30-06 Match Ammo Crimp or ?

[1903shooter]

Gents,


I am looking to make some match loads up for my 1903A3 and 1903 and M1. Remington brass new, CCI #34 primers, 44gr Varget, topped by a Nosler Custom Competition 155gr bullet. Would any of you reloaders out there put a slight crimp on the round, I have been told by some more senior reloaders that this improves accuracy. Thanks, 03:sos::sos::sos:

[John Kepler]

That "a crimp improves accuracy" is a near-mythical position that has never been supported by any significantly repeatable data that I've seen....where the use of neck-tension only has just GOBS of data supporting it, not to mention things like benchrest championships, NRA National Highpower Championships, et. al.!

Some folks swear by crimping, are close to religious zealots about it, do just all kinds of things via "factory crimp dies" and assorted mumbo-jumbo to make it "work", then tend to bear teeth and snarl if you question their claims with requests for data that you can actually recapitulate....but I've never seen'um doin' much at Camp Perry either!

At the end of the day, a crimp is an additional, very difficult to control variable in the loading system. Uncontrolled variables in a precision shooting system is NEVER a good thing!

[CapnJohn]

NO on the '03/03A3, ?? on the M1 due to the possibility of the recoil/cycling kicking the bullet loose.

[Dan In Indiana]

I certainly am not a competition shooter, just a small time collector, and shooter, never crimp my rounds any more, have never noticed any difference in accuracy in my bolt guns. Don't crimp my rounds for my Grands or my M1A, rifles always shoot better than I do.

OFC

[oney]

I used to crimp when I started to reload due to being told that the recoil could dislodge bullets from cartridges in the magazine. My dies provide enough neck tension, and thus I no longer crimp any of my loads. Crimping can have an impact on pressure, and it is difficult to repeat the same crimp on each load.

The only rounds I still crimp are the dummy rounds I use to initially set up my bullet seating depth when setting up my dies.

"THIS WE'LL DEFEND!"

[colwhelen]

My experience says no crimp necessary. You need all cases to be exactly same length so it only adds an extra step to check or trim and results are not any better.

[Lance White]

A crimp is most useful if you are trying a light loading for a bolt gun and use a powder like 3031, to help insure the powder gets a sufficient chance to burn.

[jim r]

i've reload a lot for the garand and never had a bullet come lose, just my 02cents,jim

[Ron H.]

Sir, there's no need to crimp match loads. Depending on what bullets you use, crimping may actually detract from accuracy. For example, Sierra Match Kings are not designed to be crimped.

Hope this helps, and Semper Fi.

Ron H.

[AKA Hugh Uno]

first, I am not a big fan of CCI 34 primers. Why people think they need the things is a tribute to the pure hype spooned out by CCI. They are my absolute LAST choice for primers.

Second, if you go with NO CRIMP, then you can remove (or turn down a few thousandths) the neck sizer button (you will need a Lee universal De-Primer to remove the primer). This results in nice tight neck tension and no need for crimp.

I also like the Lee Factory Crimp very much, although I only impart a very modest amount of "crimp". I know it works to decrease group size and for 12 bucks, you can afford to check it out and do your own comparison if you like.

[presidents100]

Crimping is used on heavy bullets to prevent movement. Heavy in a 06 is 200 and 220 grain bullets.
Match loads have no crimp. I have never used one.
I would suggest use of a M-die for match loads.

[Steeley Eyed Missile Man]

Load ten rounds each way and see how they perform? If no difference, then I'd have to say that the crimp is unnecessary.
If you're punching paper, and the rounds go from bench to box, then a short car ride to the range and then fired, then a crimp is most likely not necessary. If it's battle rounds you're loading, and they're likely to be beat, bashed, and abused for awhile then I'd say to crimp religiously...

[cary m2a]

I'v never crimped for the 03 ,1917 or smle but put a slight crimp on M1 loads
just like the M2 ball just a thing I like to do on that load.

[JustPassingThrough]

Crimping is used on heavy bullets to prevent movement. Heavy in a 06 is 200 and 220 grain bullets.
Match loads have no crimp. I have never used one.
I would suggest use of a M-die for match loads.

I had a similar question last year and did a test.

Basically I loaded up some dummy 178gr A-Max rounds in a properly sized case, measured the OAL then loaded them in my M1. I carefully extracted the round and measured the OAL again. In every case I had between 8 and 10 mils of travel of the bullet increasing the OAL. The 168gr A-Max round was slightly less.

I loaded up 20 rounds without a crimp and ran them through the chrono. then loaded up 20 rounds exactly the same but used the lightest possible crimp I could set using the lee factory crimp die.

Without the crimp my standard deviation in velocity was ~17fps. With the crimps it was ~12fps. With the crimped rounds I had no measurable increase in OAL when repeating the above test.

Left out of this post is if accuracy improved. Thats hard for me to say because my garand shoots better then I do. :) I am shooting about 1MOA with it at the moment using a very lightly crimped round.

For me the idea of bullet movement bothers me. Whats the point of working up a load with a set distance from the lands when it moves upon chambering. Worse yet, what happens when one is unusually loose and it stops on the lands?

Just my take on it.

[John Kepler]

You've got a mis-sized expander ball, so you've got variable OACL. Now, you can screw around with a crimp-die and IT'S variables, or you "fix" your expander ball with a hunk of crocus cloth and eliminate the lot !

Guess which is simpler? Guess which is cheaper? Guess which gives an over-all better load? Simpler, cheaper, better....what's not to love!

[JustPassingThrough]

You've got a mis-sized expander ball, so you've got variable OACL. Now, you can screw around with a crimp-die and IT'S variables, or you "fix" your expander ball with a hunk of crocus cloth and eliminate the lot !

Guess which is simpler? Guess which is cheaper? Guess which gives an over-all better load? Simpler, cheaper, better....what's not to love!


Just checked the expander ball.. Came in at .3065

How do you keep your expander ball concentric when your removing material by hand? Seems to be a bunch of variability there.

You mention variables in using the Lee factory crimp die, can you elaborate? I've got my dies locked down in their turrets after initial setup and haven't touched the crimp die in over a thousand rounds. :thup:

[John Kepler]

A.) The "number" on your expander ball is meaningless....if your testing shows that you can displace the ball during cycling, then Q.E.D.: The sizing ball is too damn big and needs to be smaller.

B.) Show me in my post where the word "hand" appeared? I use a lathe and check the run-out before I use the abrasive (but I significantly question whether doing it "by hand" is an issue!). In over 30 years of competition loading, I've had to "surgically alter exactly 2 expander-balls....none of them on RCBS or Redding dies. BTW, did YOU check the run-out on YOUR current expander ball before you start getting your boxers in a bunch about inducing any asymmetry when you reduce the diameter?? You may already have a significant source of your current die-problem and don't know it!

C.) Since you're making noise like you might know your way around a machine-shop and/or have at least some engineering experience....look at the design of that Lee crimp-die and please explain to me how you feel THAT gizmo is going to be capable of delivering a CONSISTENT repeatable crimp-load, plus-minus a fractional percent? I didn't think so! A crimp is a variable. After your engineering analysis of the gizmo, then we'll have to discuss the fractional BC alterations the crimp induces in the now distorted bullet! You MAY not see such things on short-lines....but when you start shooting targets at 1000 yds, these "little things" get huge in one hell of a hurry!

D.) Don't "bench-race" about it, bring your crimped loads, your rifle, and meet a couple thousand of us Camp Perry in August and see how y'all do against all those dummies that don't crimp their gas-gun loads (which will be just about everyone you'll be shooting with!). Empiricism in action! If your loads actually shoot better than ours.....you win the sausage! If you're REALLY on your game, you'll get pirogi to go with it!

[JustPassingThrough]

A.) The "number" on your expander ball is meaningless....if your testing shows that you can displace the ball during cycling, then Q.E.D.: The sizing ball is too damn big and needs to be smaller.

There clearly is a limit to the point in which you can reduce your expander ball, so I have to disagree with the comment that you just arbitrarily reduce the size until things stick. I suspect there is a limit on how much neck tension you get. At some point you exceed the yield point on the brass and it doesn't matter how far you reduce the ball. I will machine up a couple new expander balls and see if I can find that sweet spot.


B.) Show me in my post where the word "hand" appeared? I use a lathe and check the run-out before I use the abrasive (but I significantly question whether doing it "by hand" is an issue!). In over 30 years of competition loading, I've had to "surgically alter exactly 2 expander-balls....none of them on RCBS or Redding dies. BTW, did YOU check the run-out on YOUR current expander ball before you start getting your boxers in a bunch about inducing any asymmetry when you reduce the diameter?? You may already have a significant source of your current die-problem and don't know it!

I did check the run-out and it was fine. This is an RCBS die.


C.) Since you're making noise like you might know your way around a machine-shop and/or have at least some engineering experience....look at the design of that Lee crimp-die and please explain to me how you feel THAT gizmo is going to be capable of delivering a CONSISTENT repeatable crimp-load, plus-minus a fractional percent? I didn't think so! A crimp is a variable. After your engineering analysis of the gizmo, then we'll have to discuss the fractional BC alterations the crimp induces in the now distorted bullet! You MAY not see such things on short-lines....but when you start shooting targets at 1000 yds, these "little things" get huge in one hell of a hurry!

You'll have to ask LEE to elaborate on their crimp die and the engineering that goes into it. I'd point you to the top part of they're web page.

Lee Precision, Inc. Reloading Tools and Equipment: Lee Crimping Dies (http://www.leeprecision.com/html/catalog/dies-crimp.html)

The only data I have is less deviations in velocity and better grouping vs. no crimp in my loads and in my rifle. Sadly 600 yards is my range limit at the moment. So I cant comment on distances greater then that.


D.) Don't "bench-race" about it, bring your crimped loads, your rifle, and meet a couple thousand of us Camp Perry in August and see how y'all do against all those dummies that don't crimp their gas-gun loads (which will be just about everyone you'll be shooting with!). Empiricism in action! If your loads actually shoot better than ours.....you win the sausage! If you're REALLY on your game, you'll get pirogi to go with it!

How do you propose to eliminate the rifle, load and shooter from the comparisons?

:thup:

[John Kepler]

"How do you propose to eliminate the rifle, load and shooter from the comparisons? "

I don't! It's a package...just like auto racing! Otherwise, instead of racing cars at Daytona, you'd just whip out the engine dyno sheets and give the biggest numbers the trophy! Please bear in mind that topic of the thread is "Competition Loads".

Sure you're getting better numbers for your crimped loads, since we've already established that you are generating brass with insufficient neck-tension in the first place. I don't have that problem with ANY of my competition sizing dies, making your whole "point" a distinction without much of a difference.