The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Guns, Politics, Gunsmithing & Reloading Reloading To crimp or not to crimpGo | New | Find | Notify | Tools | Reply | |
| To crimp or not to crimp | Login/Join |
one of us |
If it ain't broke, don't fix it! If you are satisfied with the group, leave it alone. ------------------ [This message has been edited by ricciardelli (edited 02-11-2002).] | |||
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| one of us |
the first reply says it all. | |||
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| <Bill> |
I never crimp rifle ammo. ------------------ | ||
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| one of us |
Crimping will give uniformity and accruacy is one school of thought and it works that way sometimes...A light crimp in a double rifle round is a sound practice IMHO, not a given however. Crimping is for tubular magazines and I agree with that. Crimping is for big bore rifles in bolt actions and I agree with that. Mostly I have chosen not to crimp in most calibers such as medium to near big bore rounds...as I am not sure I agree with the first statement....One could just let the rifle decide the question from an accuracy standpoint, that would be a smart move... A flat out statement in the gunworld is usually argueable, and rightfully so. ------------------ | |||
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| One of Us |
Well, I crimp so does some of the factory ammo. All I am going to say is this, You will not know if it makes a difference in YOUR gun unless you try.... I would recommend reduced charges at first to see where you are. DR280, It sounds like you would have fun testing this out, you might find a lesser charge will accomplish the same results as you have now. Would be curious to see your test results. TO CRIMP OR NOT TO CRIMP? Scout� | |||
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one of us |
Crimp only if you have a reason. Aside from operational considerations the others mentioned, accuracy is sometimes helped with a proper light crimp. You don't have an accuracy problem. If there are no operational considerations, and you aren't looking for a make-work project, go shoot the things! JMO, Dutch. | |||
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| One of Us |
quote: Well, I figure a good reason is to just know one way or the other. I personally have not had the opportune moment in time to check both. But, I know a slower powder may like that little extra resistance (hang time). You would never know until you looked under all the rocks. Now would you... If it aint broke, don�t fix it? If you don�t look you will never know.
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| <2ndaryexplosioneffect> |
quote: It is really hard to give you an absolutely correct answer here. It varies with gun, load, bullet etc. There are a couple of issues I feel are pretty much absolute. 1.Crimping the case mouth of the brass damages it. It also creates a variable at one of the most critical points in your load, how the case mouth lets go of the bullet. For example. If you are not neck turning your brass to make it uniform in thickness, you are getting a much stronger crimp on one side of the bullet than the other. Could that cause the bullet to cant off to one side as it enters the throat? Seems likely to me. 2.Crimping the brass into the copper jacket of the bullet damages the jacket of the bullet. Why do you think the bullet manufactures would go to the expense of putting a cannelure on certain bullets if this were not true? Think of the variables we induced here. Jacket/core separation, jacket failure, altered drag, altered center of gravity, and on and on. Use a kinetic bullet puller on a crimped round and just see what it dose to the jacket of the bullet. If you are going to crimp it must be done in the cannelure. This negates the work you have done to find the correct seating depth for the bullet in your individual rifle. So why do the factories crimp some of their loads? Primarily shipping damage induced by gorillas throwing the ammo off loading docks. The purpose of crimping is it to create a stronger grip on the bullet. How can we do this without creating more variables in our loads? You need to neck turn your brass for uniform grip on the bullet. You need to uniformly turn down the outside diameter of the expander ball in your resizing die or remove it. This creates a case neck which is uniformly smaller I.D. and grips the bullet tighter. I load from 223 to 7 STW. I neck turn everything. I neck size only with no expander ball. Shoot safe, | ||
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| One of Us |
quote:
As far as brass damage goes, YES it does limit the life of the brass. But,,,,, Is this a hunting rifle or a bench rifle? How many actual reloads do we get from brass that is lost in the field? Not saying every one will lose a couple in there lifetime. I know when the heart is pumping after that first shot; I instantly chamber the follow up round� Sometimes I have the opportunity to save that special case, sometimes I don�t. Another good reason is recoil, the jarring of gear when loaded in the truck, driving down an off road trail the hard way, etc. The crimp will maintain the position of the bullet in my hunting rounds� We could go on for a long time on this one. It is all a personal preference, and usage decision. I think we are all looking to squeeze that little extra out no matter what our shooting preferences are. (Not intended to be aggressive, asking questions and absorbing others ideas) Scout�. | |||
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| <2ndaryexplosioneffect> |
�I was just wondering something? I used one section from your post hope you don�t mind? If we are damaging the bullet casing as we crimp, what is the sharp rifling doing as it passes down the barrel of my 300 savage?� *** Good point! A lot of us idiots spend big time money on custom barrels because they are super smooth, and exact in every dimension to keep the barrel from actually damaging the bullet. Think about it. The bullet in your loaded round is not at all like the bullet that exits the muzzle. It has been resized and reshaped with all these funky grooves around it. The point is that they are all exactly the same (in theory). *** �Also, the groove in the bullet is crimped in from the factory as far as I am aware, or rolled in. Same difference..� *** Not really, and here is my real point. The typical crimp die puts 4 points of pressure on the bullet jacket. For $19.95 do you think these four points of pressure are exactly the same in every aspect,,, to .0005 of an inch??? *** �Another good reason is recoil, the jarring of gear when loaded in the truck, driving down an off road trail the hard way, etc. The crimp will maintain the position of the bullet in my hunting rounds�� *** You are correct, but. Load according to my previous post and you�ll knock the scope off and break the stock before the bullet moves. *** �For another instance, my heavy loads for my 45 Colt. If I don�t crimp to the point of just damaging the brass, the heavy recoil will dislodge my bullets changing seating depth� Possibly locking up the cylinder�. It has happened.� *** You are 100% absolutely correct. But I contend we are not talking apples to apples here. Now think about this. It is almost universally accepted that a taper crimp on 45 ACP is the best for accuracy. This taper crimp is apples to apples in relationship to our discussion because it comes back to the point of uniform case neck pressure on the bullet. Now, what if we got Redding to make up a taper crimp die for 45 Colt that would hold the bullet in place and apply all the bench rest BS we learned from our rifle reloading to our 45 Colt loads. I don�t know. Don�t shoot 45 Colt. *** "(Not intended to be aggressive, asking questions and absorbing others ideas) " No offence taken, I love the tit-for-tat. Shoot safe, | ||
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| One of Us |
You think we could get DR280 to do some actual shooting to see if there is a difference? If he were to work a load up for a crimped round, vs. a tension fit round, wonder what it would be on paper? Would like to see differences not the theory... Remember all guns are not created equal, what one will do another may not... Also remember this, In a perfect world, we would not be here...... Hahahah... DR280, would you be so humble? | |||
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| One of Us |
Oh, You have not seen my boys load the truck,,,, Lucky to have any gear at all after that one... | |||
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| <BigBob> |
DR280, It sounds as if you've found a great load for your rifle. I'd hesitate to change it. If you want to find out if you need to crimp here is an easy way to do it. Load one round without powder or primer and spray paint the bullet black. Put it in the bottom of the magazine and fire about two magazines of ammo. Remove the dummy case and see if the bullet has moved forward. If it has, the bright bullet jacket will be visible. If a crimp is required I'd suggest a taper crimp opposed to a roll crimp. Starts with a very mild crimp and try again. Use only the amount of crimp that is necessary to stop all bullet movement. Make sure that all cases have been trimmed to the same length or the extent of crimp will change with every round. I hope that this is of some help. Good luck. P.S. If your crimp gets heavy, pressures will rise. Take care.
[This message has been edited by BigBob (edited 02-14-2002).] | ||
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| <dr280> |
Wow- I love all the responses- think we could get to 850? Oh wait- that post is about who has the biggest balls,,,,,I quit reading at page 11.......... Anyway- I am very happy with the .45 group- but..... there is always a BUT, I only shot three groups with this load- and the first 2 groups were about .65 inch. The .45 group came from all individually weighed cases, bullets, and final loaded case. I had not started weighing individual components until I hit 290 fps- so the first groups don't really count..I do neck size only- and have just gotten shipment today from Midway with my new Lyman trimmer,(I was using a LEE hand tool)and a new VLD chamfer tool.(I also put a new Ruger Number 1 .280 on layaway- not a great valentines day present,-get my drift?)Once I get some SOLID group size info- thenI will decide if a crimp is needed. I don't really worry about bullet movement from hard handling- I just had read that a crimp MAY improve a group size. I know it would be worth the ten bucks to get one-just to test it and post the results. I may just pick one up tomorrow......being valentines day and all, I think my wife needs a new die.... I will keep everyone informed. Dave | ||
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| <dr280> |
Well, after some delay.... the M77 is history. The one group at .455 was just that one group. Can't seem to get any consistancy at all. Groups flying all over...now I am the proud owner of a new Ruger #1 in .280. Just ordered a new set of full length sizer dies and crimp die. The testing will begin shortly and I will have an answer the crimp/no crimp accuracy question. Dave | ||
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| <Super 88> |
Like some of the replies on this thread, I use only brass that has been neck-turned and neck-sized only. Then it's fired once in it's intended rifle. Next it's cleaned, neck-sized, loaded, then crimped using the Lee Factory Crimp die with a fairly firm crimp. I'm not a benchrest shooter,just a hunter that wants the most accurate ammo available. Using this system has allowed me to tame those infamous Barnes bullets into shooting sub-MOA groups with any rifle I own. I can't speak for others but the crimping sure works for me!!! | ||
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| one of us |
Using (or not using) a crimp is always a rifle to rifle thing. Just like, say, Barnes bullets working in some rifles and being the shits in others. It's a matter of spending the money or borrowing a die and trying it out on your own rifle(s). I have found that it seems to work in some of my longer throated rifles. It may not work the same in yours. With a Lee Crimper the "damage" is not appreciable or should it be a concern. You test to see if it helps. If it does, you crimp. Who cares about the cost of a case when you're on a hunt? The same thing is said about scopes, bullets etc. If it can improve your groups (either in your head or in the field), do it. A crimp die is approx $10, much less than most will pay to play around with Noslers, Woodleighs etc. Safe Shooting! | |||
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| <dr280> |
I started reloading with a set of collet dies for the M77. Neck sizing worked fine- but these same cases are harder to chamber in the Number 1. I have ordered the new die set and will full length and once a good load is developed- then a crimp test will happen. Dave | ||
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| one of us |
I seem to remember an article by Rick Jamison that I read a loooooong time ago to the effect that crimping actually loosened the bullet in the neck. While the crimp kept the bullet from moving forward or back, the act of crimping sprung the neck of the case away from the bullet and let it yaw from side to side...............? It sounds reasonable but to what extent it would affect accuracy, I couldn't say. | |||
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| one of us |
At the risk of offending the Jamison fans, I think that if that was always the case, the crimp die would have been a non event. These aren't benchrest rifles, so offcentre necks, long throats and untweaked rifles may be helped by the use of a crimping die. I doubt whether crimping would cause the majority to loosen and yaw. One thing is for certain - yawing is not good. I wonder, do you remember if he used his trusty old 30/06 in his tests? I think it is a Sportsman 78. Safe Shooting! | |||
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