Page 1 of 2

Manurhin 0.32 barrel

Posted: Tue Oct 29, 2019 9:15 pm
by jbshooter
Has anyone slugged a Manurhin 0.32 barrel to confirm sizing of diameters?

Re: Manurhin 0.32 barrel

Posted: Tue Oct 29, 2019 10:15 pm
by David M
yes

Re: Manurhin 0.32 barrel

Posted: Tue Oct 29, 2019 11:55 pm
by deadeyedick
Yes....my older model slugged .313” and my latest model is .315”. It is more difficult finding a projectile to suit .315” than .313” but critical regarding accuracy.

Re: Manurhin 0.32 barrel

Posted: Wed Oct 30, 2019 7:24 am
by David M
Ideal is 0.001"- 0.002" over slugged diameter (for cast soft lead).
I shot 0.312" in my old MR73.
Be careful with the die set size's.

Re: Manurhin 0.32 barrel

Posted: Wed Oct 30, 2019 12:59 pm
by jbshooter
Mine measured 0.315 and I thought was a mistake. Maybe not.

Re: Manurhin 0.32 barrel

Posted: Wed Oct 30, 2019 2:21 pm
by fc60
Greetings,

I am not familiar with the Manhurin 32.

Is it a traditional revolver or similar to the TOZ where the cylinder moves forward to contact the barrel?

Cheers,

Dave

Re: Manurhin 0.32 barrel

Posted: Wed Oct 30, 2019 3:26 pm
by Leon
No. The Manurhin MR73 is a high-quality revolver, currently being made by Chapuis Armes in France.

It's fit, finish, high-polish and blueing is beyond reproach, and is made to quality standards that American revolver manufacturers can only dream about.

Even the much-vaunted Colt Python suffers badly in comparison.

Very close to Korth quality.

Manufacturers website - https://chapuis-armes.com/en/manhurin

Comments on the durability of the Manurhin here - due to the very high quality steel & construction here -
According to a test published in Cibles № 342, the rectangle of dispersion on a target shot at with the MR73 did not change after the test firing of 20,000 full power .357 Magnum cartridges. The writer concluded that it would take at least 300,000 rounds for the bore to begin to wear. The Manurhin factory museum exhibits an MR73 used by GIGN, with a round count of 96,000 full power .357 Magnums, a number unattainable by any S&W revolver.

Interesting article here written by a friend with similar SIG P210, Korth and Manurhin interests -

https://larvatus.livejournal.com/519794.html

Re: Manurhin 0.32 barrel

Posted: Wed Oct 30, 2019 4:08 pm
by fc60
Greetings,

Thanks, Leon, for the lesson.

Just recently, I finished a set of dies to swage the Speer Plinkers to 0.315" diameter.

If your cylinder throats are also 0.315" these may work rather well.

I have a 32 revolver with 0.315" throats.

No time for me to test as yet with too many unfinished projects in the shop.

If you live in the USA, I could be talked into selling you a small sampling.

Cheers,

Dave

Re: Manurhin 0.32 barrel

Posted: Wed Oct 30, 2019 4:58 pm
by jbshooter
Hi Dave,
I'm always interested in your .32 posts.
Do you hydraulically swage the speers in your dies. I have done the same on a few samples as i have found some variance in the speer diameters - mostly coming in at 312-312.5 thou. The old Lapua's were 0.314 all the time.

Re: Manurhin 0.32 barrel

Posted: Wed Oct 30, 2019 6:03 pm
by deadeyedick
With a barrel diameter of .315” finding a projectile.001”-.002” over is one problem but more importantly you must diamond lap a flrsd approximately +.004” oversize to prevent the standard flrsd dimensions (which are set small enough to accomodate a .310” projectile) from being squeezed undersized when seating.
Unless you finish up with a seated projectile that can be removed and size checked at +.001” above bore diameter the whole exercise becomes a waste of time and accuracy will suffer.

Re: Manurhin 0.32 barrel

Posted: Wed Oct 30, 2019 6:40 pm
by fc60
Greetings JBShooter,

I use a Corbin Swage Press. Over the years, I have accumulated a variety of dies and punches.

Greetings deadeyedick,

If "flrsd" is Full Length Re-Sizing DIe, yes, you need to either order a die correct size or diamond lap one. Again, I have several case sizing dies that I use to match up with the bullet being loaded. Lee Precision will make them any size you want for a small fee.

Using Lapua cases, a sized case measuring 0.335" would offer a nice interference fit with a 0.315" bullet.

Cheers,

Dave

Re: Manurhin 0.32 barrel

Posted: Wed Oct 30, 2019 7:41 pm
by JamesHH
Leon wrote: Wed Oct 30, 2019 3:26 pm No. The Manurhin MR73 is a high-quality revolver, currently being made by Chapuis Armes in France.

It's fit, finish, high-polish and blueing is beyond reproach, and is made to quality standards that American revolver manufacturers can only dream about.
Are the current ones being built to the same standards as the originals? Just wondering as I've heard a few stories.

Re: Manurhin 0.32 barrel

Posted: Wed Oct 30, 2019 8:18 pm
by David M
I had both the .32 and the .38 MR73 Match back in the late 80's and ran both side by side for a number of years.
I found that the .38 would out shoot the .32 all the time, so I sold the .32.
I am still using my old .38 Match today.
Great gun.
Current production is as good as the early ones, however there was a small batch about 20yrs ago that was not as good.
However the .38 Match (single action) is rare and hard to find.

Re: Manurhin 0.32 barrel

Posted: Wed Oct 30, 2019 8:37 pm
by Leon
JamesHH wrote: Wed Oct 30, 2019 7:41 pm
Leon wrote: Wed Oct 30, 2019 3:26 pm No. The Manurhin MR73 is a high-quality revolver, currently being made by Chapuis Armes in France.

It's fit, finish, high-polish and blueing is beyond reproach, and is made to quality standards that American revolver manufacturers can only dream about.
Are the current ones being built to the same standards as the originals? Just wondering as I've heard a few stories.
Better.
The factory has invested in a number of 5 axis CNC machines and tolerances etc are tighter than they ever have been.

Re: Manurhin 0.32 barrel

Posted: Wed Oct 30, 2019 8:39 pm
by Leon
jbshooter wrote: Wed Oct 30, 2019 4:58 pm Hi Dave,
I'm always interested in your .32 posts.
Do you hydraulically swage the speers in your dies. I have done the same on a few samples as i have found some variance in the speer diameters - mostly coming in at 312-312.5 thou. The old Lapua's were 0.314 all the time.
I checked a large sample of the Speer .32 .314 HBWC that I have, and they all uniformly measured .31475.

Do you perhaps have the .312 Speers?

Re: Manurhin 0.32 barrel

Posted: Wed Oct 30, 2019 9:14 pm
by JamesHH
David M wrote: Wed Oct 30, 2019 8:18 pm Current production is as good as the early ones, however there was a small batch about 20yrs ago that was not as good.
Thanks, that batch 20yrs ago is probably what I was thinking of as that was around the time I was looking.

Re: Manurhin 0.32 barrel

Posted: Wed Oct 30, 2019 9:31 pm
by deadeyedick
I bought one new about a year before the OZ gun buyback ( early 2000’s ) and found its fit and finish to be excellent.
I also had one from the late 70’s or early 80’s and apart from its age the fit and finish was excellent.
I also recently bought one of the Chapius Armes production and see no deterioration ( or improvement ) in the quality. Having said that the tolerances may be more consistent from one revolver to the next as a result of updated CNC machines as mentioned by Leon.
All were a delight to own and shoot.

Re: Manurhin 0.32 barrel

Posted: Thu Oct 31, 2019 11:18 am
by fc60
Greetings Leon,

Speer HBWC originally were coated with a beeswax-like lubricant and some actually measured 0.314" with most 0.313".

The latest offering are marketed as "Plinkers". These are tumbled in a Moly type of lube. The Moly ones do shoot cleaner (less Lead fouling) than the Beeswax version. They vary in diameter from 0.312"-0.313". The same bullet will have different diameters at the nose, base and middle. I attribute the variation to a combination of the knurling process and tumbling.

I have used thousands of the Speer bullets and have never found them to be over 0.314" in diameter.

I have good results, ten shot groups under 2" at 50 yards, with either version of the Speer bullet, unaltered, using barrels of 0.311" groove diameter, or smaller, with a twist rate of 10, 12, or 14.

The barrel in the SIG-Hammerli P240 I have measures 0.3125" with a 1:400mm twist (15 3/4") and on a good day, I can get 3" groups at 50 yards via the Random Rest.

A friend tested my first batch of swaged 0.315" HBWC at 50 yards via sand bag rest and ten shots easily fit into the 3.4" ten ring we use. I expect barrel tester results to be similar if not better.

Most of the other European pistols/revolvers have 0.314" groove diameters with the 1:450mm (1:18 3/4") twist. Works well at 25 meters; but, not so good at 50 yards.

Lots of testing has convinced me that the quality of the bullet is paramount. Not to mention careful loading techniques.

Cheers,

Dave

Re: Manurhin 0.32 barrel

Posted: Thu Oct 31, 2019 1:56 pm
by jbshooter
Lots of testing has convinced me that the quality of the bullet is paramount. Not to mention careful loading techniques.

Cheers,

Dave

I think you're right with this Dave. I believe you have to load with digital precision - bullet quality and diameter, case outside diameter, powder weight consistency, alignment of reloading dies, seating and crimping dies all have an influence on end result. Then you know it is just the shooter that needs fixing.

Re: Manurhin 0.32 barrel

Posted: Fri Nov 01, 2019 3:08 am
by David M
The problem with the .3SW long is the SAAMI spec itself.
The .32 spec is bullet dia of 0.3150" - 0.006" ie. Anywhere from 0.309" to 0.315".
All other rounds 9mm, .38 Special, .38 Super are half that at 0.003".
How do you make one set of dies to suit all with such a loose spec ?
The other problem is the thin case wall and neck release tension.