Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
BCM
Member Login

Site Notices
Posted: 6/3/2008 5:26:36 PM EDT
I am going to work up about 20rnds of 308 (These are my first rifle rounds, just finished up learning on 9mm) and am wondering about the crimp on the bullet ?
I will start off with:
LC 308 MG Brass sized and trimmed to 2.005
Fed 210 primers
41.5g of IMR 4895
147g BTSP

I will be setting this up on my 550, Dillon suggests the crimp be approx .002" so I have to ask a stupid question, how do you measure the crimp I can only guess that around where the cannelure is on the bullet that it should measure approx .002" less than just below where the bullet ends in the neck, like I said it may be a stupid question but all I have are a few books and you guys to ask.

Thanks
Link Posted: 6/3/2008 5:42:10 PM EDT
Measure before you crimp, and after crimping on the same round.

You didn't say if you were reloading 308 for a semi auto or a bolt gun.

I don't crimp my 308 loads for my bolt gun.

Not a stupid question.
Link Posted: 6/3/2008 6:28:42 PM EDT

Adjusting the bullet seating die

Most bottleneck cases do not require crimping. The tension of the case mouth will usually hold the bullet properly in place without crimping the mouth of the case into the bullet. Bullet crimping works the mouth of the case excessively, and shortens case life. It also requires a bullet with a cannelure into which the case mouth is crimped. Do not attempt to crimp a bullet without a cannelure. I will discuss bullet crimping in connection with three-die sets, as most revolver bullets are crimped in place, and the procedure is the same.

Here is how to seat a bullet into the case without crimping. First, place a prepared case (a case that has been resized, re-primed and contains the proper amount of powder) into the shell holder and run it to the top of the press stroke. Second, screw the bullet seating die into the press until you feel it touch the case. Third, back the die off one turn and set the large lock ring. Now there is a proper gap between the shell holder and the die.

The next procedure is adjusting the seater plug inside the die so that it seats the bullet to the proper depth in the case. This depends on the particular bullet you are using, the length of your rifle's magazine (the reloaded cartridges must fit into the magazine), the length of your rifle's chamber throat (the bullet must not touch the rifling when chambered), and whether the reloaded cartridges are to be fired in more than one model of rifle (since these dimensions may differ). The safest procedure is to set the bullet to the cartridge overall length (COL) specified in your reloading manual. To do that will require a caliper to measure the length of the finished cartridge. If you don't have a caliper, I suggest that you purchase one wherever you buy reloading accessories. It is a handy thing to have.

If you have a factory loaded cartridge handy, the process can be simplified. First, loosen the seater plug lock nut and back the bullet seater plug as far out as possible. Second, place the factory load into the shell holder and run it all the way into the seater die. Third, screw the seater plug down into the seater die until you feel it stop against the bullet in the factory load. Tighten the seater plug lock nut. If you are reloading the same bullet as the factory load uses, your seater die is properly adjusted.

Even if you are not using the same bullet as the factory load, the adjustment of the seater die should at least be in the ballpark. Use your caliper to measure the overall length of the reloaded cartridge, and refine the adjustment of the seater plug so that the bullet you are using is seated to the cartridge overall length specified in your reloading manual. Remember to tighten the seater plug lock nut when you are finished.

If you do not have a factory load to use as a baseline, here is how to adjust the seater plug. Insert a bullet into the mouth of a prepared case and carefully run the case into the seater die with the bullet seater plug adjusted to whatever depth it came from the factory. You will feel the bullet contact the seater die and be pushed a little way into the case. Stop there. Withdraw the case from the seater die and note how far the bullet protrudes from the case. It is probably sticking out too far. Slowly run the case back into the seating die and gently seat the bullet a little deeper. (Screw the seater plug farther into the die if necessary, but it probably won't be.) Use your caliber to measure the cartridge overall length. Repeat this step until the bullet is seated to the correct overall length as specified by your reloading manual. This is now our sample cartridge.

Then withdraw the sample cartridge with its correctly seated bullet all the way to the bottom of the press stroke. Loosen the seater plug lock nut and back the seater plug all the way off. Run the sample cartridge all the way into the seater die (the top of the press stroke). Turn the seater plug into the seater die until it makes firm contact with the bullet in your sample cartridge. Tighten the seater plug lock nut; your seater die should now be correctly adjusted.

There is one final step, however. Take the newly reloaded cartridge and make sure that it chambers correctly in your rifle. (Keep the gun pointed in a safe direction and do this with the safety "on" if possible.) Insert it into the magazine to insure that it fits and feeds correctly. It should, but if it doesn't, refine the adjustment of the seater plug in the seater die until it does. Even if you didn't use a caliper to set the bullet to the correct COL and adjusted the bullet seater plug simply by trial and error, when the reloaded cartridge chambers and feeds correctly in your rifle, your bullet seating die is correctly adjusted.

For bullet seating with a roll crimp, adjust the seating die as follows. First, place a prepared (resized, primed and powder-charged) case into the shell holder and run it to the top of the ram stroke. Second, screw the seating die into the press until you feel it touch the case. Third, back off the seating die one full turn and set the large lock ring.

Lower the prepared case and place a bullet in the case mouth. Run the case with bullet slowly into the die, stopping frequently to check the bullet seating depth as the bullet is pushed into the case. Adjust the seater plug up or down so that, at the top of the press stroke, the bullet is seated into the case so that the case mouth is even with the middle of the bullet's crimping cannelure.

The next step is to adjust the die to crimp. With the uncrimped cartridge still in the seater die, back off the bullet seater plug several turns. Next, loosen the large lock ring and screw the body of the seater die into the press until you feel it touch the mouth of the case. Lower the uncrimped cartridge and turn the seater die down approximately 1/8 turn. Run the prepared cartridge fully into the seater die and check the crimp. The bullet should be held securely. Setting the seater die too far into the press will excessively crimp the case and may cause a bulge in the body of the case. Refine the adjustment of the seater die until you are satisfied with the amount of crimp, and then tighten the large lock ring.

The last step is to run a perfectly crimped cartridge all the way into the seater die. Then turn the bullet seater plug back down until it touches the bullet. Tighten the seater plug lock nut. You bullet seating die is now correctly adjusted and will seat and crimp bullets with a single stroke of the press.

Taken From........

www.chuckhawks.com/adjust_reloading_dies.htm  

Aloha, Mark

Link Posted: 6/3/2008 6:57:23 PM EDT
I crimp ALL my reloads.  But I exclusively use a Lee FCD.  For $8, it is an excellent addition to any caliber setup you have IMHO.

Hell, I even shoot a cartridge that Lee doesn't make a production run FCD for (.35 Whelen).  But for $29 I had them make me a custom FCD from a dummy round I sent them.

In my book, FCD is the only way to go.

- AG
Link Posted: 6/3/2008 9:07:15 PM EDT
I crimp for revolvers and leveraction loads only.  I've never crimped a load for anything else--semi-autos, bolt actions, gasguns or whatever.
Link Posted: 6/3/2008 11:49:18 PM EDT
The round I am loading for will be used in a M1A so from what I gather if it chambers after seating I am good to go ?
Link Posted: 6/4/2008 5:27:18 AM EDT
You need to back up here a minute, you need to work a load for your gun!  Did you try and chamber a sized case in your gun?  Sometimes MG fired brass is pretty sloppy and might be in need of a Small base sizer die!
Link Posted: 6/4/2008 8:18:31 AM EDT

Quoted:
The round I am loading for will be used in a M1A so from what I gather if it chambers after seating I am good to go ?


No.  For slamfire and functional reasons, the brass must be slightly shorter at the shoulder than the chamber.  You verify this with your case gage.  If it won't chamber, and you measured with your case gage to make sure the resizing die is set properly, then you probably need to SB resize your MG brass.  Basically, if the round drops into the case gage, then you're good to go.

From a crimp perspective, if you chamber a round from the magazine and the bullet doesn't move a bunch, then you don't need to crimp it.
Link Posted: 6/4/2008 8:25:45 AM EDT
To crimp or not?


www.scidetroit.com/bulletseating.htm


www.speer-bullets.com/default.asp?s1=5&s2=30  



Aloha, Mark

PS.........since you're beginning.  For your M1A (magazine fed rifle)......I suggest:

If your bullet has a cannelure...........crimp it in the groove.

IF your bullet doesn't...........then just use neck tension (or very little crimp), enough, so that the bullet won't telescope back into the case under recoil forces or when feeding into the chamber.  Test by pushing (not too hard) the bullet end of a loaded cartridge against a block of wood.


Link Posted: 6/4/2008 8:41:30 AM EDT
As for "checking" IF your re-loads will function.........may I suggest.


6) I use a single station press (RCBS Rock Chucker). You could use a progressive Dillon IF you wanted to. It's a personal choice. But, with whatever press you choose, consider shell plate/shell holder and/or press "flex.”  I use a regular FL size/de-capper die, NOT the small base dies. To begin, FL size and de-cap, 1 or 2 cases for a test. Gauge the re-sized case(s), to confirm that the "correct size" has been achieved.  I use a Forster Products case gauge (the Wilson gauge is also a popular choice).  Insert a case into the die, the case needs to be between the high and low cuts on the gauge to pass. The base end, checks the headspace, while the other end, is used to check if the case will need to be trimmed (a job for later on).   IF, it’s not the “correct size,” your die setting will need adjustment. Lower the ram and simply screw the die in or out a little. Don’t forget about the lock nut. Then, re-size another couple of test cases and check your work again. Repeat the test and adjustments, as needed.  When you're satisfied that your test cases are properly re-sized, do the entire lot.

For those who don't know about it.........IMHO........"the secret" to re-loading a bottle neck cartridge for a gas gun is.......a case gauge.  There are many different brands and ways to gauge your re-loads.  

Examples……..

www.sinclairintl.com/cgi-bin/category.cgi?category=REMTHT&type=store



Note that this was my step #6.  The main idea is to test, while you're producing ammo......so, there is no bad "surprise" when you reach the range.

Aloha, Mark
Link Posted: 6/4/2008 10:21:07 AM EDT
I do not crimp my rifle reloads.

If I were bound & determined to crimp despite good info that it is not needed, I have heard good things about the Lee Factory Crimp Die and would probably use it.

ETA -
There's no way I would crimp a rifle load unless the bullet had a cannelure, AKA a "crimp grove". Even then I don't crimp.
Link Posted: 6/4/2008 4:50:41 PM EDT

Quoted:
As for "checking" IF your re-loads will function.........may I suggest.


6) I use a single station press (RCBS Rock Chucker). You could use a progressive Dillon IF you wanted to. It's a personal choice. But, with whatever press you choose, consider shell plate/shell holder and/or press "flex.”  I use a regular FL size/de-capper die, NOT the small base dies. To begin, FL size and de-cap, 1 or 2 cases for a test. Gauge the re-sized case(s), to confirm that the "correct size" has been achieved.  I use a Forster Products case gauge (the Wilson gauge is also a popular choice).  Insert a case into the die, the case needs to be between the high and low cuts on the gauge to pass. The base end, checks the headspace, while the other end, is used to check if the case will need to be trimmed (a job for later on).   IF, it’s not the “correct size,” your die setting will need adjustment. Lower the ram and simply screw the die in or out a little. Don’t forget about the lock nut. Then, re-size another couple of test cases and check your work again. Repeat the test and adjustments, as needed.  When you're satisfied that your test cases are properly re-sized, do the entire lot.

For those who don't know about it.........IMHO........"the secret" to re-loading a bottle neck cartridge for a gas gun is.......a case gauge.  There are many different brands and ways to gauge your re-loads.  

Examples……..

www.sinclairintl.com/cgi-bin/category.cgi?category=REMTHT&type=store



Note that this was my step #6.  The main idea is to test, while you're producing ammo......so, there is no bad "surprise" when you reach the range.

Aloha, Mark


I have a Dillon 308 case gage, I checked about 50pcs of the MG Brass from Top Brass randomly out of 1000 in the gage, the rear of the gage has a low cut in it and the base of the resized cases sat slightly above it and on the high part it drops down just abit acutally the base kind of sits in the middle of the two and on the bullet end the mouth is pretty close if not right at being flush on top so I can only assume they are sized correctly as they all measured 2.005"
They do go right in the chamber with no problems and extract pretty easily, if they are sized correctly is there some way to use one to set my resizer die ?

The bullets have a serrated line around then about 1/16" wide so I am assuming that I seat to the cannelure, check OAL then give it about a .02 of a crimp ? and see how they chamber

And if they are sized correctly should I run them all thru again just in case one was not done correctly ?
Link Posted: 6/5/2008 12:00:53 PM EDT
They should be fine.  If they don't cycle 100%, screw the die down a hair more till they drop into the min length step on the gage and try again.

Ideally, you'd take your fired cases, measure and then set the die so that it pushes the shoulder back by 0.002-0.004".  It can be difficult to get an accurate measurement on the type of gage you have, so I'd find something between min and max that works and run with it.

It'd be pretty hard to get one of them longer than the others (the shoulder that is).  I would recommend you trim or measure them all to make sure they don't exceed the max trim length.
Link Posted: 6/5/2008 12:43:46 PM EDT


I have a Dillon 308 case gage, I checked about 50pcs of the MG Brass from Top Brass randomly out of 1000 in the gage, the rear of the gage has a low cut in it and the base of the resized cases sat slightly above it and on the high part it drops down just abit acutally the base kind of sits in the middle of the two and on the bullet end the mouth is pretty close if not right at being flush on top so I can only assume they are sized correctly as they all measured 2.005"  


Assuming that you've re-sized all of the cases with consistency, that sounds GTG.  

BTW, I do things as a "lot."  So, I always F/L size my fired brass. After re-sizing, I'll take a small test sample and IF one case needs a trim.......I'll run the whole lot though the trimmer.  First Time: New, once fired (purchased and given) and range pick up brass are always trimmed (with few exceptions) for consistency sake.

IF it's not done with your brand of trimmer..........don't forget to slightly chamfer and slightly de-burr the necks.  I'll ease bullet seating. USE THIS STYLE OF TOOL..........

www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=364181&t=11082005

For ME........AT or BETWEEN the high and low cuts, is "good enough."  Though, individuals will vary as to their own specs. for ammo (all at the high or all at the low cut).  Whatever, "floats your boat."

I've been told: You actually place the gauge (w/cartridge case) headstamp end down, on a flat surface.  The case will sit on the flat surface.  The neck end should be, at or between the two cuts, to be correct.  Though, since you have a caliper.........measuring works too.



They do go right in the chamber with no problems and extract pretty easily, if they are sized correctly is there some way to use one to set my resizer die ?  
 

To "set the die"......use the lock ring to lock the position.  That way IF you remove the die.....then you will just have to screw it back in (back down to the lock ring).  Of course, you'll run a few test cases to check.  That is the biggest reason why, I don't like the LEE brand of lock ring.



The bullets have a serrated line around then about 1/16" wide so I am assuming that I seat to the cannelure, check OAL then give it about a .02 of a crimp ? and see how they chamber


Yes, that band around the bullet is the "cannelure."   You can seat it there or go longer or shorter, it's up to you.  As for the .02 crimp.  Well, it doesn't have to be "exact science."  "Good enough" is what I look for.  And, yes, testing throughout the process is always good.



And if they are sized correctly should I run them all thru again just in case one was not done correctly ?


You mean the re-sizer die?

That is not needed, since you've been testing throughout the process.  And, YOU HAVE FAITH, RIGHT?

Besides, I've found that loaded cartridges won't fit the F/L sizer die (w/de-capper removed).  Because, once the bullet is seated...........the case neck will be bigger due to expansion of the brass in the neck, when the bullet was seated.

Perhaps, I should say, YMWV.............as there might be exceptions.

Aloha, Mark
Link Posted: 6/6/2008 6:40:17 AM EDT
I loved the Lee factory crimp die,
Except in 223.  I haver used 3 of them and All have caused my rounds to get bent.

Total ugly mess.  But with 308 it is amazing.
Top Top