Home Forums Hunting & Shooting Hunting Rifles Ruger American .223 - 75gr A Max query

Fellow Campfire Members;
Good afternoon to you all, I trust this sunny Friday afternoon finds each of your households well.

This morning's range session was the first time I've been able to test the one and only box of 75gr A Max bullets I've seen or been able to lay hands on this side of the medicine line.

Previous to this, the rifle's 1:8 twist barrel will put 3 mystery 62gr HP bullets into 9/16" to 5/8" - the average velocity on that load being 2827fps pushed by 27gr of Varget.

For heavier projectiles it seems to like 75gr Hornady HP Match - this morning it put 5 shots into 15/16" with an average velocity of 2806fps - this load 25gr of Varget.

The same load of Varget produced 2835fps with the 75gr A Max - 4 shots going into a nice round 1" and the fifth shot up and to the left a bit making 1¼".

The next load was 24gr of RL15 which produced 2714fps - 4 shots going into a 1" horizontal string, but a 5 shot "group" of 3" - again one shot going up and to the left.

After that was 24gr of IMR4895 which made 2828fps - 4 shots going into 1 5/16" and 5 making a 2" patch - and again it's above the group but not to the left this time.

The last test batch was 23gr of 748 that averaged 2684fps and sprayed the 5 bullets evenly into 3¼".

I have checked the action screw tension and it's where I believe it needs to be on a Ruger American which is really bloody tight.

There is no contact whatsoever on the floopy fore end.

So my initial thought is that it might not be in love with the 75gr A Max, but I'm wondering if my velocities are a tad slow and aren't stabilizing the bullet?

Oh, I apologize in not mentioning that the COAL is 2.430" with the A Max - they're just so giving the lands a bit of a peck on the cheek.

Half of me thinks I might insert a wee plastic shim into the fore end to see if the barrel prefers a tiny bit of dampening and try the last of my Varget again.

Anyway folks, if anyone feels like weighing in I'd love to hear some thoughts on the subject if any of you gentle readers are so inclined.

Thanks in advance and all the best to you all this weekend.

Dwayne

I'd guess that your forend is touching just a tad when you shoot it.

Dakota Deer;
Thanks for the reply, I appreciate it.

I've been doing my best to put the front action screw on the bags pretty much when I shoot this thing - as the fore end isn't the stiffest at all.

It surely could be that though as it doesn't take much pressure at all to make it contact.

Perhaps I'll be installing some reinforcing tubing like I've seen others do on the 'net.

Thanks again and all the best to you and yours this weekend.

Dwayne

Boyds makes a laminate that many have had luck with if your so inclined to buy one. May also give a more generous free float or a shim at the foreend like you suggested. I'm not sure if I would stick the front action screw on the bags if it were me due to not being able to repeat it perfectly each time but that is just my opinion. Good luck and have a good weekend as well.

P.S. Rem brass, H335 or LeverEvolution powder, CCI 400's and a 75 kiss with moly has been a highly recommended load for a 223.

I have one in 223 that is a Predator Model Dwayne....

with all of those combos you speak of, mine will do less than half an inch at 100 yds...

mine is pretty much as it came from the factory, except I have a couple of mags that Cotis did, that are opened up for a longer length bullet... so the 75s and 80s can be seated out..

mine seems to be real partial to 80 grain Match bullets and the 80 grain A Max....

for the 75 grain weights, mine prefers the 75 gr BTHP from Hornady over their 75 gr AMax...

Dwayne,
It's possible your rifle likes lighter bullets better.
Can you get your hands on some sierra 69 grain tipped matchkings ?

My 1/8 223 AI loves them.

I'm going out of town for a few days,if you can't find any,PM me and I'll send you a box.
Mike

I assume I can legally do that ?

mikeone;
Thanks for the very kind offer sir and top of the morning to you.

It's my understanding that you'd be breaking the law if you were to export any reloading components up here.

We live within an hour of the medicine line and pre 911 we'd make monthly runs across into Oroville, WA and on my personal list was powder, bullets and primers.

Those days appear to be behind us now and in my opinion more's the pity for it.

Anyway sir, we're able to find Remington and Winchester bulk bullets up here a fair bit - hence the "mystery" 62gr HP that are in a plastic bag I picked up somewhere along the way a decade or two ago for my .22-250AI.

Primers are somewhat available up here now as long as one isn't too, too picky - I'm running the CCI BR4 primers for instance because they were actually there in stock.

Thanks again for the kind offer though sir, I do appreciate it. All the best to you and yours this weekend.

Dwayne

Since no one helped you with the stability part, That bullet is on the edge.
Remember that stability is about RPM for a length of a thing, it's weight is almost irrelevant. The 75gr Amax is very long, noticeably more than the 77gr SMK.

MV*720/Twist = RPM

That is your formula, remember the Hornady bullets (NOT SXSP) has a RPM limit of about 290,000.
It is completely normal for a barrel to be a 1/2-twist faster or slower than advertised. Also how smooth your barrel internals are plays a BIG role. Lucky for you you have a Ruger, smooth stuff typically.

http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi

Use the links on the left to find bullet lengths, then input your specifics.

Darkker;
Thanks very much for the link and informative reply, I appreciate it.

A quick question or two if I may and thanks in advance.

So when I punched in the numbers for the 75gr HP Match - .986" long - I got a value of 1.702.

The 75gr A Max is 1.118" long and the value dropped to 1.348.

I am guessing here that this could be the reason that the 748 load that was slower only gets a 1.316 value and that's likely not "quite" enough?

Thanks in advance and thanks again. All the best to you this weekend sir.

Dwayne

Rather enjoyed the Twist Notion...as that was some FUNNY schit! 1-8" is GOLDEN,even at 16" in a SAAMI Krunchenticker(loaded long/fed single,for substantiation confirmations). Read that again. Now one more time. Some 1-9's will do it too and knowing me,I've prolly got more than a few of those too.

Delving deeper,I happily shoot the 75'Max at 3500fps outta a 1-7.7" Krieger 22-250AI,though I'm no Krieger fan. If only for conversation and to mention,that they cain't be spun "too fast",whether lineal or rotational.

The RAR's weakest mechanical link,is it's handle,which is absolute fhuqking dog schit. That's hardly a Deal Breaker,given the price point and them skimped pennies,will grant lotsa opportunity for lotsa folks...as nothing else is even close,in regards to Bang for The Buck.

Firstly,kiss the A-Max square.

Secondly,spend $.13 and preclude The Fore End Bitch Slap Scenario. This under the COURTEOUS Assumption,that you Started At The Fhuqking Start(though you haven't).



Vertical being the bane,typical of Goat [bleep] Milk jugs.



Playing with Fore End Pressure here.





Long Story short,this is THE Cure in OEM guise. Milk jugs very typically like to be snugged firmly into the shoulder pocket,to aid in consistency. Hint.


[img]http://imagizer.imageshack.us/v2/1280x1024q90/661/h1epnZ.jpg[/img]


Vertical Be Gone.

[img]http://imagizer.imageshack.us/v2/1280x1024q90/540/cFGKwS.jpg[/img]

Horizontal Be Gone/Milk Jug Be Gone. Note the SAS Plug & Plays(THANKS again!). it's a straight up Vulcan Mind [bleep],out to welllllllll beyond the 1000yd line and I've not even bedded it yet. The Plywood Lion is THE Schnizzle.

[img]http://imagizer.imageshack.us/v2/1280x1024q90/661/q2x07o.jpg[/img]



Prolly gonna help Hummers too. Hint.

[img]http://imagizer.imageshack.us/v2/1280x1024q90/673/6JF45x.jpg[/img]

Gotta run...THE Cast & Blast continues...................

Big Stick;
Thanks for the informative reply sir, I was hoping I might get you in between streams and bear runs for some input - and hopefully this finds you and yours well too.

While I might not have started exactly at the start, I'm fairly near that point with the COAL and kissing the lands.

I really like your solution for the fore end though Stick - even a thicker than stock Canuck can spook up some tape and get that mod performed I'm thinking.

Thanks again and all the best to you and yours this summer Stick.

Dwayne

PS:
10-4 on the SAS Plug and Plays - somehow I managed to obtain "unobtainium" and they absolutely do work as advertised.

I suspect they're de rigueur for 75 A Max and such projectiles of similar ilk.

Stick,

What stock is the Plywood one?

A Boyd's? which model?

Stick,

Can I ask you what are your loads for the 75 grainers? Assuming pretty much same load for HPBTs as A-Maxes?

Guess I'm really asking what powder.

Thanks!

SWAG here, H335...

Hint....

The magazine is no prize winner either. Whatever happened to the project on here to make the new rear piece for the mags to allow for longer COAL?

On the positive side, they sure are accurate and the kids love shooting it.

jeffbird;
Good day to you sir, hopefully this finds you well.

The magazine extensions are the "plug & play" that Stick was referring to. They are available if you contact shortactionsmoker here on the 'Fire I'm certain he'll be able to help you find some.

I have one installed on the .223 in question and it works very well.

I did shim the front catch on the factory magazine in order to keep the front of it up a wee bit more which helped the feeding on longer cartridges.

Hopefully that was useful information for you or someone out there this morning. All the best to you in the upcoming week.

Dwayne

Thanks for the info BC.
Good day and a tip of the hat to you as well sir.

They'll be shipping soon...

And you'll be posting the particulars on how to place an order?