224 Allen Mag is alive!!!............

Fiftydriver

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To all,

Saturday I took the day and fitted and chambered the barrel to my 224 AM test rifle. Took most of the day. Ran into a bit of a problem when I loaded up some rounds to live fire test the rifle. Seems the brass I was using was a bit thicker in the neck then the cases I used to draw up the reamer print off from.

They were to tight when chambered. As such Sunday morning I got up and took 1.5 thou off the neck thickness and this worked perfectly. Got a couple cases formed and then had family things to attend.

This is not a major issue, in fact a good thing. If someone wants a tight necked chamber the reamer is good to go. If they do not want to neck turn, I am ordering a properly sized neck reamer for that purpose.

Anyway, don't have any hard data yet but a fireforming load of 60.0 gr of AA8700 under the 100 gr ULD RBBT did a fine job of forming the cases and is still a very mild loading.

Don;t have the Sako extractor fitted to the bolt yet but tip the rifle up and the fired case fall out. Must be a pretty mild load!!

Comparing case capacitied with the parent(22-270 WSM) and the 224 AM I came up with 87.2 gr vs 92.5 gr for the 224 AM. Not that I am concerned about case capacity as there is more then enough!!

353528.jpg


This pic shows two 22-270 WSM fireforming loads on the left, two formed 224 AM cases in the middle and a 22-250 AI loaded round on the right for size comparisions.

You can see the body taper is reduced in the 224 AM cases. Also, the seating depth of the 100 gr ULD RBBTs in the fireforming loads is deeper then it needs to be by about 50 thou just to give a pressure cushion for the first loads. Not alot of data for a 100 gr .224" bullet with a 60 gr powder charge!!

There is not a dramatic visual appearance change from the 22-270 WSM to the formed 224 AM. Slight shoulder angle increase and a shoulder diameter increase of around 15 thou.

This week I have to get back on customers rifles but hopefully will get the rifle bedded and barrel break in started during the week. Possibly be able to get some chrono numbers next weekend.

I was actually a bit suprised that there were no ignition or pressure issues at all forming these cases using the slow ball powder. Just have to find out what burn rate will work best now with the 100 and 107 gr ULD RBBTs. I have Ramshot Magnum, Magpro, 8700 and WC872 to try. That covers a pretty wide range of burn rates so I am sure one of them will produce top performance. We will see.

More to come, just a short update.

Kirby Allen(50)
 
Glad to hear that the little monster 22 cal will be making some holes and numbers soon!

Keep us posted on the progress.
 
Here you go again………. /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif

Just about the time I think it's o.k. to take the lock off of the checkbook you come up with another barn burner, and in a caliber I've been considering. I don't want one……I don't want one……I don't want one……… It's not working. /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif

Looks like another winner from APS.

Now you've got to get us some numbers and data along with some pics. If it shoots as good as it looks, the varmints and yotes are in big trouble.
 
Been waitin' for that kind of word.

Like the neck turning feature. Don't know why, just guess I'm used to it.

Looking forward to performance number.

As N. Dynamite says: SWEET /ubbthreads/images/graemlins/cool.gif /ubbthreads/images/graemlins/cool.gif
 
Kirby, 224AM looks good, and really looking forward to the test results.

I know it is a trivial matter, but I believe that you might have made a "typo" on the case capacities. Should it be 77.2 for the 22/270WSM and 82.5 for the 224AM? Chuck Hawks lists the 270 WSM as 78.9, and the Short Mag website lists the 270 WSM as 82.0 grains.

Regarding the best powder for the 100 and 107 grain bullets, if my previous experiences with the .224 Clark (63.8 grains)are of any benefit, then my guess is that WC872 will be the best powder, unless the soon to be released H869 proves to be slower than the old H870.

I have never used a "Short Mag Case, but out of curiosity, is there a general consensus as to how much body taper is necessary with the WSM and RSAUM cases, for them to feed well from the magazine.

I note the standard .270 WSM has .017 body taper in its 2.100 inch length, but have not read anywhere how much you can reduce that standard taper before encountering magazine feed problems. It appears that anything less than about .010 body taper in a 2.500 inch case leads to feed problems. Looking forward to that first test report. Brian.
 
ss7mm,

Well, if it works the way I hope it will then it will surely be an impressive little round. Offering ballistic potential dramatically above that of a 30-378 Wby loaded with a 180 gr Ballistic Tip.

That is yet to be proven though so we will see??

Will keep reporting.

Kirby Allen(50)
 
Sniper2,

Yes the 100 and 107 gr ULD RBBTs are built on a very heavy jacket for a 224 bullet. We will see how much velocity they are able to take. One benefit of the extremely long bullet with high BC is that if we can get anywhere near 3400 fps they will be awsome ballistically.

Again we will see.

Kirby Allen(50)
 
Brain,

The case capacities I gave were from filling the cases to the mouth with 8700 and then weighing the total powder that each case would hold.

I suspect your capacities are water capacities.

My five cases for the 22-270 WSM averaged 226.7 gr empty and 313.9 gr filled to the mouth with 8700 for an average total powder capacity of 87.2 gr.

The 224 AM cases averaged 229.1 gr empty and 321.6 gr filled with 8700 for an average powder volume of 92.5 gr.

Now usible powder capacity will be dramatically less. I am predicting that with 8700 or 872 that I will top out in the 66 to 68 gr range with top loads but we will see.

The 224 AM has about 0.010" of taper and thats as square as I like to make them. I am sure feeding will be a bit choppy unless out of a center feed magazine. I am looking at the 10 round H-S Precision DM system for the WSM currently but right now the rifle will be a single shot.

Kirby Allen(50)
 
What brand of brass are you using or which would you recommend. Maybe a 100 W-W will get 50 good ones. Maybe 100 Normas will get 100???

Some say the Norma necks are quite thick??

Your tho'ts???
 
Roy in Idaho,

I am using Win 270 WSM cases currently. The Norma hulls would certainly increase case consistancy for sure but I have not played with them yet.

Generally the Norma necks are a bit thicker then Win cases but that is not always the case. Just have to form some and see what the mic.

Good Shooting!!

Kirby Allen(50)
 
Oldfamily,

Yes, I am very optomistic and excited as well. Only problem is that I need to get caught up on customers rifles. Have had a few issues with tooling but got those straightened out so now its time to get some rifles built and shipped. Weekends will be my playtime though!!

I assure you the first critters hammered with the 224 AM will show up here first!!

Kirby Allen(50)
 
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