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View Full Version : Polygonal rifling Bersa Thunder Pro UC40


Marty8613
February 25, 2014, 09:01 AM
Okay, so apparently this is a late 1800s invention, yet I have never heard of it. I have pretty much determined that I like the Bersa Thunder Pro UC40 for my .40 carry (collecting calibers). It has an ambidextrous safety (need this) and swappable mag release (I will make that a lefty). Seems sized right for what I want and won't cause me pinky issues once I extend the mags (I do this a lot). I like the look.

I see it has polygonal rifling, which is apparently a rifling without sharp edges, there are still lands and grooves, but they are all rounded to 'hills and valleys'. Anyone have any experience with this type of rifling? How does it effect power and accuracy? Seems to me that it would make for more fps (less friction and deformation down the barrel)) but maybe less accurate (little less spin). Am I wrong in these assumptions (Man I hate when that happens)?

If I could find a rental place with this or the full size model, I would shoot it and not have to ask around, no luck so far. If you know of one in the DFW area, let me know.

Thanks,
Marty

EAA Witness Polymer 45 Full Size
Bersa Thunder 380 Duo

PSP
February 25, 2014, 10:40 AM
Polygonal rifling usually offers a better gas seal which may result in a small velocity increase. The main attribute is longer life and perhaps a bit easier cleaning. spin rates are no different. Accuracy is the same.

TunnelRat
February 25, 2014, 11:15 AM
Two smaller companies by the names of Glock and Heckler & Koch have been using polygonal rifling for decades to the tune of millions of firearms sold.

Waspinator
February 25, 2014, 11:32 AM
I recently bought a Bersa UCPro 9mm. I like it a lot and find that it is more accurate then I am (found this out when I handed it to a friend and he shot great with it, better then me, lol).

The safety/decocker and slide release levers are well placed and are easy to manipulate. I really like that it has a decocker so I can chamber a round and choose not to use the safety (so first shot is like my revolvers). That said, the decocker, when engaged, drops the hammer with authority (you can't control the speed). It is a little disconcerting at first, but once I got used to it I am more comfortable using it now. I like how the magazine drops easily from the magwell, some guns I handled you had to remove the mag by hand after releasing it. Not the Bersa UCPro, it flies out of the gun.. which you have to be careful while at the range, so your mag doesn't go flying. The takedown for cleaning is so ridiculously easy.. I love it.

Only thing I that I wish I could change? Well, I wish there was some aftermarket grips for the Bersa UC's. There is one guy who makes custom wood grips (at a price $$$), but no one makes any rubber grips or anything like that. The grips are fine that come with it and have aggressive checkering and such, but the plastic is very hard in the hand.

All-in-all, they are great , all metal, compact, DA/SA semi-auto that is accurate and built well. I only owned mine for a few weeks and I have about 250 rounds through it already without a single failure to report.

Marty8613
February 25, 2014, 11:37 AM
Yeah Glock doesn't float my boat, but H&K is a favorite. From what I am reading about the physics involved, this makes more of a difference in rifles. The only caveat I see in pistols is that lead is a bit too soft and tends to veneer inside of the barrel, but jacketed rounds actually perform a bit better.

Seems that the deformation is lessened, while at the same time the pressure is increased (greater fps) over the cut land and groove method. The area of contact is decreased within the barrel. I see claims both ways as to accuracy, but I suspect the detractors are referring to lead rounds, which tend to 'pile up' on the edges, since there is no where for the lead to deform to, except to the head. Looks like this method gives a better seal to the round overall, AND increases the life of the barrel, since it wears down much more slowly. With the greater fps and more symetric round (less drag) upon exiting the barrel, looks like some range advantages can be had.

I think I am convinced well enough to go ahead with the Bersa, and this might lean me towards Glock 9mm (I don't have an H&K budget), when I get over my hatred of stiker fired and 9mm both.

I do still welcome any comments as to polygonal rifling and experiences.... is there anyone who has really thought about it?

Marty8613
February 25, 2014, 11:42 AM
Quote

"I recently bought a Bersa UCPro 9mm. I like it a lot and find that it is more accurate then I am (found this out when I handed it to a friend and he shot great with it, better then me, lol)."


Oh ouch, I have thankfully never had this happen. Thanks for the update. I think I'll do it.

2nd question, just how are you guys getting those quote boxes?

Sweet Shooter
February 25, 2014, 11:44 AM
I had the Bersa Pro 40 for a while. It was a quality piece for the money. It does have feed issues with some ammo types, and I failed to get it to shoot well for me.
YMMV
-SS-

TunnelRat
February 25, 2014, 11:47 AM
I do still welcome any comments as to polygonal rifling and experiences.... is there anyone who has really thought about it?

Not sure what you mean by "really thought about it". All the pistols I own currently have polygonal rifling. I prefer it. I don't shoot lead rounds and you're not supposed to because you can get leading in the barrel as you mentioned. I find it ridiculously easy to clean. As for accuracy, my HK pistols are the most accurate I have ever owned.

lee n. field
February 25, 2014, 12:25 PM
Seems sized right for what I want and won't cause me pinky issues once I extend the mags (I do this a lot). I like the look.

Extended magazines? The only ones I'm aware of are for the full size Bersa Thunders.

I see it has polygonal rifling, which is apparently a rifling without sharp edges, there are still lands and grooves, but they are all rounded to 'hills and valleys'.

Bersa's advertising is weird. The rifling is described as "sharp and deep". And also polygonal.

Anyone have any experience with this type of rifling? ...but maybe less accurate (little less spin).

Not with Bersa's. My UC45 has the older type barrel. All Glocks have it. Use the search, you'll find lots of discussions on it. Said not to be safe to shoot cast lead through polygonal rifled Glock barrels. It's one of those religious quarrels that will take a century to sort out.

Lead bullets might stabilize more poorly through the polygonal rifling, than the conventional land and groove rifling. Might.

My understanding is, Bersa is OK with you shooting cast bullets through their polygonal barrels. You'd probably want to double check that.

Marty8613
February 25, 2014, 12:50 PM
Still can't figure out the quote boxes, oh well.

If extended mags aren't available, I would machine some +2 extensions. My job involves FP Lamps, RPTV Lamps, and other plastics (read plastic housings). I am used to having things molded. I am looking at the extensions done for the 380. Something similar to that. I have my Bersa Thunder 380 single stack up to 10+1, I am trying to acquire the 'Blue' revision 9 round magazine, reported to work with it. To get it to 11+1.


As it is, with this model, that hook for the pinky is much smaller, I am hoping it wont interfere like the standard one did on the 380.

michael t
February 25, 2014, 01:44 PM
You can use the mags from the full size model they fit in UC just stick out

http://bersachat.com


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Marty8613
February 25, 2014, 02:29 PM
Quote:
You can use the mags from the full size model they fit in UC just stick out


There you go. I can mold a new cap for the end to make it pretty.

Marty8613
March 26, 2014, 06:03 PM
Quite happy and yes polygonal rifling. Maybe I will attempt a range report after Sundays shoot.

Firestorm Mini 40 Pro