Reloading .44 AMP, IMR 4227, 200 gr. XTP

[cstarr3]

Greeting High Road Travelers!

A few years ago I had the opportunity to buy a Pasadena Model AutoMag and so I bought it (an impulse buy that, despite losing my job a month later, I still do not regret). I made the mistake of shooting up all the factory ammo that came with the gun (~30 rounds of 200 gr. "Wildey's Here" brand ammo). I have been trying to find a load that this gun likes, and have so far failed. The AutoMag, like a lot of semi-auto magnums, is a little finicky and is a picky eater. My particular gun is not happy with its diet, and it does not like to send the slide all the way rearward. As such, lock open on the last round is rare, and stripping a new round off the magazine doesn't happen; it just scrapes along the top of the next round and jams as a result. Despite my failing, I figured I'd share my data.

I used data from Hornady's Reloading Manual, 9th Edition. The manual says that 26.5 gr. IMR 4227 should get 1450 fps, and 27.1 gr. should get 1500 fps. I chronographed 50 rounds loaded with IMR 4227 in Starline brass behind 200 grain Hornady XTP bullets (primed with CCI 350 Large Pistol Magnum primers). Per Hornady No. 9, I loaded to a COAL of 1.600". I started with 10 rounds of 26.2 grains of 4227 and increased the load by 0.2 grains every 10 rounds. I used a Shooting Chrony Gamma at about 6 feet from the muzzle. When developing load, I keep track of the weights of bullets and COAL for individual rounds, and I give their averages for each string with the data. Even though the average bullet weight was at or near the 200 grain mark, the individual weights ranged from 199.1 gr. to 200.6 gr.

Minor cratering was apparent on many primers across the load range, though it was more common and more noticeable on the hotter loads. Primer flattening was minor on the lighter loads, but quite noticeable on the hotter loads.

I used MS Excel to fit trend lines to the average velocities. V is the velocity in fps, and w is the charge weight in grains. The linear trend line was v = 57.0w + 3.6 and had an R^2 value of .919. The polynomial trend line was v = 71.4w^2 - 3743w + 50537.9 and had an R^2 of .999. To reach the 1600 fps that was listed in Hornady No. 9 as the max for H110, one would need 28.0 grains of IMR 4227 according to the linear trend line, and 27.5 gr. IMR 4227 according to the polynomial trend line.

Needless to say (but I'm saying it all the same) this is for informational use. If you duplicate these loads, you do so at your own risk. If you hurt yourself, you assume full responsibility for your actions.

26.2 gr. IMR 4227
Low: 1478
High: 1555
Avg: 1503
E.S.: 76.39
σ: 22.56
Avg. Bullet Weight: 200.0 gr.
Avg. COAL: 1.600”
Individual Velocities
1478
1507
1483
1499
1555
1479
1513
1513
1507
1497

26.4 gr. IMR 4227
Low: 1485
High: 1531
Avg: 1505
E.S.: 46.03
σ: 12.60
Avg. Bullet Weight: 200.0 gr.
Avg. COAL: 1.600”
Individual Velocities
1493
1485
1509
1503
1531
1502
1514
1500
1514
1503

26.6 gr. IMR 4227
Low: 1487
High: 1551
Avg: 1514
E.S.: 64.28
σ: 22.20
Avg. Bullet Weight: 199.8 gr.
Avg. COAL: 1.600”
Individual Velocities
1551
1524
1524
1488
1546
1506
1495
1487
1510
1512

26.8 gr. IMR 4227
Low: 1509
High: 1551
Avg: 1529
E.S.: 41.61
σ: 14.00
Avg. Bullet Weight: 200.1 gr.
Avg. COAL: 1.600”
Individual Velocities
1551
1520
1509
1536
1519
1524
1535
1513
1541
1543

27.0 gr. IMR 4227
Low: 1539
High: 1559
Avg: 1548
E.S.: 19.44
σ: 5.91
Avg. Bullet Weight: 200.1 gr.
Avg. COAL: 1.601”
Individual Velocities
1556
1539
1546
1542
1547
1559
1548
1548
1550
1546

I hope to get some loads worked up with H110 within the next few weeks for .44 AMP. I also hope to eventually work up some loads for 240 grain XTPs. But, as far as reloading goes, I have a lot of irons in the fire right now, so it may be a while yet.

 

[Jim Watson]

Kent Lomont wrote three articles on the care and feeding of the Automag in its heyday.
Handloaders Digest 7th, 1975
Gun Digest 31st 1977, 32nd 1978.

As I recall H110 was THE powder.
Lubrication to prevent galling and smooth operation was important.

 

[Patocazador]

I bought a .44 AMP in the '70s with a 6" barrel and a 10 1/2" .357 AMP barrel.

H-110 gave me the most accurate hunting loads with .44 AMP with 296 a close second. 4227 never produced the velocity nor accuracy of H-110 with my efforts.
I used CDM cases at first but then started forming my own from cut-off, picked-up, .30-06 range brass. Although I bought some new Norma cases, I never loaded any.

The .357AMP shoots well with a 150 gr psp Remington bullet. It feeds OK too.

 

[cstarr3]

Hi All! Thanks for the replies.

I checked around at local thrift stores and used book stores, and couldn't find any of the titles mentioned by Jim Watson. I will probably gather up some coins out of the couch cushions and order these books off of Abe Books in the near future. I do try to keep the gun well lubricated and clean. Although I have never seen an Auto Mag go for the price that I got mine for, I still can't afford to buy another one just because I neglected the one I have. But, like anything second-hand, I cannot care for my baby enough to undo mistakes made by the previous owner. One of the recoil rods seems to be less than perfectly smooth, and the other has some definite wearing, so I think I am going to replace both of them when I have the money. Unfortunately, the last ones I found for sale was going for north of $200. I don't know if that was apiece, or a set of two, but either way it seems like a lot of money for what is essentially a really long hex screw.

As I noted in the original post, the graphs indicated far-over-max loads with IMR 4227 to be able to accomplish the same velocities as H110 [Note: I have no plans of going over max published loads. Although I have a spare hand just in case one gets blown of by a KB, I still have only ONE Auto Mag]. I decided to try out the published IMR 4227 loads first because my automatic powder meter likes it much better than H110, which it will not spit out in the proper amounts for anything. My powder throw also seems to like it. I don't know if it the batch I got, or just the nature of the formula, but H110 seems to like to stick to stuff a little more than IMR 4227 (like Longshot... I swear, I think they used scotch tape adhesive as a bonding agent in that stuff). But if IMR 4227 can't do it without getting explosively dangerous, H110 is going to be my new go-to powder for this caliber.

I recently looked into getting a Hornady Quick Trickle, as that seems like it will be a little more useful for metering H110. I use H110 for .357 magnum, .460 Magnum, and .50 Action Express, and will probably be using it for .44 AMP and .44 Magnum, so I think it may be a worthwhile investment to be able to load it more easily than I currently can. If it doesn't work out so well, I can always give it to my brother, whose equipment is mostly Hornady.

I recently found out that company called Auto Mag LTD, Corp. is setting up to "remake" the Auto Mag. They want to do many things, including making parts for original guns, making new uppers for original guns, and making entirely new guns with some of the old kinks in the design worked out to make shooting (and owning) them a more pleasant experience. They seemed to be focused on making high-quality products, and so are certainly not going to cut corners. But they are also not going to be cheap. Although I could spend myself into Federal levels of debt on cool toys, I am exceptionally excited about the possibility of a .357 AMP upper, and even more excited about having a place to go to get parts for my current piece (original Pasadena model, but it was sold without the case, cleaning rod, etc. from the original set-up). If they end up selling .200" recoil rods for less than $100 apiece, I'll be able to afford them.

Well, my response was longer than I planned... but I like the Auto Mag, and I like the .44 AMP. I let one of my brothers shoot the Auto Mag and he liked it, and then he shot the Desert Eagle in .44 mag and replied "Not a fan. I like the other one, better." I agree. At the least, I wish IWI/Magnum Research had Desert Eagle barrels in the .44 AMP. I mean, they can chamber the thing to .50 AE without changing the bolt... you could have a single bolt for .44 AMP, .475 Wildey, and .45 Win Mag (I think they are close enough size to work with the same bolt). Oh well, I talk of dreams, which are the children of an idle brain, begot of nothing but vain fantasy, which is as thin of substance as the air, and more inconstant than the wind.

Thanks again
-cstarr3