40 S&W bullet dimensions

[Bmeehan19]

I just acquired a RIA Pro Match 40. Here are the dimensions from the slugging and plunk test!

 

OAL 1.289

Slugging .395-.3955

crimp .422-.423

 

I used a .401 Berrys RNFP for both. 

 

What should the max OAL be?  And the ideal projectile diameter (.400-.401)?

 

Thanks in advance. 

 

Bryan

Edited May 17, 2018 by Bmeehan19

[Steve RA]

Was the slugging dimension .395 ????    If not, what was it ???

[Bmeehan19]

Just now, Steve RA said:

Was the slugging dimension .395 ????    If not, what was it ???

Yes. Sorry. Edited original post

[Steve RA]

If that was the groove diameter it seems you are in the ball park with the .401s,  if it was bore I'd probably go a thou or two more.

[Bmeehan19]

So since the bullet is a negative of the barrel. I measured the smallest grooved portion, the rigling. Im not up on the correct terminology. This is my first time slugging. It seems the wider sections of tge bullet didnt touch the barrel near the tip. 

[Steve RA]

Smallest portion is bore diameter - which you measured.  Largest portion is groove diameter.  That is the one you should measure for determining best bullet size for your barrel.

[Bmeehan19]

That dimension looks like .403. You can see in the pic that it doesnt contact the projectile all the way up. Should it?  So I would need a .405 projectile? It wasnt the easiest to get this thing through. Although I have no comparison. 

[Steve RA]

A larger projectile is usually better with lead or coated projectiles.  Plated you can go a little less and jacketed least of all.  Looks like you were measuring a hollow point - which would be jacketed - and your pretty much stuck with their dimensions.

 

Main thing is how is the accuracy ??  If good - you are good to go.  If not - try some other bullet and see how it is accuracy wise.

[Bmeehan19]

These are Berrys 180 RNFP .401 plated. I shot it the other day with factory jacketed ammo and it kinda seemed all over the place. Like 25’ 7-8” group. It did seem to get tighter after 4-5 mags continuous shooting, but after it cooled it opened back up. A lot of flyers kinda. 

Edited May 17, 2018 by Bmeehan19

[bjones6686]

Try between 1.175-1.200 OAL. That's what seems to feed the best in my experience of 40cal in 1911's/2011's. I've loaded both 165gr RNFP and 180gr RNFP with great success. I'd also suggest trying a bullet with .401 diameter. Most coated lead bullets come in .401 diameter.

[Bmeehan19]

2 minutes ago, bjones6686 said:

Try between 1.175-1.200 OAL. That's what seems to feed the best in my experience of 40cal in 1911's/2011's. I've loaded both 165gr RNFP and 180gr RNFP with great success. I'd also suggest trying a bullet with .401 diameter. Most coated lead bullets come in .401 diameter.

Thanks. Ill start there. I have .401 plated rnfp Im gonna try first. The initial was factory .400 jacketed. Im going shooting tomorrow. 

[Steve RA]

Sorry I was wrong on my guess as to the bullet shape.  I'd try something a little larger in diameter.