FMJ vs JHP

[Gunnut]

Regarding 38 Super 115gr. and 124gr. bullets, during the transition from magazine, up the ramp and into the chamber is one bullet nose configuration more reliable than another?  

Are FMJ and JHP bullets typically the same length and have no effect regarding case capacity?

(Edited by Gunnut at 12:10 am on Dec. 12, 2002)

[warpspeed]

my experience has been the FMJ are less picky about the OAL than the JHP. The JHP are more accurate so for me it's worth the time to find the right OAL to make them feed 100%.

As far as the same dimensions, I don't know. I'll have to measure.

[warpspeed]

I had 2 sample packs of bullets from Montana Gold.  All the 115 gr JHP measured .5535" OAL, but the 115 gr FMJ were .5610" OAL, a difference of 75 thousandths.

I think that the bullet length itself is not a big issue as much as the shape. Depending on you seating dies, if you switch back and forth, the point on the bullet that contacts the dies will result in a different amount of the bullet in the case and subsequent OAL of teh loaded bullet. So if you are concerned, you will need to have a different OAL for each bullet. And I would think in 38 super,loading to major pf, you would be.

[Gunnut]

Thanks, Warpspeed for the reply.  .075" OAL difference between JHP and FMJ bullets seems significant for such a high pressure load.  OAL of loaded cartridges don't seem to vary nearly that much. This was probably more of an issue at the old PF.

Using 3n37 or n350 which bullet would best serve for both major IPSC loads and minor loads?

Ed.

[L9X25]

Gunnut,

Keep in mind that a FMJ bullet, although often longer than a comparable weight JHP or FP, can usually be loaded to much longer OAL and still function properly in the magazines.  In an SV/STI type gun people often load as long a 1.260+ with reliability.  Most that load JHP or FP type bullets keep the OAL much shorter.  The actual case volume available is very comparable between the 2 types after you account for the OAL and projectile length.

Leo

[Gunnut]

Oops, fuzzy math. The difference between the two bullets is .0075".  That makes more sense.

Ed.

[warpspeed]

Gunnut,

FWIW I routinely switch between FMJ and JHP 115's in my 9x19 steel loads without any feeding problems. I am not even close to being worried about pressure as the velocity is around 1000 fps so I only look at the function of the gun and it has not been a problem.