IAI / AMT Range Session Results

Morning Gentlemen  >>  Well, between range sessions last Sunday and Saturday, I finally got some meaningful load development results with these iai / amt semiauto's.  If interested, peruse.  Gonna jot down results (at least to this point) and my thoughts.  Comments certainly welcomed.  If not interested, exit out and I'll chat with ya on another topic    .

AMT AutoMag V - .50 Action Express :

Didn't have any reloading data to rely on for this cartridge and the hard cast 420 gr. Hunters Supply FP I wanted to use so I was kinda flying by the seat of my pants.  I used H110, CCI350 primers and Starline brass.  Initial loads ran from 18.0 grs. to 20.0 grs. in 1/2 gr. increments.

• 18.0 grs. - 880.7 fps
• 18.5 grs. - 876.7 fps
• 19.0 grs. - 915.0 fps
• 19.5 grs. - 936.0 fps
• 20.0 grs. - 951.6 fps (2-shots)

All velocity averages were based on 3-shot groups, 'cept for the last.  The 3rd shot of that group jammed into the rifling, not allowing the slide to close completely and locking things up tight.  Kinda perplexing.  But with a common sense cause once I got back to the shop and measured things.  As the loads progressed, the recoil increased.  And the last bullet moved just enough to cause the problem.  I had seated things just so they'd fit in the magazine at 1.683".  Slight bullet movement wouldn't have mattered at all with a .500" bullet, but with these cast being .501", she jammed up good.  Gonna be kinda tricky using just a taper crimp with these heavy bullets.  Anyway, got things freed up and went back to the bench.  Made loads of 18.5 grs. to 20.0 grs. but this time used a 1.560" COL.

• 18.5 grs. - 909.7 fps
• 19.0 grs. - 956.7 fps
• 19.5 grs. - 968.5 fps
• 20.0 grs. - 1012.3 fps

No jams.  And the last goup printed 1.737" at 20 yds., ctc.  Plenty accurate for a possible hog hunt.  Not really sure about the top end with this combo.  Should find it with the 20.5 - 22.0 grn. increments I'll be putting together next.  1100 - 1150 sure seems reasonable if I can keep the bullets from jumping to badly. 

Did notice something else     ...     this handgun has a strange tendency to eject spent cases right back into your face    .  And it seemed like as the pressures increased, likelyhood of getting rung up on the forehead increased.  That 20.0 grn. group, 2 of the 3 got me.  Will need to have 50 look into possible cures for this.  It is certainly an excercise in concentration holding for a respectable group when you don't know when you're gonna get hit.

IAI AutoMag IV - .45 Win Mag :

I used CCI 350's, H110, Starline brass and the 250 gr. hard cast FP from Hunters Supply for this cartridge.  Was real excited to see what this one would offer.  I prepared loads in 1/2 gr. increments from 24.0 up to 26.0 grs.  Relied on Hodgdon data for this one, with their MAX load listing 1380 fps using 26.0 gr. of H110 and a jacketed bullet.  Got the first two shots fired from my 24.0 gr. starting load and the chrony read 1417 & 1428 fps.  Mercy sake.  Smoking !!!  As the gun tried to cycle the third shot, it locked up alla the above .50 AE issue.  Ran back to the reloading bench and from the original 1.552" OAL back up to a 1.466" OAL.  Got back to the shooting bench for the third shot of that opening load and it read 1447 fps.  Wasn't all that concerned about the 1431 fps average as Hornady printed MAX loads claiming similar velocities but I was very suprised at the amount of powder needed to reach that speed in this handgun.  I shot the next increment, 24.5 grs.     ...     1471, 1503 & 1517 fps.  Needless to say, loads 25.0, 25.5 and 26.0 aren't getting shot.  1497 fps with a 250 gr. bullet is well above what I was hoping for with this gun.  The cases are handling it fine but I just don't think I want to put the gun through that strain.  As things stand now, I believe I'll be calling 24.0 grs. of H110 my MAX load.  Also, between shots two and three of that last group, the front site when flying.  Only by the grace of god was it found in the high grass where I was shooting.  Will certainly have to figure out a way to have that little sucker securely fastened before the next range session.

IAI Javalina - 10mm Auto :

I used CCI 300's, Blue Dot, Winchester brass and the 180 gr. hard cast FP from Hunters Supply for this development.  I have a load worked up for this round using the 180 gr. Gold Dot and 11.0 grs. of Blue Dot so for these cast bullets, I started at 10.0 grs. and loaded up 10.5, 11.0 and 11.5.

• 10.0 grs. - 1289.7 fps
• 10.5 grs. - 1345.3 fps  MAX LOAD
• 11.0 grs. - 1390.3 fps
• 11.5 grs. - Did Not Shoot

Fresh primers seated solidly.  So it boils down to the strain that I want to put on this gun.  The 10.5 grn. load meets what I was getting with the Gold Dot's.  At nearly 1350 fps, I feel good with that being called my MAX load.

AMT AutoMag III - 9mm Win Mag :

This was another round where there was no reloading data to work with.  Pulled a little from the older 9mm Mauser info. and with a little educated guessing came up with an 8.0 gr. starting point, using Blue Dot.  Also used CCI 500's, out of production Winchester brass (probably collectors stuff I shouldn't be using   ) and the 147 gr. Speer Gold Dot.  Went in 2 tenths increments.

• 8.0 grs. - 1012.9 fps
• 8.2 grs. - 1000.8 fps
• 8.4 grs. - 1023.7 fps
• 8.6 grs. - 1108.3 fps
• 8.8 grs. - 1172.3 fps
• 9.0 grs. - 1230.7 fps

Starting loads weren't even creating enough pressures to properly run the slide.  Had to manually do so up to the 8.4 grn. loads.  Then it started throwing cases but was having troubles having enough umph as it fell back to chamber a round.  The 8.8 and 9.0 loads seemed to generate the pressures necessary to make the slide extract and feed properly.  Ran into issues then with the extractor occasionally having problems clamping over the rim of the case.  When I'd finished running the last loads over the chrony I went back to the shop where 50 polished the extractor surface.  This should take care of that problem.  I made up the next loads of 9.2, 9.4 and 9.6 grs.  Looking forward to seeing if the polished surface takes care of the problem.  Again, not really sure about the top end with this cartridge.  Only data for this round lists 1475 fps with a 115 gr. bullet in a factory load so that don't really tell me alot using the 147.  I would imagine we'll be breaking into the 1350's with these next loads.  See how the gun and cases respond to that.

I feel pretty good about where things are with the .45 and 10.  One more range session to confirm accuracy and I should be able to take them off the "to do" list.

.500 S&W Mag results are coming.  Had a little accident with the middle finger of my shooting hand some weeks back and can't put on my shooting glove because of it so the heavy recoiling revolvers are out for a bit.  Give it another couple weeks of healing and should be able to get things rolling.

Will post more on the .50 and 9mm as it happens.  Later.  >>  korey

Yeah, the AMT is brutal on cases.  Had to get myself a small metal file to smooth down the nicks when they happen.  Never messed with the Desert Eagle .50AE's but have heard they are similarly rough on cases.  >>  klallen

Edited by klallen