I want to reload up some 52gr A-Maxs for my 24" heavy barreled 1-9 twist AR-15. I already have some new Win Brass, those bullets, CCI primers and Varget powder. I have reloaded for my .223 bolt rifle before, but never for my AR. Should I load them up to magazine length and start shooting? I was hoping I dont need to crimp, but I dont know if its required for the AR-15. I did a search and some one said I dont need to measure the Varget, just fill it up full in the case and wipe flush with finger and seat the Amax? Does anyone really do that?

You do need to measure your Varget.

You don't need to crimp.

WOW "someone" sounds pretty wreckless. please don't just fill the case and call it good. follow the loading manual.

as for crimp im not shooting that exact bullet but i am shooting 55g fmj and i have had no issues not crimping.

Posted 02 May 2004 20:31 Hide Post
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As far as your 223 goes, you can probably skip the measureing and just put the VARGET in a margarine tub, dip the case in it, wipe it flush with your finger and shoot 40 grain VMax's with accuracy that will astound you!!


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That will give you 26 - 26.5gr of Varget. That will work well with bullets up to 55gr (a max load with 55gr).
That's one of my favorite 52gr loads.



that's what I found in my search. I said WOW also.

Filling to the top and wiping sounds like your wife must have a good insurance policy on you!!!
MEASURE your powder. USE published load data.
NEVER trust someone elses load data!!!
Now that is done,I shoot the 50 gr vmax in my AR and I do crimp them with a lee die.
And varget was the worst powder I've tried in my AR for accuracy.

quote:

Originally posted by steven g:
I want to reload up some 52gr A-Maxs for my 24" heavy barreled 1-9 twist AR-15. I already have some new Win Brass, those bullets, CCI primers and Varget powder. I have reloaded for my .223 bolt rifle before, but never for my AR. Should I load them up to magazine length and start shooting? I was hoping I dont need to crimp, but I dont know if its required for the AR-15. I did a search and some one said I dont need to measure the Varget, just fill it up full in the case and wipe flush with finger and seat the Amax? Does anyone really do that?

I belief that crimping is necessary for all semi auto rifles since the bolt is pushed forward at high speed, which could result in the bullet being pushed into the case. This could cause high pressure and result in problems.

http://www.exteriorballistics....ics/gasgunreload.cfm Military 5.56 has a bullet pull requirement of 35 to 45 lbs. When you seat a bullet, the neck area should expand by .002" or more. This will give the proper neck tension/bullet pull.
Neck Tension - From Link > When we stop to consider the vigorous (read, downright violent) chambering cycle a loaded round endures in a Service Rifle, it becomes pretty clear it suffers abuse that would never happen in a bolt-action. This is simply the nature of the beast. It needs to be dealt with since there is no way around it.

There are two distinctly different forces that need to be considered: those that force the bullet deeper into the case, and those that pull it out of the case. When the round is stripped from the magazine and launched up the feed ramp, any resistance encountered by the bullet risks having it set back deeper into the case. Due to the abrupt stop the cartridge makes when the shoulder slams to a halt against the chamber, inertia dictates that the bullet will continue to move forward. This is exactly the same principle a kinetic bullet puller operates on, and it works within a chamber as well. Some years ago, we decided to examine this phenomenon more closely. During tests here at Sierra’s range, we chambered a variety of factory Match ammunition in an AR-15 rifle. This ammunition was from one of the most popular brands in use today, loaded with Sierra’s 69 grain MatchKing bullet. To conduct the test, we chambered individual rounds by inserting them into the magazines and manually releasing the bolt. We then repeated the tests by loading two rounds into the magazine, chambering and firing the first, and then extracting and measuring the second round. This eliminated any potential variation caused by the difference between a bolt that had been released from an open position (first round in the magazine) and those subsequent rounds that were chambered by the normal semi-automatic operation of the rifle. Measuring the rounds before chambering and then re-measuring after they were carefully extracted resulted in an average increase of three thousandths (0.003") of forward bullet movement. Some individual rounds showed up to seven thousandths (0.007") movement. Please bear in mind that these results were with factory ammunition, normally having a higher bullet pull than handloaded ammunition.

To counteract this tendency, the semi-auto shooter is left with basically two options: applying a crimp or increasing neck tension. The first option, crimping, brings up some other issues that can be troublesome. In general, crimping degrades accuracy. Most match bullets are not cannelured (which also seriously damages accuracy potential), a requirement for correct application of most crimps. Still, there are taper crimp dies available from most of the major manufacturers. Lee offers their “Factory Crimp” die as an alternative, which seems to be one of the better options for those bullets without a cannelure. That having been said, crimping is still, at best, an occasionally necessary evil. Avoid it if at all possible.

The other—and in our opinion, better—option is increased neck tension. This, in turn, leaves us with two more options depending on what type of equipment you’re using. The object of either is simply a tighter grip on the bullet. Using conventional sizing dies, (i.e., those utilizing an expander ball) this is accomplished by reducing the diameter of the ball itself. This can be done by chucking the expander/decapping rod into a drill and turning it down slightly with fine emery cloth or a stone. The goal here is to decrease the diameter two or three thousandths (0.002" to 0.003") under bullet diameter. This is a trial and error process, and must be done slowly. The end result is an expander ball that opens the case neck up somewhat less than the as-issued item. This, in turn, increases the grip of the case neck on the seated bullet.

A better alternative to achieve the same effect is the use of a bushing die, such as those from Redding Reloading. This is by far the best solution, not just for Service Rifles, but for a broad range of reloading applications. The basis for this system is a fairly conventional sizing die, at least where the body and shoulder of the case is concerned. In the neck area, however, the die is fitted with a removable bushing. Available in .001" increments (as measured at the inside diameter of the bushing), they can be matched with a specific batch of brass to provide optimum neck tension. This tension can be increased or decreased by simply moving up or down in bushing size. The one drawback to this system, if it can be called a drawback, is the absolute necessity of sorting cases and loading them in batches. This, of course, is how virtually all loading should be done anyway.

I'll wade into the crimp or not arguement with not crimped. I don't crimp 52 or 77 gn Sierras. Neither will pull with an inertial puller.

52 gn SMK, 25 gn H335, WSR primer.
77 gn SMK, 24 gn Varget, CCI400 primer.

Testing 24.5 gn Varget with the 77's this spring, over 60 degrees out.

You will notice that the maximum charge of Varget for the bullet you intend to use has a C by it. That means that the powder will fill the case enough at that weight so that the powder will be compressed when the bullet is seated. So, in this case, filling it to the rim and wiping off the excess will work, but it isn't a generally recommended practice. Doing that with some powder/bullet combinations will have explosive results.

To crimp or not to crimp. The .223 with this weight of bullet doesn't really need to be crimped, but the rigors of auto-loading may make it advisable.

Do you have an overall length gauge that does not measure off the bullet tip, but off of the ogive?

If so, next time you are at the range or feel an area is safe enough to do so, repeatedly chamber the same round over and over, stopping each time to measure the OAL. You might be surprised by the results.

That should give you an idea as to whether or not you should crimp.

Personally, I load them on Wilson inline dies using an arbor press, but still crimp them using a Redding taper die. But my methods varies by rifle. For my 300WSM, for example, I load them the same, but instead of the taper crimp die I used a Lee collet die crimp.

Experiment and have fun! That's what all this is about anyway, right?

No crimp needed but PLEASE use a scale.

For what it's worth, make sure your brass is clean.

When I used to tumble using walnut media I would add rouge to get it polished clean. Then I'd tumble again to get the polish off but there was always residue inside the neck. Not sure if that affected neck tension/pull but now that I use S.S. Media the brass comes out cleaner than clean. And that has to be better.

If you don't polish your cases and crimp your bullets your sling swivels will rust.

Actually...Newtons 1st law of inertia states the bullet would remain in postition while the case moves around it, so the bullet would "move backward" in relation to the case when the bolt moved forward suddenly and when the bolt stopped suddenly the bullet would continue it's movement under the force of momentum until stopped by some other force...not to put too fine a point on it...filling the case with powder so the bullet rests on a column of powder is one way to help stop possible bullet movement.

BUT...as pointed out whether you need to crimp or not depends on several other factors...crimping in military ammo has more to do with sealing and making sure the bullets DON'T move under many adverse conditions.

Use a bushing die so you can adjust the amount of sizing on the neck, then use trial and error as 243winxb pointed out very well.

Google for forums related to AR15 competition. You will find more information on those forums directly related to your questions.

I never crimped bullets up to 68-69 gr when I had my H-Bar, sized 0.002" less than bullet diameter, but never tried anything heavier. Never had any trouble with bullets moving under bolt acceleration/deceleration that I know of.

A roll crimp if improperly applied can actually cause the neck tension to decrease, then it is only the "rolled" brass that holds the bullet...I've run across this problem in many calibers so now if I think I need more neck tension...in leverguns with tubular mags or very heavy recoiling large caliber rifles with heavy bullets...I use a taper crimp die and Lee factory crimp dies are what I use for the most part.

Luck

As recoil occurs, all the rounds in the magazine will be subject to that recoil. the bullets can have a tendency to creep out of the case, which could cause the rounds to stick in the magazine, possibly causing a failure to feed. I always crimp my semi-auto rounds.