Home Forums Hunting & Shooting AR and Tactical Rifles 75 grain A MAX

Folks,
I've got a 20" 1-7.7 twist VARMATCH barrel ,I guess it's closer to 8 twist than 7 .

I'm wondering if any of youall are shooting this bullet in an AR 15 platform.

Hornady " suggests " a col of 2.380 or 2.390 if don't recall which but it's a long overall length . I'm wondering if anybody has loaded them shorter and how it worked out .
I can understand their reason it's ogive is way back . Maybe you guys know of a different kind of mag or a modification. I appreciate any pros / cons you can pass my way.

Thank you in advance for your time and help.

Semper Fi,
Soup

I loaded a dummy round up to mag length (2.260) and laughed at the results. The 75 A-Max is best to be saved for bolt guns.

With enough neck tension and full powder charges(safe powder charges though) it'll look ugly at 2.250 for the mag length rounds. Ammo must be worked to pressure with that length though, but if worked up at that short length you will be fine.

And for the laugh comment, it is right. I have beaten the snot out of a lot of folks at Camp Perry wiht that laughing load though....

Mag length is better off at 75 bthp... but the amax worked for me just fine for its purposes.

I purchased a box of them about a month ago for my AR, it's built based on an Anderson Lower and 18.5 inch barrel with a Wylde chamber. I worked up to 26 gr of CFE 223, tried a three shot group at 100 yards, the bullets hit all over the place, about a six inch group. I called Hornady and the tech that I talked to told me that due to their length they have to be seated to 2.360 oal and single loaded in ARs because of the magazine length restrictions, 2.260 is the max oal if you are using a magazine in your AR. I gave the rest of them to a friend who has a 223 bolt action. I would try the new Sierra 77 gr tmk bullets, I am getting groups averaging .800 with CFE 223

I love me some 75 A-Max in my 223 Montucky, but for my AR rifles, please pass the 77gr TMK.

I haven't done it but there was some guys cutting the front out of a P-mag from the top down to where the mag well starts to end. Might give it a shot.

Hmmmmm...be an interesting experiment. Pmags are cheap

I did cut mags for 75 JLK VLDs in the late 80s. They work.

But I just had to laugh at the Hornady rep... has NO clue what might work and might not....

Its far from ideal, but it does work.

Can't really see wasting the effort for the incremental advantage of SMK or TMK's at any sane & practical ranges.

Maybe for something very special, but that's stretching.

MM

A-max is world's better than the SMK in both BC and terminal performance and the TMK's were too finicky in my guns.

Sane and practical? What's that?

We be loonies, or not?

I've certainly done a lot more to gain much less...

I use 'em in my Rem 700 bolt guns.........removed the magazine block so them can be seated to kiss.

Better things to do than dink with 'em in modd'ed AR mags or feed 'em singly.

Have it though, ya'll.................

MM

More than a few competitors over some years wished I hadn't monkey'd with em. LOL.

Jeff, at what range did you begin to see an advantage over the SMK's?

MM

I ran them as 300 yard rapid fire, they were heads and tails above the SMKs in wind drift at that range, often we shot 300 with no sighters, 10 down the tube with generally no clue if your guess was right.

If I was shooting them single load, I ran JLKs instead of amax or smks

I could easily see the wind difference in slow fire reduced matches, between 75 amax and 77 smk windage wise. Accuracy wise actually too.

200 yards I saw no difference.

500 and 600 yards definitely a difference, but then if you compared 75 amax to 80 smk there was not enough difference to worry about, but compared to 77s, yes.

I've never fired an amax 75 past 600 yards that I can recall.

TTT

I've cut the front out of P-Mags to shoot the 75gr A-Max. I also use the the same mags for my 6x45 with the 100gr Hornady BTSP.

How much can you increase the OAL, doing that?