" at 50 and 14-6 1994 1.375" at 50. So old guns do shoot better

Tom

[9146gt]

I have had good accuracy results using a 125 gr XTP or Zero .357 bullet with .355 and 1 in 10 twist barrels. Recut the crown and forcing cone to make sure they are concentric.

Did you keep the ledge and the 90 degree cut on the muzzel or use a 11 degree cutter?

Tom

[toothguy]

I have had good accuracy results using a 125 gr XTP or Zero .357 bullet with .355 and 1 in 10 twist barrels. Recut the crown and forcing cone to make sure they are concentric.

Did you keep the ledge and the 90 degree cut on the muzzel or use a 11 degree cutter?

Tom

45 degrees for the crown and 11 degrees for the forcing cone. The crown doesn't need to be cut deep just concentric. On my V-Comp the crown was cut at a 90 then a slight chamfer was added and cut off center from the factory. If yours is cut at a 90 only, then I would leave the crown alone and just recut and center the forcing cone.

[frankbray]

With the factory barrels and twist rates you need 158-160 bullets to be accurate at 50 yards. I have 4 627's 2 in 38 super and 2 in 357mag. I've spent days, weeks and months testing every bullet, powder, primer and case for the Icore far and near. Only heavy hard cast bullets grouped at 50 yards in the 1.5 inch range.

Toothguy is correct if you want to change out the barrel and twist rate you can use 125 JHP and they will group. The negative side of JHP in that the Moonclips don't drop right in the cylinder charge holes when you're speed loading. Toothguy is a Bianchi shooter no speed loading is required. Icore guys need quick and fast speed loading ability smooth round bullet profiles.

Before you start tearing the factory gun apart try hard cast bullets 158-160 round nose sized to 355.

[DougCarden]

Another option is to find a bulletcaster that runs a magma 160RN Super mould. I get my 160s sized .358 and coated so they don't smoke from Twoalphabullets.com The .358 doesnt hurt at all, and you can load the bullet in 9mm through .357 with no issues.....

DougC

[9146gt]

I will try the 160 gn projectiles.

The 929 is a 1/10 twist are all the 627 barrels 1/18.75 ?

Tom

[toothguy]

I will try the 160 gn projectiles.

The 929 is a 1/10 twist are all the 627 barrels 1/18.75 ?

Tom

I believe that is correct about the Smith and Wesson twist rates. My Bianchi 686 has a Walther 1 in 10 twist, .355, 6 inch barrel. I was able to get lighter bullets 110 gr to 115 gr to group well at 50 yrds but at higher velocities than minor. The 125 gr bullets work well because they are a good combination of accuracy at minor velocity and reasonably flat trajectory for Action Pistol.

DougCarden knows his stuff and always has advice worth following. The bullet profile of the 160 is going to load better, the recoil impulse will be soft and the price is going to be much less for ICORE or USPSA shooting.

[JohnRodriguez]

billy bullets uses the magma 160 mold, but without the grease groove, and it comes out to 170gr. Rudy's been selling them for several years now.

[9146gt]

Going to try 160 sns coated .

Twist rate has me confused. Toothguy has good results with 1/10 twist with 110 115 bullets. My factory barrel does not shoot 115 zeros or Winchester factory 147 very well. Others here get good results with 160 hard cast an 1/18.75 twist.. I have seen great results 1.5" and under with 115 projectiles and KKM 1/32 twist in semi autos.....so would 1/32 work in a revolver and who would make a barrel

Tom

[Toolguy]

The slower twist rates require higher velocity to shoot good groups at 50 yds. with a light bullet. I think a 1 in 32 will be dismal in a revolver. I have had the best all around performance from 1 in 10 twist. The tighter twist will shoot heavy and light bullets well to 50, the heavier bullets shooting good groups out to 100. My Bianchi Open gun (686) rebarreled with a Walther 1 in 10 shoots 3/8" groups from a ransom rest at 25 yards with 125 gr. hollow points, 130 power factor, haven't got the chance to try it at 50 in a ransom rest, and about 2" groups off sandbags at 100 yds. with 170 gr. hollow points at about 210 power factor.

The way to get better groups out of a factory 1 in 18-3/4 barrel is to shoot higher velocity and/or heavier bullets.

[wheelie]

Here is a calculator that might provide some answers.

http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi

Also, I'd look at what PPC shooters use in custom guns as a general guide.

EDIT:

I was working on my post when Toolguy posted.

IMO, he offers sound advice.

Edited October 27, 2014 by wheelie

[9146gt]

The slower twist rates require higher velocity to shoot good groups at 50 yds. with a light bullet. I think a 1 in 32 will be dismal in a revolver. I have had the best all around performance from 1 in 10 twist. The tighter twist will shoot heavy and light bullets well to 50, the heavier bullets shooting good groups out to 100. My Bianchi Open gun (686) rebarreled with a Walther 1 in 10 shoots 3/8" groups from a ransom rest at 25 yards with 125 gr. hollow points, 130 power factor, haven't got the chance to try it at 50 in a ransom rest, and about 2" groups off sandbags at 100 yds. with 170 gr. hollow points at about 210 power factor.

The way to get better groups out of a factory 1 in 18-3/4 barrel is to shoot higher velocity and/or heavier bullets.

929 is a 9mm with a 1/10 twist. Why does a 1911 9mm .355 KKM barrel 1/32 twist shoot the same load 5.2 gn Autocomp Zero #135 115 gn bullet at 1.095 aol at 1187 fps 136 power factor in 1.2 inches at 50. Same load in the 929 is 1115 fps 128 . Will try equal fps as the 1911 and try that load in the 929.Would be interesting to try a Walther barrel in 1.18.75 with 9mm and see what happens.

I thought heavy bullets require a faster twist.

Tom

Edited October 27, 2014 by 9146gt

[Alan550]

Tom, you're not right, generally speaking. The formula for calculating twist rate is: 150 divided by the projectile length (in calibers) X the diameter = twist rate in inches. That works for everything from a .17 up to cannons! Got that from an article by Charles Petty in the NRA mag a few years ago.

For my 115 HAPs it works out to 33.06" and for the 147 MG it becomes 24.68" for twist rate. Longer/heavier = faster in every case, but each barrel is a different animal unto itself, as you know!

Alan~^~

Edited October 27, 2014 by Alan550

[9146gt]

Key board did what i told it to typed slower Edted it to faster.

Hey Alan,so 115 gn projectile in a 9mm revolver should work great with a 1/32 twist?

Tom

[Alan550]

Key board did what i told it to typed slower Edted it to faster.

Hey Alan,so 115 gn projectile in a 9mm revolver should work great with a 1/32 twist?

Tom

According to that formula, YES. The AR-15s shooting heavy bullets need a 1-7 twist. Longer bullets need a faster twist, short one a slow twist rate. Use that formula above and figure it for your specific bullet length/diameter. You're a pretty high-tech kinda guy, do your own numbers and you'll get the right answer.

Alan~^~

Edited October 27, 2014 by Alan550

[wheelie]

Go look at the link I posted.

There is a correction factor for lower velocities like we would have in revolvers and pistols. Greenhill is based on rifle velocities, IIRC. The faster 1-10 twist does indicate use of heavier bullets would be preferable.

Now the big question is why your revolver does not shoot the same load as well as your auto pistol. The answer is that every gun is its own rule. Especially when you get down to shooting off a Ransom or sandbags. And revolvers are tough to get the last drop of accuracy out of. Sometimes tough to get decent accuracy. I'd try some well regarded 9mm factory ammo to see what it does. If you can't get quality factory ammo to shoot reasonably well after a few different brands, the gun might have a problem. Or not. Maybe I'd try to find whatever Jerry M shot the 1000 yard plate with. It might shoot OK.

3.5 inches at 50 is not the end of the world, not unacceptable for USPSA. I'd feel fortunate and think with a little load development it'd certainly do better. If you can get them, try a few other powders and bullets.

What do the Bullseye guys who shoot 9mm use?

[9146gt]

Go look at the link I posted.

There is a correction factor for lower velocities like we would have in revolvers and pistols. Greenhill is based on rifle velocities, IIRC. The faster 1-10 twist does indicate use of heavier bullets would be preferable.

Now the big question is why your revolver does not shoot the same load as well as your auto pistol. The answer is that every gun is its own rule. Especially when you get down to shooting off a Ransom or sandbags. And revolvers are tough to get the last drop of accuracy out of. Sometimes tough to get decent accuracy. I'd try some well regarded 9mm factory ammo to see what it does. If you can't get quality factory ammo to shoot reasonably well after a few different brands, the gun might have a problem. Or not. Maybe I'd try to find whatever Jerry M shot the 1000 yard plate with. It might shoot OK.

3.5 inches at 50 is not the end of the world, not unacceptable for USPSA. I'd feel fortunate and think with a little load development it'd certainly do better. If you can get them, try a few other powders and bullets.

What do the Bullseye guys who shoot 9mm use?

I played with that link...did not find the info for lower velocities will look at it again.

My Bullseye 9mm 1911 will shoot Atlanta Arms 115 gn match at 1.5" and my loads at 1.2" The 929 shot that load same lot of ammo 4 shots about 6". Shot 160 SNS cast .38 super with N320 today and got 2.5" best yet. All groups string horizontally ? Have some .357 125 jacketed to try next. For powders will try Bullseye ,Power Pistol, WST,231.

I also plan to shoot the 929 in Bianchi metallic. Does Walther still make the barrels for S&W Performance Center?

Tom

[DougCarden]

Add more crimp to see if that will keep it from stringing.....

After that make some incremetal loads. What ever you loaded . load 12 up at .02 grain more. 3.2, 3.4, 3.6 etc. I like to shoot paper plates at 50 so I can keep them them and make notes on them. When the load goes from stringing to circular you are getting there....Good luck!

DougC

[longbarrel]

My one in 14 twist open revo shoots 2 inches at 50 with 160's. 2.5 inches with 138 wadcutters.

2 of my stock smiths shoot 2 inches at 50 with 140 truncated and 160 RN.

No particular load development. Just 50 fps over minor is my goal. All off of prone.

Any smith revo should shoot 3 inches or less or something is not right.

Troy

[9146gt]

As the 929 ia a 8 shot moon clip N frame Smith is seems to be a very different animal

Tom

[toothguy]

My one in 14 twist open revo shoots 2 inches at 50 with 160's. 2.5 inches with 138 wadcutters.

2 of my stock smiths shoot 2 inches at 50 with 140 truncated and 160 RN.

No particular load development. Just 50 fps over minor is my goal. All off of prone.

Any smith revo should shoot 3 inches or less or something is not right.

Troy

Off the subject but great shooting at the Cup. It's amazing that you shot a 1918 with a make-shift open revolver and even more amazing that the one 8 you shot was during the Practical and not the Mover (Multi Gun Aggregate).