Flat base vs concave base

[Eddietruett]

Has anyone here ever compared the accuracy of flat base fmj to concave base fmj. I’ve always heard concave was more accurate but I can’t tell any difference shooting offhand. Curious if anyone has ever done a test off the bench or a Ransom Rest

 

[rockquarry]

What are some bullet brands that offer jacketed bullets with concave bases? I'm not familiar with these as I generally shoot cast bullets in handguns.

 

[Skeet 028]

Remington concave bases in 50 gr 224 match bullets loaded in 222 at least. And they made some handgun bullets with concave bases...44s and 45 I think. Maybe Winchester too in 44 jacketed

 

[Mike SC Hunter]

Remington concave bases in 50 gr 224 match bullets loaded in 222 at least. And they made some handgun bullets with concave bases...44s and 45 I think. Maybe Winchester too in 44 jacketed

Hum..........Would like to see pics.

 

[Mike SC Hunter]

Remington concave bases in 50 gr 224 match bullets loaded in 222 at least. And they made some handgun bullets with concave bases...44s and 45 I think. Maybe Winchester too in 44 jacketed

Hum..........Would like to see pics. OR are you just talking about boat tail bullets and flat base bullets?

 

[Eddietruett]

Hum..........Would like to see pics. OR are you just talking about boat tail bullets and flat base bullets?

No, handgun bullets mainly for 9mm and 45. Right now, Everglades ammo has both styles for both calibers I’m pretty sure. We had a discussion Sunday with our shooting group and it seems opinions are split. I can’t imagine at 25 and shorter it could make a big difference nut thought I’d get opinions here

 

[Eddietruett]

Concave fml

Here is a picture

 

[SMSgt]

Don't over think it.

 

[zeke]

Back when i was buying factory rounds, took a liking to Win 115 gn Q4172. They came in a 50 round white box and were very accurate in all the 9mm pistols owned. Found this unusual given the varying bore diameters. Noticeably more accurate than Winchesters other 115 fmj white box loading when shooting steel at 25 yds. Finally took one apart and discovered it was a 115 gn fmjhb, which they sell as separate components. Have been using them ever since. They can be seated out further than most, and offer a longer shank than the flat base fmj.

 

[Nevada Ed]

The only concave bullet that I have noticed in my reloading bullets were
made by Winchester in the light 110gr JHP bullet design for my 38 & 357 loads.

I always woundered why they were concave, but they shot just as good as
the other FB bullets by the other guys.

 

[WR Moore]

Remington RNL .38 bullets used to have a slightly concave base. Doubt that there's any real advantage, HBWCs used to have very thin skirts to improve bore sealing.

 

[rockquarry]

The only concave bullet that I have noticed in my reloading bullets were
made by Winchester in the light 110gr JHP bullet design for my 38 & 357 loads.

I always woundered why they were concave, but they shot just as good as
the other FB bullets by the other guys.

Concave might have something to do with the manufacturing process. Another explanation might be that any amount of concave depth will make the bullet longer than one with a flat base bullet of the same weight. A longer bullet with more bearing surface (even if it's slight) will in theory (and maybe in practice) almost always increase the accuracy capability.

I didn't know such bullets existed.

 

[USBP SW]

I have to dig around but I think that I used Winchester bullets of that design in the 70's. I found them to be accurate and I felt that the powder capacity of the case was enhanced slightly. However, the method of manufacture could be less consistent, the base of the bullet is the most critical area, if the jacket ends at the base, the consistency could conceivably affect the accuracy. In the case of the Winchester bullets I mentioned, they were hollow points, the jacket ended at the hollow point and the bases were very consistent. At standard handgun shooting distances, it may not be very noticeable.

 

[Skeet 028]

Back in Nov. I bought 80 pounds of Winchester 44 cal (240s?) that had concave bases and they were hollow points. I split them with a friend and sold all mine. Only paid 60 bucks total and I mostly shoot lead in 44s. I will look for the Remington 22 match bullets but am positive they were concave slightly. And I think I have a box or two of Remington lead 32 cal .314 80 gr bullets that are concave too-

 

[nedlate]

Here are a couple of pictures of concave bases on Speer bullets.
Ed

 

[WR Moore]

On the Speer's, probably due to the shape of the swaging punch. There may be some practical tool & die reason for the design.

 

[DanGee]

Remington's swaged lead bullets commonly had concave bases. I bought several thousand in .35, .44, and .45 calibers back in the 1980s when Midway offered them for cheap. Haven't seen them for sale in a while, but they are good bullets.

 

[reddog81]

Rocky Mountain Reloads has 115 grain 9mm bullets with a concave base. They look about the same as 124 grain bullets except the concave rear end.

I’d expect accuracy to be very similar assuming similar quality bullets. Any defects on the bullet base will cause issues but uniform bases shouldn’t be a problem.

 

[STORMINORMAN]

Berry's hollow base thick plate bullets (HB-XXTP) typically allow for both higher fps and deeper seating without increasing pressure.

Their 124gr HB-FPTP is excellent in 9mm and 357 SIG for good range ammo.

Cheers!

 

[mtgianni]

I think if there is an advantage it would show up after 400 yards. That makes it immaterial for a handgun.